exec_outcome
stringclasses
1 value
code_uid
stringlengths
32
32
file_name
stringclasses
111 values
prob_desc_created_at
stringlengths
10
10
prob_desc_description
stringlengths
63
3.8k
prob_desc_memory_limit
stringclasses
18 values
source_code
stringlengths
117
65.5k
lang_cluster
stringclasses
1 value
prob_desc_sample_inputs
stringlengths
2
802
prob_desc_time_limit
stringclasses
27 values
prob_desc_sample_outputs
stringlengths
2
796
prob_desc_notes
stringlengths
4
3k
lang
stringclasses
5 values
prob_desc_input_from
stringclasses
3 values
tags
listlengths
0
11
src_uid
stringlengths
32
32
prob_desc_input_spec
stringlengths
28
2.37k
difficulty
int64
-1
3.5k
prob_desc_output_spec
stringlengths
17
1.47k
prob_desc_output_to
stringclasses
3 values
hidden_unit_tests
stringclasses
1 value
PASSED
c9aa6ff1a54fb5e670328b11e2df4930
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class Main { static BufferedReader bf; static PrintWriter out; static Scanner sc; static StringTokenizer st; static long mod = (long)(1e9+7); static long mod2 = 998244353; static long fact[] = new long[1001]; static long inverse[] = new long[1001]; public static void main (String[] args)throws IOException { bf = new BufferedReader(new InputStreamReader(System.in)); out = new PrintWriter(System.out); sc = new Scanner(System.in); // fact[0] = 1; // inverse[0] = 1; // for(int i = 1;i<fact.length;i++){ // fact[i] = (fact[i-1] * i)%mod; // inverse[i] = binaryExpo(fact[i], mod-2); // } // int t = nextInt(); // while(t-->0){ solve(); // } } public static void solve() throws IOException{ int n = nextInt(); req(1,n); int index = nextInt(); int left = 0; if(index != 1){ req(1,index); left= nextInt(); } int l = -1; int r = -1; if((index != 1) && left == index){ l = 1; r = index-1; } else{ l = index+1; r = n; } int ans = -1; while(l <= r){ int mid = (l + (r - l)/2); if(mid < index){ req(mid,index); int idx = nextInt(); if(idx == index){ ans = mid; l = mid+1; } else{ r = mid-1; } } else{ req(index,mid); int idx = nextInt(); if(idx == index){ ans = mid; r = mid-1; } else{ l = mid+1; } } } out.println("! " + ans); out.flush(); } public static void req(int l,int r){ out.println("? " + l + " " + r); out.flush(); } public static int[] bringSame(int u,int v ,int parent[][],int[]depth){ if(depth[u] < depth[v]){ int temp = u; u = v; v = temp; } int k = depth[u] - depth[v]; for(int i = 0;i<=18;i++){ if((k & (1<<i)) != 0){ u = parent[u][i]; } } return new int[]{u,v}; } public static void findDepth(List<List<Integer>>list,int cur,int parent,int[]depth,int[][]p){ List<Integer>temp = list.get(cur); p[cur][0] = parent; for(int i = 0;i<temp.size();i++){ int next = temp.get(i); if(next != parent){ depth[next] = depth[cur]+1; findDepth(list,next,cur,depth,p); } } } public static int lca(int u, int v,int[][]parent){ if(u == v)return u; for(int i = 18;i>=0;i--){ if(parent[u][i] != parent[v][i]){ u = parent[u][i]; v = parent[v][i]; } } return parent[u][0]; } public static void plus(int node,int low,int high,int tlow,int thigh,int[]tree){ if(low >= tlow && high <= thigh){ tree[node]++; return; } if(high < tlow || low > thigh)return; int mid = (low + high)/2; plus(node*2,low,mid,tlow,thigh,tree); plus(node*2 + 1 , mid + 1, high,tlow, thigh,tree); } public static boolean allEqual(int[]arr,int x){ for(int i = 0;i<arr.length;i++){ if(arr[i] != x)return false; } return true; } public static long helper(StringBuilder sb){ return Long.parseLong(sb.toString()); } public static int min(int node,int low,int high,int tlow,int thigh,int[][]tree){ if(low >= tlow&& high <= thigh)return tree[node][0]; if(high < tlow || low > thigh)return Integer.MAX_VALUE; int mid = (low + high)/2; // println(low+" "+high+" "+tlow+" "+thigh); return Math.min(min(node*2,low,mid,tlow,thigh,tree) ,min(node*2+1,mid+1,high,tlow,thigh,tree)); } public static int max(int node,int low,int high,int tlow,int thigh,int[][]tree){ if(low >= tlow && high <= thigh)return tree[node][1]; if(high < tlow || low > thigh)return Integer.MIN_VALUE; int mid = (low + high)/2; return Math.max(max(node*2,low,mid,tlow,thigh,tree) ,max(node*2+1,mid+1,high,tlow,thigh,tree)); } public static long[] help(List<List<Integer>>list,int[][]range,int cur){ List<Integer>temp = list.get(cur); if(temp.size() == 0)return new long[]{range[cur][1],1}; long sum = 0; long count = 0; for(int i = 0;i<temp.size();i++){ long []arr = help(list,range,temp.get(i)); sum += arr[0]; count += arr[1]; } if(sum < range[cur][0]){ count++; sum = range[cur][1]; } return new long[]{sum,count}; } public static long findSum(int node,int low, int high,int tlow,int thigh,long[]tree,long mod){ if(low >= tlow && high <= thigh)return tree[node]%mod; if(low > thigh || high < tlow)return 0; int mid = (low + high)/2; return((findSum(node*2,low,mid,tlow,thigh,tree,mod) % mod) + (findSum(node*2+1,mid+1,high,tlow,thigh,tree,mod)))%mod; } public static boolean allzero(long[]arr){ for(int i =0 ;i<arr.length;i++){ if(arr[i]!=0)return false; } return true; } public static long count(long[][]dp,int i,int[]arr,int drank,long sum){ if(i == arr.length)return 0; if(dp[i][drank]!=-1 && arr[i]+sum >=0)return dp[i][drank]; if(sum + arr[i] >= 0){ long count1 = 1 + count(dp,i+1,arr,drank+1,sum+arr[i]); long count2 = count(dp,i+1,arr,drank,sum); return dp[i][drank] = Math.max(count1,count2); } return dp[i][drank] = count(dp,i+1,arr,drank,sum); } public static void help(int[]arr,char[]signs,int l,int r){ if( l < r){ int mid = (l+r)/2; help(arr,signs,l,mid); help(arr,signs,mid+1,r); merge(arr,signs,l,mid,r); } } public static void merge(int[]arr,char[]signs,int l,int mid,int r){ int n1 = mid - l + 1; int n2 = r - mid; int[]a = new int[n1]; int []b = new int[n2]; char[]asigns = new char[n1]; char[]bsigns = new char[n2]; for(int i = 0;i<n1;i++){ a[i] = arr[i+l]; asigns[i] = signs[i+l]; } for(int i = 0;i<n2;i++){ b[i] = arr[i+mid+1]; bsigns[i] = signs[i+mid+1]; } int i = 0; int j = 0; int k = l; boolean opp = false; while(i<n1 && j<n2){ if(a[i] <= b[j]){ arr[k] = a[i]; if(opp){ if(asigns[i] == 'R'){ signs[k] = 'L'; } else{ signs[k] = 'R'; } } else{ signs[k] = asigns[i]; } i++; k++; } else{ arr[k] = b[j]; int times = n1 - i; if(times%2 == 1){ if(bsigns[j] == 'R'){ signs[k] = 'L'; } else{ signs[k] = 'R'; } } else{ signs[k] = bsigns[j]; } j++; opp = !opp; k++; } } while(i<n1){ arr[k] = a[i]; if(opp){ if(asigns[i] == 'R'){ signs[k] = 'L'; } else{ signs[k] = 'R'; } } else{ signs[k] = asigns[i]; } i++; k++; } while(j<n2){ arr[k] = b[j]; signs[k] = bsigns[j]; j++; k++; } } public static long nck(int n,int k){ return ((fact[n] * (inverse[n-k])%mod) * inverse[k])%mod; } public static long binaryExpo(long base,long expo){ if(expo == 0)return 1; long val; if(expo%2 == 1){ val = (binaryExpo(base, expo/2)); val = (val * val)%mod; val = (val * base)%mod; } else{ val = binaryExpo(base, expo/2); val = (val*val)%mod; } return (val%mod); } public static boolean isSorted(int[]arr){ for(int i =1;i<arr.length;i++){ if(arr[i] < arr[i-1]){ return false; } } return true; } //function to find the topological sort of the a DAG public static boolean hasCycle(int[]indegree,List<List<Integer>>list,int n,List<Integer>topo){ Queue<Integer>q = new LinkedList<>(); for(int i =1;i<indegree.length;i++){ if(indegree[i] == 0){ q.add(i); topo.add(i); } } while(!q.isEmpty()){ int cur = q.poll(); List<Integer>l = list.get(cur); for(int i = 0;i<l.size();i++){ indegree[l.get(i)]--; if(indegree[l.get(i)] == 0){ q.add(l.get(i)); topo.add(l.get(i)); } } } if(topo.size() == n)return false; return true; } // function to find the parent of any given node with path compression in DSU public static int find(int val,int[]parent){ if(val == parent[val])return val; return parent[val] = find(parent[val],parent); } // function to connect two components public static void union(int[]rank,int[]parent,int u,int v){ int a = find(u,parent); int b= find(v,parent); if(a == b)return; if(rank[a] == rank[b]){ parent[b] = a; rank[a]++; } else{ if(rank[a] > rank[b]){ parent[b] = a; } else{ parent[a] = b; } } } // public static int findN(int n){ int num = 1; while(num < n){ num *=2; } return num; } // code for input public static void print(String s ){ System.out.print(s); } public static void print(int num ){ System.out.print(num); } public static void print(long num ){ System.out.print(num); } public static void println(String s){ System.out.println(s); } public static void println(int num){ System.out.println(num); } public static void println(long num){ System.out.println(num); } public static void println(){ System.out.println(); } public static int Int(String s){ return Integer.parseInt(s); } public static long Long(String s){ return Long.parseLong(s); } public static String[] nextStringArray()throws IOException{ return bf.readLine().split(" "); } public static String nextString()throws IOException{ return bf.readLine(); } public static long[] nextLongArray(int n)throws IOException{ String[]str = bf.readLine().split(" "); long[]arr = new long[n]; for(int i =0;i<n;i++){ arr[i] = Long.parseLong(str[i]); } return arr; } public static int[][] newIntMatrix(int r,int c)throws IOException{ int[][]arr = new int[r][c]; for(int i =0;i<r;i++){ String[]str = bf.readLine().split(" "); for(int j =0;j<c;j++){ arr[i][j] = Integer.parseInt(str[j]); } } return arr; } public static long[][] newLongMatrix(int r,int c)throws IOException{ long[][]arr = new long[r][c]; for(int i =0;i<r;i++){ String[]str = bf.readLine().split(" "); for(int j =0;j<c;j++){ arr[i][j] = Long.parseLong(str[j]); } } return arr; } static class pair{ int one; int two; pair(int one,int two){ this.one = one ; this.two =two; } } public static long gcd(long a,long b){ if(b == 0)return a; return gcd(b,a%b); } public static long lcm(long a,long b){ return (a*b)/(gcd(a,b)); } public static boolean isPalindrome(String s){ int i = 0; int j = s.length()-1; while(i<=j){ if(s.charAt(i) != s.charAt(j)){ return false; } i++; j--; } return true; } // these functions are to calculate the number of smaller elements after self public static void sort(int[]arr,int l,int r){ if(l < r){ int mid = (l+r)/2; sort(arr,l,mid); sort(arr,mid+1,r); smallerNumberAfterSelf(arr, l, mid, r); } } public static void smallerNumberAfterSelf(int[]arr,int l,int mid,int r){ int n1 = mid - l +1; int n2 = r - mid; int []a = new int[n1]; int[]b = new int[n2]; for(int i = 0;i<n1;i++){ a[i] = arr[l+i]; } for(int i =0;i<n2;i++){ b[i] = arr[mid+i+1]; } int i = 0; int j =0; int k = l; while(i<n1 && j < n2){ if(a[i] < b[j]){ arr[k++] = a[i++]; } else{ arr[k++] = b[j++]; } } while(i<n1){ arr[k++] = a[i++]; } while(j<n2){ arr[k++] = b[j++]; } } public static String next(){ while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(bf.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } static int nextInt() { return Integer.parseInt(next()); } static long nextLong() { return Long.parseLong(next()); } static double nextDouble() { return Double.parseDouble(next()); } static String nextLine(){ String str = ""; try { str = bf.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } // use some math tricks it might help // sometimes just try to think in straightforward plan in A and B problems don't always complecate the questions with thinking too much differently // always use long number to do 10^9+7 modulo // if a problem is related to binary string it could also be related to parenthesis // *****try to use binary search(it is a very beautiful thing it can work in some of the very unexpected problems ) in the question it might work****** // try sorting // try to think in opposite direction of question it might work in your way // if a problem is related to maths try to relate some of the continuous subarray with variables like - > a+b+c+d or a,b,c,d in general // if the question is to much related to left and/or right side of any element in an array then try monotonic stack it could work. // in range query sums try to do binary search it could work // analyse the time complexity of program thoroughly // anylyse the test cases properly // if we divide any number by 2 till it gets 1 then there will be (number - 1) operation required // try to do the opposite operation of what is given in the problem //think about the base cases properly //If a question is related to numbers try prime factorisation or something related to number theory // keep in mind unique strings //you can calculate the number of inversion in O(n log n) // in a matrix you could sometimes think about row and cols indenpendentaly. // Try to think in more constructive(means a way to look through various cases of a problem) way. // observe the problem carefully the answer could be hidden in the given test cases itself. (A, B , C); // when we have equations like (a+b = N) and we have to find the max of (a*b) then the values near to the N/2 must be chosen as (a and b); // give emphasis to the number of occurences of elements it might help. // if a number is even then we can find the pair for each and every number in that range whose bitwise AND is zero. // if a you find a problem related to the graph make a graph // There is atleast one prime number between the interval [n , 3n/2]; // If a problem is related to maths then try to form an mathematical equation.
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
010c6fbbdf4f4cc40bb82699b319860d
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; // import java.util.concurrent.CountDownLatch; // import javax.lang.model.element.QualifiedNameable; // import javax.swing.ViewportLayout; // import javax.swing.plaf.basic.BasicTreeUI.TreeCancelEditingAction; // import javax.swing.plaf.metal.MetalComboBoxUI.MetalPropertyChangeListener; // import javax.swing.text.html.HTMLDocument.HTMLReader.CharacterAction; // import org.w3c.dom.Node; import java.lang.*; import java.math.BigInteger; // import java.net.CookieHandler; // import java.security.SecureRandomParameters; // import java.security.cert.CollectionCertStoreParameters; // import java.text.BreakIterator; import java.io.*; @SuppressWarnings("unchecked") public class Main { static FastReader in; static PrintWriter out; static int bit(long n) { return (n == 0) ? 0 : (1 + bit(n & (n - 1))); } static void p(Object o) { out.print(o); } static void pn(Object o) { out.println(o); } static void pni(Object o) { out.println(o); out.flush(); } static String n() throws Exception { return in.next(); } static String nln() throws Exception { return in.nextLine(); } static int ni() throws Exception { return Integer.parseInt(in.next()); } static long nl() throws Exception { return Long.parseLong(in.next()); } static double nd() throws Exception { return Double.parseDouble(in.next()); } static class FastReader { static BufferedReader br; static StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } public FastReader(String s) throws Exception { br = new BufferedReader(new FileReader(s)); } String next() throws Exception { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { throw new Exception(e.toString()); } } return st.nextToken(); } String nextLine() throws Exception { String str = ""; try { str = br.readLine(); } catch (IOException e) { throw new Exception(e.toString()); } return str; } } static long power(long a, long b) { if (a == 0L) return 0L; if (b == 0) return 1; long val = power(a, b / 2); val = val * val; if ((b % 2) != 0) val = val * a; return val; } static long power(long a, long b, long mod) { if (a == 0L) return 0L; if (b == 0) return 1; long val = power(a, b / 2L, mod) % mod; val = (val * val) % mod; if ((b % 2) != 0) val = (val * a) % mod; return val; } static ArrayList<Long> prime_factors(long n) { ArrayList<Long> ans = new ArrayList<Long>(); while (n % 2 == 0) { ans.add(2L); n /= 2L; } for (long i = 3; i <= Math.sqrt(n); i++) { while (n % i == 0) { ans.add(i); n /= i; } } if (n > 2) { ans.add(n); } return ans; } static void sort(ArrayList<Long> a) { Collections.sort(a); } static void reverse_sort(ArrayList<Long> a) { Collections.sort(a, Collections.reverseOrder()); } static void swap(long[] a, int i, int j) { long temp = a[i]; a[i] = a[j]; a[j] = temp; } static void swap(List<Long> a, int i, int j) { long temp = a.get(i); a.set(j, a.get(i)); a.set(j, temp); } static void sieve(boolean[] prime) { int n = prime.length - 1; Arrays.fill(prime, true); for (int i = 2; i * i <= n; i++) { if (prime[i]) { for (int j = i * i; j <= n; j += i) { prime[j] = false; } } } } static long gcd(long a, long b) { if (b == 0) return a; return gcd(b, a % b); } public static void sort(long[] arr, int l, int r) { if (l >= r) return; int mid = (l + r) / 2; sort(arr, l, mid); sort(arr, mid + 1, r); merge(arr, l, mid, r); } public static void sort(int[] arr, int l, int r) { if (l >= r) return; int mid = (l + r) / 2; sort(arr, l, mid); sort(arr, mid + 1, r); merge(arr, l, mid, r); } static void merge(int[] arr, int l, int mid, int r) { int[] left = new int[mid - l + 1]; int[] right = new int[r - mid]; for (int i = l; i <= mid; i++) { left[i - l] = arr[i]; } for (int i = mid + 1; i <= r; i++) { right[i - (mid + 1)] = arr[i]; } int left_start = 0; int right_start = 0; int left_length = mid - l + 1; int right_length = r - mid; int temp = l; while (left_start < left_length && right_start < right_length) { if (left[left_start] < right[right_start]) { arr[temp] = left[left_start++]; } else { arr[temp] = right[right_start++]; } temp++; } while (left_start < left_length) { arr[temp++] = left[left_start++]; } while (right_start < right_length) { arr[temp++] = right[right_start++]; } } static void merge(long[] arr, int l, int mid, int r) { long[] left = new long[mid - l + 1]; long[] right = new long[r - mid]; for (int i = l; i <= mid; i++) { left[i - l] = arr[i]; } for (int i = mid + 1; i <= r; i++) { right[i - (mid + 1)] = arr[i]; } int left_start = 0; int right_start = 0; int left_length = mid - l + 1; int right_length = r - mid; int temp = l; while (left_start < left_length && right_start < right_length) { if (left[left_start] < right[right_start]) { arr[temp] = left[left_start++]; } else { arr[temp] = right[right_start++]; } temp++; } while (left_start < left_length) { arr[temp++] = left[left_start++]; } while (right_start < right_length) { arr[temp++] = right[right_start++]; } } static HashMap<Long, Integer> map_prime_factors(long n) { HashMap<Long, Integer> map = new HashMap<>(); while (n % 2 == 0) { map.put(2L, map.getOrDefault(2L, 0) + 1); n /= 2L; } for (long i = 3; i <= Math.sqrt(n); i++) { while (n % i == 0) { map.put(i, map.getOrDefault(i, 0) + 1); n /= i; } } if (n > 2) { map.put(n, map.getOrDefault(n, 0) + 1); } return map; } static long divisor(long n) { long count = 0; for (long i = 1L; i * i <= n; i++) { if (n % i == 0) { if (i == n / i) count += i; else { count += i; count += n / i; } } } return count; } // static void smallest_prime_factor(int n) { // smallest_prime_factor[1] = 1; // for (int i = 2; i <= n; i++) { // if (smallest_prime_factor[i] == 0) { // smallest_prime_factor[i] = i; // for (int j = i * i; j <= n; j += i) { // if (smallest_prime_factor[j] == 0) { // smallest_prime_factor[j] = i; // } // } // } // } // } // static int[] smallest_prime_factor; // static int count = 1; // static int[] p = new int[100002]; // static long[] flat_tree = new long[300002]; // static int[] in_time = new int[1000002]; // static int[] out_time = new int[1000002]; // static long[] subtree_gcd = new long[100002]; // static int w = 0; // static boolean poss = true; /* * (a^b^c)%mod * Using fermats Little theorem * x^(mod-1)=1(mod) * so b^c can be written as b^c=x*(mod-1)+y * then (a^(x*(mod-1)+y))%mod=(a^(x*(mod-1))*a^(y))mod * the term (a^(x*(mod-1)))%mod=a^(mod-1)*a^(mod-1) * */ // ---------------------------------------------------Segment_Tree----------------------------------------------------------------// static class comparator implements Comparator<node> { public int compare(node a, node b) { return a.value - b.value > 0 ? 1 : -1; } } static class Segment_Tree { private long[] segment_tree; public Segment_Tree(int n) { this.segment_tree = new long[4 * n + 1]; } void build(int index, int left, int right, int[] a) { if (left == right) { segment_tree[index] = a[left]; return; } int mid = (left + right) / 2; build(2 * index + 1, left, mid, a); build(2 * index + 2, mid + 1, right, a); segment_tree[index] = segment_tree[2 * index + 1] + segment_tree[2 * index + 2]; } long query(int index, int left, int right, int l, int r) { if (left > right) return 0; if (left >= l && r >= right) { return segment_tree[index]; } if (l > right || left > r) return 0; int mid = (left + right) / 2; return query(2 * index + 1, left, mid, l, r) + query(2 * index + 2, mid + 1, right, l, r); } void update(int index, int left, int right, int node, int val) { if (left == right) { segment_tree[index] += val; return; } int mid = (left + right) / 2; if (node <= mid) update(2 * index + 1, left, mid, node, val); else update(2 * index + 2, mid + 1, right, node, val); segment_tree[index] = segment_tree[2 * index + 1] + segment_tree[2 * index + 2]; } } // ------------------------------------------------------ DSU // --------------------------------------------------------------------// class dsu { private int[] parent; private int[] rank; private int[] size; public dsu(int n) { this.parent = new int[n + 1]; this.rank = new int[n + 1]; this.size = new int[n + 1]; for (int i = 0; i <= n; i++) { parent[i] = i; rank[i] = 1; size[i] = 1; } } int findParent(int a) { if (parent[a] == a) return a; else return parent[a] = findParent(parent[a]); } void join(int a, int b) { int parent_a = findParent(a); int parent_b = findParent(b); if (parent_a == parent_b) return; if (rank[parent_a] > rank[parent_b]) { parent[parent_b] = parent_a; size[parent_a] += size[parent_b]; } else if (rank[parent_a] < rank[parent_b]) { parent[parent_a] = parent_b; size[parent_b] += size[parent_a]; } else { parent[parent_a] = parent_b; size[parent_b] += size[parent_a]; rank[parent_b]++; } } } // ------------------------------------------------Comparable---------------------------------------------------------------------// static class pair implements Comparable<pair> { int a; int b; int dir; public pair(int a, int b, int dir) { this.a = a; this.b = b; this.dir = dir; } public int compareTo(pair p) { // if (this.b == Integer.MIN_VALUE || p.b == Integer.MIN_VALUE) // return (int) (this.index - p.index); return (int) (this.a - p.a); } } static class pair2 implements Comparable<pair2> { long a; int index; public pair2(long a, int index) { this.a = a; this.index = index; } public int compareTo(pair2 p) { return (int) (this.a - p.a); } } static class node { long value; int index; public node(long value, int index) { this.value = value; this.index = index; } } // static int ans = 0; static int ans = 0; static int leaf = 0; static boolean poss = true; static int bottom = Integer.MAX_VALUE; static int right = Integer.MAX_VALUE; static int max_right; static int max_bottom; static long mod = 1000000007L; int glo = 0; static int[] dx = { 0, 0, -1, 1 }; static int[] dy = { 1, -1, 0, 0 }; public static void main(String[] args) throws Exception { in = new FastReader(); out = new PrintWriter(System.out); int tc = 1; while (tc-- > 0) { int n=ni(); pn("? 1 "+n); out.flush(); int second=ni(); if(second!=1)pn("? 1 "+second); if(second!=1)out.flush(); boolean left=((second!=1) &&(ni()==second) )?true:false; if(left){ int l=1; int r=second; while(l+1<r){ int mid=l+(r-l)/2; pn("? "+mid+" "+second); out.flush(); int val=ni(); if(val==second) { l=mid; }else r=mid; } pn("! "+l); }else{ int l=second; int r=n; while(l+1<r){ int mid=l+(r-l)/2; pn("? "+second+" "+mid); out.flush(); int val=ni(); if(val==second) { r=mid; }else l=mid; } pn("! "+r); } } out.flush(); out.close(); } static void dfs(int i, int j, int[][] c, boolean[][] visited) { int n = c.length; visited[i][j] = true; for (int k = 0; k < 4; k++) { int a = i + dx[k]; int b = j + dy[k]; if (a >= 0 && b >= 0 && a < n && b < n && !visited[a][b]) { dfs(a, b, c, visited); } } } static void factorial(long[] fact, long[] fact_inv, int n, long mod) { fact[0] = 1; for (int i = 1; i < n; i++) { fact[i] = (i * fact[i - 1]) % mod; } for (int i = 0; i < n; i++) { fact_inv[i] = power(fact[i], mod - 2, mod);// (1/x)%m can be calculated by fermat's little theoram which is // (x**(m-2))%m when m is prime } //(a^(b^c))%m is equal to, let res=(b^c)%(m-1) then (a^res)%m //https://www.geeksforgeeks.org/find-power-power-mod-prime/?ref=rp } static void find(int i, int n, int[] row, int[] col, int[] d1, int[] d2) { if (i >= n) { ans++; return; } for (int j = 0; j < n; j++) { if (col[j] == 0 && d1[i - j + n - 1] == 0 && d2[i + j] == 0) { col[j] = 1; d1[i - j + n - 1] = 1; d2[i + j] = 1; find(i + 1, n, row, col, d1, d2); col[j] = 0; d1[i - j + n - 1] = 0; d2[i + j] = 0; } } } static int answer(int l, int r, int[][] dp) { if (l > r) return 0; if (l == r) { dp[l][r] = 1; return 1; } if (dp[l][r] != -1) return dp[l][r]; int val = Integer.MIN_VALUE; int mid = l + (r - l) / 2; val = 1 + Math.max(answer(l, mid - 1, dp), answer(mid + 1, r, dp)); return dp[l][r] = val; } static TreeSet<Integer> ans(int n) { TreeSet<Integer> set = new TreeSet<>(); for (int i = 1; i * i <= n; i++) { if (n % i == 0) { set.add(i); set.add(n / i); } } set.remove(1); return set; } // static long find(String s, int i, int n, long[] dp) { // // pn(i); // if (i >= n) // return 1L; // if (s.charAt(i) == '0') // return 0; // if (i == n - 1) // return 1L; // if (dp[i] != -1) // return dp[i]; // if (s.substring(i, i + 2).equals("10") || s.substring(i, i + 2).equals("20")) // { // return dp[i] = (find(s, i + 2, n, dp)) % mod; // } // if ((s.charAt(i) == '1' || (s.charAt(i) == '2' && s.charAt(i + 1) - '0' <= // 6)) // && ((i + 2 < n ? (s.charAt(i + 2) != '0' ? true : false) : (i + 2 == n ? true // : false)))) { // return dp[i] = (find(s, i + 1, n, dp) + find(s, i + 2, n, dp)) % mod; // } else // return dp[i] = (find(s, i + 1, n, dp)) % mod; static void print(int[] a) { for (int i = 0; i < a.length; i++) p(a[i] + " "); pn(""); } static long count(long n) { long count = 0; while (n != 0) { count += n % 10; n /= 10; } return count; } static void swap(int[] a, int i, int j) { int temp = a[i]; a[i] = a[j]; a[j] = temp; } static int LcsOfPrefix(String a, String b) { int i = 0; int j = 0; int count = 0; while (i < a.length() && j < b.length()) { if (a.charAt(i) == b.charAt(j)) { j++; count++; } i++; } return a.length() + b.length() - 2 * count; } static void reverse(int[] a, int n) { for (int i = 0; i < n / 2; i++) { int temp = a[i]; a[i] = a[n - i - 1]; a[n - i - 1] = temp; } } static char get_char(int a) { return (char) (a + 'a'); } static int find1(int[] a, int val) { int ans = -1; int l = 0; int r = a.length - 1; while (l <= r) { int mid = l + (r - l) / 2; if (a[mid] <= val) { l = mid + 1; ans = mid; } else r = mid - 1; } return ans; } static int find2(int[] a, int val) { int l = 0; int r = a.length - 1; int ans = -1; while (l <= r) { int mid = l + (r - l) / 2; if (a[mid] <= val) { ans = mid; l = mid + 1; } else r = mid - 1; } return ans; } // static void dfs(List<List<Integer>> arr, int node, int parent, long[] val) { // p[node] = parent; // in_time[node] = count; // flat_tree[count] = val[node]; // subtree_gcd[node] = val[node]; // count++; // for (int adj : arr.get(node)) { // if (adj == parent) // continue; // dfs(arr, adj, node, val); // subtree_gcd[node] = gcd(subtree_gcd[adj], subtree_gcd[node]); // } // out_time[node] = count; // flat_tree[count] = val[node]; // count++; // } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
0a5fece048154fd9c41d2681e851c032
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.HashSet; import java.util.Random; import java.util.Stack; import java.util.StringTokenizer; // CFPS -> CodeForcesProblemSet public final class CFPS { static FastReader fr = new FastReader(); static PrintWriter out = new PrintWriter(System.out); static final int gigamod = 1000000007; static int t = 1; static double epsilon = 0.0000001; static boolean[] isPrime; static int[] smallestFactorOf; @SuppressWarnings("unused") public static void main(String[] args) { OUTER: for (int tc = 0; tc < t; tc++) { int n = fr.nextInt(); int lptr = 0, rptr = n - 1; // First, we will find the secondLargestIdx, which will be // pivotal in solving the problem. (PUN INTENDED). out.println("? 1 " + (n)); out.flush(); int slIdx = fr.nextInt() - 1; // Now, we will reduce the search space once, just to ensure that // slIdx does not belong to it. if (lptr < slIdx) { // We can consider [lptr, slIdx] for the query. out.println("? 1 " + (slIdx + 1)); out.flush(); int slNew = fr.nextInt() - 1; if (slNew == slIdx) // This exact segment contains the max. rptr = slIdx - 1; else lptr = slIdx + 1; } else { // We will have to consider [slIdx, rptr] for the query. out.println("? " + (slIdx + 1) + " " + (rptr + 1)); out.flush(); int slNew = fr.nextInt() - 1; if (slNew == slIdx) // This segment contains the max. lptr = slIdx + 1; else rptr = slIdx - 1; } while (lptr != rptr) { if (rptr == lptr + 1) { // [lptr, lptr + 1] is the search space. out.println("? " + (lptr + 1) + " " + (lptr + 2)); out.flush(); int slNew = fr.nextInt() - 1; if (slNew == lptr) lptr = rptr; else rptr = lptr; continue; } // out.println(lptr + " " + rptr); // Now, we will try to shrink the search space. if (rptr < slIdx) { // [lptr, rptr] is on the left of slIdx. int mid = lptr + (rptr - lptr) / 2; // Now, we will query [mid, slIdx]. out.println("? " + (mid + 1) + " " + (slIdx + 1)); out.flush(); int slNew = fr.nextInt() - 1; if (slNew == slIdx) { // [mid, rptr] is the new search space. lptr = mid; } else // [mid, rptr] does not contain the max. rptr = mid - 1; } else if (lptr > slIdx) { // [lptr, rptr] is on the right of slIdx. int mid = lptr + (rptr - lptr) / 2; // Now, we will query [slIdx, mid] out.println("? " + (slIdx + 1) + " " + (mid + 1)); out.flush(); int slNew = fr.nextInt() - 1; if (slNew == slIdx) // [lptr, mid] is the new search space. rptr = mid; else lptr = mid + 1; } } out.println("! " + (lptr + 1)); } out.close(); } public static class FenwickTree { long[] array; // 1-indexed array, In this array We save cumulative information to perform efficient range queries and updates public FenwickTree(int size) { array = new long[size + 1]; } public long rsq(int ind) { assert ind > 0; long sum = 0; while (ind > 0) { sum += array[ind]; //Extracting the portion up to the first significant one of the binary representation of 'ind' and decrementing ind by that number ind -= ind & (-ind); } return sum; } public long rsq(int a, int b) { assert b >= a && a > 0 && b > 0; return rsq(b) - rsq(a - 1); } public void update(int ind, long value) { assert ind > 0; while (ind < array.length) { array[ind] += value; //Extracting the portion up to the first significant one of the binary representation of 'ind' and incrementing ind by that number ind += ind & (-ind); } } public int size() { return array.length - 1; } } static int longestPrefixPalindromeLen(char[] s) { int n = s.length; StringBuilder sb = new StringBuilder(); for (int i = 0; i < n; i++) sb.append(s[i]); StringBuilder sb2 = new StringBuilder(sb); sb.append('^'); sb.append(sb2.reverse()); // out.println(sb.toString()); char[] newS = sb.toString().toCharArray(); int m = newS.length; int[] pi = piCalcKMP(newS); return pi[m - 1]; } static int KMPNumOcc(char[] text, char[] pat) { int n = text.length; int m = pat.length; char[] patPlusText = new char[n + m + 1]; for (int i = 0; i < m; i++) patPlusText[i] = pat[i]; patPlusText[m] = '^'; // Seperator for (int i = 0; i < n; i++) patPlusText[m + i] = text[i]; int[] fullPi = piCalcKMP(patPlusText); int answer = 0; for (int i = 0; i < n + m + 1; i++) if (fullPi[i] == m) answer++; return answer; } static int[] piCalcKMP(char[] s) { int n = s.length; int[] pi = new int[n]; for (int i = 1; i < n; i++) { int j = pi[i - 1]; while (j > 0 && s[i] != s[j]) j = pi[j - 1]; if (s[i] == s[j]) j++; pi[i] = j; } return pi; } static String toBinaryString(long num, int bits) { StringBuilder sb = new StringBuilder(Long.toBinaryString(num)); sb.reverse(); for (int i = sb.length(); i < bits; i++) sb.append('0'); return sb.reverse().toString(); } // Manual implementation of RB-BST for C++ PBDS functionality. // Modification required according to requirements. public static final class RedBlackCountSet { // Colors for Nodes: private static final boolean RED = true; private static final boolean BLACK = false; // Pointer to the root: private Node root; // Public constructor: public RedBlackCountSet() { root = null; } // Node class for storing key value pairs: private class Node { long key; long value; Node left, right; boolean color; long size; // Size of the subtree rooted at that node. public Node(long key, long value, boolean color) { this.key = key; this.value = value; this.left = this.right = null; this.color = color; this.size = value; } } /***** Invariant Maintenance functions: *****/ // When a temporary 4 node is formed: private Node flipColors(Node node) { node.left.color = node.right.color = BLACK; node.color = RED; return node; } // When there's a right leaning red link and it is not a 3 node: private Node rotateLeft(Node node) { Node rn = node.right; node.right = rn.left; rn.left = node; rn.color = node.color; node.color = RED; return rn; } // When there are 2 red links in a row: private Node rotateRight(Node node) { Node ln = node.left; node.left = ln.right; ln.right = node; ln.color = node.color; node.color = RED; return ln; } /***** Invariant Maintenance functions end *****/ // Public functions: public void put(long key) { root = put(root, key); root.color = BLACK; // One of the invariants. } private Node put(Node node, long key) { // Standard insertion procedure: if (node == null) return new Node(key, 1, RED); // Recursing: int cmp = Long.compare(key, node.key); if (cmp < 0) node.left = put(node.left, key); else if (cmp > 0) node.right = put(node.right, key); else node.value++; // Invariant maintenance: if (node.left != null && node.right != null) { if (node.right.color = RED && node.left.color == BLACK) node = rotateLeft(node); if (node.left.color == RED && node.left.left.color == RED) node = rotateRight(node); if (node.left.color == RED && node.right.color == RED) node = flipColors(node); } // Property maintenance: node.size = node.value + size(node.left) + size(node.right); return node; } private long size(Node node) { if (node == null) return 0; else return node.size; } public long rank(long key) { return rank(root, key); } // Modify according to requirements. private long rank(Node node, long key) { if (node == null) return 0; int cmp = Long.compare(key, node.key); if (cmp < 0) return rank(node.left, key); else if (cmp > 0) return node.value + size(node.left) + rank(node.right, key); else return node.value + size(node.left); } } static long modDiv(long a, long b) { return mod(a * power(b, gigamod - 2, gigamod)); } static class SegTree { // Setting up the parameters. int n; // Size of the array long[] sumTree; long[] ogArr; long[] maxTree; long[] minTree; boolean[] prpgtMarked; // For segment assignment operation with // lazy updates public static final int sumMode = 0; public static final int maxMode = 1; public static final int minMode = 2; // Constructor public SegTree(long[] arr, int mode) { if (mode == sumMode) { Arrays.fill(sumTree = new long[4 * (n = ((ogArr = arr.clone()).length))], -1); buildSum(0, n - 1, 0); } else if (mode == maxMode) { Arrays.fill(maxTree = new long[4 * (n = ((ogArr = arr.clone()).length))], -1); buildMax(0, n - 1, 0); } else if (mode == minMode) { Arrays.fill(minTree = new long[4 * (n = ((ogArr = arr.clone()).length))], Long.MAX_VALUE - 1); buildMin(0, n - 1, 0); } prpgtMarked = new boolean[minTree.length]; } /**********Code for sum***********/ /*********************************/ // Build the segment tree node-by-node private long buildSum(int l, int r, int segIdx) { return sumTree[segIdx] = (l == r) ? ogArr[l] : (buildSum(l, l + (r - l) / 2, 2 * segIdx + 1) + buildSum((l + (r - l) / 2) + 1, r, 2 * segIdx + 2)); } // Change a single element public void changeForSum(int idx, long to) { changeForSum(idx, to, 0, n - 1, 0); } private long changeForSum(int idx, long to, int l, int r, int segIdx) { return sumTree[segIdx] = ((l == r) ? (ogArr[idx] = to) : ((0 * ((idx <= (l + (r - l) / 2)) ? changeForSum(idx, to, l, l + (r - l) / 2, 2 * segIdx + 1) : changeForSum(idx, to, (l + (r - l) / 2) + 1, r, 2 * segIdx + 2))) + sumTree[2 * segIdx + 1] + sumTree[2 * segIdx + 2])); } // Return the sum arr[l, r] public long segSum(int l, int r) { if (l > r) return 0; return segSum(l, r, 0, n - 1, 0); } private long segSum(int segL, int segR, int l, int r, int segIdx) { if (segL == l && segR == r) return sumTree[segIdx]; if (segR <= l + (r - l) / 2) return segSum(segL, segR, l, l + (r - l) / 2, 2 * segIdx + 1); if (segL >= l + (r - l) / 2 + 1) return segSum(segL, segR, l + (r - l) / 2 + 1, r, 2 * segIdx + 2); return segSum(segL, l + (r - l) / 2, l, l + (r - l) / 2, 2 * segIdx + 1) + segSum(l + (r - l) / 2 + 1, segR, l + (r - l) / 2 + 1, r, 2 * segIdx + 2); } /********End of code for sum********/ /***********************************/ /*******Start of code for max*******/ /***********************************/ // Build the max tree node-by-node private long buildMax(int l, int r, int segIdx) { return maxTree[segIdx] = (l == r) ? ogArr[l] : Math.max(buildMax(l, (l + (r - l) / 2), 2 * segIdx + 1), buildMax(l + (r - l) / 2 + 1, r, 2 * segIdx + 2)); } // Change a single element public void changeForMax(int idx, long to) { changeForMax(0, n - 1, idx, to, 0); } private long changeForMax(int l, int r, int idx, long to, int segIdx) { return maxTree[segIdx] = (l == r && l == idx) ? (ogArr[idx] = to) : Math.max(changeForMax(l, l + (r - l) / 2, idx, to, 2 * segIdx + 1), changeForMax(l + (r - l) / 2 + 1, r, idx, to, 2 * segIdx + 2)); } public long segMax(int segL, int segR) { if (segL > segR) return 0; return segMax(0, n - 1, segL, segR, 0); } private long segMax(int l, int r, int segL, int segR, int segIdx) { int midL = l + (r - l) / 2; if (segL == segR && segL == l) return ogArr[segL]; if (segR <= midL) return segMax(l, midL, segL, segR, 2 * segIdx + 1); if (segL >= midL + 1) return segMax(midL + 1, r, segL, segR, 2 * segIdx + 2); return Math.max(segMax(l, midL, segL, midL, 2 * segIdx + 1), segMax(midL + 1, r, midL + 1, segR, 2 * segIdx + 2)); } /*******End of code for max*********/ /***********************************/ /*******Start of code for min*******/ /***********************************/ private long buildMin(int l, int r, int segIdx) { return minTree[segIdx] = (l == r) ? ogArr[l] : Math.min(buildMin(l, (l + (r - l) / 2), 2 * segIdx + 1), buildMin(l + (r - l) / 2 + 1, r, 2 * segIdx + 2)); } // Change a single element public void pointUpdate(int idx, long to) { pointUpdate(0, n - 1, idx, to, 0); } private long pointUpdate(int l, int r, int idx, long to, int segIdx) { asmtPush(l, r, segIdx); return minTree[segIdx] = (l == r && l == idx) ? (to) : Math.min(pointUpdate(l, l + (r - l) / 2, idx, to, 2 * segIdx + 1), pointUpdate(l + (r - l) / 2 + 1, r, idx, to, 2 * segIdx + 2)); } // Change a whole segment public void rangeUpdate(int segL, int segR, long to) { rangeUpdate(0, n - 1, segL, segR, to, 0); } private long rangeUpdate(int l, int r, int segL, int segR, long to, int segIdx) { asmtPush(l, r, segIdx); // Since we will obviously recurse. if (l == segL && r == segR) { prpgtMarked[segIdx] = true; return minTree[segIdx] = to; } int midL = l + (r - l) / 2; if (segR <= midL) return minTree[segIdx] = rangeUpdate(l, midL, segL, segR, to, 2 * segIdx + 1); if (segL >= midL + 1) return minTree[segIdx] = rangeUpdate(midL + 1, r, segL, segR, to, 2 * segIdx + 2); return minTree[segIdx] = Math.min(rangeUpdate(l, midL, segL, midL, to, 2 * segIdx + 1), rangeUpdate(midL + 1, r, midL + 1, segR, to, 2 * segIdx + 2)); } public long rangeMin(int segL, int segR) { if (segL > segR) return 0; return rangeMin(0, n - 1, segL, segR, 0); } private long rangeMin(int l, int r, int segL, int segR, int segIdx) { asmtPush(l, r, segIdx); int midL = l + (r - l) / 2; if (segL == l && segR == r) return minTree[segIdx]; if (segR <= midL) return rangeMin(l, midL, segL, segR, 2 * segIdx + 1); if (segL >= midL + 1) return rangeMin(midL + 1, r, segL, segR, 2 * segIdx + 2); return Math.min(rangeMin(l, midL, segL, midL, 2 * segIdx + 1), rangeMin(midL + 1, r, midL + 1, segR, 2 * segIdx + 2)); } /*******End of code for min*********/ /***********************************/ /*** Auxiliary functions for all modes ***/ // If it is determined that a whole segment has to be assigned some value // 'v', all children are bound to have the exact value 'v'. void asmtPush(int l, int r, int segIdx) { if (!prpgtMarked[segIdx]) return; int child1 = 2 * segIdx + 1, child2 = 2 * segIdx + 2; if (child2 > 4 * n - 1) child2 = child1; if (child1 > 4 * n - 1) return; minTree[child1] = minTree[child2] = minTree[segIdx]; prpgtMarked[child1] = prpgtMarked[child2] = true; prpgtMarked[segIdx] = false; } /*** Auxiliary functions for all modes end***/ public String toString() { return CFPS.toString(minTree); } } @SuppressWarnings("serial") static class CountMap<T> extends HashMap<T, Integer>{ CountMap() { } CountMap(T[] arr) { this.putCM(arr); } public Integer putCM(T key) { if (super.containsKey(key)) { return super.put(key, super.get(key) + 1); } else { return super.put(key, 1); } } public Integer removeCM(T key) { Integer count = super.get(key); if (count == null) return -1; if (count == 1) return super.remove(key); else return super.put(key, super.get(key) - 1); } public Integer getCM(T key) { Integer count = super.get(key); if (count == null) return 0; return count; } public void putCM(T[] arr) { for (T l : arr) this.putCM(l); } } static void coprimeGenerator(int m, int n, ArrayList<Point> coprimes, int limit, int numCoprimes) { if (m > limit) return; if (m <= limit && n <= limit) coprimes.add(new Point(m, n)); if (coprimes.size() > numCoprimes) return; coprimeGenerator(2 * m - n, m, coprimes, limit, numCoprimes); coprimeGenerator(2 * m + n, m, coprimes, limit, numCoprimes); coprimeGenerator(m + 2 * n, n, coprimes, limit, numCoprimes); } static long hash(long i) { return (i * 2654435761L % gigamod); } static long hash2(long key) { long h = Long.hashCode(key); h ^= (h >>> 20) ^ (h >>> 12) ^ (h >>> 7) ^ (h >>> 4); return h & (gigamod-1); } // Maps elements in a 2D matrix serially to elements in // a 1D array. static int mapTo1D(int row, int col, int n, int m) { return row * m + col; } // Inverse of what the one above does. static int[] mapTo2D(int idx, int n, int m) { int[] rnc = new int[2]; rnc[0] = idx / m; rnc[1] = idx % m; return rnc; } static class Point implements Comparable<Point> { long x; long y; long id; Point() { x = y = id = 0; } Point(Point p) { this.x = p.x; this.y = p.y; this.id = p.id; } Point(long a, long b, long id) { this.x = a; this.y = b; this.id = id; } Point(long a, long b) { this.x = a; this.y = b; } @Override public int compareTo(Point o) { if (this.x < o.x) return -1; if (this.x > o.x) return 1; if (this.y < o.y) return -1; if (this.y > o.y) return 1; return 0; } public boolean equals(Point that) { return this.compareTo(that) == 0; } } static double distance(Point p1, Point p2) { return Math.sqrt(Math.pow(p2.y-p1.y, 2) + Math.pow(p2.x-p1.x, 2)); } static HashMap<Integer, Integer> smolNumPrimeFactorization(int num) { if (smallestFactorOf == null) primeGenerator(2750132); CountMap<Integer> fnps = new CountMap<>(); while (num != 1) { fnps.putCM(smallestFactorOf[num]); num /= smallestFactorOf[num]; } return fnps; } // Returns map of factor and its power in the number. static HashMap<Long, Integer> primeFactorization(long num) { HashMap<Long, Integer> map = new HashMap<>(); while (num % 2 == 0) { num /= 2; Integer pwrCnt = map.get(2L); map.put(2L, pwrCnt != null ? pwrCnt + 1 : 1); } for (long i = 3; i * i <= num; i += 2) { while (num % i == 0) { num /= i; Integer pwrCnt = map.get(i); map.put(i, pwrCnt != null ? pwrCnt + 1 : 1); } } // If the number is prime, we have to add it to the // map. if (num != 1) map.put(num, 1); return map; } static HashSet<Long> divisors(long num) { HashSet<Long> divisors = new HashSet<Long>(); divisors.add(1L); divisors.add(num); for (long i = 2; i * i <= num; i++) { if (num % i == 0) { divisors.add(num/i); divisors.add(i); } } return divisors; } // Returns the index of the first element // larger than or equal to val. static int bsearch(int[] arr, int val, int lo, int hi) { int idx = -1; while (lo <= hi) { int mid = lo + (hi - lo)/2; if (arr[mid] >= val) { idx = mid; hi = mid - 1; } else lo = mid + 1; } return idx; } static int bsearch(long[] arr, long val, int lo, int hi) { int idx = -1; while (lo <= hi) { int mid = lo + (hi - lo)/2; if (arr[mid] >= val) { idx = mid; hi = mid - 1; } else lo = mid + 1; } return idx; } // Returns the index of the last element // smaller than or equal to val. static int bsearch(long[] arr, long val, int lo, int hi, boolean sMode) { int idx = -1; while (lo <= hi) { int mid = lo + (hi - lo)/2; if (arr[mid] >= val) { hi = mid - 1; } else { idx = mid; lo = mid + 1; } } return idx; } static int bsearch(int[] arr, long val, int lo, int hi, boolean sMode) { int idx = -1; while (lo <= hi) { int mid = lo + (hi - lo)/2; if (arr[mid] > val) { hi = mid - 1; } else { idx = mid; lo = mid + 1; } } return idx; } static long factorial(long n) { if (n <= 1) return 1; long factorial = 1; for (int i = 1; i <= n; i++) factorial = mod(factorial * i); return factorial; } static long factorialInDivision(long a, long b) { if (a == b) return 1; if (b < a) { long temp = a; a = b; b = temp; } long factorial = 1; for (long i = a + 1; i <= b; i++) factorial = mod(factorial * i); return factorial; } static long nCr(long n, long r, long[] fac) { long p = 998244353; // Base case if (r == 0) return 1; // Fill factorial array so that we // can find all factorial of r, n // and n-r /*long fac[] = new long[(int)n + 1]; fac[0] = 1; for (int i = 1; i <= n; i++) fac[i] = fac[i - 1] * i % p;*/ return (fac[(int)n] * modInverse(fac[(int)r], p) % p * modInverse(fac[(int)n - (int)r], p) % p) % p; } static long modInverse(long n, long p) { return power(n, p - 2, p); } static long power(long x, long y, long p) { long res = 1; // Initialize result x = x % p; // Update x if it is more than or // equal to p while (y > 0) { // If y is odd, multiply x with result if ((y & 1)==1) res = (res * x) % p; // y must be even now y = y >> 1; // y = y/2 x = (x * x) % p; } return res; } static long nPr(long n, long r) { return factorialInDivision(n, n - r); } static int logk(long n, long k) { return (int)(Math.log(n) / Math.log(k)); } // Sieve of Eratosthenes: static boolean[] primeGenerator(int upto) { isPrime = new boolean[upto + 1]; smallestFactorOf = new int[upto + 1]; Arrays.fill(smallestFactorOf, 1); Arrays.fill(isPrime, true); isPrime[1] = isPrime[0] = false; for (long i = 2; i < upto + 1; i++) if (isPrime[(int) i]) { smallestFactorOf[(int) i] = (int) i; // Mark all the multiples greater than or equal // to the square of i to be false. for (long j = i; j * i < upto + 1; j++) { if (isPrime[(int) j * (int) i]) { isPrime[(int) j * (int) i] = false; smallestFactorOf[(int) j * (int) i] = (int) i; } } } return isPrime; } static long gcd(long a, long b) { if (b == 0) { return a; } else { return gcd(b, a % b); } } static int gcd(int a, int b) { if (b == 0) { return a; } else { return gcd(b, a % b); } } static long gcd(long[] arr) { int n = arr.length; long gcd = arr[0]; for (int i = 1; i < n; i++) { gcd = gcd(gcd, arr[i]); } return gcd; } static int gcd(int[] arr) { int n = arr.length; int gcd = arr[0]; for (int i = 1; i < n; i++) { gcd = gcd(gcd, arr[i]); } return gcd; } static long lcm(long[] arr) { long lcm = arr[0]; int n = arr.length; for (int i = 1; i < n; i++) { lcm = (lcm * arr[i]) / gcd(lcm, arr[i]); } return lcm; } static long lcm(long a, long b) { return (a * b)/gcd(a, b); } static boolean less(int a, int b) { return a < b ? true : false; } static boolean isSorted(int[] a) { for (int i = 1; i < a.length; i++) { if (less(a[i], a[i - 1])) return false; } return true; } static boolean isSorted(long[] a) { for (int i = 1; i < a.length; i++) { if (a[i] < a[i - 1]) return false; } return true; } static void swap(int[] a, int i, int j) { int temp = a[i]; a[i] = a[j]; a[j] = temp; } static void swap(long[] a, int i, int j) { long temp = a[i]; a[i] = a[j]; a[j] = temp; } static void swap(double[] a, int i, int j) { double temp = a[i]; a[i] = a[j]; a[j] = temp; } static void swap(char[] a, int i, int j) { char temp = a[i]; a[i] = a[j]; a[j] = temp; } static void sort(int[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); } static void sort(char[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); } static void sort(long[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); } static void sort(double[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); } static void reverseSort(int[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); int n = arr.length; for (int i = 0; i < n/2; i++) swap(arr, i, n - 1 - i); } static void reverseSort(char[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); int n = arr.length; for (int i = 0; i < n/2; i++) swap(arr, i, n - 1 - i); } static void reverse(char[] arr) { int n = arr.length; for (int i = 0; i < n / 2; i++) swap(arr, i, n - 1 - i); } static void reverseSort(long[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); int n = arr.length; for (int i = 0; i < n/2; i++) swap(arr, i, n - 1 - i); } static void reverseSort(double[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); int n = arr.length; for (int i = 0; i < n/2; i++) swap(arr, i, n - 1 - i); } static void shuffleArray(long[] arr, int startPos, int endPos) { Random rnd = new Random(); for (int i = startPos; i < endPos; ++i) { long tmp = arr[i]; int randomPos = i + rnd.nextInt(endPos - i); arr[i] = arr[randomPos]; arr[randomPos] = tmp; } } static void shuffleArray(int[] arr, int startPos, int endPos) { Random rnd = new Random(); for (int i = startPos; i < endPos; ++i) { int tmp = arr[i]; int randomPos = i + rnd.nextInt(endPos - i); arr[i] = arr[randomPos]; arr[randomPos] = tmp; } } static void shuffleArray(double[] arr, int startPos, int endPos) { Random rnd = new Random(); for (int i = startPos; i < endPos; ++i) { double tmp = arr[i]; int randomPos = i + rnd.nextInt(endPos - i); arr[i] = arr[randomPos]; arr[randomPos] = tmp; } } private static void shuffleArray(char[] arr, int startPos, int endPos) { Random rnd = new Random(); for (int i = startPos; i < endPos; ++i) { char tmp = arr[i]; int randomPos = i + rnd.nextInt(endPos - i); arr[i] = arr[randomPos]; arr[randomPos] = tmp; } } static boolean isPrime(long n) { if (n <= 1) return false; if (n <= 3) return true; if (n % 2 == 0 || n % 3 == 0) return false; for (long i = 5; i * i <= n; i = i + 6) if (n % i == 0 || n % (i + 2) == 0) return false; return true; } static String toString(int[] dp) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < dp.length; i++) sb.append(dp[i] + " "); return sb.toString(); } static String toString(boolean[] dp) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < dp.length; i++) sb.append(dp[i] + " "); return sb.toString(); } static String toString(long[] dp) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < dp.length; i++) sb.append(dp[i] + " "); return sb.toString(); } static String toString(char[] dp) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < dp.length; i++) sb.append(dp[i] + ""); return sb.toString(); } static String toString(int[][] dp) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < dp.length; i++) { for (int j = 0; j < dp[i].length; j++) { sb.append(dp[i][j] + " "); } sb.append('\n'); } return sb.toString(); } static String toString(long[][] dp) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < dp.length; i++) { for (int j = 0; j < dp[i].length; j++) { sb.append(dp[i][j] + " "); } sb.append('\n'); } return sb.toString(); } static String toString(double[][] dp) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < dp.length; i++) { for (int j = 0; j < dp[i].length; j++) { sb.append(dp[i][j] + " "); } sb.append('\n'); } return sb.toString(); } static String toString(char[][] dp) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < dp.length; i++) { for (int j = 0; j < dp[i].length; j++) { sb.append(dp[i][j] + " "); } sb.append('\n'); } return sb.toString(); } static long mod(long a, long m) { return (a%m + m) % m; } static long mod(long num) { return (num % gigamod + gigamod) % gigamod; } // Uses weighted quick-union with path compression. static class UnionFind { private int[] parent; // parent[i] = parent of i private int[] size; // size[i] = number of sites in tree rooted at i // Note: not necessarily correct if i is not a root node private int count; // number of components public UnionFind(int n) { count = n; parent = new int[n]; size = new int[n]; for (int i = 0; i < n; i++) { parent[i] = i; size[i] = 1; } } // Number of connected components. public int count() { return count; } // Find the root of p. public int find(int p) { while (p != parent[p]) p = parent[p]; return p; } public boolean connected(int p, int q) { return find(p) == find(q); } public int numConnectedTo(int node) { return size[find(node)]; } // Weighted union. public void union(int p, int q) { int rootP = find(p); int rootQ = find(q); if (rootP == rootQ) return; // make smaller root point to larger one if (size[rootP] < size[rootQ]) { parent[rootP] = rootQ; size[rootQ] += size[rootP]; } else { parent[rootQ] = rootP; size[rootP] += size[rootQ]; } count--; } public static int[] connectedComponents(UnionFind uf) { // We can do this in nlogn. int n = uf.size.length; int[] compoColors = new int[n]; for (int i = 0; i < n; i++) compoColors[i] = uf.find(i); HashMap<Integer, Integer> oldToNew = new HashMap<>(); int newCtr = 0; for (int i = 0; i < n; i++) { int thisOldColor = compoColors[i]; Integer thisNewColor = oldToNew.get(thisOldColor); if (thisNewColor == null) thisNewColor = newCtr++; oldToNew.put(thisOldColor, thisNewColor); compoColors[i] = thisNewColor; } return compoColors; } } static class UGraph { // Adjacency list. private HashSet<Integer>[] adj; private static final String NEWLINE = "\n"; private int E; public UGraph(int V) { adj = (HashSet<Integer>[]) new HashSet[V]; E = 0; for (int i = 0; i < V; i++) adj[i] = new HashSet<Integer>(); } public void addEdge(int from, int to) { if (adj[from].contains(to)) return; E++; adj[from].add(to); adj[to].add(from); } public HashSet<Integer> adj(int from) { return adj[from]; } public int degree(int v) { return adj[v].size(); } public int V() { return adj.length; } public int E() { return E; } public String toString() { StringBuilder s = new StringBuilder(); s.append(V() + " vertices, " + E() + " edges " + NEWLINE); for (int v = 0; v < V(); v++) { s.append(v + ": "); for (int w : adj[v]) { s.append(w + " "); } s.append(NEWLINE); } return s.toString(); } public static void dfsMark(int current, boolean[] marked, UGraph g) { if (marked[current]) return; marked[current] = true; Iterable<Integer> adj = g.adj(current); for (int adjc : adj) dfsMark(adjc, marked, g); } public static void dfsMark(int current, int from, long[] distTo, boolean[] marked, UGraph g, ArrayList<Integer> endPoints) { if (marked[current]) return; marked[current] = true; if (from != -1) distTo[current] = distTo[from] + 1; HashSet<Integer> adj = g.adj(current); int alreadyMarkedCtr = 0; for (int adjc : adj) { if (marked[adjc]) alreadyMarkedCtr++; dfsMark(adjc, current, distTo, marked, g, endPoints); } if (alreadyMarkedCtr == adj.size()) endPoints.add(current); } public static void bfsOrder(int current, UGraph g) { } public static void dfsMark(int current, int[] colorIds, int color, UGraph g) { if (colorIds[current] != -1) return; colorIds[current] = color; Iterable<Integer> adj = g.adj(current); for (int adjc : adj) dfsMark(adjc, colorIds, color, g); } public static int[] connectedComponents(UGraph g) { int n = g.V(); int[] componentId = new int[n]; Arrays.fill(componentId, -1); int colorCtr = 0; for (int i = 0; i < n; i++) { if (componentId[i] != -1) continue; dfsMark(i, componentId, colorCtr, g); colorCtr++; } return componentId; } public static boolean hasCycle(UGraph ug) { int n = ug.V(); boolean[] marked = new boolean[n]; boolean[] hasCycleFirst = new boolean[1]; for (int i = 0; i < n; i++) { if (marked[i]) continue; hcDfsMark(i, ug, marked, hasCycleFirst, -1); } return hasCycleFirst[0]; } // Helper for hasCycle. private static void hcDfsMark(int current, UGraph ug, boolean[] marked, boolean[] hasCycleFirst, int parent) { if (marked[current]) return; if (hasCycleFirst[0]) return; marked[current] = true; HashSet<Integer> adjc = ug.adj(current); for (int adj : adjc) { if (marked[adj] && adj != parent && parent != -1) { hasCycleFirst[0] = true; return; } hcDfsMark(adj, ug, marked, hasCycleFirst, current); } } } static class Digraph { // Adjacency list. private HashSet<Integer>[] adj; private static final String NEWLINE = "\n"; private int E; public Digraph(int V) { adj = (HashSet<Integer>[]) new HashSet[V]; E = 0; for (int i = 0; i < V; i++) adj[i] = new HashSet<Integer>(); } public void addEdge(int from, int to) { if (adj[from].contains(to)) return; E++; adj[from].add(to); } public HashSet<Integer> adj(int from) { return adj[from]; } public int V() { return adj.length; } public int E() { return E; } public Digraph reversed() { Digraph dg = new Digraph(V()); for (int i = 0; i < V(); i++) for (int adjVert : adj(i)) dg.addEdge(adjVert, i); return dg; } public String toString() { StringBuilder s = new StringBuilder(); s.append(V() + " vertices, " + E() + " edges " + NEWLINE); for (int v = 0; v < V(); v++) { s.append(v + ": "); for (int w : adj[v]) { s.append(w + " "); } s.append(NEWLINE); } return s.toString(); } public static int[] KosarajuSharirSCC(Digraph dg) { int[] id = new int[dg.V()]; Digraph reversed = dg.reversed(); // Gotta perform topological sort on this one to get the stack. Stack<Integer> revStack = Digraph.topologicalSort(reversed); // Initializing id and idCtr. id = new int[dg.V()]; int idCtr = -1; // Creating a 'marked' array. boolean[] marked = new boolean[dg.V()]; while (!revStack.isEmpty()) { int vertex = revStack.pop(); if (!marked[vertex]) sccDFS(dg, vertex, marked, ++idCtr, id); } return id; } private static void sccDFS(Digraph dg, int source, boolean[] marked, int idCtr, int[] id) { marked[source] = true; id[source] = idCtr; for (Integer adjVertex : dg.adj(source)) if (!marked[adjVertex]) sccDFS(dg, adjVertex, marked, idCtr, id); } public static Stack<Integer> topologicalSort(Digraph dg) { // dg has to be a directed acyclic graph. // We'll have to run dfs on the digraph and push the deepest nodes on stack first. // We'll need a Stack<Integer> and a int[] marked. Stack<Integer> topologicalStack = new Stack<Integer>(); boolean[] marked = new boolean[dg.V()]; // Calling dfs for (int i = 0; i < dg.V(); i++) if (!marked[i]) runDfs(dg, topologicalStack, marked, i); return topologicalStack; } static void runDfs(Digraph dg, Stack<Integer> topologicalStack, boolean[] marked, int source) { marked[source] = true; for (Integer adjVertex : dg.adj(source)) if (!marked[adjVertex]) runDfs(dg, topologicalStack, marked, adjVertex); topologicalStack.add(source); } } static class FastReader { private BufferedReader bfr; private StringTokenizer st; public FastReader() { bfr = new BufferedReader(new InputStreamReader(System.in)); } String next() { if (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(bfr.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } char nextChar() { return next().toCharArray()[0]; } String nextString() { return next(); } int[] nextIntArray(int n) { int[] arr = new int[n]; for (int i = 0; i < n; i++) arr[i] = nextInt(); return arr; } double[] nextDoubleArray(int n) { double[] arr = new double[n]; for (int i = 0; i < arr.length; i++) arr[i] = nextDouble(); return arr; } long[] nextLongArray(int n) { long[] arr = new long[n]; for (int i = 0; i < n; i++) arr[i] = nextLong(); return arr; } int[][] nextIntGrid(int n, int m) { int[][] grid = new int[n][m]; for (int i = 0; i < n; i++) { char[] line = fr.next().toCharArray(); for (int j = 0; j < m; j++) grid[i][j] = line[j] - 48; } return grid; } } } // NOTES: // ASCII VALUE OF 'A': 65 // ASCII VALUE OF 'a': 97 // Range of long: 9 * 10^18 // ASCII VALUE OF '0': 48 // Primes upto 'n' can be given by (n / (logn)).
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
9af93967053aff08f2ec32cc97aa9d03
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; ////*************************************************************************** /* public class E_Gardener_and_Tree implements Runnable{ public static void main(String[] args) throws Exception { new Thread(null, new E_Gardener_and_Tree(), "E_Gardener_and_Tree", 1<<28).start(); } public void run(){ WRITE YOUR CODE HERE!!!! JUST WRITE EVERYTHING HERE WHICH YOU WRITE IN MAIN!!! } } */ /////************************************************************************** public class C2_Guessing_the_Greatest_hard_version_{ public static void main(String[] args) { FastScanner s= new FastScanner(); //PrintWriter out=new PrintWriter(System.out); //end of program //out.println(answer); //out.close(); StringBuilder res = new StringBuilder(); int n=s.nextInt(); long index= query(1,n); int check=1; if(index==1){ check=1; } else if(index==n){ check=-1; } else{ long a1=query(1,index); //long a2=query(index,n); if(a1==index){ check=-1; } else{ check=1; } } if(check==1){ long start=index; long end=n; long mid=0; while(start<end){ mid=(start+end)/2; if(start+1==end){ break; } long a1=query(index,mid); if(a1==index){ end=mid; } else{ start=mid; } } System.out.println("! "+end+" \n"); System.out.println(); System.out.flush(); } else{ long start=1; long end=index; long mid=0; while(start<end){ mid=(start+end)/2; if(start+1==end){ break; } long a1=query(mid,index); if(a1==index){ start=mid; } else{ end=mid; } } System.out.println("! "+start+" \n"); System.out.println(); System.out.flush(); } } private static long query(long l, long r) { FastScanner s= new FastScanner(); System.out.println("? "+l+" "+r+" \n"); System.out.println(); System.out.flush(); long a=s.nextLong(); return a; } static class FastScanner { BufferedReader br; StringTokenizer st; public FastScanner(String s) { try { br = new BufferedReader(new FileReader(s)); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public FastScanner() { br = new BufferedReader(new InputStreamReader(System.in)); } String nextToken() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(nextToken()); } long nextLong() { return Long.parseLong(nextToken()); } double nextDouble() { return Double.parseDouble(nextToken()); } } static long modpower(long x, long y, long p) { long res = 1; // Initialize result x = x % p; // Update x if it is more than or // equal to p if (x == 0) return 0; // In case x is divisible by p; while (y > 0) { // If y is odd, multiply x with result if ((y & 1) != 0) res = (res * x) % p; // y must be even now y = y >> 1; // y = y/2 x = (x * x) % p; } return res; } // SIMPLE POWER FUNCTION=> static long power(long x, long y) { long res = 1; // Initialize result while (y > 0) { // If y is odd, multiply x with result if ((y & 1) != 0) res = res * x; // y must be even now y = y >> 1; // y = y/2 x = x * x; // Change x to x^2 } return res; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
f1522b964b01e447561090fe641335e1
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; import java.math.*; import java.math.BigInteger; //import javafx.util.*; public final class B { static StringBuilder ans=new StringBuilder(); static FastReader in=new FastReader(); static ArrayList<ArrayList<Integer>> g; static long mod=1000000007; static int D1[],D2[],par[]; static boolean set[]; static long INF=Long.MAX_VALUE; public static void main(String args[])throws IOException { int N=i(); int index=ask(1,N); if(index==N || index==1) { if(index==1)System.out.println("! "+f2(1,N,index)); else System.out.println("! "+f1(1,N,index)); } else if(ask(1,index)==index) { System.out.println("! "+f1(1,index,index)); } else System.out.println("! "+f2(index,N,index)); } static int f1(int l,int r,int index) { while(r-l>1) { int m=(l+r)/2; if(ask(m,index)==index)l=m; else r=m; } return l; } static int f2(int l,int r,int index) { while(r-l>1) { int m=(l+r)/2; if(ask(index,m)==index)r=m; else l=m; } return r; } static long fact(long N) { long num=1L; while(N>=1) { num=((num%mod)*(N%mod))%mod; N--; } return num; } static boolean reverse(long A[],int l,int r) { while(l<r) { long t=A[l]; A[l]=A[r]; A[r]=t; l++; r--; } if(isSorted(A))return true; else return false; } static boolean isSorted(long A[]) { for(int i=1; i<A.length; i++)if(A[i]<A[i-1])return false; return true; } static boolean isPalindrome(char X[],int l,int r) { while(l<r) { if(X[l]!=X[r])return false; l++; r--; } return true; } static long min(long a,long b,long c) { return Math.min(a, Math.min(c, b)); } static void print(int a) { System.out.println("! "+a); } static int ask(int a,int b) { System.out.println("? "+a+" "+b); return i(); } static int find(int a) { if(par[a]<0)return a; return par[a]=find(par[a]); } static void union(int a,int b) { a=find(a); b=find(b); if(a!=b) { par[a]+=par[b]; //transfers the size par[b]=a; //changes the parent } } static void swap(char A[],int a,int b) { char ch=A[a]; A[a]=A[b]; A[b]=ch; } static void sort(long[] a) //check for long { ArrayList<Long> l=new ArrayList<>(); for (long i:a) l.add(i); Collections.sort(l); for (int i=0; i<a.length; i++) a[i]=l.get(i); } static void setGraph(int N) { g=new ArrayList<ArrayList<Integer>>(); for(int i=0; i<=N; i++) { g.add(new ArrayList<Integer>()); } } static long pow(long a,long b) { long mod=1000000007; long pow=1; long x=a; while(b!=0) { if((b&1)!=0)pow=(pow*x)%mod; x=(x*x)%mod; b/=2; } return pow; } static long toggleBits(long x)//one's complement || Toggle bits { int n=(int)(Math.floor(Math.log(x)/Math.log(2)))+1; return ((1<<n)-1)^x; } static int countBits(long a) { return (int)(Math.log(a)/Math.log(2)+1); } static void sort(int[] a) { ArrayList<Integer> l=new ArrayList<>(); for (int i:a) l.add(i); Collections.sort(l); for (int i=0; i<a.length; i++) a[i]=l.get(i); } static boolean isPrime(long N) { if (N<=1) return false; if (N<=3) return true; if (N%2 == 0 || N%3 == 0) return false; for (int i=5; i*i<=N; i=i+6) if (N%i == 0 || N%(i+2) == 0) return false; return true; } static long GCD(long a,long b) { if(b==0) { return a; } else return GCD(b,a%b ); } //Debugging Functions Starts static void print(char A[]) { for(char c:A)System.out.print(c+" "); System.out.println(); } static void print(boolean A[]) { for(boolean c:A)System.out.print(c+" "); System.out.println(); } static void print(int A[]) { for(int a:A)System.out.print(a+" "); System.out.println(); } static void print(long A[]) { for(long i:A)System.out.print(i+ " "); System.out.println(); } static void print(ArrayList<Integer> A) { for(int a:A)System.out.print(a+" "); System.out.println(); } //Debugging Functions END //---------------------- //IO FUNCTIONS STARTS static HashMap<Integer,Integer> Hash(int A[]) { HashMap<Integer,Integer> mp=new HashMap<>(); for(int a:A) { int f=mp.getOrDefault(a,0)+1; mp.put(a, f); } return mp; } static int i() { return in.nextInt(); } static long l() { return in.nextLong(); } static int[] input(int N){ int A[]=new int[N]; for(int i=0; i<N; i++) { A[i]=in.nextInt(); } return A; } static long[] inputLong(int N) { long A[]=new long[N]; for(int i=0; i<A.length; i++)A[i]=in.nextLong(); return A; } //IO FUNCTIONS END } //class pair implements Comparable<pair>{ // int index; long a; // pair(long a,int index) // { // this.a=a; // this.index=index; // } // public int compareTo(pair X) // { // if(this.a>X.a)return 1; // if(this.a==X.a)return this.index-X.index; // return -1; // } //} //Code For FastReader //Code For FastReader //Code For FastReader //Code For FastReader class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br=new BufferedReader(new InputStreamReader(System.in)); } String next() { while(st==null || !st.hasMoreElements()) { try { st=new StringTokenizer(br.readLine()); } catch(IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } //gey double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str=""; try { str=br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
94dca4f4ac55ffd66fc3cf33827afc7c
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; public class C2 { public static void main(String[] args) throws IOException{ BufferedReader f = new BufferedReader(new InputStreamReader(System.in)); PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out)); int n = Integer.parseInt(f.readLine()); int s = query(f, out, 0, n-1); boolean dir = query(f, out, 0, s) == s; if(dir){ int l = 0; int r = s; while(r > l+1){ int mid = (l+r)/2; if(query(f, out, mid, s) == s) { l = mid; }else{ r = mid; } } out.println("! " + (l+1)); }else{ int l = s; int r = n-1; while(r > l+1){ int mid = (l+r)/2; if(query(f, out, s, mid) == s) { r = mid; }else{ l = mid; } } out.println("! " + (r+1)); } out.close(); } public static int query(BufferedReader f, PrintWriter out, int l, int r) throws IOException{ if(l == r) return -1; out.println("? " + (l+1) + " " + (r+1)); out.flush(); return Integer.parseInt(f.readLine())-1; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
79ea6f6fc6ea6383cb9167d08fc8d06f
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class Main { public static void main(String args[]) { FastReader input=new FastReader(); PrintWriter out=new PrintWriter(System.out); int T=1; while(T-->0) { int n=input.nextInt(); out.println("?"+" "+1+" "+n); out.flush(); int in=input.nextInt(); char pos='r'; if(in==1) { pos='r'; } else if(in==n) { pos='l'; } else { out.println("? "+1+" "+in); out.flush(); int in1=input.nextInt(); if(in1==in) { pos='l'; } else { pos='r'; } } if(pos=='l') { int i=1; int j=in; while(i<j) { int mid=(i+j)/2; out.println("? "+mid+" "+in); out.flush(); int in1=input.nextInt(); if(in1==in) { i=mid+1; } else { j=mid; } } out.println("!"+" "+(i-1)); } else { int i=in+1; int j=n; while(i<j) { int mid=(i+j)/2; out.println("? "+in+" "+mid); out.flush(); int in1=input.nextInt(); if(in1==in) { j=mid; } else { i=mid+1; } } out.println("!"+" "+(i)); } } out.close(); } static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str=""; try { str=br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
6626732f719194fa20c3832a4934b4b9
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.lang.reflect.Array; import java.text.DecimalFormat; import java.util.*; import java.io.*; public class Equal { static class pair implements Comparable<pair> { int x; int y; public pair(int u, int v) { this.x = u; this.y = v; } @Override public int compareTo(pair o) { return o.x-x; } } static int[][]mem=new int[1001][1001]; // static int dp(int n,int k){ // if(n>=mem.length) // return 0; // if(k<0||k>=mem.length) // return 0; // if(mem[n][k]!=-1) // return mem[n][k]; // } static String timeInc(String time,int h,int m){ String []s =time.split(":"); int i=0; int hh=0; int mm=0; while (i<s[0].length()&&s[0].charAt(i)=='0'){ i++; } if(i<s[0].length()) hh=Integer.parseInt(s[0].substring(i)); i=0; while (i<s[1].length()&&s[1].charAt(i)=='0'){ i++; } if(i<s[1].length()) mm=Integer.parseInt(s[1].substring(i)); mm++; if(mm%m==0){ mm=0; hh++; if(hh%h==0) hh=0; } String hs=""+hh; while(hs.length()<2) hs="0"+hs; String ms=""+mm; while (ms.length()<2) ms="0"+ms; return hs+":"+ms; } static boolean validMirror(String s,int h,int m){ HashSet<Character>hs=new HashSet<>(); hs.add('3'); hs.add('4'); hs.add('6'); hs.add('7'); hs.add('9'); for (int i = 0; i <s.length() ; i++) { if(hs.contains(s.charAt(i))){ return false; } } String mirrored=""; for (int i = s.length()-1; i >=0 ; i--) { if(s.charAt(i)=='5'){ mirrored+="2"; continue; } if(s.charAt(i)=='2'){ mirrored+="5"; continue; } mirrored+=s.charAt(i); } int i=0; int hh=0; int mm=0; String []s2 =mirrored.split(":"); while (i<s2[0].length()&&s2[0].charAt(i)=='0'){ i++; } if(i<s2[0].length()) hh=Integer.parseInt(s2[0].substring(i)); i=0; while (i<s2[1].length()&&s2[1].charAt(i)=='0'){ i++; } if(i<s2[1].length()) mm=Integer.parseInt(s2[1].substring(i)); if(hh>=h||mm>=m) return false; return true; } public static void main(String[] args) throws IOException { //BufferedReader br = new BufferedReader(new FileReader("name.in")); BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st; PrintWriter out = new PrintWriter(System.out); int n=Integer.parseInt(br.readLine()); boolean found=false; int p=-1; int q=0; System.out.println("? 1 "+n); int second=Integer.parseInt(br.readLine()); int beg=-1; int end=-1; if(second>1&&second!=n) { System.out.println("? 1 " + second); int before = Integer.parseInt(br.readLine()); if (before == second) { beg = 1; end = second; } else { beg = second; end = n; } } else{ beg=1; end=n; } while(!found&&q<20){ int mid=(beg+end)>>1; if(end-beg==1){ if(end<=second) mid=end; else mid=beg; if(end==second||beg==second){ found=true; p=end+beg-second; break; } } if(mid>second){ System.out.println("? "+second+" "+mid); } else { System.out.println("? "+mid+" "+second); } int x=Integer.parseInt(br.readLine()); if(end-beg==1){ found=true; if(x==second) p=mid; else { if(end<=second) p=beg; else p=end; } } else { if (x == second) { if (mid < second) { if(second-mid==1){ found=true; p=mid; } beg = mid; } else { end = mid; if(mid-second==1){ found=true; p=mid; } } } else { if (mid < second) { if(mid-beg==1){ found=true; p=beg; } end = mid; } else { if(end-mid==1){ found=true; p=end; } beg = mid; } } } q++; } System.out.println("! "+p); out.flush(); out.close(); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
67690286a36634f083b021b769d144bd
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; public class Main { static Scanner sc = new Scanner(System.in); static PrintWriter out = new PrintWriter(System.out); static BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); // long mod = 998244353; // long mod = (long)1e9+7; long mod = 998244353; public static void main(String[] args) throws Exception { Main main = new Main(); // int t = sc.nextInt(); int t = 1; for(int i=1; i<=t; i++){ main.solve(); } out.flush(); } void solve() throws Exception { int n = neInt(); out.println("? 1 "+n); out.flush(); int secMax = neInt(); boolean inRight=true; if(secMax>1){ out.println("? 1 "+secMax); out.flush(); int temp = neInt(); if(temp==secMax){ inRight = false; } } int co = inRight?1:-1; int lo=1,hi; if(inRight){ hi = n-secMax+1; } else hi = secMax; while(hi>lo+1){ int mid = (hi+lo)/2; int idx = secMax+mid*co-co; out.println("? "+Math.min(idx,secMax)+" "+Math.max(idx,secMax)); out.flush(); int temp = neInt(); if(temp==secMax) hi = mid; else lo = mid; } int ans = secMax+hi*co-co; out.println("! "+ans); } String neS(){ return sc.next(); } int neInt(){ return Integer.parseInt(sc.next()); } long neLong(){ return Long.parseLong(sc.next()); } int paIn(String s){return Integer.parseInt(s);} public int minimumLengthEncoding(String[] words) { int n = words.length; Arrays.sort(words, (o1, o2)->(o1.length()-o2.length())); int ans = 0; for(int i=0; i<n; i++){ boolean found = false; for(int j=i+1; j<n && (!found); j++){ found |= words[j].endsWith(words[i]); } if(!found) ans += words[i].length()+1; } return ans; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
76fd9d43f5decff608b51a611aac0208
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.StringTokenizer; import static java.lang.Double.parseDouble; import static java.lang.Integer.compare; import static java.lang.Integer.parseInt; import static java.lang.Long.parseLong; import static java.lang.System.in; public class Main { private static final int MOD = (int) (1E9 + 7); static FastScanner scanner = new FastScanner(in); public static void main(String[] args) throws IOException { // Write your solution here int t = 1; //t = parseInt(scanner.nextLine()); while (t-- > 0) { solve(); } } private static void solve() throws IOException { int n = scanner.nextInt(); int secMax = query(1, n); int ans = 0; if (query(secMax, n) == secMax) { int l = secMax + 1, r = n; while (l <= r) { int mid = (l + r) / 2; if (query(secMax, mid) == secMax) { ans = mid; r = mid - 1; } else { l = mid + 1; } } } else { int l = 1, r = secMax - 1; while (l <= r) { int mid = (l + r) / 2; if (query(mid, secMax) == secMax) { ans = mid; l = mid + 1; } else { r = mid - 1; } } } System.out.println("! " + ans); } private static int query(int l, int h) { if(l == h) return -1; System.out.println("? " + l + " " + h); System.out.flush(); return scanner.nextInt(); } private static class Pair implements Comparable<Pair> { int index, value; public Pair(int index, int value) { this.index = index; this.value = value; } public int compareTo(Pair o) { if (value != o.value) return compare(value, o.value); return compare(index, o.index); } @Override public String toString() { return "Pair{" + "index=" + index + ", value=" + value + '}'; } } static class FastScanner { BufferedReader br; StringTokenizer st; FastScanner(File f) { try { br = new BufferedReader(new FileReader(f)); } catch (FileNotFoundException e) { e.printStackTrace(); } } FastScanner(InputStream f) { br = new BufferedReader(new InputStreamReader(f)); } String nextLine() { try { return br.readLine(); } catch (IOException e) { return null; } } String next() { while (st == null || !st.hasMoreTokens()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return parseInt(next()); } long nextLong() { return parseLong(next()); } double nextDouble() { return parseDouble(next()); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
df18c9416bbde5a06cd757fdab97b6fa
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.util.InputMismatchException; import java.util.*; import java.io.*; import java.lang.*; public class Main{ public static class InputReader { private InputStream stream; private byte[] buf = new byte[1024]; private int curChar; private int numChars; private InputReader.SpaceCharFilter filter; private BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); public InputReader(InputStream stream) { this.stream = stream; } public int read() { if (numChars==-1) throw new InputMismatchException(); if (curChar >= numChars) { curChar = 0; try { numChars = stream.read(buf); } catch (IOException e) { throw new InputMismatchException(); } if(numChars <= 0) return -1; } return buf[curChar++]; } public String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } public int nextInt() { int c = read(); while(isSpaceChar(c)) c = read(); int sgn = 1; if (c == '-') { sgn = -1; c = read(); } int res = 0; do { if(c<'0'||c>'9') throw new InputMismatchException(); res *= 10; res += c - '0'; c = read(); } while (!isSpaceChar(c)); return res * sgn; } public long nextLong() { int c = read(); while (isSpaceChar(c)) c = read(); int sgn = 1; if (c == '-') { sgn = -1; c = read(); } long res = 0; do { if (c < '0' || c > '9') throw new InputMismatchException(); res *= 10; res += c - '0'; c = read(); } while (!isSpaceChar(c)); return res * sgn; } public double nextDouble() { int c = read(); while (isSpaceChar(c)) c = read(); int sgn = 1; if (c == '-') { sgn = -1; c = read(); } double res = 0; while (!isSpaceChar(c) && c != '.') { if (c == 'e' || c == 'E') return res * Math.pow(10, nextInt()); if (c < '0' || c > '9') throw new InputMismatchException(); res *= 10; res += c - '0'; c = read(); } if (c == '.') { c = read(); double m = 1; while (!isSpaceChar(c)) { if (c == 'e' || c == 'E') return res * Math.pow(10, nextInt()); if (c < '0' || c > '9') throw new InputMismatchException(); m /= 10; res += (c - '0') * m; c = read(); } } return res * sgn; } public String readString() { int c = read(); while (isSpaceChar(c)) c = read(); StringBuilder res = new StringBuilder(); do { res.appendCodePoint(c); c = read(); } while (!isSpaceChar(c)); return res.toString(); } public boolean isSpaceChar(int c) { if (filter != null) return filter.isSpaceChar(c); return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1; } public String next() { return readString(); } public interface SpaceCharFilter { public boolean isSpaceChar(int ch); } } static long gcd(long a, long b){ if (a == 0) return b; return gcd(b % a, a); } static long lcm(long a, long b) { return (a*b)/gcd(a, b); } public static void sortbyColumn(int arr[][], int col) { Arrays.sort(arr, new Comparator<int[]>() { @Override public int compare(final int[] entry1, final int[] entry2) { if (entry1[col] > entry2[col]) return 1; else return -1; } }); } static long func(long a[],int size,int s){ long max1=a[s]; long maxc=a[s]; for(int i=s+1;i<size;i++){ maxc=Math.max(a[i],maxc+a[i]); max1=Math.max(maxc,max1); } return max1; } public static class Pair<U extends Comparable<U>, V extends Comparable<V>> implements Comparable<Pair<U, V>> { public U x; public V y; public Pair(U x, V y) { this.x = x; this.y = y; } public int hashCode() { return (x == null ? 0 : x.hashCode() * 31) + (y == null ? 0 : y.hashCode()); } public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Pair<U, V> p = (Pair<U, V>) o; return (x == null ? p.x == null : x.equals(p.x)) && (y == null ? p.y == null : y.equals(p.y)); } public int compareTo(Pair<U, V> b) { int cmpU = x.compareTo(b.x); return cmpU != 0 ? cmpU : y.compareTo(b.y); } public String toString() { return String.format("(%s, %s)", x.toString(), y.toString()); } } static class MultiSet<U extends Comparable<U>> { public int sz = 0; public TreeMap<U, Integer> t; public MultiSet() { t = new TreeMap<>(); } public void add(U x) { t.put(x, t.getOrDefault(x, 0) + 1); sz++; } public void remove(U x) { if (t.get(x) == 1) t.remove(x); else t.put(x, t.get(x) - 1); sz--; } } static void shuffle(long[] a) { Random get = new Random(); for (int i = 0; i < a.length; i++) { int r = get.nextInt(a.length); long temp = a[i]; a[i] = a[r]; a[r] = temp; } } static long myceil(long a, long b){ return (a+b-1)/b; } static long C(long n,long r){ long count=0,temp=n; long ans=1; long num=n-r+1,div=1; while(num<=n){ ans*=num; //ans+=MOD; ans%=MOD; ans*=mypow(div,MOD-2); //ans+=MOD; ans%=MOD; num++; div++; } ans+=MOD; return ans%MOD; } static long fact(long a){ long i,ans=1; for(i=1;i<=a;i++){ ans*=i; ans%=MOD; } return ans%=MOD; } static void sieve(int n){ is_sieve[0]=1; is_sieve[1]=1; int i,j,k; for(i=2;i<n;i++){ if(is_sieve[i]==0){ sieve[i]=i; tr.add(i); for(j=i*i;j<n;j+=i){ if(j>n||j<0){ break; } is_sieve[j]=1; sieve[j]=i; } } } } static void calc(int n){ int i,j; dp[n-1]=0; if(n>1) dp[n-2]=1; for(i=n-3;i>=0;i--){ long ind=n-i-1; dp[i]=((ind*(long)mypow(10,ind-1))%MOD+dp[i+1])%MOD; } } static long mypow(long x,long y){ long temp; if( y == 0) return 1; temp = mypow(x, y/2); if (y%2 == 0) return (temp*temp)%MOD; else return ((x*temp)%MOD*(temp)%MOD)%MOD; } static long dist[],dp[]; static int visited[],recStack[]; static ArrayList<Integer> adj[]; //static int dp[][][]; static int MOD=1000000007,max=0; static char chm='#'; static int[] sieve,is_sieve; static TreeSet<Integer> tr; static int ask(int l,int r){ InputStream inputStream = System.in; OutputStream outputStream = System.out; InputReader in = new InputReader(inputStream); PrintWriter w = new PrintWriter(outputStream); w.println("? "+(l+1)+" "+(r+1)); w.flush(); int ans=in.nextInt(); return ans-1; } public static void main(String args[]){ InputStream inputStream = System.in; OutputStream outputStream = System.out; InputReader in = new InputReader(inputStream); PrintWriter w = new PrintWriter(outputStream); int t,i,j,tno=0,tte; //t=in.nextInt(); t=1; //tte=t; while(t-->0){ int n,q,flag=0,ans=0; n=in.nextInt(); int smax=ask(0,n-1); if(smax==0||ask(0,smax)!=smax){ int l=smax,r=n-1; while(r-l>1){ int m=(l+r)/2; if(ask(smax,m)==smax){ r=m; }else{ l=m; } } w.println("! "+(r+1)); }else{ int l=0,r=smax; while(r-l>1){ int m=(l+r)/2; if(ask(m,smax)==smax){ l=m; }else{ r=m; } } w.println("! "+(l+1)); } } w.close(); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
227f67719df07e1eae2dc733a47c55c8
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
//package Current; import java.util.*; public class Main { static final long mod = (long) 1e9 + 7; static class pair { int x, y; public pair(int x, int y) { this.x = x; this.y = y; } } public static void main(String args[]) { Scanner sc = new Scanner(System.in); int t = 1; // t = sc.nextInt(); while (t-- > 0) { // Start code int n = sc.nextInt(); int ans = 0; int smax = ask(1, n, sc); if (smax == 1 || ask(1, smax, sc) != smax) { int l = smax + 1, r = n; while (l <= r) { int mid = l + (r - l) / 2; int p = ask(smax, mid, sc); if (p == smax) { ans = mid; r = mid - 1; } else l = mid + 1; } } else { int l = 1, r = smax - 1; while (l <= r) { int mid = l + (r - l) / 2; int p = ask(mid, smax, sc); if (p == smax) { ans = mid; l = mid + 1; } else r = mid - 1; } } println("! " + ans); } sc.close(); } static int ask(int l, int r, Scanner sc) { println("? " + l + " " + r); System.out.flush(); int x = sc.nextInt(); return x; } static void print(Object o) { System.out.print(o + " "); } static void println(Object o) { System.out.println(o); } static void swap(int arr[], int i, int j) { int temp = arr[i]; arr[i] = arr[j]; arr[j] = temp; } static ArrayList<Long> factorial(int num) { ArrayList<Long> fac = new ArrayList<>(); fac.add((long) 0); fac.add((long) 1); for (int i = 2; i < num; i++) { fac.add((fac.get(i - 1) * i) % mod); } return fac; } static long ncr(long x, long y, ArrayList<Long> fac) { if (y >= x) return (long) 1; long res = fac.get((int) x); long z = (fac.get((int) y) * fac.get((int) (x - y))) % mod; z = modInv(z); res = (res * z) % mod; return res; } static long modInv(long x) { return modExpo(x, mod - 2); } static long modExpo(long x, long y) { long res = 1; x = x % mod; while (y > 0) { if (y % 2 == 1) res = (res * x) % mod; y = y / 2; x = (x * x) % mod; } return res; } static int lowerBound(int n, long[] arr, long value) { int res = (int) 1e7; int l = 0, r = n - 1; while (l <= r) { int mid = l + (r - l) / 2; if (arr[mid] >= value) { res = mid; r = mid - 1; } else l = mid + 1; } return res; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
99979edb06719b8f97bb99811b4eac8f
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; import java.util.function.BiFunction; public class C { static FastReader reader = new FastReader(); static OutputWriter out = new OutputWriter(System.out); static int ask(int l, int r) { out.println("? " + l + " " + r);out.flush(); return reader.nextInt(); } static int solve(int l, int r) { if(l == r) { return l; } if(l + 1 == r) { return ask(l, r) == l ? r : l; } int t1 = ask(l, r); if(t1 != r && ask(t1, r) == t1) { //we are at left most point l = t1 + 1; while(l <= r) { int m = (l + r) / 2; int t2 = ask(t1, m); if(t2 == t1) { r = m - 1; } else { l = m + 1; } }//[1,2,4,3, 5] return l; } else { r = t1 - 1; while(l <= r) { int m = (l + r) / 2; int t2 = ask(m, t1); if(t2 == t1) { l = m + 1; } else { r = m - 1; } } return r; //we are at right most point } } public static void main(String[] args) { try { int n = reader.nextInt(); int ans = solve(1, n); out.println("! " + ans); } finally { out.flush(); } } static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } public static class OutputWriter { private final PrintWriter writer; public OutputWriter(OutputStream outputStream) { writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream))); } public OutputWriter(Writer writer) { this.writer = new PrintWriter(writer); } public void print(char[] array) { writer.print(array); } public void print(Object... objects) { for (int i = 0; i < objects.length; i++) { if (i != 0) { writer.print(' '); } writer.print(objects[i]); } } public void print(int[] array) { for (int i = 0; i < array.length; i++) { if (i != 0) { writer.print(' '); } writer.print(array[i]); } } public void print(double[] array) { for (int i = 0; i < array.length; i++) { if (i != 0) { writer.print(' '); } writer.print(array[i]); } } public void print(long[] array) { for (int i = 0; i < array.length; i++) { if (i != 0) { writer.print(' '); } writer.print(array[i]); } } public void println(int[] array) { print(array); writer.println(); } public void println(double[] array) { print(array); writer.println(); } public void println(long[] array) { print(array); writer.println(); } public void println() { writer.println(); } public void println(Object... objects) { print(objects); writer.println(); } public void print(char i) { writer.print(i); } public void println(char i) { writer.println(i); } public void println(char[] array) { writer.println(array); } public void printf(String format, Object... objects) { writer.printf(format, objects); } public void close() { writer.close(); } public void flush() { writer.flush(); } public void print(long i) { writer.print(i); } public void println(long i) { writer.println(i); } public void print(int i) { writer.print(i); } public void println(int i) { writer.println(i); } public void separateLines(int[] array) { for (int i : array) { println(i); } } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
7202fc148ce102afa753ac40a20a92b5
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class guessingthegreatesteasy { public static void main(String[] args) throws IOException { BufferedReader f = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(f.readLine()); int n = Integer.parseInt(st.nextToken()); System.out.println("? " + 1 + " " + n); int secondMax = 0; System.out.flush(); secondMax = Integer.parseInt(f.readLine()); boolean left = true; if(secondMax > 1) { System.out.println("? " + 1 + " " + secondMax); System.out.flush(); left = Integer.parseInt(f.readLine()) == secondMax; } if(secondMax == 1 || !left) { int low = secondMax; int high = n; while(high - low > 1) { int mid = (low - high) / 2 + high; System.out.println("? " + secondMax + " " + mid); System.out.flush(); int secondSecondMax = Integer.parseInt(f.readLine()); if(secondSecondMax != secondMax) low = mid; else high = mid; } System.out.println("! " + high); } else{ int high = secondMax; int low = 1; while(high - low > 1) { int mid = (low - high) / 2 + high; System.out.println("? " + mid + " " + secondMax); System.out.flush(); int secondSecondMax = Integer.parseInt(f.readLine()); if(secondSecondMax != secondMax) high = mid; else low = mid; } System.out.println("! " + low); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
b59d48e856674851ad72da3fb5c59a4c
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.*; public class Practice { public static void main(String[] args) throws Exception { Scanner s = new Scanner(System.in); int n = s.nextInt(); System.out.flush(); getAns(n, s); } private static void getAns(int n, Scanner s) { // TODO Auto-generated method stub int sec=call(0,n-1,s); if(sec==0||call(0,sec,s)!=sec) { int l=sec,r=n-1; while(r-l>1) { int m=(l+r)/2; if(call(sec,m,s)!=sec) { l=m; }else { r=m; } }System.out.println("! "+(r+1)); }else { int l=0,r=sec; while(r-l>1) { int m=(l+r)/2; if(call(m,sec,s)!=sec) { r=m; }else { l=m; } }System.out.println("! "+(l+1)); } } private static int call(int l, int r,Scanner s) { // TODO Auto-generated method stub System.out.println("? "+(l+1)+" "+(r+1)); int sec=s.nextInt(); System.out.flush(); return sec-1; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
e401a4b9a137c543d7f634bfc649faba
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; /* polyakoff */ public class Main { static FastReader in; static PrintWriter out; static Random rand = new Random(); static final int oo = (int) 1e9 + 10; static final long OO = (long) 2e18 + 10; static final int MOD = (int) 1e9 + 7; static int ask(int l, int r) { out.printf("? %d %d\n", l, r); out.flush(); return in.nextInt(); } static void solve() { int n = in.nextInt(); int l = 1, r = n; int second = ask(l, r); while (true) { if (r - l + 1 == 2) { int first = second == l ? l + 1 : l; out.printf("! %d\n", first); out.flush(); return; } else if (r - l + 1 == 3) { int pos = ask(l, l + 1); int first; if (second != r) first = pos == second ? (second == l ? l + 1 : l) : r; else first = pos == l ? l + 1 : l; out.printf("! %d\n", first); out.flush(); return; } int mid = (l + r) / 2; if (second <= mid) { int pos = ask(l, mid); if (pos == second) r = mid; else { int l2 = mid + 1, r2 = r; while (l2 < r2) { int mid2 = (l2 + r2) / 2; if (ask(second, mid2) == second) r2 = mid2; else l2 = mid2 + 1; } out.printf("! %d\n", l2); out.flush(); return; } } else { int pos = ask(mid + 1, r); if (pos == second) l = mid + 1; else { int l2 = l, r2 = mid; while (l2 < r2) { int mid2 = (l2 + r2) / 2; if (ask(mid2 + 1, second) == second) l2 = mid2 + 1; else r2 = mid2; } out.printf("! %d\n", l2); out.flush(); return; } } } } public static void main(String[] args) { in = new FastReader(); out = new PrintWriter(System.out); int T = 1; // T = in.nextInt(); while (T-- > 0) solve(); out.flush(); out.close(); } static class FastReader { BufferedReader br; StringTokenizer st; FastReader() { this(System.in); } FastReader(String file) throws FileNotFoundException { this(new FileInputStream(file)); } FastReader(InputStream is) { br = new BufferedReader(new InputStreamReader(is)); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String next() { while (st == null || !st.hasMoreTokens()) { st = new StringTokenizer(nextLine()); } return st.nextToken(); } String nextLine() { String line; try { line = br.readLine(); } catch (IOException e) { throw new RuntimeException(e); } return line; } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
b052870c39aadff5e6e3457386c4f30b
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; import java.awt.*; public class C { BufferedReader in; PrintWriter ob; StringTokenizer st; public static void main(String[] args) throws IOException { new C().run(); } void run() throws IOException { in=new BufferedReader(new InputStreamReader(System.in)); ob=new PrintWriter(System.out); solve(); System.out.flush(); } void solve() throws IOException { int n = ni(); System.out.println("? 1 "+n); int s_max_pos = ni(); int left_sec_max = 0; if( s_max_pos != 1 ) { System.out.println("? 1"+" "+s_max_pos); left_sec_max = ni(); } if( s_max_pos != 1 && left_sec_max == s_max_pos ) { int left = 1, right = s_max_pos; while( right - left > 1 ) { int mid = left + (right - left)/2; System.out.println("? "+mid+" "+s_max_pos); int res = ni(); if ( res == s_max_pos ) left = mid; else right = mid - 1; } if( right == s_max_pos ) { System.out.println("! "+left); return; } System.out.println("? "+right+" "+s_max_pos); int f = ni(); if( f == s_max_pos ) System.out.println("! "+right); else System.out.println("! "+left); } else { int left = s_max_pos, right = n; while( right - left > 1 ) { int mid = left + (right - left)/2; System.out.println("? "+s_max_pos+" "+mid); int res = ni(); if ( res == s_max_pos ) right = mid; else left = mid + 1; } if( left == s_max_pos ) { System.out.println("! "+right); return; } System.out.println("? "+s_max_pos+" "+left); int f = ni(); if( f == s_max_pos ) System.out.println("! "+left); else System.out.println("! "+right); } } String ns() throws IOException { return nextToken(); } long nl() throws IOException { return Long.parseLong(nextToken()); } int ni() throws IOException { return Integer.parseInt(nextToken()); } double nd() throws IOException { return Double.parseDouble(nextToken()); } String nextToken() throws IOException { if(st==null || !st.hasMoreTokens()) st=new StringTokenizer(in.readLine()); return st.nextToken(); } int[] nia(int start,int b) throws IOException { int a[]=new int[b]; for(int i=start;i<b;i++) a[i]=ni(); return a; } long[] nla(int start,int n) throws IOException { long a[]=new long[n]; for (int i=start; i<n ;i++ ) { a[i]=nl(); } return a; } public void tr(Object... o) { ob.println(Arrays.deepToString(o)); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
714c899693470612772cccc79242dbb1
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.Scanner; public class C { static Scanner sc = new Scanner(System.in); public static long ask(long l, long r) { if(l >= r) return -1; System.out.println("? " + l + " " + r); long x = sc.nextLong(); return x; } public static void main(String[] args) { long n = sc.nextLong(); long pos = ask(1, n); if(ask(1, pos) == pos) { long ini = 1, fin = pos; while(ini < fin) { long mid = (ini + fin + 1)/2; if(ask(mid, n) == pos) { ini = mid; } else { fin = mid - 1; } } System.out.println("! " + ini); } else { long ini = pos, fin = n; while(ini < fin) { long mid = (ini + fin)/2; if(ask(1, mid) == pos) { fin = mid; } else { ini = mid+1; } } System.out.println("! " + ini); } sc.close(); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
486d4e9deb7d0f1605474a065f19bcca
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.StringTokenizer; public class C { public static void main(String[] args) { FastScanner fs = new FastScanner(); int t = 1;//fs.nextInt(); while (t-- > 0) { int n = fs.nextInt(); int overall = query( 1, n, fs ); boolean left = false; if (overall != 1) { if (query( 1, overall, fs ) == overall) left = true; } if (left) { int low = 1, high = overall - 1; while (low <= high) { int mid = (low + high) >> 1; if (query( mid, overall, fs ) == overall) low = mid + 1; else high = mid - 1; } System.out.println( "! " + high ); System.out.flush(); } else { int low = overall + 1, high = n; while (low <= high) { int mid = (low + high) >> 1; if (query( overall, mid, fs ) == overall) high = mid - 1; else low = mid + 1; } System.out.println( "! " + low ); System.out.flush(); } } } static int query(int low, int high, FastScanner fs) { System.out.println( "? " + low + " " + high ); System.out.flush(); return fs.nextInt(); } private static class FastScanner { BufferedReader br = new BufferedReader( new InputStreamReader( System.in ) ); StringTokenizer st = new StringTokenizer( "" ); public String next() { while (!st.hasMoreElements()) try { st = new StringTokenizer( br.readLine() ); } catch (IOException e) { e.printStackTrace(); } return st.nextToken(); } int nextInt() { return Integer.parseInt( next() ); } int[] readArray(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } long nextLong() { return Long.parseLong( next() ); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
0f09c47526c46bd33122723eba1e8b69
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.OutputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.HashMap; import java.io.IOException; import java.io.InputStreamReader; import java.util.StringTokenizer; import java.util.Map; import java.io.BufferedReader; import java.io.InputStream; /** * Built using CHelper plug-in * Actual solution is at the top */ public class Main { public static void main(String[] args) { InputStream inputStream = System.in; OutputStream outputStream = System.out; FastReader in = new FastReader(inputStream); PrintWriter out = new PrintWriter(outputStream); C1GuessingTheGreatestEasyVersion solver = new C1GuessingTheGreatestEasyVersion(); solver.solve(1, in, out); out.close(); } static class C1GuessingTheGreatestEasyVersion { Map<String, Integer> map; public void solve(int testNumber, FastReader in, PrintWriter out) { map = new HashMap<>(); int n = in.nextInt(); int sed = query(1, n, in, out); out.println("! " + cal(1, n, sed, in, out)); out.flush(); } private int cal(int l, int r, int sed, FastReader in, PrintWriter out) { if (l == r) { return l; } //int p = query(l,r,in,out); //if (l+1 == r) return p == l ? r : l; int mid = (l + r) / 2; if (sed <= mid) { if (Math.min(sed, l) == mid) { return cal(mid + 1, r, sed, in, out); } int lp = query(Math.min(sed, l), mid, in, out); if (lp == sed) { return cal(l, mid, sed, in, out); } else { return cal(mid + 1, r, sed, in, out); } } else { if (mid + 1 == Math.max(r, sed)) { return cal(l, mid, sed, in, out); } int rp = query(mid + 1, Math.max(r, sed), in, out); if (rp == sed) { return cal(mid + 1, r, sed, in, out); } else { return cal(l, mid, sed, in, out); } } } private int query(int l, int r, FastReader in, PrintWriter out) { Integer num = map.get(l + "#" + r); if (num != null) return num; out.println("? " + l + " " + r); out.flush(); num = in.nextInt(); map.put(l + "#" + r, num); return num; } } static class FastReader { BufferedReader br; StringTokenizer st = new StringTokenizer(""); public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } public FastReader(InputStream in) { br = new BufferedReader(new InputStreamReader(in)); } public String next() { while (st == null || (!st.hasMoreElements())) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } public int nextInt() { return Integer.parseInt(next()); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
3ac47936f07e3052791133c76ce4b9fe
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
// 18-Feb-2021 import java.util.*; import java.io.*; public class C { static class FastReader { BufferedReader br; StringTokenizer st; private FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } int[] nextIntArray(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } int[] nextIntArrayOne(int n) { int[] a = new int[n + 1]; for (int i = 1; i < n + 1; i++) a[i] = nextInt(); return a; } long[] nextLongArray(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nextLong(); return a; } long[] nextLongArrayOne(int n) { long[] a = new long[n + 1]; for (int i = 1; i < n + 1; i++) a[i] = nextLong(); return a; } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } static PrintWriter w = new PrintWriter(System.out); static FastReader s = new FastReader(); public static void main(String[] args) { int n = s.nextInt(); int ans = -1; int maxInd = query(1,n); if(maxInd == query(1,maxInd)) { int l = 1, r = maxInd - 1; while(l <= r) { int mid = (l + r) / 2; if(query(mid, maxInd) == maxInd) { ans = mid; l =mid + 1; }else { r = mid - 1; } } }else { int l = maxInd + 1, r = n; while(l <= r) { int mid = (l + r) / 2; if(query(maxInd,mid) == maxInd) { ans = mid; r =mid - 1; }else { l = mid + 1; } } } w.println("! " + ans); w.flush(); } private static int query(int l, int r) { if(l == r) return Integer.MIN_VALUE; w.println("? "+ l +" " + r); w.flush(); return s.nextInt(); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
ae91dde692f5296d1efc11246598a674
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import javax.print.DocFlavor; import javax.swing.text.html.parser.Entity; import java.awt.*; import java.io.*; import java.lang.reflect.Array; import java.util.*; import java.util.List; import java.util.stream.Collectors; public class Main { static FastScanner sc; static PrintWriter pw; static final long INF = 200000000000000l; static final int MOD = 1000000007; static final int N = 1005; static int mul(int a, int b) { return (int) ((a * 1l * b) % MOD); } public static int pow(int a, int n) { int res = -1; while(n != 0) { if((n & 1) == 1) { res = mul(res, a); } a = mul(a, a); n >>= 1; } return res; } public static int inv(int a) { return pow(a, MOD-2); } public static List<Integer> getPrimes() { List<Integer> ans = new ArrayList<>(); boolean[] prime = new boolean[N]; Arrays.fill(prime, true); prime[0] = prime[1] = false; for(int i = 2; i < N; ++i) { if(prime[i]) { ans.add(i); if (i * 1l * i <= N) for (int j = i * i; j < N; j += i) prime[j] = false; } } return ans; } public static long gcd(long a, long b) { if(b == 0) return a; else return gcd(b, a % b); } public static class A { long x; long y; A(long a, long b) { this.x = a; this.y = b; } } public static void solve() throws IOException { int n = sc.nextInt(); pw.println("? 1 " + n); pw.flush(); int second = sc.nextInt(); int l = 0, r = 0; boolean left = true; if(second == n) { left = false; r = second; l = 0; } else if(second == 1) { l = second; r = n + 1; } else { pw.println("? " + second + " " + n); pw.flush(); if(second == sc.nextInt() && second != n) { l = second; r = n + 1; } else { r = second; l = 0; left = false; } } while(r - l >= 2) { int mid = (l + r) / 2; if(left) { pw.println("? " + second + " " + mid); pw.flush(); int x = sc.nextInt(); if(x == second) r = mid; else l = mid; } else { pw.println("? " + mid + " " + second); pw.flush(); int x = sc.nextInt(); if(x == second) l = mid; else r = mid; } } pw.println("! " + (left ? (l + 1) : (l)) ); } public static void main(String[] args) throws IOException { sc = new FastScanner(System.in); pw = new PrintWriter(System.out); int xx = 1; while(xx > 0) { solve(); xx--; } pw.close(); } } class FastScanner { static StringTokenizer st = new StringTokenizer(""); static BufferedReader br; public FastScanner(InputStream inputStream) { br = new BufferedReader(new InputStreamReader(inputStream)); } public String next() throws IOException { while (!st.hasMoreTokens()) st = new StringTokenizer(br.readLine()); return st.nextToken(); } public int nextInt() throws IOException { return Integer.parseInt(next()); } public long nextLong() throws IOException { return Long.parseLong(next()); } public double nextDouble() throws IOException { return Double.parseDouble(next()); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
5bd8c0f96c8931838309238e1ce0ae9d
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.awt.*; import java.io.*; import java.lang.reflect.Array; import java.util.*; import java.util.List; import java.util.concurrent.LinkedBlockingQueue; public class Coding { private static BufferedReader bi = new BufferedReader(new InputStreamReader(System.in)); private static BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(System.out)); private static int[] po = new int[20]; public static void main(String[] args) { try { run(); } catch (Exception e) { e.printStackTrace(); } } public static void run() throws Exception { InputModule inp = new InputModule(); OutputModule out = new OutputModule(); int t = 1; while (t > 0) { int n = inp.cinInt(); int l = 1, r = n; int ans = l; if (n == 2) { writer.append("? " + l + " " + r + "\n"); writer.flush(); int idx = inp.cinInt(); if (idx == l) { ans = r; } else { ans = l; } } else { boolean right = true; int prev = -1; int st = -1, en = -1, sidx = -1; while ((r - l > 1)) { int idx; if (prev == -1) { writer.append("? " + l + " " + r + "\n"); writer.flush(); idx = inp.cinInt(); } else { idx = prev; } int mid = (l + r) / 2; if (idx <= mid) { if (l == mid) { st = mid + 1; en = r; sidx = idx; break; } else { writer.append("? " + l + " " + mid + "\n"); writer.flush(); int idx2 = inp.cinInt(); prev = idx2; if (idx == idx2) { r = mid; } else { st = mid + 1; en = r; sidx = idx; break; } } } else { if (r == (mid + 1)) { st = l; en = mid; sidx = mid + 1; right = false; break; } else { writer.append("? " + (mid + 1) + " " + r + "\n"); writer.flush(); int idx2 = inp.cinInt(); prev = idx2; if (idx == idx2) { l = mid + 1; } else { st = l; en = mid; sidx = idx; right = false; break; } } } } // System.out.println(st + " " + en + " " + sidx + " " + right); if (st == -1) { if (l == r) ans = l; else { writer.append("? " + l + " " + r + "\n"); writer.flush(); int idx = inp.cinInt(); if (idx == l) { ans = r; } else { ans = l; } } } else { if (right) { while (en - st > 1) { int mi = (st + en) / 2; writer.append("? " + sidx + " " + mi + "\n"); writer.flush(); int iddx = inp.cinInt(); if (iddx == sidx) { en = mi; } else { st = mi+1; } } } else { while (en - st > 1) { int mi = (st + en) / 2; writer.append("? " + (mi+1) + " " + sidx + "\n"); writer.flush(); int iddx = inp.cinInt(); if (iddx == sidx) { st = mi + 1; } else { en = mi; } } } if (st == en) ans = st; else { writer.append("? " + st + " " + en + "\n"); writer.flush(); int idx = inp.cinInt(); if (idx == st) { ans = en; } else { ans = st; } } } } writer.append("! " + ans + "\n"); writer.flush(); t--; } } private static class InputModule { private int cinInt() throws Exception { return Integer.parseInt(bi.readLine().split(" ")[0].trim()); } private long cinLong() throws Exception { return Long.parseLong(bi.readLine().split(" ")[0].trim()); } private Double cinDouble() throws Exception { return Double.parseDouble(bi.readLine().split(" ")[0].trim()); } private String cinString() throws Exception { return bi.readLine(); } private int[] cinIntArray(int n) throws Exception { String input = bi.readLine(); String[] values = input.split(" "); int[] ar = new int[n]; for (int i = 0; i < n; ++i) { ar[i] = Integer.parseInt(values[i]); } return ar; } private int[] cinIntArray() throws Exception { String input = bi.readLine(); String[] values = input.split(" "); int[] ar = new int[values.length]; for (int i = 0; i < values.length; ++i) { ar[i] = Integer.parseInt(values[i]); } return ar; } private long[] cinLongArray(int n) throws Exception { String input = bi.readLine(); String[] values = input.split(" "); long[] ar = new long[n]; for (int i = 0; i < n; ++i) { ar[i] = Long.parseLong(values[i]); } return ar; } private String[] cinStringArray(int n) throws Exception { return bi.readLine().split(" "); } } private static class OutputModule { private void printInt(int ans) throws Exception { writer.append(ans + "\n"); writer.flush(); } private void printLong(long ans) throws Exception { writer.append(ans + "\n"); writer.flush(); } private void printDouble(Double ans) throws Exception { writer.append(String.format("%.10f", ans)); writer.append("\n"); writer.flush(); } private void printString(String ans) throws Exception { writer.append(ans + "\n"); writer.flush(); } private void printIntArray(int[] ans) throws Exception { for (int i = 0; i < ans.length; ++i) { writer.append(ans[i] + " "); } writer.append("\n"); writer.flush(); } private void printLongArray(long[] ans) throws Exception { for (int i = 0; i < ans.length; ++i) { writer.append(ans[i] + " "); } writer.append("\n"); writer.flush(); } private void printIntList(List<Integer> list) throws Exception { for (int i = 0; i < list.size(); ++i) { writer.append(list.get(i) + " "); } writer.append("\n"); writer.flush(); } private void printLongList(List<Long> list) throws Exception { for (int i = 0; i < list.size(); ++i) { writer.append(list.get(i) + " "); } writer.append("\n"); writer.flush(); } private void printIntMatrix(int[][] mat, int n, int m) throws Exception { for (int i = 0; i < n; ++i) { for (int j = 0; j < m; ++j) { writer.append(mat[i][j] + " "); } writer.append("\n"); } writer.flush(); } private void printLongMatrix(long[][] mat, int n, int m) throws Exception { for (int i = 0; i < n; ++i) { for (int j = 0; j < m; ++j) { writer.append(mat[i][j] + " "); } writer.append("\n"); } writer.flush(); } private void printPoint(Point p) throws Exception { writer.append(p.x + " " + p.y + "\n"); writer.flush(); } private void printPoints(List<Point> p) throws Exception { for (Point pp : p) { writer.append(pp.x + " " + pp.y + "\n"); } writer.flush(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
c176b6a1e45dd0ee639ab68d4ae5ee91
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; public class Main { static FastScanner sc = new FastScanner(System.in); static PrintWriter pw = new PrintWriter(System.out); static StringBuilder sb = new StringBuilder(); public static void main(String[] args) throws Exception { int n = sc.nextInt(); System.out.println("? 1 " + n); int center = sc.nextInt(); if (center == 1) { int left = 1; int right = n; while (right - left > 1) { int mid = (left + right) / 2; System.out.println("? " + center + " " + mid); int now = sc.nextInt(); if (center == now) { right = mid; } else { left = mid; } } System.out.println("! " + right); } else if (center == n) { int left = 1; int right = n; while (right - left > 1) { int mid = (left + right) / 2; System.out.println("? " + mid + " " + center); int now = sc.nextInt(); if (center == now) { left = mid; } else { right = mid; } } System.out.println("! " + left); } else { System.out.println("? 1 " + center); int now = sc.nextInt(); if (center == now) { int left = 1; int right = center; while (right - left > 1) { int mid = (left + right) / 2; System.out.println("? " + mid + " " + center); now = sc.nextInt(); if (center == now) { left = mid; } else { right = mid; } } System.out.println("! " + left); } else { int left = center; int right = n; while (right - left > 1) { int mid = (left + right) / 2; System.out.println("? " + center + " " + mid); now = sc.nextInt(); if (center == now) { right = mid; } else { left = mid; } } System.out.println("! " + right); } } } static class GeekInteger { public static void save_sort(int[] array) { shuffle(array); Arrays.sort(array); } public static int[] shuffle(int[] array) { int n = array.length; Random random = new Random(); for (int i = 0, j; i < n; i++) { j = i + random.nextInt(n - i); int randomElement = array[j]; array[j] = array[i]; array[i] = randomElement; } return array; } public static void save_sort(long[] array) { shuffle(array); Arrays.sort(array); } public static long[] shuffle(long[] array) { int n = array.length; Random random = new Random(); for (int i = 0, j; i < n; i++) { j = i + random.nextInt(n - i); long randomElement = array[j]; array[j] = array[i]; array[i] = randomElement; } return array; } } } class FastScanner { private BufferedReader reader = null; private StringTokenizer tokenizer = null; public FastScanner(InputStream in) { reader = new BufferedReader(new InputStreamReader(in)); tokenizer = null; } public String next() { if (tokenizer == null || !tokenizer.hasMoreTokens()) { try { tokenizer = new StringTokenizer(reader.readLine()); } catch (IOException e) { throw new RuntimeException(e); } } return tokenizer.nextToken(); } public String nextLine() { if (tokenizer == null || !tokenizer.hasMoreTokens()) { try { return reader.readLine(); } catch (IOException e) { throw new RuntimeException(e); } } return tokenizer.nextToken("\n"); } public long nextLong() { return Long.parseLong(next()); } public int nextInt() { return Integer.parseInt(next()); } public double nextDouble() { return Double.parseDouble(next()); } public String[] nextArray(int n) { String[] a = new String[n]; for (int i = 0; i < n; i++) a[i] = next(); return a; } public int[] nextIntArray(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } public long[] nextLongArray(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nextLong(); return a; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
342076fe85ede31ba9c01d6a5ccd3846
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.Closeable; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.PrintWriter; import java.util.StringTokenizer; public class GuessingTheGreatest implements Closeable { private InputReader in = new InputReader(System.in); private PrintWriter out = new PrintWriter(System.out); public void solve() { int n = in.ni(); int pivot = ask(0, n - 1); int left, right; if (pivot > 0 && pivot < n - 1) { int leftHalf = ask(0, pivot); if (leftHalf == pivot) { left = 0; right = pivot - 1; } else { left = pivot + 1; right = n - 1; } } else if (pivot == n - 1) { left = 0; right = n - 2; } else { left = 1; right = n - 1; } int max; if (pivot < left) { max = n + 5; while (left <= right) { int mid = left + (right - left) / 2; int response = ask(pivot, mid); if (response == pivot) { max = Math.min(max, mid); right = mid - 1; } else { left = mid + 1; } } } else { max = -1; while (left <= right) { int mid = left + (right - left) / 2; int response = ask(mid, pivot); if (response == pivot) { max = Math.max(mid, max); left = mid + 1; } else { right = mid - 1; } } } answer(max); } private int ask(int left, int right) { out.printf("? %d %d\n", left + 1, right + 1); out.flush(); return in.ni() - 1; } private void answer(int idx) { out.printf("! %d\n", idx + 1); out.flush(); } @Override public void close() throws IOException { in.close(); out.close(); } static class InputReader { public BufferedReader reader; public StringTokenizer tokenizer; public InputReader(InputStream stream) { reader = new BufferedReader(new InputStreamReader(stream), 32768); tokenizer = null; } public String next() { while (tokenizer == null || !tokenizer.hasMoreTokens()) { try { tokenizer = new StringTokenizer(reader.readLine()); } catch (IOException e) { throw new RuntimeException(e); } } return tokenizer.nextToken(); } public int ni() { return Integer.parseInt(next()); } public long nl() { return Long.parseLong(next()); } public void close() throws IOException { reader.close(); } } public static void main(String[] args) throws IOException { try (GuessingTheGreatest instance = new GuessingTheGreatest()) { instance.solve(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
c9d3127cc0055b58335f4646bdb4570d
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class C { static BufferedReader br; public static void main(String[] args) throws NumberFormatException, IOException { // TODO Auto-generated method stub br = new BufferedReader(new InputStreamReader(System.in)); int n = Integer.parseInt(br.readLine()); System.out.println("? " + 1 + " " + n); System.out.flush(); int resp = Integer.parseInt(br.readLine()); if(n == 2) { if(resp == 1) System.out.println("! 2"); else System.out.println("! 1"); System.out.flush(); }else { boolean go = true; if(resp == 1) { go = false; } int x = 1; int mv = resp; if(go) { System.out.println("? " + x + " " + mv); System.out.flush(); resp = Integer.parseInt(br.readLine()); } if(resp == mv && go) { int l = 1; int r = mv; int mid; while(r - l > 1) { mid = (r + l) / 2; System.out.println("? " + mid + " " + mv); System.out.flush(); resp = Integer.parseInt(br.readLine()); if(resp == mv) { l = mid; }else { r = mid; } } System.out.println("? " + l + " " + r); System.out.flush(); resp = Integer.parseInt(br.readLine()); if(resp == l) System.out.println("! " + r); else System.out.println("! " + l); System.out.flush(); }else { int l = mv; int r = n; int mid; while(r-l > 1) { mid = (r + l)/2; System.out.println("? " + mv + " " + mid); System.out.flush(); resp = Integer.parseInt(br.readLine()); if(resp == mv) { r = mid; }else { l = mid; } } System.out.println("? " + l + " " + r); System.out.flush(); resp = Integer.parseInt(br.readLine()); if(resp == l) System.out.println("! " + r); else System.out.println("! " + l); System.out.flush(); } } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
55f6470a0f38ee49d6fd0ea3e57f94dd
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.OutputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.InputMismatchException; import java.io.IOException; import java.io.InputStream; /** * Built using CHelper plug-in * Actual solution is at the top */ public class Main { public static void main(String[] args) throws Exception { Thread thread = new Thread(null, new TaskAdapter(), "", 1 << 27); thread.start(); thread.join(); } static class TaskAdapter implements Runnable { @Override public void run() { InputStream inputStream = System.in; OutputStream outputStream = System.out; FastReader in = new FastReader(inputStream); PrintWriter out = new PrintWriter(outputStream); C1GuessingTheGreatestEasyVersion solver = new C1GuessingTheGreatestEasyVersion(); solver.solve(1, in, out); out.close(); } } static class C1GuessingTheGreatestEasyVersion { FastReader s; PrintWriter w; public void solve(int testNumber, FastReader s, PrintWriter w) { int n = s.nextInt(); this.s = s; this.w = w; int min = query(1, n); int mid = 1 + n >> 1; if (n == 2) { if (min == 1) w.println("! 2"); else w.println("! 1"); w.flush(); return; } int l = 1, r; if (min == n) { r = min - 1; while (l <= r) { mid = l + r >> 1; int res = query(min - mid, min); if (res == min) r = mid - 1; else l = mid + 1; } ++r; w.println("! " + (min - r)); } else if (min == 1) { r = n - min; while (l <= r) { mid = l + r >> 1; int res = query(min, min + mid); if (res == min) r = mid - 1; else l = mid + 1; } ++r; w.println("! " + (min + r)); } else { int minot = query(1, min); if (minot == min) { r = min - 1; while (l <= r) { mid = l + r >> 1; int res = query(min - mid, min); if (res == min) r = mid - 1; else l = mid + 1; } ++r; w.println("! " + (min - r)); } else { r = n - min; while (l <= r) { mid = l + r >> 1; int res = query(min, min + mid); if (res == min) r = mid - 1; else l = mid + 1; } ++r; w.println("! " + (min + r)); } } w.flush(); } int query(int l, int r) { w.println("? " + l + " " + r); w.flush(); return s.nextInt(); } } static class FastReader { private InputStream stream; private byte[] buf = new byte[1024]; private int curChar; private int numChars; private FastReader.SpaceCharFilter filter; public FastReader(InputStream stream) { this.stream = stream; } public int read() { if (numChars == -1) throw new InputMismatchException(); if (curChar >= numChars) { curChar = 0; try { numChars = stream.read(buf); } catch (IOException e) { throw new InputMismatchException(); } if (numChars <= 0) return -1; } return buf[curChar++]; } public int nextInt() { int c = read(); while (isSpaceChar(c)) c = read(); int sgn = 1; if (c == '-') { sgn = -1; c = read(); } int res = 0; do { if (c < '0' || c > '9') throw new InputMismatchException(); res *= 10; res += c - '0'; c = read(); } while (!isSpaceChar(c)); return res * sgn; } public boolean isSpaceChar(int c) { if (filter != null) return filter.isSpaceChar(c); return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1; } public interface SpaceCharFilter { public boolean isSpaceChar(int ch); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
6a3a1925f3afe3f4684f25192b25a298
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.util.StringTokenizer; public class C { public int ask(IO io, int l, int r) throws IOException { if (l == r) { return r + 1; } io.println("? " + l + " " + r); io.flush(); return io.nextInt(); } public void run() throws IOException { IO io = new IO(); int n = io.nextInt(); int d = ask(io, 1, n); if (ask(io, 1, d) == d) { int l = 1; int r = d; int m; while (r - l > 1) { m = (r + l) / 2; if (ask(io, m, d) == d) { l = m; } else { r = m; } } io.println("! " + l); io.flush(); } else { int l = d; int r = n; int m; while (r - l > 1) { m = (r + l) / 2; if (ask(io, d, m) == d) { r = m; } else { l = m; } } io.println("! " + r); io.flush(); } io.close(); } public static void main(String[] args) throws IOException { new C().run(); } } class IO { public IO() { br = new BufferedReader(new InputStreamReader(System.in)); out = new PrintWriter(System.out); } BufferedReader br; StringTokenizer in; PrintWriter out; public String nextToken() throws IOException { while (in == null || !in.hasMoreTokens()) { in = new StringTokenizer(br.readLine()); } return in.nextToken(); } public int nextInt() throws IOException { return Integer.parseInt(nextToken()); } public double nextDouble() throws IOException { return Double.parseDouble(nextToken()); } public long nextLong() throws IOException { return Long.parseLong(nextToken()); } public void print(String a) { out.print(a); } public void println(String a) { out.println(a); } public void close() { out.close(); } public void flush() { out.flush(); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
28ae890820894e0f83286170bd2d7e07
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
//created by Whiplash99 import java.io.*; import java.util.*; public class C { private static int count; private static void flush(){System.out.flush();} private static void ask(int l, int r) throws Exception { count++; if(count>20) throw new Exception(); System.out.println("? "+l+" "+r); flush(); } private static void answer(int x) { System.out.println("! "+x); flush(); } public static void main(String[] args) throws Exception { BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); int i,N; count=0; N=Integer.parseInt(br.readLine().trim()); ask(1,N); int p=Integer.parseInt(br.readLine().trim()); boolean flag=true; int ans=0; if(p>1) { ask(1,p); ans=p-1; int tmp=Integer.parseInt(br.readLine().trim()); if(tmp==p) { flag=false; int l=1,r=p-1,mid; while (l<=r) { mid=(l+r)/2; ask(mid,p); tmp=Integer.parseInt(br.readLine().trim()); if(tmp==p) { ans=mid; l=mid+1; } else r=mid-1; } } } if(flag) { int l=p+1,r=N,mid; ans=p+1; while (l<=r) { mid=(l+r)/2; ask(p,mid); int tmp=Integer.parseInt(br.readLine().trim()); if(tmp==p) { ans=mid; r=mid-1; } else l=mid+1; } } answer(ans); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
3aa28bb65599992fc7df0820f2f1affb
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; import java.util.function.BinaryOperator; import java.util.stream.Collectors; public class Main { private final static long mod = 1000000007; private final static int MAXN = 1000001; private static long power(long x, long y, long m) { long temp; if (y == 0) return 1; temp = power(x, y / 2, m); temp = (temp * temp) % m; if (y % 2 == 0) return temp; else return ((x % m) * temp) % m; } private static long power(long x, long y) { return power(x, y, mod); } public int solve(int[] nums) { Map<Pair<Integer,Integer>,Integer>dp=new HashMap<>(); int ans=0; for(int i=1;i<nums.length;i++){ for(int j=i+1;j<nums.length;j++) { Pair<Integer,Integer>prev=new Pair<>(nums[j]-nums[i],nums[i]); Integer v=dp.get(prev); Pair<Integer,Integer>curr=new Pair<>(nums[i],nums[j]); if(v!=null){ dp.put(curr,Math.max(dp.get(prev),v+1)); } else { dp.put(curr, 2); } ans=Math.max(ans,dp.get(curr)); } } return ans; } private static long gcd(long a, long b) { if (b == 0) return a; return gcd(b, a % b); } static int nextPowerOf2(int a) { return 1 << nextLog2(a); } static int nextLog2(int a) { return (a == 0 ? 0 : 32 - Integer.numberOfLeadingZeros(a - 1)); } private static long modInverse(long a, long m) { long m0 = m; long y = 0, x = 1; if (m == 1) return 0; while (a > 1) { long q = a / m; long t = m; m = a % m; a = t; t = y; y = x - q * y; x = t; } if (x < 0) x += m0; return x; } private static int[] getLogArr(int n) { int arr[] = new int[n + 1]; for (int i = 1; i < n + 1; i++) { arr[i] = (int) (Math.log(i) / Math.log(2) + 1e-10); } return arr; } private static int log[] = getLogArr(MAXN); private static long getLRSpt(long st[][], int L, int R, BinaryOperator<Long> binaryOperator) { int j = log[R - L + 1]; return binaryOperator.apply(st[L][j], st[R - (1 << j) + 1][j]); } private static long[][] getSparseTable(int array[], BinaryOperator<Long> binaryOperator) { int k = log[array.length + 1] + 1; long st[][] = new long[array.length + 1][k + 1]; for (int i = 0; i < array.length; i++) st[i][0] = array[i]; for (int j = 1; j <= k; j++) { for (int i = 0; i + (1 << j) <= array.length; i++) { st[i][j] = binaryOperator.apply(st[i][j - 1], st[i + (1 << (j - 1))][j - 1]); } } return st; } private static long getULDRSpt(long st[][][][], int U, int L,int D, int R, BinaryOperator<Long> binaryOperator) { int k = log[D - U + 1]; int l = log[R - L + 1]; long a= binaryOperator.apply(st[U][L][k][l], st[D - (1 << k) + 1][R - (1 << l) + 1][k][l]); long b= binaryOperator.apply(st[U][R - (1 << l) + 1][k][l], st[D - (1 << k) + 1][L][k][l]); return binaryOperator.apply(a,b); } private static long[][][][] getSparseTable2D(int arr[][], BinaryOperator<Long>bo){ int n=arr.length; int m=arr[0].length; int k=log[n+1]+2; int l=log[m+1]+2; long st[][][][]=new long[n][m][k][l]; for(int i=0;i<n;i++){ for(int j=0;j<m;j++){ st[i][j][0][0]=arr[i][j]; } } for(int x=1;x<k;x++){ for(int y=1;y<l;y++){ for(int i=0;i+(1<<x)<=n;i++){ for(int j=0;j+(1<<y)<=m;j++){ st[i][j][x][y]=bo.apply(bo.apply(st[i][j][x - 1][y-1], st[i + (1 << (x - 1))][j][x - 1][y-1]), bo.apply(st[i][j+(1 << (y - 1))][x - 1][y-1], st[i + (1 << (x - 1))][j+(1 << (y - 1))][x - 1][y-1])); } } } } return st; } static class Subset { int parent; int rank; @Override public String toString() { return "" + parent; } } static int find(Subset[] Subsets, int i) { if (Subsets[i].parent != i) Subsets[i].parent = find(Subsets, Subsets[i].parent); return Subsets[i].parent; } static void union(Subset[] Subsets, int x, int y) { int xroot = find(Subsets, x); int yroot = find(Subsets, y); if (Subsets[xroot].rank < Subsets[yroot].rank) Subsets[xroot].parent = yroot; else if (Subsets[yroot].rank < Subsets[xroot].rank) Subsets[yroot].parent = xroot; else { Subsets[xroot].parent = yroot; Subsets[yroot].rank++; } } private static int maxx(Integer... a) { return Collections.max(Arrays.asList(a)); } private static int minn(Integer... a) { return Collections.min(Arrays.asList(a)); } private static long maxx(Long... a) { return Collections.max(Arrays.asList(a)); } private static long minn(Long... a) { return Collections.min(Arrays.asList(a)); } private static class Pair<T extends Comparable<T>, U extends Comparable<U>> implements Comparable<Pair<T, U>> { T a; U b; public Pair(T a, U b) { this.a = a; this.b = b; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Pair pair = (Pair) o; return a.equals(pair.a) && b.equals(pair.b); } @Override public int hashCode() { return Objects.hash(a, b); } @Override public String toString() { return "(" + a + "," + b + ')'; } @Override public int compareTo(Pair<T, U> o) { return (this.a.equals(o.a) ? this.b.equals(o.b) ? 0 : this.b.compareTo(o.b) : this.a.compareTo(o.a)); } } public static int upperBound(List<Integer> list, int value) { int low = 0; int high = list.size(); while (low < high) { final int mid = (low + high) / 2; if (value >= list.get(mid)) { low = mid + 1; } else { high = mid; } } return low; } private static int[] getLPSArray(String pattern) { int i, j, n = pattern.length(); int[] lps = new int[pattern.length()]; lps[0] = 0; for (i = 1, j = 0; i < n; ) { if (pattern.charAt(i) == pattern.charAt(j)) { lps[i++] = ++j; } else if (j > 0) { j = lps[j - 1]; } else { lps[i++] = 0; } } return lps; } private static List<Integer> findPattern(String text, String pattern) { List<Integer> matchedIndexes = new ArrayList<>(); if (pattern.length() == 0) { return matchedIndexes; } int[] lps = getLPSArray(pattern); int i = 0, j = 0, n = text.length(), m = pattern.length(); while (i < n) { if (text.charAt(i) == pattern.charAt(j)) { i++; j++; } if (j == m) { matchedIndexes.add(i - j); j = lps[j - 1]; } if (i < n && text.charAt(i) != pattern.charAt(j)) { if (j > 0) { j = lps[j - 1]; } else { i++; } } } return matchedIndexes; } private static long getLCM(long a, long b) { return (Math.max(a, b) / gcd(a, b)) * Math.min(a, b); } static long fac[] = new long[2000005]; static long ifac[] = new long[2000005]; private static void preCompute(int n) { fac = new long[n + 1]; ifac = new long[n + 1]; fac[0] = ifac[0] = fac[1] = ifac[1] = 1; int i; for (i = 2; i < n + 1; i++) { fac[i] = (i * fac[i - 1]) % mod; ifac[i] = (power(i, mod - 2) * ifac[i - 1]) % mod; } } private static long C(int n, int r) { if (n < 0 || r < 0) return 1; if (r > n) return 1; return (fac[n] * ((ifac[r] * ifac[n - r]) % mod)) % mod; } static long getSum(long BITree[], int index) { long sum = 0; index = index + 1; while (index > 0) { sum += BITree[index]; index -= index & (-index); } return sum; } public static void updateBIT(long BITree[], int index, long val) { index = index + 1; while (index <= BITree.length - 1) { BITree[index] += val; index += index & (-index); } } long[] constructBITree(int arr[], int m) { int n = arr.length; long BITree[] = new long[m + 1]; for (int i = 1; i <= n; i++) BITree[i] = 0; for (int i = 0; i < n; i++) updateBIT(BITree, i, arr[i]); return BITree; } private static String getBinaryString(int a[], int l, int r){ if(l>r||l>a.length-1||r>a.length-1||l<0||r<0)return ""; StringBuilder sb = new StringBuilder(); int i=l; while(i<=r&&a[i]==0)i++; for (;i<=r;i++){ sb.append(a[i]); } return sb.toString(); } private static int cmpBS(String a, String b){ if(a.length()==b.length()){ return a.compareTo(b); } else return a.length()-b.length(); } public static int[] threeEqualParts(int[] A) { int ans[]=new int[2]; ans[0]=ans[1]=-1; int lo1=0,hi1=A.length-3,mid1,curr; while (lo1<=hi1){ mid1=lo1+(hi1-lo1)/2; int lo=mid1+1,hi=A.length-2,mid; String leftS=getBinaryString(A,0,mid1); String midS=getBinaryString(A,lo, hi);; String rightS=""; while(lo<=hi){ mid=lo+(hi-lo)/2; midS=getBinaryString(A,mid1+1, mid); rightS=getBinaryString(A,mid+1,A.length-1); if(midS.equals(rightS)&&leftS.equals(midS)){ ans[0]=mid1; ans[1]=mid+1; return ans; } else if(cmpBS(rightS,midS) < 0){ hi=mid-1; } else { lo=mid+1; } //System.out.println(mid1+" "+lo+" "+hi); } if(cmpBS(leftS,midS) < 0) { hi1=mid1-1; } else { lo1=mid1+1; } } return ans; } private static int upperBound(int a[], int l, int r, int x) { if (l > r) return -1; if (l == r) { if (a[l] <= x) { return -1; } else { return a[l]; } } int m = (l + r) / 2; if (a[m] <= x) { return upperBound(a, m + 1, r, x); } else { return upperBound(a, l, m, x); } } private static void mul(long A[][], long B[][]) { int i, j, k, n = A.length; long C[][] = new long[n][n]; for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { for (k = 0; k < n; k++) { C[i][j] = (C[i][j] + (A[i][k] * B[k][j]) % mod) % mod; } } } for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { A[i][j] = C[i][j]; } } } private static void power(long A[][], long base[][], long n) { if (n < 2) { return; } power(A, base, n / 2); mul(A, A); if (n % 2 == 1) { mul(A, base); } } private static void print(int... a) { System.out.println(Arrays.toString(a)); } static void reverse(Integer a[], int l, int r) { while (l < r) { int t = a[l]; a[l] = a[r]; a[r] = t; l++; r--; } } private static int cntBits(int n){ int cnt=0; while(n>0){ cnt+=n%2; n/=2; } return cnt; } public void rotate(Integer[] nums, int k) { k = k % nums.length; reverse(nums, 0, nums.length - k - 1); reverse(nums, nums.length - k, nums.length - 1); reverse(nums, 0, nums.length - 1); } private static boolean isSorted(int a[]) { for (int i = 0; i < a.length - 1; i++) { if (a[i] > a[i + 1]) return false; } return true; } private static int upperBound(long csum[], long val){ int lo=0,hi=csum.length-1,mid,ans=csum.length; while(lo<=hi){ mid=lo+(hi-lo)/2; if(csum[mid]<=val){ lo=mid+1; } else { ans=mid; hi=mid-1; } } return ans; } private static int lowerBound(long csum[], long val){ int lo=0,hi=csum.length-1,mid,ans=-1; while(lo<=hi){ mid=lo+(hi-lo)/2; if(csum[mid]<val){ lo=mid+1; ans=mid; } else { hi=mid-1; } } return ans; } public int countRangeSum(int[] nums, int lower, int upper) { int i,j,k,n=nums.length,ans=0; long csum[]=new long[n]; long prev=0; for(i=0;i<n;i++){ csum[i]=prev+nums[i]; prev=csum[i]; } Arrays.sort(csum); ans=upperBound(csum, upper)-lowerBound(csum,lower)-1; for(i=0;i<n;i++){ ans+=upperBound(csum, upper+csum[i])-lowerBound(csum,lower+csum[i])-1; } return ans; } private static String reverse(String s) { if ("".equals(s)) return ""; return reverse(s.substring(1)) + s.charAt(0); } private static boolean isPrime(int n) { if (n <= 1) return false; if (n <= 3) return true; if (n % 2 == 0 || n % 3 == 0) return false; for (int i = 5; i * i <= n; i = i + 6) if (n % i == 0 || n % (i + 2) == 0) return false; return true; } private static Map<Integer, Integer> bit = new HashMap<>(); private static void update(int i, int val){ while(i<=1000000){ bit.put(i,bit.getOrDefault(i,0)+val); i+=i&-i; } } private static long get(int i){ long sum=0; while (i>0){ sum+=bit.getOrDefault(i,0); i-=i&-i; } return sum; } private static Set<Long> getDivisors(long n) { Set<Long> divisors = new HashSet<>(); for (long i = 1; i <= Math.sqrt(n); i++) { if (n % i == 0) { divisors.add(i); divisors.add(n / i); } } return divisors; } private static int getMed(List<Integer> arrList, int offset, int limit) { List<Integer> tmp=new ArrayList<>(); for(int i=0;i<limit&&i+offset<arrList.size();i++){ tmp.add(arrList.get(i+offset)); } Collections.sort(tmp); return tmp.get((tmp.size()-1)/2); } private static void trv(int a[],int l,int r, Map<Integer,Integer> map, int d){ if(r<l)return; if(r==l){ map.put(l, d); return; } int mx=0,mxi=-1; for(int i=l;i<=r;i++) { if(a[i]>mx){ mx=a[i]; mxi=i; } } map.put(mxi,d); trv(a,l,mxi-1,map,d+1); trv(a,mxi+1,r,map,d+1); } private static Map<String, Integer> kv=new HashMap<>(); private static int get2nd(int l, int r,FastReader in,FastWriter out) throws Exception { String key=String.format("%d %d",l,r); if(kv.get(key)==null){ out.println("? "+key); int v=in.nextInt(); kv.put(key,v); } return kv.get(key); } public static void main(String[] args) throws Exception { long START_TIME = System.currentTimeMillis(); try (FastReader in = new FastReader(); FastWriter out = new FastWriter()) { int n,t, i, j, m, ti, tidx, gm, l=1, r=2,k,q; //for (t = in.nextInt(), tidx = 1; tidx <= t; tidx++) { //out.print(String.format("Case #%d: ", tidx)); long x = 0, y = 0, z = 0, sum = 0, bhc = 0, ans = 0,ans1=0,d,g,curr=0; n=in.nextInt(); if(n==1){ out.println("! 1"); } else { int smi=get2nd(1,n,in,out); l=1; r=n; if(r>smi&&smi>1){ int v=get2nd(1,smi,in,out); if(v==smi){ r=smi; } else l=smi; } if(smi<r) { int l1=smi+1; int r1=r; while (l1 <= r1) { int mid = (l1 + r1) / 2; int v = get2nd(smi,mid,in,out); if (v == smi) { r = mid; r1=mid-1; } else l1 = mid+1; } } if(l<smi){ int l1=l; int r1=smi-1; while (l1 <= r1) { int mid = (l1 + r1) / 2; int v = get2nd(mid,smi,in,out); if (v == smi) { l = mid; l1 = mid+1; } else { r1=mid-1; } } } out.println("! "+(smi==l?r:l)); } } if (args.length > 0 && "ex_time".equals(args[0])) { out.print("\nTime taken: "); out.println(System.currentTimeMillis() - START_TIME); } out.commit(); } catch (Exception e) { e.printStackTrace(); } } public static class FastReader implements Closeable { private BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); private StringTokenizer st; String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (Exception e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } int[] nextIntArr(int n) { int[] arr = new int[n]; for (int i = 0; i < n; i++) { arr[i] = nextInt(); } return arr; } Integer[] nextIntegerArr(int n) { Integer[] arr = new Integer[n]; for (int i = 0; i < n; i++) { arr[i] = nextInt(); } return arr; } double[] nextDoubleArr(int n) { double[] arr = new double[n]; for (int i = 0; i < n; i++) { arr[i] = nextDouble(); } return arr; } long[] nextLongArr(int n) { long[] arr = new long[n]; for (int i = 0; i < n; i++) { arr[i] = nextLong(); } return arr; } List<Long> nextLongList(int n) { List<Long> retList = new ArrayList<>(); for (int i = 0; i < n; i++) { retList.add(nextLong()); } return retList; } String[] nextStrArr(int n) { String[] arr = new String[n]; for (int i = 0; i < n; i++) { arr[i] = next(); } return arr; } int[][] nextIntArr2(int n, int m) { int[][] arr = new int[n][m]; for (int i = 0; i < n; i++) { arr[i] = nextIntArr(m); } return arr; } long[][] nextLongArr2(int n, int m) { long[][] arr = new long[n][m]; for (int i = 0; i < n; i++) { arr[i] = nextLongArr(m); } return arr; } @Override public void close() throws IOException { br.close(); } } public static class FastWriter implements Closeable { BufferedWriter bw; StringBuilder sb = new StringBuilder(); List<String> list = new ArrayList<>(); Set<String> set = new HashSet<>(); public FastWriter() { bw = new BufferedWriter(new OutputStreamWriter(System.out)); } <T> void commit() throws IOException { bw.write(sb.toString()); bw.flush(); sb = new StringBuilder(); } public <T> void print(T obj) throws IOException { sb.append(obj.toString()); commit(); } public void println() throws IOException { print("\n"); } public <T> void println(T obj) throws IOException { print(obj.toString() + "\n"); } <T> void printArrLn(T[] arr) throws IOException { for (int i = 0; i < arr.length - 1; i++) { print(arr[i] + " "); } println(arr[arr.length - 1]); } <T> void printArr2(T[][] arr) throws IOException { for (int j = 0; j < arr.length; j++) { for (int i = 0; i < arr[j].length - 1; i++) { print(arr[j][i] + " "); } println(arr[j][arr[j].length - 1]); } } <T> void printColl(Collection<T> coll) throws IOException { List<String> stringList = coll.stream().map(e -> ""+e).collect(Collectors.toList()); println(String.format("%s",String.join(" ", stringList))); } void printCharN(char c, int n) throws IOException { for (int i = 0; i < n; i++) { print(c); } } void printIntArr2(int[][] arr) throws IOException { for (int j = 0; j < arr.length; j++) { for (int i = 0; i < arr[j].length - 1; i++) { print(arr[j][i] + " "); } println(arr[j][arr[j].length - 1]); } } @Override public void close() throws IOException { bw.close(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
84e179ef2f7a73eab6aa261e33d7777c
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class C { public static void main(String[] args) { FastScanner in = new FastScanner(); PrintWriter out = new PrintWriter(System.out); int n = in.nextInt(); int low = 1, high = n; out.println("? "+low+" "+high); out.flush(); int index = in.nextInt(); int left = 0; if(index!=1){ out.println("? "+low+" "+index); out.flush(); left = in.nextInt(); } if(n==2){ if(left==0) out.println("! "+n); else out.println("! "+1); } else if(left==index){ low = 1; high = index-1; while(low<=high){ int mid = (low+high)/2; out.println("? "+mid+" "+index); out.flush(); int x = in.nextInt(); if(x==index) low = mid+1; else high = mid-1; } out.println("! "+high); } else{ low = index+1; high = n; while(low<=high){ int mid = (low+high)/2; out.println("? "+index+" "+mid); out.flush(); int x = in.nextInt(); if(x==index) high = mid-1; else low = mid+1; } out.println("! "+low); } out.flush(); } static class FastScanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); String next() { while(!st.hasMoreTokens()) try { st = new StringTokenizer(br.readLine()); } catch(IOException e) {} return st.nextToken(); } String nextLine(){ try{ return br.readLine(); } catch(IOException e) { } return ""; } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } int[] readArray(int n) { int a[] = new int[n]; for(int i=0;i<n;i++) a[i] = nextInt(); return a; } } static final Random random = new Random(); static void ruffleSort(int[] a){ int n = a.length; for(int i=0;i<n;i++){ int j = random.nextInt(n), temp = a[j]; a[j] = a[i]; a[i] = temp; } Arrays.sort(a); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
b7054454051ca20e0c4508c9f6670854
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.ArrayList; import java.util.Arrays; import java.util.StringTokenizer; import java.util.List; import java.util.*; public class realfast implements Runnable { private static final int INF = (int) 1e9; // long in= 1000000007; long fac[]= new long[1000001]; long inv[]=new long[1000001]; public void solve() throws IOException { Scanner in = new Scanner(System.in); //int t = readInt(); int n = in.nextInt(); System.out.println("? "+1+" "+n); System.out.flush(); int val = in.nextInt(); int pal=-1; int nal=-1; if(val!=1) { System.out.println("? "+1+" "+val); System.out.flush(); pal = in.nextInt(); } if(val!=n){ System.out.println("? "+(val)+" "+n); System.out.flush(); nal = in.nextInt(); } int left =0; int right =0; int ans =0; if(nal==val) { left=val+1; right=n; ans=right; while(left<=right) { int mid = left+(right-left)/2; System.out.println("? "+val+" "+mid); System.out.flush(); int pal1 = in.nextInt(); if(pal1==val) { ans= mid; right=mid-1; } else left=mid+1; } } else { left=1; right=val-1; ans= left; while(left<=right) { int mid = left+(right-left)/2; System.out.println("? "+mid+" "+val); System.out.flush(); int pal1=in.nextInt(); if(pal1==val) { ans=mid; left=mid+1; } else right=mid-1; } } System.out.println("! "+ans); //int ans =right; //System.out. } public int value (int seg[], int left , int right ,int index, int l, int r) { if(left>right) { return -100000000; } if(right<l||left>r) return -100000000; if(left>=l&&right<=r) return seg[index]; int mid = left+(right-left)/2; int val = value(seg,left,mid,2*index+1,l,r); int val2 = value(seg,mid+1,right,2*index+2,l,r); return Math.max(val,val2); } public int gcd(int a , int b ) { if(a<b) { int t =a; a=b; b=t; } if(a%b==0) return b ; return gcd(b,a%b); } public long pow(long n , long p,long m) { if(p==0) return 1; long val = pow(n,p/2,m);; val= (val*val)%m; if(p%2==0) return val; else return (val*n)%m; } /////////////////////////////////////////////////////////////////////////////////////////////////////////////////// public static void main(String[] args) { new Thread(null, new realfast(), "", 128 * (1L << 20)).start(); } private static final boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") != null; private BufferedReader reader; private StringTokenizer tokenizer; private PrintWriter out; @Override public void run() { try { if (ONLINE_JUDGE || !new File("input.txt").exists()) { reader = new BufferedReader(new InputStreamReader(System.in)); out = new PrintWriter(System.out); } else { reader = new BufferedReader(new FileReader("input.txt")); out = new PrintWriter("output.txt"); } solve(); } catch (IOException e) { throw new RuntimeException(e); } finally { try { reader.close(); } catch (IOException e) { // nothing } out.close(); } } private String readString() throws IOException { while (tokenizer == null || !tokenizer.hasMoreTokens()) { tokenizer = new StringTokenizer(reader.readLine()); } return tokenizer.nextToken(); } @SuppressWarnings("unused") private int readInt() throws IOException { return Integer.parseInt(readString()); } @SuppressWarnings("unused") private long readLong() throws IOException { return Long.parseLong(readString()); } @SuppressWarnings("unused") private double readDouble() throws IOException { return Double.parseDouble(readString()); } } class edge implements Comparable<edge>{ int u ; int v; edge(int u, int v) { this.u=u; this.v=v; } public int compareTo(edge e) { return this.v-e.v; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
46f8080a42715db7cf73d6461aee3869
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; public class C1486 { static int n; static Scanner sc; static PrintWriter pw; public static int query(int l, int r) throws IOException { pw.printf("? %d %d%n", l, r); pw.flush(); return sc.nextInt(); } public static void ans(int idx) throws IOException { pw.printf("! %d%n", idx); pw.flush(); } public static void main(String[] args) throws IOException { sc = new Scanner(System.in); pw = new PrintWriter(System.out); n = sc.nextInt(); int s = query(1, n); int lo = 2; int hi = n; int ans = 0; boolean sFirst = false; if (s == 1) { sFirst = true; } else { int g = query(1, s); if (g != s) { sFirst = true; } } if (sFirst) { while (lo <= hi) { int mid = lo + hi >> 1; int q = query(1, mid); if (q != s) { lo = mid + 1; } else { ans = mid; hi = mid - 1; } } } else { lo = 1; hi = n - 1; while (lo <= hi) { int mid = lo + hi >> 1; int q = query(mid, n); if (q != s) { hi = mid - 1; } else { ans = mid; lo = mid + 1; } } } ans(ans); pw.close(); } static class Scanner { BufferedReader br; StringTokenizer st; public Scanner(InputStream s) { br = new BufferedReader(new InputStreamReader(s)); } public Scanner(FileReader f) { br = new BufferedReader(f); } public String next() throws IOException { while (st == null || !st.hasMoreTokens()) st = new StringTokenizer(br.readLine()); return st.nextToken(); } public int nextInt() throws IOException { return Integer.parseInt(next()); } public long nextLong() throws IOException { return Long.parseLong(next()); } public double nextDouble() throws IOException { return Double.parseDouble(next()); } public int[] nextIntArr(int n) throws IOException { int[] arr = new int[n]; for (int i = 0; i < n; i++) { arr[i] = Integer.parseInt(next()); } return arr; } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
91e2b82ff4e48c9a4b827ad184951e6a
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; public class EdA { static long[] mods = {1000000007, 998244353, 1000000009}; static long mod = mods[0]; public static MyScanner sc; public static PrintWriter out; public static void main(String[] omkar) throws Exception{ // TODO Auto-generated method stub sc = new MyScanner(); out = new PrintWriter(System.out); // String input1 = bf.readLine().trim(); // String input2 = bf.readLine().trim(); // COMPARING INTEGER OBJECTS U DO DOT EQUALS NOT == int lr = 0;//-1 = left, 1= right; int n = sc.nextInt(); out.println("? 1 " + n); out.flush(); int pos = sc.nextInt(); if (pos == 1){ lr = 1; } else if (pos == n){ lr = -1; } else{ out.println("? 1 " + pos); out.flush(); int left = sc.nextInt(); if (left == pos){ lr = -1; } else{ lr = 1; } } if (lr == -1){ int l = 1; int r = pos-1; while(l < r){ int mid = (l+r+1)/2; out.println("? " + mid + " " + pos); out.flush(); int v = sc.nextInt(); if (v == pos){ l = mid; } else{ r = mid-1; } } out.println("! " + l); out.close(); } else{ int l = pos+1; int r = n; while(l < r){ int mid = (l+r)/2; out.println("? " + pos + " " + mid); out.flush(); int v = sc.nextInt(); if (v == pos){ r = mid; } else{ l = mid+1; } } out.println("! " + l); out.close(); } // for(int j = 0;j<array.length;j++){ // out.print(array[j] + " "); // } // out.println(); } static class Pair implements Comparable<Pair>{ private int x; private int y; public Pair(int x, int y){ this.x = x; this.y = y; } public int compareTo(Pair other){ return Integer.compare(x, other.x); } } static class Pair2 implements Comparable<Pair2>{ private int x; private int y; public Pair2(int x, int y){ this.x = x; this.y = y; } public int compareTo(Pair2 other){ return Integer.compare(y, other.y); } } public static void sort(int[] array){ ArrayList<Integer> copy = new ArrayList<>(); for (int i : array) copy.add(i); Collections.sort(copy); for(int i = 0;i<array.length;i++) array[i] = copy.get(i); } static String[] readArrayString(int n){ String[] array = new String[n]; for(int j =0 ;j<n;j++) array[j] = sc.next(); return array; } static int[] readArrayInt(int n){ int[] array = new int[n]; for(int j = 0;j<n;j++) array[j] = sc.nextInt(); return array; } static int[] readArrayInt1(int n){ int[] array = new int[n+1]; for(int j = 1;j<=n;j++){ array[j] = sc.nextInt(); } return array; } static long[] readArrayLong(int n){ long[] array = new long[n]; for(int j =0 ;j<n;j++) array[j] = sc.nextLong(); return array; } static double[] readArrayDouble(int n){ double[] array = new double[n]; for(int j =0 ;j<n;j++) array[j] = sc.nextDouble(); return array; } static int minIndex(int[] array){ int minValue = Integer.MAX_VALUE; int minIndex = -1; for(int j = 0;j<array.length;j++){ if (array[j] < minValue){ minValue = array[j]; minIndex = j; } } return minIndex; } static int minIndex(long[] array){ long minValue = Long.MAX_VALUE; int minIndex = -1; for(int j = 0;j<array.length;j++){ if (array[j] < minValue){ minValue = array[j]; minIndex = j; } } return minIndex; } static int minIndex(double[] array){ double minValue = Double.MAX_VALUE; int minIndex = -1; for(int j = 0;j<array.length;j++){ if (array[j] < minValue){ minValue = array[j]; minIndex = j; } } return minIndex; } static long power(long x, long y){ if (y == 0) return 1; if (y%2 == 1) return (x*power(x, y-1))%mod; return power((x*x)%mod, y/2)%mod; } static void verdict(boolean a){ out.println(a ? "YES" : "NO"); } public static class MyScanner { BufferedReader br; StringTokenizer st; public MyScanner() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try{ str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } } //StringJoiner sj = new StringJoiner(" "); //sj.add(strings) //sj.toString() gives string of those stuff w spaces or whatever that sequence is
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
94a747d05278e11bcdea1ff26f4139e3
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; public class Main { public static void main(String[] args) throws Exception { int n=sc.nextInt(); pw.println("? "+1+" "+n); pw.flush(); int v=sc.nextInt(); int x=0; if(v!=1) { pw.println("? "+1+" "+v); pw.flush(); x=sc.nextInt(); } if(x==v&&v!=1) { int low=1; int high=v-1; int mid=(low+high)/2; while(low<=high) { pw.println("? "+mid+" "+v); pw.flush(); x=sc.nextInt(); if(x==v) { low=mid+1; }else { high=mid-1; } mid=(low+high)/2; } pw.println("! "+high); }else { int low=v+1; int high=n; int mid=(low+high)/2; while(low<=high) { pw.println("? "+v+" "+mid); pw.flush(); x=sc.nextInt(); if(x==v) { high=mid-1; }else { low=mid+1; } mid=(low+high)/2; } pw.println("! "+low); } pw.close(); } static class Scanner { StringTokenizer st; BufferedReader br; public Scanner(InputStream s) { br = new BufferedReader(new InputStreamReader(s)); } public Scanner(FileReader r) { br = new BufferedReader(r); } public String next() throws IOException { while (st == null || !st.hasMoreTokens()) st = new StringTokenizer(br.readLine()); return st.nextToken(); } public int nextInt() throws IOException { return Integer.parseInt(next()); } public long nextLong() throws IOException { return Long.parseLong(next()); } public String nextLine() throws IOException { return br.readLine(); } public double nextDouble() throws IOException { String x = next(); StringBuilder sb = new StringBuilder("0"); double res = 0, f = 1; boolean dec = false, neg = false; int start = 0; if (x.charAt(0) == '-') { neg = true; start++; } for (int i = start; i < x.length(); i++) if (x.charAt(i) == '.') { res = Long.parseLong(sb.toString()); sb = new StringBuilder("0"); dec = true; } else { sb.append(x.charAt(i)); if (dec) f *= 10; } res += Long.parseLong(sb.toString()) / f; return res * (neg ? -1 : 1); } public long[] nextlongArray(int n) throws IOException { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nextLong(); return a; } public Long[] nextLongArray(int n) throws IOException { Long[] a = new Long[n]; for (int i = 0; i < n; i++) a[i] = nextLong(); return a; } public int[] nextIntArray(int n) throws IOException { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } public Integer[] nextIntegerArray(int n) throws IOException { Integer[] a = new Integer[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } public boolean ready() throws IOException { return br.ready(); } } static class pair implements Comparable<pair> { long x; long y; public pair(long x, long y) { this.x = x; this.y = y; } public String toString() { return x + " " + y; } public boolean equals(Object o) { if (o instanceof pair) { pair p = (pair) o; return p.x == x && p.y == y; } return false; } public int hashCode() { return new Double(x).hashCode() * 31 + new Double(y).hashCode(); } public int compareTo(pair other) { if (this.x == other.x) { return Long.compare(this.y, other.y); } return Long.compare(this.x, other.x); } } static class tuble implements Comparable<tuble> { int x; int y; int z; public tuble(int x, int y, int z) { this.x = x; this.y = y; this.z = z; } public String toString() { return x + " " + y + " " + z; } public int compareTo(tuble other) { if (this.x == other.x) { if (this.y == other.y) { return this.z - other.z; } return this.y - other.y; } else { return this.x - other.x; } } } static long mod = 1000000007; static Random rn = new Random(); static Scanner sc = new Scanner(System.in); static PrintWriter pw = new PrintWriter(System.out); }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
53c5e887c6d83c435cd1a0a0e688b3c1
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import javax.sound.midi.Track; import java.io.*; public class tr0 { static PrintWriter out; static StringBuilder sb; static long mod = (long) 1e9 + 7; static long inf = (long) 1e16; static int n, m; static ArrayList<Integer>[] ad; static int[][] remove, add; static int[][] memo, memo1[]; static boolean vis[]; static long[] f, inv, ncr[]; static HashMap<Integer, Integer> hm; static int[] pre, suf, Smax[], Smin[]; static int idmax, idmin; static ArrayList<Integer> av; static HashMap<Integer, Integer> mm; static boolean[] msks; static int[] lazy[], lazyCount; static int[] a, dist; static char[][] g; static int ave; static ArrayList<Integer> gl; static int[][] arr; public static void main(String[] args) throws Exception { Scanner sc = new Scanner(System.in); out = new PrintWriter(System.out); int n = sc.nextInt(); int pos = query(1, n); if (n == 2) { System.out.println("! " + (n - pos + 1)); System.out.flush(); return; } int ans = 0; if (pos != n) { int l = query(pos, n); if (l == pos) { int sign = 1; int dest = pos; for (int p = 17; p >= 0; p--) { if ((dest + sign * (1 << p)) <= n) { dest += sign * (1 << p); int q = query(pos, dest); if (q == pos) { ans = dest; sign = -1; } else { sign = 1; } } } } else { int sign = -1; ans = pos; int dest = pos; for (int p = 17; p >= 0; p--) { if ((dest + sign * (1 << p)) >= 1) { dest += sign * (1 << p); int q = query(dest, pos); if (q == pos) { ans = dest; sign = 1; } else { sign = -1; } } } } } else { int sign = -1; int dest = pos; for (int p = 17; p >= 0; p--) { if ((dest + sign * (1 << p)) >= 1) { dest += sign * (1 << p); int q = query(dest, pos); if (q == pos) { ans = dest; sign = 1; } else { sign = -1; } } } } System.out.println("! " + ans); System.out.flush(); // out.flush(); 1 2 3 } static int query(int l, int r) throws IOException { Scanner sc1 = new Scanner(System.in); System.out.println("? " + l + " " + r); System.out.flush(); return sc1.nextInt(); } static class Scanner { StringTokenizer st; BufferedReader br; public Scanner(InputStream system) { br = new BufferedReader(new InputStreamReader(system)); } public Scanner(String file) throws Exception { br = new BufferedReader(new FileReader(file)); } public String next() throws IOException { while (st == null || !st.hasMoreTokens()) st = new StringTokenizer(br.readLine()); return st.nextToken(); } public String nextLine() throws IOException { return br.readLine(); } public int nextInt() throws IOException { return Integer.parseInt(next()); } public double nextDouble() throws IOException { return Double.parseDouble(next()); } public char nextChar() throws IOException { return next().charAt(0); } public Long nextLong() throws IOException { return Long.parseLong(next()); } public int[] nextArrInt(int n) throws IOException { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } public long[] nextArrLong(int n) throws IOException { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nextLong(); return a; } public int[] nextArrIntSorted(int n) throws IOException { int[] a = new int[n]; Integer[] a1 = new Integer[n]; for (int i = 0; i < n; i++) a1[i] = nextInt(); Arrays.sort(a1); for (int i = 0; i < n; i++) a[i] = a1[1].intValue(); return a; } public long[] nextArrLongSorted(int n) throws IOException { long[] a = new long[n]; Long[] a1 = new Long[n]; for (int i = 0; i < n; i++) a1[i] = nextLong(); Arrays.sort(a1); for (int i = 0; i < n; i++) a[i] = a1[1].longValue(); return a; } public boolean ready() throws IOException { return br.ready(); } public void waitForInput() throws InterruptedException { Thread.sleep(3000); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
d3dacf9f6d87e8ebac68010b5ad887cc
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
//stan hu tao import static java.lang.Math.max; import static java.lang.Math.min; import static java.lang.Math.abs; import java.util.*; import java.io.*; import java.math.*; public class x1486C1 { public static void main(String hi[]) throws Exception { BufferedReader infile = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(infile.readLine()); int N = Integer.parseInt(st.nextToken()); System.out.println("? 1 "+N); System.out.flush(); int middle = Integer.parseInt(infile.readLine()); int res = 0; if(middle > 1) { System.out.println("? 1 "+middle); System.out.flush(); int dex = Integer.parseInt(infile.readLine()); if(dex == middle) { int low = 1; int high = middle-1; while(low != high) { int mid = (low+high+1)/2; System.out.println("? "+mid+" "+middle); System.out.flush(); dex = Integer.parseInt(infile.readLine()); if(dex == middle) low = mid; else high = mid-1; } res = low; } } if(res == 0 && middle < N) { //should always be true int low = middle+1; int high = N; while(low != high) { int mid = (low+high)/2; System.out.println("? "+middle+" "+mid); System.out.flush(); int dex = Integer.parseInt(infile.readLine()); if(dex == middle) high = mid; else low = mid+1; } res = low; } System.out.println("! "+res); System.out.flush(); } public static int[] readArr(int N, BufferedReader infile, StringTokenizer st) throws Exception { int[] arr = new int[N]; st = new StringTokenizer(infile.readLine()); for(int i=0; i < N; i++) arr[i] = Integer.parseInt(st.nextToken()); return arr; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
d3bc4a52008d4a5f2ec21184dfcd4a05
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; public class Div708 { //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// //////// ///////// //////// ///////// //////// HHHH HHHH EEEEEEEEEEEEE MMMM MMMM OOOOOO SSSSSSS EEEEEEEEEEEEE ///////// //////// HHHH HHHH EEEEEEEEEEEEE MMMMMM MMMMMM OOO OOO SSSS SSS EEEEEEEEEEEEE ///////// //////// HHHH HHHH EEEEE MMMM MMM MMM MMMM OOO OOO SSSS SSS EEEEE ///////// //////// HHHH HHHH EEEEE MMMM MMMMMM MMMM OOO OOO SSSS EEEEE ///////// //////// HHHH HHHH EEEEE MMMM MMMM OOO OOO SSSSSSS EEEEE ///////// //////// HHHHHHHHHHHHHHHH EEEEEEEEEEE MMMM MMMM OOO OOO SSSSSS EEEEEEEEEEE ///////// //////// HHHHHHHHHHHHHHHH EEEEEEEEEEE MMMM MMMM OOO OOO SSSSSSS EEEEEEEEEEE ///////// //////// HHHH HHHH EEEEE MMMM MMMM OOO OOO SSSS EEEEE ///////// //////// HHHH HHHH EEEEE MMMM MMMM OOO OOO SSS SSSS EEEEE ///////// //////// HHHH HHHH EEEEEEEEEEEEE MMMM MMMM OOO OOO SSS SSSS EEEEEEEEEEEEE ///////// //////// HHHH HHHH EEEEEEEEEEEEE MMMM MMMM OOOOOO SSSSSSS EEEEEEEEEEEEE ///////// //////// ///////// //////// ///////// //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// static Scanner sc; static int Query(int l, int r) throws IOException { if (l == r) return l; System.out.println("? " + l + " " + r); return sc.nextInt(); } public static void main(String[] args) throws IOException { sc = new Scanner(System.in); PrintWriter pw = new PrintWriter(System.out); int n = sc.nextInt(); int snd = Query(1, n); int l = 1; int r = n; if (l != snd && r != snd) { int v = Query(l, snd); if (v == snd) { r = snd; } else l = snd; } if (l == snd) { int ans = snd + 1; while (l <= r) { int mid = l + r >> 1; int v = Query(snd, mid); if (v != snd) { ans = mid + 1; l = mid + 1; } else { r = mid - 1; } } System.out.println("! " + ans); } else { int ans = snd - 1; while (l <= r) { int mid = l + r >> 1; int v = Query(mid, snd); if (v != snd) { ans = mid - 1; r = mid - 1; } else { l = mid + 1; } } System.out.println("! " + ans); } pw.flush(); } static class Scanner { StringTokenizer st; BufferedReader br; public Scanner(FileReader r) { br = new BufferedReader(r); } public Scanner(InputStream s) { br = new BufferedReader(new InputStreamReader(s)); } public String next() throws IOException { while (st == null || !st.hasMoreTokens()) st = new StringTokenizer(br.readLine()); return st.nextToken(); } public int[] nextIntArr(int n) throws IOException { int[] a = new int[n]; for (int i = 0; i < n; i++) { a[i] = nextInt(); } return a; } public int nextInt() throws IOException { return Integer.parseInt(next()); } public long nextLong() throws IOException { return Long.parseLong(next()); } public String nextLine() throws IOException { return br.readLine(); } public double nextDouble() throws IOException { String x = next(); StringBuilder sb = new StringBuilder("0"); double res = 0, f = 1; boolean dec = false, neg = false; int start = 0; if (x.charAt(0) == '-') { neg = true; start++; } for (int i = start; i < x.length(); i++) if (x.charAt(i) == '.') { res = Long.parseLong(sb.toString()); sb = new StringBuilder("0"); dec = true; } else { sb.append(x.charAt(i)); if (dec) f *= 10; } res += Long.parseLong(sb.toString()) / f; return res * (neg ? -1 : 1); } public boolean ready() throws IOException { return br.ready(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
bb8a7340bcbb119ad429238c03456c39
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; public class C { static Scanner sc; public static void main(String[] args) { sc = new Scanner(System.in); int n = sc.nextInt(); System.out.printf("? %d %d\n", 1, n); int m = sc.nextInt(); if(m > 1) { System.out.printf("? %d %d\n", 1, m); int r = sc.nextInt(); if(r == m) { findmaxleft(m, n); } else { findmaxright(m, n); } } else { findmaxright(1, n); } } static void findmaxleft(int m, int n) { int a = 1, b = m; while(b - a > 1) { int c = (a + b)/2; System.out.printf("? %d %d\n", c, m); int r = sc.nextInt(); if(r == m) a = c; else b = c; } System.out.printf("! %d\n", a); } static void findmaxright(int m, int n) { int a = m, b = n; while(b - a > 1) { int c = (a + b)/2; System.out.printf("? %d %d\n", m, c); int r = sc.nextInt(); if(r == m) b = c; else a = c; } System.out.printf("! %d\n", b); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
38b2c036c795f87d7b0807896c16b000
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; public class C_1486 { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(System.in); PrintWriter pw = new PrintWriter(System.out); int n = sc.nextInt(); pw.printf("? 1 %d\n", n); pw.flush(); int max2 = sc.nextInt(); if(n == 2) { pw.println("! " + (max2 == 1 ? 2 : 1)); } else { int start, end; if(max2 == 1) { start = 2; end = n; } else if(max2 == n) { start = 1; end = n - 1; } else { pw.printf("? 1 %d\n", max2); pw.flush(); int ans = sc.nextInt(); if(ans == max2) { start = 1; end = max2 - 1; } else { start = max2 + 1; end = n; } } while(start < end) { int mid = (start + end) >> 1; if(mid > max2) { pw.printf("? %d %d\n", max2, mid); pw.flush(); int ans = sc.nextInt(); if(ans == max2) { end = mid; } else { start = mid + 1; } } else { pw.printf("? %d %d\n", mid + 1, max2); pw.flush(); int ans = sc.nextInt(); if(ans == max2) { start = mid + 1; } else { end = mid; } } } pw.println("! " + start); } pw.flush(); } public static class Scanner { StringTokenizer st; BufferedReader br; public Scanner(InputStream system) { br = new BufferedReader(new InputStreamReader(system)); } public Scanner(String file) throws Exception { br = new BufferedReader(new FileReader(file)); } public String next() throws IOException { while (st == null || !st.hasMoreTokens()) st = new StringTokenizer(br.readLine()); return st.nextToken(); } public String nextLine() throws IOException { return br.readLine(); } public int nextInt() throws IOException { return Integer.parseInt(next()); } public double nextDouble() throws IOException { return Double.parseDouble(next()); } public char nextChar() throws IOException { return next().charAt(0); } public long nextLong() throws IOException { return Long.parseLong(next()); } public int[] nextIntArray(int n) throws IOException { int[] array = new int[n]; for (int i = 0; i < n; i++) array[i] = nextInt(); return array; } public Integer[] nextIntegerArray(int n) throws IOException { Integer[] array = new Integer[n]; for (int i = 0; i < n; i++) array[i] = new Integer(nextInt()); return array; } public long[] nextLongArray(int n) throws IOException { long[] array = new long[n]; for (int i = 0; i < n; i++) array[i] = nextLong(); return array; } public double[] nextDoubleArray(int n) throws IOException { double[] array = new double[n]; for (int i = 0; i < n; i++) array[i] = nextDouble(); return array; } public static int[] shuffle(int[] a) { int n = a.length; Random rand = new Random(); for (int i = 0; i < n; i++) { int tmpIdx = rand.nextInt(n); int tmp = a[i]; a[i] = a[tmpIdx]; a[tmpIdx] = tmp; } return a; } public boolean ready() throws IOException { return br.ready(); } public void waitForInput() throws InterruptedException { Thread.sleep(3000); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
f47491750ea38cf7594341a93f6d0c17
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class F { static int query(int l, int r) throws IOException { System.out.printf("? %d %d\n", l, r); return sc.nextInt(); } static Scanner sc = new Scanner(); public static void main(String[] args) throws IOException { int n = sc.nextInt(); int scnd = query(1, n); boolean left = scnd != 1 && query(1, scnd) == scnd; int lo = 2, hi = left ? scnd : n - scnd + 1; int ans = -1; while (lo <= hi) { int mid = lo + hi >> 1; int x; if (left) x = query(scnd - mid + 1, scnd); else x = query(scnd, scnd + mid - 1); if (x == scnd) { ans = mid; hi = mid - 1; } else lo = mid + 1; } if (left) ans = scnd - ans + 1; else ans = scnd + ans - 1; System.out.printf("! %d\n", ans); } static class Scanner { BufferedReader br; StringTokenizer st; Scanner() { br = new BufferedReader(new InputStreamReader(System.in)); } Scanner(String fileName) throws FileNotFoundException { br = new BufferedReader(new FileReader(fileName)); } String next() throws IOException { while (st == null || !st.hasMoreTokens()) st = new StringTokenizer(br.readLine()); return st.nextToken(); } String nextLine() throws IOException { return br.readLine(); } int nextInt() throws IOException { return Integer.parseInt(next()); } long nextLong() throws NumberFormatException, IOException { return Long.parseLong(next()); } double nextDouble() throws NumberFormatException, IOException { return Double.parseDouble(next()); } boolean ready() throws IOException { return br.ready() || st.hasMoreTokens(); } int[] nxtArr(int n) throws IOException { int[] ans = new int[n]; for (int i = 0; i < n; i++) ans[i] = nextInt(); return ans; } } static void sort(int[] a) { shuffle(a); Arrays.sort(a); } static void shuffle(int[] a) { int n = a.length; Random rand = new Random(); for (int i = 0; i < n; i++) { int tmpIdx = rand.nextInt(n); int tmp = a[i]; a[i] = a[tmpIdx]; a[tmpIdx] = tmp; } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 8
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
9cc0b248a9a08710b866e564dfa468cb
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; public class Solve{ static Scanner sc=new Scanner(System.in); public static void main(String[] args){ int n=sc.nextInt(); int l=0; int r=n-1; int sec=q(l+1,r+1); if(q(l+1,sec+1)!=sec || sec==0) { // right l=sec;r=n-1; while(r-l>1) { int m=(l+r)/2; if(q(sec+1,m+1)==sec) { r=m; } else { l=m; } } r++; System.out.println("! "+r); } else { //left l=0;r=sec; while(r-l>1) { int m=(l+r)/2; if(q(m+1,sec+1)==sec) { l=m; } else { r=m; } } l++; System.out.println("! "+l); } } static int q(int l,int r){ if(l>=r) return -1; System.out.println("? "+l+" "+r); System.out.flush(); return sc.nextInt()-1; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
48c7e6e83a72fea32415c3a102b2796f
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; public class Solve{ static Scanner sc=new Scanner(System.in); public static void main(String[] args){ int n=sc.nextInt(); int l=0; int r=n-1; int sec=q(l+1,r+1); if(q(l+1,sec+1)!=sec || sec==0) { l=sec;r=n-1; while(r-l>1){ int m=(l+r)/2; if(q(sec+1,m+1)==sec){ r=m; } else{ l=m; } } r++; System.out.println("! "+r); } else { //left l=0;r=sec; while(r-l>1){ int m=(l+r)/2; if(q(m+1,sec+1)==sec){ l=m; } else{ r=m; } } l++; System.out.println("! "+l); } } static int q(int l,int r){ if(l>=r) return -1; System.out.println("? "+l+" "+r); System.out.flush(); return sc.nextInt()-1; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
44556f972f048f5c237561bab6626f69
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; import java.math.*; public class Main { static int right(int max,int start,int end,int n) { FastScanner f = new FastScanner(); if(end<start) { return 1000000000; } else { int mid=(start+end)/2; System.out.println("? "+(max+1)+" "+(mid+1)); int place=f.nextInt()-1; if(place==max) { return Math.min(mid, right(max,start,mid-1,n)); } else { return right(max,mid+1,end,n); } } } static int left(int max,int start,int end) { // System.out.println(start+" "+end); FastScanner f = new FastScanner(); if(end<start) { return -1000000000; } else { int mid=(start+end)/2; System.out.println("? "+(mid+1)+" "+(max+1)); int place=f.nextInt()-1; if(place==max) { return Math.max(mid, left(max,mid+1,end)); } else { return left(max,start,mid-1); } } } public static void main(String[] args) throws IOException { FastScanner f = new FastScanner(); int t=1; // t=f.nextInt(); PrintWriter out=new PrintWriter(System.out); int mod=1000000007; while(t>0) { t--; int n=f.nextInt(); System.out.println("? "+1+" "+(n)); int ind=f.nextInt()-1; if(ind==(n-1)) { System.out.println("! "+(left(ind,0,ind-1)+1)); } else if(ind==0) { System.out.println("! "+(right(ind,ind+1,n-1,n)+1)); } else { System.out.println("? "+(ind+1)+" "+(n)); int place=f.nextInt()-1; if(place==ind) { System.out.println("! "+(right(ind,ind+1,n-1,n)+1)); } else { System.out.println("! "+(left(ind,0,ind-1)+1)); } } } out.close(); } static void sort(int [] a) { ArrayList<Integer> q = new ArrayList<>(); for (int i: a) q.add(i); Collections.sort(q); for (int i = 0; i < a.length; i++) a[i] = q.get(i); } static class FastScanner { BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st=new StringTokenizer(""); String next() { while (!st.hasMoreTokens()) try { st=new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } int[] readArray(int n) { int[] a=new int[n]; for (int i=0; i<n; i++) a[i]=nextInt(); return a; } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } long[] readLongArray(int n) { long[] a=new long[n]; for (int i=0; i<n; i++) a[i]=nextLong(); return a; } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
0af7ca6c92fa2ba94940385b7ae8d847
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; import java.math.*; public class Main { static int right(int max,int start,int end,int n) { FastScanner f = new FastScanner(); if(end<start) { return 1000000000; } else { int mid=(start+end)/2; System.out.println("? "+(max+1)+" "+(mid+1)); int place=f.nextInt()-1; if(place==max) { return Math.min(mid, right(max,start,mid-1,n)); } else { return right(max,mid+1,end,n); } } } static int left(int max,int start,int end) { // System.out.println(start+" "+end); FastScanner f = new FastScanner(); if(end<start) { return 0; } else { int mid=(start+end)/2; System.out.println("? "+(mid+1)+" "+(max+1)); int place=f.nextInt()-1; if(place==max) { return Math.max(mid, left(max,mid+1,end)); } else { return left(max,start,mid-1); } } } public static void main(String[] args) throws IOException { FastScanner f = new FastScanner(); int t=1; // t=f.nextInt(); PrintWriter out=new PrintWriter(System.out); int mod=1000000007; while(t>0) { t--; int n=f.nextInt(); System.out.println("? "+1+" "+(n)); int ind=f.nextInt()-1; if(ind==(n-1)) { System.out.println("! "+(left(ind,0,ind-1)+1)); } else if(ind==0) { System.out.println("! "+(right(ind,ind+1,n-1,n)+1)); } else { System.out.println("? "+(ind+1)+" "+(n)); int place=f.nextInt()-1; if(place==ind) { System.out.println("! "+(right(ind,ind+1,n-1,n)+1)); } else { System.out.println("! "+(left(ind,0,ind-1)+1)); } } } out.close(); } static void sort(int [] a) { ArrayList<Integer> q = new ArrayList<>(); for (int i: a) q.add(i); Collections.sort(q); for (int i = 0; i < a.length; i++) a[i] = q.get(i); } static class FastScanner { BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st=new StringTokenizer(""); String next() { while (!st.hasMoreTokens()) try { st=new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } int[] readArray(int n) { int[] a=new int[n]; for (int i=0; i<n; i++) a[i]=nextInt(); return a; } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } long[] readLongArray(int n) { long[] a=new long[n]; for (int i=0; i<n; i++) a[i]=nextLong(); return a; } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
c21cc507ec5d29f24733a3b36202bf3a
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; import java.math.*; public class Main { static int right(int max,int start,int end,int n) { FastScanner f = new FastScanner(); if(end<start) { return n-1; } else { int mid=(start+end)/2; System.out.println("? "+(max+1)+" "+(mid+1)); int place=f.nextInt()-1; if(place==max) { return Math.min(mid, right(max,start,mid-1,n)); } else { return right(max,mid+1,end,n); } } } static int left(int max,int start,int end) { // System.out.println(start+" "+end); FastScanner f = new FastScanner(); if(end<start) { return 0; } else { int mid=(start+end)/2; System.out.println("? "+(mid+1)+" "+(max+1)); int place=f.nextInt()-1; if(place==max) { return Math.max(mid, left(max,mid+1,end)); } else { return left(max,start,mid-1); } } } public static void main(String[] args) throws IOException { FastScanner f = new FastScanner(); int t=1; // t=f.nextInt(); PrintWriter out=new PrintWriter(System.out); int mod=1000000007; while(t>0) { t--; int n=f.nextInt(); System.out.println("? "+1+" "+(n)); int ind=f.nextInt()-1; if(ind==(n-1)) { System.out.println("! "+(left(ind,0,ind-1)+1)); } else if(ind==0) { System.out.println("! "+(right(ind,ind+1,n-1,n)+1)); } else { System.out.println("? "+(ind+1)+" "+(n)); int place=f.nextInt()-1; if(place==ind) { System.out.println("! "+(right(ind,ind+1,n-1,n)+1)); } else { System.out.println("! "+(left(ind,0,ind-1)+1)); } } } out.close(); } static void sort(int [] a) { ArrayList<Integer> q = new ArrayList<>(); for (int i: a) q.add(i); Collections.sort(q); for (int i = 0; i < a.length; i++) a[i] = q.get(i); } static class FastScanner { BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st=new StringTokenizer(""); String next() { while (!st.hasMoreTokens()) try { st=new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } int[] readArray(int n) { int[] a=new int[n]; for (int i=0; i<n; i++) a[i]=nextInt(); return a; } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } long[] readLongArray(int n) { long[] a=new long[n]; for (int i=0; i<n; i++) a[i]=nextLong(); return a; } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
65c073bd159736bd271ed480686a826b
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class CF { static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } static FastReader fs = new FastReader(); public static void main(String[] args) { try { System.setIn(new FileInputStream("input.txt")); System.setOut(new PrintStream(new FileOutputStream("output.txt"))); } catch (Exception e) { System.err.println("Error"); } int n = fs.nextInt(); int smax = ask(1, n); int ans = -1; if(ask(1, smax) == smax) { int l = 1, r = smax-1; while(l <= r) { int mid = (l+r)/2; if(ask(mid, smax) == smax) { ans = mid; l = mid+1; } else { r = mid-1; } } } else { int l = smax+1, r = n; while(l <= r) { int mid = (l+r)/2; if(ask(smax, mid) == smax) { ans = mid; r = mid-1; } else { l = mid+1; } } } System.out.println("! " + ans); } public static int ask(int l, int r) { if(l == r) return -1; System.out.println("? " + l + " " + r); int inx = fs.nextInt(); System.out.flush(); return inx; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
278dfbbceca5bb020214fb66782d73ff
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class CF { static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } static FastReader fs = new FastReader(); public static void main(String[] args) { try { System.setIn(new FileInputStream("input.txt")); System.setOut(new PrintStream(new FileOutputStream("output.txt"))); } catch (Exception e) { System.err.println("Error"); } int n = fs.nextInt(); int smax = ask(1, n); if(ask(1, smax) == smax) { int l = 1, r = smax; while(l < r) { int mid = (l+r+1)/2; if(ask(mid, n) == smax) { l = mid; } else { r = mid-1; } } System.out.println("! " + l); } else { int l = smax, r = n; while(l < r) { int mid = (l+r)/2; if(ask(1, mid) == smax) { r = mid; } else { l = mid+1; } } System.out.println("! "+ l); } } public static int ask(int l, int r) { if(l == r) return -1; System.out.println("? " + l + " " + r); int inx = fs.nextInt(); System.out.flush(); return inx; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
f4953807e72a6362f3f11471f9a9f0ed
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; import java.math.*; import java.awt.geom.*; import static java.lang.Math.*; public class Solution implements Runnable { long mod1 = (long) 1e9 + 7; int mod2 = 998244353; public void solve() throws Exception { int n=sc.nextInt(); int start=1; int end=n; boolean right=false,left=false; int smx=query(start, end); if(smx==1) { right=true; } else if(smx==n) left=true; else if(query(smx,end)==smx) { right=true; } else left=true; if(right) { start=smx; end=n; boolean flag=false; int min=n; while(start<end) { int mid=(start+end)/2; if(end-start==1) { int q1=0; if(smx<start) { q1=query(smx,start); } if(q1==smx) { min=Math.min(min, start); } min=Math.min(min, end); break; } if(query(smx,mid)==smx) { min=mid; end=mid; } else { start=mid; } } print(min); } else { start=1; end=smx; boolean flag=false; int min=1; while(start<end) { int mid=(start+end)/2; if(end-start==1) { int q1=0; if(smx<start) { q1=query(end,smx); } if(q1==smx) { min=Math.max(min, end); } min=Math.max(min, start); break; } if(query(mid,smx)==smx) { min=mid; start=mid; } else { end=mid; } } print(min); } } public void print(int x) { System.out.println("! "+x); System.out.flush(); } public int query(int l,int r) throws Exception{ System.out.print("? "+l+" "+r); System.out.println(); System.out.flush(); int x=sc.nextInt(); return x; } static long gcd(long a, long b) { if (a == 0) return b; return gcd(b % a, a); } static void sort(int[] a) { ArrayList<Integer> l = new ArrayList<>(); for (int i : a) l.add(i); Collections.sort(l); for (int i = 0; i < a.length; i++) a[i] = l.get(i); } static long ncr(int n, int r, long p) { if (r > n) return 0l; if (r > n - r) r = n - r; long C[] = new long[r + 1]; C[0] = 1; for (int i = 1; i <= n; i++) { for (int j = Math.min(i, r); j > 0; j--) C[j] = (C[j] + C[j - 1]) % p; } return C[r] % p; } void sieveOfEratosthenes(boolean prime[], int size) { for (int i = 0; i < size; i++) prime[i] = true; for (int p = 2; p * p < size; p++) { if (prime[p] == true) { for (int i = p * p; i < size; i += p) prime[i] = false; } } } static int LowerBound(int a[], int x) { // smallest index having value >= x int l = -1, r = a.length; while (l + 1 < r) { int m = (l + r) >>> 1; if (a[m] >= x) r = m; else l = m; } return r; } static int UpperBound(int a[], int x) {// biggest index having value <= x int l = -1, r = a.length; while (l + 1 < r) { int m = (l + r) >>> 1; if (a[m] <= x) l = m; else r = m; } return l + 1; } public long power(long x, long y, long p) { long res = 1; // out.println(x+" "+y); x = x % p; if (x == 0) return 0; while (y > 0) { if ((y & 1) == 1) res = (res * x) % p; y = y >> 1; x = (x * x) % p; } return res; } static Throwable uncaught; BufferedReader in; FastScanner sc; PrintWriter out; @Override public void run() { try { in = new BufferedReader(new InputStreamReader(System.in)); out = new PrintWriter(System.out); sc = new FastScanner(in); solve(); } catch (Throwable uncaught) { Solution.uncaught = uncaught; } finally { out.close(); } } public static void main(String[] args) throws Throwable { Thread thread = new Thread(null, new Solution(), "", (1 << 26)); thread.start(); thread.join(); if (Solution.uncaught != null) { throw Solution.uncaught; } } } class FastScanner { BufferedReader in; StringTokenizer st; public FastScanner(BufferedReader in) { this.in = in; } public String nextToken() throws Exception { while (st == null || !st.hasMoreTokens()) { st = new StringTokenizer(in.readLine()); } return st.nextToken(); } public int nextInt() throws Exception { return Integer.parseInt(nextToken()); } public int[] readArray(int n) throws Exception { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } public long nextLong() throws Exception { return Long.parseLong(nextToken()); } public double nextDouble() throws Exception { return Double.parseDouble(nextToken()); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
62163abea677b58aa629533d9f04512f
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; import java.math.*; import java.awt.geom.*; import static java.lang.Math.*; public class Solution implements Runnable { long mod1 = (long) 1e9 + 7; int mod2 = 998244353; public void solve() throws Exception { int n=sc.nextInt(); int start=1; int end=n; boolean right=false,left=false; int smx=query(start, end); if(smx==1) { right=true; } else if(smx==n) left=true; else if(query(smx,end)==smx) { right=true; } else left=true; if(right) { start=smx; end=n; boolean flag=false; int min=n; while(start+1<end) { int mid=(start+end)/2; if(end-start==1) { min=Math.min(min, end); break; } if(query(smx,mid)==smx) { min=mid; end=mid; } else { start=mid; } } print(min); } else { start=1; end=smx; boolean flag=false; int min=1; while(start<end) { int mid=(start+end)/2; if(end-start==1) { min=Math.max(min, start); break; } if(query(mid,smx)==smx) { min=mid; start=mid; } else { end=mid; } } print(min); } } public void print(int x) { System.out.println("! "+x); System.out.flush(); } public int query(int l,int r) throws Exception{ System.out.print("? "+l+" "+r); System.out.println(); System.out.flush(); int x=sc.nextInt(); return x; } static long gcd(long a, long b) { if (a == 0) return b; return gcd(b % a, a); } static void sort(int[] a) { ArrayList<Integer> l = new ArrayList<>(); for (int i : a) l.add(i); Collections.sort(l); for (int i = 0; i < a.length; i++) a[i] = l.get(i); } static long ncr(int n, int r, long p) { if (r > n) return 0l; if (r > n - r) r = n - r; long C[] = new long[r + 1]; C[0] = 1; for (int i = 1; i <= n; i++) { for (int j = Math.min(i, r); j > 0; j--) C[j] = (C[j] + C[j - 1]) % p; } return C[r] % p; } void sieveOfEratosthenes(boolean prime[], int size) { for (int i = 0; i < size; i++) prime[i] = true; for (int p = 2; p * p < size; p++) { if (prime[p] == true) { for (int i = p * p; i < size; i += p) prime[i] = false; } } } static int LowerBound(int a[], int x) { // smallest index having value >= x int l = -1, r = a.length; while (l + 1 < r) { int m = (l + r) >>> 1; if (a[m] >= x) r = m; else l = m; } return r; } static int UpperBound(int a[], int x) {// biggest index having value <= x int l = -1, r = a.length; while (l + 1 < r) { int m = (l + r) >>> 1; if (a[m] <= x) l = m; else r = m; } return l + 1; } public long power(long x, long y, long p) { long res = 1; // out.println(x+" "+y); x = x % p; if (x == 0) return 0; while (y > 0) { if ((y & 1) == 1) res = (res * x) % p; y = y >> 1; x = (x * x) % p; } return res; } static Throwable uncaught; BufferedReader in; FastScanner sc; PrintWriter out; @Override public void run() { try { in = new BufferedReader(new InputStreamReader(System.in)); out = new PrintWriter(System.out); sc = new FastScanner(in); solve(); } catch (Throwable uncaught) { Solution.uncaught = uncaught; } finally { out.close(); } } public static void main(String[] args) throws Throwable { Thread thread = new Thread(null, new Solution(), "", (1 << 26)); thread.start(); thread.join(); if (Solution.uncaught != null) { throw Solution.uncaught; } } } class FastScanner { BufferedReader in; StringTokenizer st; public FastScanner(BufferedReader in) { this.in = in; } public String nextToken() throws Exception { while (st == null || !st.hasMoreTokens()) { st = new StringTokenizer(in.readLine()); } return st.nextToken(); } public int nextInt() throws Exception { return Integer.parseInt(nextToken()); } public int[] readArray(int n) throws Exception { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } public long nextLong() throws Exception { return Long.parseLong(nextToken()); } public double nextDouble() throws Exception { return Double.parseDouble(nextToken()); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
1c0685ee7841dd9aa69b983e753bdcb7
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; import java.math.*; import java.awt.geom.*; import static java.lang.Math.*; public class Solution implements Runnable { long mod1 = (long) 1e9 + 7; int mod2 = 998244353; public void solve() throws Exception { int n=sc.nextInt(); int start=1; int end=n; boolean right=false,left=false; int smx=query(start, end); if(smx==1) { right=true; } else if(smx==n) left=true; else if(query(smx,end)==smx) { right=true; } else left=true; if(right) { start=smx; end=n; boolean flag=false; int min=n; while(start+1<end) { int mid=(start+end)/2; if(query(smx,mid)==smx) { min=mid; end=mid; } else { start=mid; } } print(min); } else { start=1; end=smx; boolean flag=false; int min=1; while(start+1<end) { int mid=(start+end)/2; if(query(mid,smx)==smx) { min=mid; start=mid; } else { end=mid; } } print(min); } } public void print(int x) { System.out.println("! "+x); System.out.flush(); } public int query(int l,int r) throws Exception{ System.out.print("? "+l+" "+r); System.out.println(); System.out.flush(); int x=sc.nextInt(); return x; } static long gcd(long a, long b) { if (a == 0) return b; return gcd(b % a, a); } static void sort(int[] a) { ArrayList<Integer> l = new ArrayList<>(); for (int i : a) l.add(i); Collections.sort(l); for (int i = 0; i < a.length; i++) a[i] = l.get(i); } static long ncr(int n, int r, long p) { if (r > n) return 0l; if (r > n - r) r = n - r; long C[] = new long[r + 1]; C[0] = 1; for (int i = 1; i <= n; i++) { for (int j = Math.min(i, r); j > 0; j--) C[j] = (C[j] + C[j - 1]) % p; } return C[r] % p; } void sieveOfEratosthenes(boolean prime[], int size) { for (int i = 0; i < size; i++) prime[i] = true; for (int p = 2; p * p < size; p++) { if (prime[p] == true) { for (int i = p * p; i < size; i += p) prime[i] = false; } } } static int LowerBound(int a[], int x) { // smallest index having value >= x int l = -1, r = a.length; while (l + 1 < r) { int m = (l + r) >>> 1; if (a[m] >= x) r = m; else l = m; } return r; } static int UpperBound(int a[], int x) {// biggest index having value <= x int l = -1, r = a.length; while (l + 1 < r) { int m = (l + r) >>> 1; if (a[m] <= x) l = m; else r = m; } return l + 1; } public long power(long x, long y, long p) { long res = 1; // out.println(x+" "+y); x = x % p; if (x == 0) return 0; while (y > 0) { if ((y & 1) == 1) res = (res * x) % p; y = y >> 1; x = (x * x) % p; } return res; } static Throwable uncaught; BufferedReader in; FastScanner sc; PrintWriter out; @Override public void run() { try { in = new BufferedReader(new InputStreamReader(System.in)); out = new PrintWriter(System.out); sc = new FastScanner(in); solve(); } catch (Throwable uncaught) { Solution.uncaught = uncaught; } finally { out.close(); } } public static void main(String[] args) throws Throwable { Thread thread = new Thread(null, new Solution(), "", (1 << 26)); thread.start(); thread.join(); if (Solution.uncaught != null) { throw Solution.uncaught; } } } class FastScanner { BufferedReader in; StringTokenizer st; public FastScanner(BufferedReader in) { this.in = in; } public String nextToken() throws Exception { while (st == null || !st.hasMoreTokens()) { st = new StringTokenizer(in.readLine()); } return st.nextToken(); } public int nextInt() throws Exception { return Integer.parseInt(nextToken()); } public int[] readArray(int n) throws Exception { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } public long nextLong() throws Exception { return Long.parseLong(nextToken()); } public double nextDouble() throws Exception { return Double.parseDouble(nextToken()); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
1ef7ff5d0062050777f1c642dfa9c41e
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.InputMismatchException; /** * Created by Wilson on * Feb. 08, 2021 */ public class HardMaxelementInteractive { public static void main(String[] args) { InputStream inputStream = System.in; OutputStream outputStream = System.out; InputReader in = new InputReader(inputStream); OutputWriter out = new OutputWriter(outputStream); CSearchingLocalMinimum solver = new CSearchingLocalMinimum(); solver.solve(in, out); out.close(); } static class CSearchingLocalMinimum { OutputWriter out; InputReader in; int query(int l,int r) { out.printLine("?", l,r); out.flush(); return in.readInt(); } void writeOutput(int ans) { out.printLine("!", ans); out.flush(); } public void solve(InputReader in, OutputWriter out) { this.out = out; this.in = in; int n = in.readInt(); if (n == 1) { writeOutput(1); return; } //The idea here is to use the first divide the array into 2 halfs //and checks which side of the array as the biggest element //1)if first side has it, query b/w mid and smax always changing l and //r, get the middle of l and r and then query for second largest b/w middle and smax(which is to the right) //since l side always gets mid whenever new query is equal to smax, then we return the //r whenever r-l <= 1 //2) if the second side has the biggest, always query between mid and smax (which is to left end of the // first accepted part) //here, r side always gets the mid whenever new query (mid, smax) returns value equal to smax //then we return l whenever r - l <= 1 int l,r,smax,mid,ans; smax = query(1, n); if (smax == 1 || query(1, smax) != smax) { l = smax; r = n; while (r - l > 1) { int m = (l + r) / 2; if (query(smax, m) == smax) { r = m; } else { l = m; } } writeOutput(r); } else { l = 1; r = smax; while (r - l > 1) { int m = (l + r) / 2; if (query(m, smax) == smax) { l = m; } else { r = m; } } writeOutput(l); } } } static class OutputWriter { private final PrintWriter writer; public OutputWriter(OutputStream outputStream) { writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream))); } public OutputWriter(Writer writer) { this.writer = new PrintWriter(writer); } public void print(Object... objects) { for (int i = 0; i < objects.length; i++) { if (i != 0) { writer.print(' '); } writer.print(objects[i]); } } public void printLine(Object... objects) { print(objects); writer.println(); } public void close() { writer.close(); } public void flush() { writer.flush(); } } static class InputReader { private InputStream stream; private byte[] buf = new byte[1024]; private int curChar; private int numChars; private SpaceCharFilter filter; public InputReader(InputStream stream) { this.stream = stream; } public int read() { if (numChars == -1) { throw new InputMismatchException(); } if (curChar >= numChars) { curChar = 0; try { numChars = stream.read(buf); } catch (IOException e) { throw new InputMismatchException(); } if (numChars <= 0) { return -1; } } return buf[curChar++]; } public int readInt() { int c = read(); while (isSpaceChar(c)) { c = read(); } int sgn = 1; if (c == '-') { sgn = -1; c = read(); } int res = 0; do { if (c < '0' || c > '9') { throw new InputMismatchException(); } res *= 10; res += c - '0'; c = read(); } while (!isSpaceChar(c)); return res * sgn; } public boolean isSpaceChar(int c) { if (filter != null) { return filter.isSpaceChar(c); } return isWhitespace(c); } public static boolean isWhitespace(int c) { return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1; } public interface SpaceCharFilter { public boolean isSpaceChar(int ch); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
f3d243d60829e52d93f113d7de13f0b6
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.InputMismatchException; /** * Created by Wilson on * Feb. 08, 2021 */ public class HardMaxelementInteractive { public static void main(String[] args) { InputStream inputStream = System.in; OutputStream outputStream = System.out; InputReader in = new InputReader(inputStream); OutputWriter out = new OutputWriter(outputStream); CSearchingLocalMinimum solver = new CSearchingLocalMinimum(); solver.solve(in, out); out.close(); } static class CSearchingLocalMinimum { OutputWriter out; InputReader in; int query(int l,int r) { out.printLine("?", l+1,r+1); out.flush(); return in.readInt()-1; } void writeOutput(int ans) { out.printLine("!", ans); out.flush(); } public void solve(InputReader in, OutputWriter out) { this.out = out; this.in = in; int n = in.readInt(); if (n == 1) { writeOutput(1); return; } //The idea here is to use the first divide the array into 2 halfs //and checks which side of the array as the biggest element //1)if first side has it, query b/w mid and smax always changing l and //r, get the middle of l and r and then query for second largest b/w middle and smax(which is to the right) //since l side always gets mid whenever new query is equal to smax, then we return the //r whenever r-l <= 1 //2) if the second side has the biggest, always query between mid and smax (which is to left end of the // first accepted part) //here, r side always gets the mid whenever new query (mid, smax) returns value equal to smax //then we return l whenever r - l <= 1 int l,r,smax,mid,ans; l =1; r = n; smax = query(0, n - 1); if (smax == 0 || query(0, smax) != smax) { l = smax; r = n - 1; while (r - l > 1) { int m = (l + r) / 2; if (query(smax, m) == smax) { r = m; } else { l = m; } } writeOutput(r+1); } else { l = 0; r = smax; while (r - l > 1) { int m = (l + r) / 2; if (query(m, smax) == smax) { l = m; } else { r = m; } } writeOutput(l+1); } } } static class OutputWriter { private final PrintWriter writer; public OutputWriter(OutputStream outputStream) { writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream))); } public OutputWriter(Writer writer) { this.writer = new PrintWriter(writer); } public void print(Object... objects) { for (int i = 0; i < objects.length; i++) { if (i != 0) { writer.print(' '); } writer.print(objects[i]); } } public void printLine(Object... objects) { print(objects); writer.println(); } public void close() { writer.close(); } public void flush() { writer.flush(); } } static class InputReader { private InputStream stream; private byte[] buf = new byte[1024]; private int curChar; private int numChars; private SpaceCharFilter filter; public InputReader(InputStream stream) { this.stream = stream; } public int read() { if (numChars == -1) { throw new InputMismatchException(); } if (curChar >= numChars) { curChar = 0; try { numChars = stream.read(buf); } catch (IOException e) { throw new InputMismatchException(); } if (numChars <= 0) { return -1; } } return buf[curChar++]; } public int readInt() { int c = read(); while (isSpaceChar(c)) { c = read(); } int sgn = 1; if (c == '-') { sgn = -1; c = read(); } int res = 0; do { if (c < '0' || c > '9') { throw new InputMismatchException(); } res *= 10; res += c - '0'; c = read(); } while (!isSpaceChar(c)); return res * sgn; } public boolean isSpaceChar(int c) { if (filter != null) { return filter.isSpaceChar(c); } return isWhitespace(c); } public static boolean isWhitespace(int c) { return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1; } public interface SpaceCharFilter { public boolean isSpaceChar(int ch); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
c7a3521fb17ae796920708b5b8e0de04
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; import java.util.ArrayList; import java.util.Arrays.*; import static java.util.Collections.*; import static java.lang.Math.*; import static java.util.Arrays.*; public class cf { static final int SCAN_LINE_LENGTH = 100002; private static final boolean thread = false; @SuppressWarnings("all") static final boolean HAS_TEST_CASES = (1 == 0) ? true : false; static int n, a[], e[][], vis[], m, b[]; @SuppressWarnings("all") private static Vector<Integer> adj[], v = new Vector<>(); @SuppressWarnings("unchecked") static void solve() throws Exception { n = ni(); int a = -1, l = 1, r = n, m; m = get(l, r); if (m != l && m == get(l, m)) { r = m - 1; a = r; while (l <= r) { int mid = (l + 1 + r) / 2; if (r - l == 1) { a = (get(l, r) == l) ? r : l; break; } if (get(mid, m) == m) { a = mid; l = mid + 1; } else r = mid - 1; } } else { l = m + 1; a = l; while (l <= r) { int mid = (l + r) / 2; if (r - l == 1) { a = (get(l, r) == l) ? r : l; break; } if (get(m, mid) == m) { a = mid; r = mid - 1; } else l = mid + 1; } } pni("! " + a); } private static int get(int l, int r) throws IOException { int m; if (l >= r) return -1; pni("? " + l + " " + r); m = ni(); return m; } public static void main(final String[] args) throws Exception { if (!thread) { final int testcases = HAS_TEST_CASES ? ni() : 1; for (int i = 1; i <= testcases; i++) { // pni(i + " t"); // out.print("Case #" + (i + 1) + ": "); try { solve(); } catch (final Exception e) { // pni("idk Exception"); // e.printStackTrace(System.err); // System.exit(0); pni(i); throw e; } } out.flush(); } r.close(); out.close(); } @SuppressWarnings("all") private static final int MOD = (int) (1e9 + 7), MOD_FFT = 998244353; private static final Reader r = new Reader(); private static final PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out)); public static long[] enumPows(int a, int n, int mod) { a %= mod; long[] pows = new long[n + 1]; pows[0] = 1; for (int i = 1; i <= n; i++) pows[i] = pows[i - 1] * a % mod; return pows; } @SuppressWarnings("all") private static boolean eq(long a, long b) { return Long.compare(a, b) == 0; } @SuppressWarnings("all") private static ArrayList<Integer> seive(int n) { ArrayList<Integer> p = new ArrayList<>(); int[] f = new int[n + 1]; for (int i = 2; i <= n; i++) { if (f[i] == 1) continue; for (int j = i * i; j <= n && j < f.length; j += i) { f[j] = 1; } } for (int i = 2; i < f.length; i++) { if (f[i] == 0) p.add(i); } return p; } @SuppressWarnings("all") private static void s(int[] a) { Integer[] t = new Integer[a.length]; for (int i = 0; i < t.length; i++) { t[i] = a[i]; } sort(t); for (int i = 0; i < t.length; i++) { a[i] = t[i]; } } int pow(int a, int b, int m) { int ans = 1; while (b != 0) { if ((b & 1) != 0) ans = (ans * a) % m; b /= 2; a = (a * a) % m; } return ans; } int modinv(int k) { return pow(k, MOD - 2, MOD); } @SuppressWarnings("all") private static void swap(final int i, final int j) { final int temp = a[i]; a[i] = a[j]; a[j] = temp; } @SuppressWarnings("all") private static boolean isMulOverflow(final long A, final long B) { if (A == 0 || B == 0) return false; final long result = A * B; if (A == result / B) return true; return false; } @SuppressWarnings("all") private static int gcd(final int a, final int b) { if (b == 0) return a; return gcd(b, a % b); } @SuppressWarnings("all") private static long gcd(final long a, final long b) { if (b == 0) return a; return gcd(b, a % b); } @SuppressWarnings("all") private static class Pair<T, E> implements Comparable<Pair<T, E>> { T fir; E snd; Pair() { } Pair(final T x, final E y) { this.fir = x; this.snd = y; } // @Override // @SuppressWarnings("unchecked") // public int compareTo(final Pair<T, E> o) { // final int c = ((Comparable<T>) fir).compareTo(o.fir); // return c != 0 ? c : ((Comparable<E>) snd).compareTo(o.snd); // } @Override @SuppressWarnings("unchecked") public int compareTo(final Pair<T, E> o) { final int c = ((Comparable<T>) fir).compareTo(o.fir); return c; } } @SuppressWarnings("all") private static class pi implements Comparable<pi> { int fir, snd; pi() { } pi(final int a, final int b) { fir = a; snd = b; } public int compareTo(final pi o) { return fir == o.fir ? snd - o.snd : fir - o.fir; } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + fir; result = prime * result + snd; return result; } @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; pi other = (pi) obj; if (fir != other.fir) return false; if (snd != other.snd) return false; return true; } } @SuppressWarnings("all") private static <T> void checkV(final Vector<T> adj[], final int i) { adj[i] = adj[i] == null ? new Vector<>() : adj[i]; } @SuppressWarnings("all") private static int[] na(final int n) throws Exception { final int[] a = new int[n]; for (int i = 0; i < n; i++) { a[i] = ni(); } return a; } @SuppressWarnings("all") private static int[] na1(final int n) throws Exception { final int[] a = new int[n + 1]; for (int i = 1; i < a.length; i++) { a[i] = ni(); } return a; } @SuppressWarnings("all") private static String n() throws IOException { return r.readToken(); } @SuppressWarnings("all") private static char[] ns() throws IOException { return r.readToken().toCharArray(); } @SuppressWarnings("all") private static String nln() throws IOException { return r.readLine(); } private static int ni() throws IOException { return r.nextInt(); } @SuppressWarnings("all") private static long nl() throws IOException { return r.nextLong(); } @SuppressWarnings("all") private static double nd() throws IOException { return r.nextDouble(); } @SuppressWarnings("all") private static void p(final Object o) { out.print(o); } @SuppressWarnings("all") private static void pn(final Object o) { out.println(o); } @SuppressWarnings("all") private static void pn() { out.println(""); } @SuppressWarnings("all") private static void pi(final Object o) { out.print(o); out.flush(); } @SuppressWarnings("all") private static void pni() { out.println(""); out.flush(); } private static void pni(final Object o) { out.println(o); out.flush(); } private static class Reader { private final int BUFFER_SIZE = 1 << 17; private final DataInputStream din; private final byte[] buffer; private int bufferPointer, bytesRead; // private StringTokenizer st; public Reader() { din = new DataInputStream(System.in); buffer = new byte[BUFFER_SIZE]; bufferPointer = bytesRead = 0; } @SuppressWarnings("all") public Reader(final String file_name) throws IOException { din = new DataInputStream(new FileInputStream(file_name)); buffer = new byte[BUFFER_SIZE]; bufferPointer = bytesRead = 0; } final byte[] buf = new byte[SCAN_LINE_LENGTH]; public String readLine() throws IOException { int cnt = 0; int c; o: while ((c = read()) != -1) { if (c == '\n') if (cnt == 0) continue o; else break; buf[cnt++] = (byte) c; } return new String(buf, 0, cnt); } public String readToken() throws IOException { int cnt = 0; int c; o: while ((c = read()) != -1) { if (!(c >= 33 && c <= 126)) if (cnt == 0) continue o; else break; buf[cnt++] = (byte) c; } return new String(buf, 0, cnt); } public int nextInt() throws IOException { int ret = 0; byte c = read(); while (c <= ' ') c = read(); final boolean neg = (c == '-'); if (neg) c = read(); do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); if (neg) return -ret; return ret; } public long nextLong() throws IOException { long ret = 0; byte c = read(); while (c <= ' ') c = read(); final boolean neg = (c == '-'); if (neg) c = read(); do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); if (neg) return -ret; return ret; } public double nextDouble() throws IOException { double ret = 0, div = 1; byte c = read(); while (c <= ' ') c = read(); final boolean neg = (c == '-'); if (neg) c = read(); do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); if (c == '.') { while ((c = read()) >= '0' && c <= '9') { ret += (c - '0') / (div *= 10); } } if (neg) return -ret; return ret; } private void fillBuffer() throws IOException { bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); if (bytesRead == -1) buffer[0] = -1; } private byte read() throws IOException { if (bufferPointer == bytesRead) fillBuffer(); return buffer[bufferPointer++]; } public void close() throws IOException { if (din == null) return; din.close(); } } // static { // if (thread) // new Thread(null, new Runnable() { // @Override // public void run() { // try { // final int testcases = HAS_TEST_CASES ? ni() : 1; // for (int i = 1; i <= testcases; i++) { // // out.print("Case #" + (i + 1) + ": "); // try { // solve(); // } catch (final ArrayIndexOutOfBoundsException e) { // e.printStackTrace(System.err); // System.exit(-1); // } catch (final Exception e) { // pni("idk Exception in solve"); // e.printStackTrace(System.err); // System.exit(-1); // } // } // out.flush(); // } catch (final Throwable t) { // t.printStackTrace(System.err); // System.exit(-1); // } // } // }, "rec", (1L << 28)).start(); // } @SuppressWarnings({ "all", }) private static <T> T deepCopy(final T old) { try { return (T) deepCopyObject(old); } catch (final IOException | ClassNotFoundException e) { e.printStackTrace(System.err); System.exit(-1); } return null; } private static Object deepCopyObject(final Object oldObj) throws IOException, ClassNotFoundException { ObjectOutputStream oos = null; ObjectInputStream ois = null; try { final ByteArrayOutputStream bos = new ByteArrayOutputStream(); // A oos = new ObjectOutputStream(bos); // B // serialize and pass the object oos.writeObject(oldObj); // C oos.flush(); // D final ByteArrayInputStream bin = new ByteArrayInputStream(bos.toByteArray()); // E ois = new ObjectInputStream(bin); // F // return the new object return ois.readObject(); // G } catch (final ClassNotFoundException e) { pni("Exception in ObjectCloner = " + e); throw (e); } finally { oos.close(); ois.close(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
bd083abd3cc55978ef6d25985841a286
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class D { static class pair implements Comparable<pair> { int f; int s; double th; int id; public pair() { } public pair(int a, int b, int c) { f = a; s = b; th = (f * 1.00000) / (s * 1.00000); id = c; } @Override public int compareTo(pair o) { // TODO Auto-generated method stub if (this.th > o.th) return -1; if (this.th == o.th) { return this.s - o.s; } else return 1; } } static int mod = (int) 1e9 + 7; static int ar[]; static Scanner sc = new Scanner(System.in); static StringBuilder out = new StringBuilder(); static ArrayList<Integer> grEven[]; static ArrayList<Integer> grOdd[]; static void sort(int a[], int n) { ArrayList<Integer> al = new ArrayList<>(); for (int i = 0; i < n; i++) { al.add(a[i]); } Collections.sort(al); for (int i = 0; i < n; i++) { a[i] = al.get(i); } } static void in(int a[], int n) throws IOException { for (int i = 0; i < n; i++) a[i] = sc.nextInt(); } public static void main(String[] args) throws IOException { int t = 1;// sc.nextInt(); while (t-- > 0) { int n = sc.nextInt(); int l = 1; int r = n; int ans = 0; System.out.println("? " + l + " " + r); System.out.flush(); int max = sc.nextInt(); if (n == 2) { if (max == 1) System.out.println("! " + 2); else System.out.println("! " + 1); continue; } if (max == 1) { l = max + 1; } else if (max == r) { r = max - 1; } else { System.out.println("? " + l + " " + max); System.out.flush(); if (sc.nextInt() == max) { r = max - 1; } else { l = max + 1; } } int cnt = 2; if (max == l - 1) { cnt++; while (l <= r) { cnt++; int mid = (l + r) / 2; System.out.println("? " + max + " " + mid); System.out.flush(); int m1 = sc.nextInt(); if (m1 == max) { r = mid - 1; ans = mid; } else { l = mid + 1; } } } else { cnt++; while (l <= r) { int mid = (l + r) / 2; System.out.println("? " + mid + " " + max); System.out.flush(); int m1 = sc.nextInt(); if (m1 == max) { l = mid + 1; ans = mid; } else { r = mid - 1; } } } System.out.println("! " + ans); } System.out.println(out); } // static Reader sc=new Reader(); static class Reader { final private int BUFFER_SIZE = 1 << 16; private DataInputStream din; private byte[] buffer; private int bufferPointer, bytesRead; public Reader() { din = new DataInputStream(System.in); buffer = new byte[BUFFER_SIZE]; bufferPointer = bytesRead = 0; } public Reader(String file_name) throws IOException { din = new DataInputStream(new FileInputStream(file_name)); buffer = new byte[BUFFER_SIZE]; bufferPointer = bytesRead = 0; } public String readLine() throws IOException { byte[] buf = new byte[64]; // line length int cnt = 0, c; while ((c = read()) != -1) { if (c == '\n') break; buf[cnt++] = (byte) c; } return new String(buf, 0, cnt); } public int nextInt() throws IOException { int ret = 0; byte c = read(); while (c <= ' ') c = read(); boolean neg = (c == '-'); if (neg) c = read(); do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); if (neg) return -ret; return ret; } public long nextLong() throws IOException { long ret = 0; byte c = read(); while (c <= ' ') c = read(); boolean neg = (c == '-'); if (neg) c = read(); do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); if (neg) return -ret; return ret; } public double nextDouble() throws IOException { double ret = 0, div = 1; byte c = read(); while (c <= ' ') c = read(); boolean neg = (c == '-'); if (neg) c = read(); do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); if (c == '.') { while ((c = read()) >= '0' && c <= '9') { ret += (c - '0') / (div *= 10); } } if (neg) return -ret; return ret; } private void fillBuffer() throws IOException { bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); if (bytesRead == -1) buffer[0] = -1; } private byte read() throws IOException { if (bufferPointer == bytesRead) fillBuffer(); return buffer[bufferPointer++]; } public void close() throws IOException { if (din == null) return; din.close(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
578ffe72772b0bc07ad3decea248b234
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.OutputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintStream; import java.io.OutputStream; import java.io.PrintWriter; import java.io.BufferedWriter; import java.io.IOException; import java.io.InputStreamReader; import java.util.StringTokenizer; import java.io.Writer; import java.io.OutputStreamWriter; import java.io.BufferedReader; import java.io.InputStream; /** * Built using CHelper plug-in * Actual solution is at the top */ public class Main { public static void main(String[] args) { InputStream inputStream = System.in; OutputStream outputStream = System.out; InputReader in = new InputReader(inputStream); OutputWriter out = new OutputWriter(outputStream); C2GuessingTheGreatestHardVersion solver = new C2GuessingTheGreatestHardVersion(); solver.solve(1, in, out); out.close(); } static class C2GuessingTheGreatestHardVersion { public void solve(int testNumber, InputReader in, OutputWriter out) { int n = in.nextInt(); int smax = q(0, n - 1, in); int ans = 0; if (smax > 0 && q(0, smax, in) == smax) { int lo = 0, hi = smax - 1; ans = lo; while (lo <= hi) { int mid = (lo + hi) / 2; if (q(mid, smax, in) == smax) { ans = mid; lo = mid + 1; } else { hi = mid - 1; } } } else { int lo = smax + 1; int hi = n - 1; ans = hi; while (lo <= hi) { int mid = (lo + hi) / 2; if (q(smax, mid, in) != smax) { lo = mid + 1; } else { ans = mid; hi = mid - 1; } } } System.out.println("! " + (ans + 1)); } int q(int l, int r, InputReader in) { System.out.println("? " + (l + 1) + " " + (r + 1)); return in.nextInt() - 1; } } static class InputReader { BufferedReader reader; StringTokenizer tokenizer; public InputReader(InputStream stream) { reader = new BufferedReader(new InputStreamReader(stream), 32768); tokenizer = null; } public String next() { while (tokenizer == null || !tokenizer.hasMoreTokens()) { try { tokenizer = new StringTokenizer(reader.readLine()); } catch (IOException e) { throw new RuntimeException(e); } } return tokenizer.nextToken(); } public int nextInt() { return Integer.parseInt(next()); } } static class OutputWriter { private final PrintWriter writer; public OutputWriter(OutputStream outputStream) { writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream))); } public OutputWriter(Writer writer) { this.writer = new PrintWriter(writer); } public void close() { writer.close(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
18d24cf15a7c7c9657eb8278c9b3f6f1
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import static java.lang.Math.max; import static java.lang.Math.min; import static java.lang.Math.abs; import java.util.*; import java.io.*; import java.math.*; public class Template { public static void main(String[] args) throws Exception{ BufferedReader infile = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(infile.readLine()); int N = Integer.parseInt(st.nextToken()); System.out.println("? 1 " + N); System.out.flush(); int secondLarge = Integer.parseInt(infile.readLine()); int ans = 0; if(secondLarge > 1) { // check left then System.out.println("? 1 " + secondLarge); System.out.flush(); int index = Integer.parseInt(infile.readLine()); if(index == secondLarge) { // definitely we check left one int start = 1; int end = secondLarge- 1; while(start < end) { int mid = (start+end+1)/2; System.out.println("? " + mid + " " + secondLarge); System.out.flush(); index = Integer.parseInt(infile.readLine()); if(index == secondLarge) { start = mid; } else { end = mid-1; } } ans = start; } } if(ans == 0 && secondLarge < N) { // then go for right int start = secondLarge+1; int end = N; while(start < end) { int mid = (start+end)/2; System.out.println("? " + secondLarge + " " + mid); System.out.flush(); int index = Integer.parseInt(infile.readLine()); if(index == secondLarge) { end = mid; } else { start = mid+1; } } ans = start; } System.out.println("! " + ans); System.out.flush(); } public static int[] readArr(int N, BufferedReader infile, StringTokenizer st) throws Exception { int[] arr = new int[N]; st = new StringTokenizer(infile.readLine()); for(int i=0; i < N; i++) arr[i] = Integer.parseInt(st.nextToken()); return arr; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
cc04fde564a68607817d3d9398fd6239
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import static java.lang.Math.max; import static java.lang.Math.min; import static java.lang.Math.abs; import java.util.*; import java.io.*; import java.math.*; public class Template { public static void main(String[] args) throws Exception{ BufferedReader infile = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(infile.readLine()); int N = Integer.parseInt(st.nextToken()); System.out.println("? 1 " + N); System.out.flush(); int middle = Integer.parseInt(infile.readLine()); int res = 0; // check on left if(middle > 1) { System.out.println("? 1 " + middle); System.out.flush(); int index = Integer.parseInt(infile.readLine()); if(index == middle) { int start = 1; int end = middle-1; while(start != end) { int mid = (start+end+1)/2; System.out.println("? " + mid + " " + middle); System.out.flush(); index = Integer.parseInt(infile.readLine()); if(index == middle) { start = mid; } else { end = mid-1; } } res = start; } } // otherwise check on right if(res == 0 && middle < N) { int start = middle+1; int end = N; while(start != end) { int mid = (start+end)/2; System.out.println("? " + middle + " " + mid); System.out.flush(); int index = Integer.parseInt(infile.readLine()); if(index == middle) { end = mid; } else { start = mid+1; } } res = start; } System.out.println("! " + res); System.out.flush(); } public static int[] readArr(int N, BufferedReader infile, StringTokenizer st) throws Exception { int[] arr = new int[N]; st = new StringTokenizer(infile.readLine()); for(int i=0; i < N; i++) arr[i] = Integer.parseInt(st.nextToken()); return arr; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
31dda17ff565bc6bde6c603fb7e38deb
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.StringTokenizer; import java.util.Arrays; import java.util.Random; import java.io.FileWriter; import java.io.PrintWriter; /* Solution Created: 19:43:18 18/02/2021 Custom Competitive programming helper. */ public class Main { public static void solve() { int n = in.nextInt(); int second = ask(1, n); boolean left = second!=1 && (ask(1,second)==second); int ans; if(left){ int l = 1, r = second-1; ans = second-1; while(l<=r){ int md = (l+r)/2; if(ask(md, second)==second){ ans = md; l = md+1; }else r = md-1; } }else{ int l = second+1, r = n; ans = second+1; while(l<=r){ int md = (l+r)/2; if(ask(second, md)==second){ ans = md; r = md-1; }else l = md+1; } } found(ans); } static int ask(int l, int r){ out.println("? "+l+" "+r); out.flush(); return in.nextInt(); } static void found(int i){ out.println("! "+i); out.flush(); } public static void main(String[] args) { in = new Reader(); out = new Writer(); int t = 1; while(t-->0) solve(); out.exit(); } static Reader in; static Writer out; static class Reader { static BufferedReader br; static StringTokenizer st; public Reader() { this.br = new BufferedReader(new InputStreamReader(System.in)); } public Reader(String f){ try { this.br = new BufferedReader(new FileReader(f)); } catch (IOException e) { e.printStackTrace(); } } public int[] na(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } public double[] nd(int n) { double[] a = new double[n]; for (int i = 0; i < n; i++) a[i] = nextDouble(); return a; } public long[] nl(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nextLong(); return a; } public char[] nca() { return next().toCharArray(); } public String[] ns(int n) { String[] a = new String[n]; for (int i = 0; i < n; i++) a[i] = next(); return a; } public int nextInt() { ensureNext(); return Integer.parseInt(st.nextToken()); } public double nextDouble() { ensureNext(); return Double.parseDouble(st.nextToken()); } public Long nextLong() { ensureNext(); return Long.parseLong(st.nextToken()); } public String next() { ensureNext(); return st.nextToken(); } public String nextLine() { try { return br.readLine(); } catch (Exception e) { e.printStackTrace(); return null; } } private void ensureNext() { if (st == null || !st.hasMoreTokens()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } } } static class Util{ private static Random random = new Random(); static long[] fact; public static void initFactorial(int n, long mod) { fact = new long[n+1]; fact[0] = 1; for (int i = 1; i < n+1; i++) fact[i] = (fact[i - 1] * i) % mod; } public static long modInverse(long a, long MOD) { long[] gcdE = gcdExtended(a, MOD); if (gcdE[0] != 1) return -1; // Inverted doesn't exist long x = gcdE[1]; return (x % MOD + MOD) % MOD; } public static long[] gcdExtended(long p, long q) { if (q == 0) return new long[] { p, 1, 0 }; long[] vals = gcdExtended(q, p % q); long tmp = vals[2]; vals[2] = vals[1] - (p / q) * vals[2]; vals[1] = tmp; return vals; } public static long nCr(int n, int r, long MOD) { if (r == 0) return 1; return (fact[n] * modInverse(fact[r], MOD) % MOD * modInverse(fact[n - r], MOD) % MOD) % MOD; } public static long nCr(int n, int r) { return (fact[n]/fact[r])/fact[n-r]; } public static long nPr(int n, int r, long MOD) { if (r == 0) return 1; return (fact[n] * modInverse(fact[n - r], MOD) % MOD) % MOD; } public static long nPr(int n, int r) { return fact[n]/fact[n-r]; } public static boolean isPrime(int n) { if (n <= 1) return false; if (n <= 3) return true; if (n % 2 == 0 || n % 3 == 0) return false; for (int i = 5; i * i <= n; i = i + 6) if (n % i == 0 || n % (i + 2) == 0) return false; return true; } public static boolean[] getSieve(int n) { boolean[] isPrime = new boolean[n+1]; for (int i = 2; i <= n; i++) isPrime[i] = true; for (int i = 2; i*i <= n; i++) if (isPrime[i]) for (int j = i; i*j <= n; j++) isPrime[i*j] = false; return isPrime; } public static int gcd(int a, int b) { int tmp = 0; while(b != 0) { tmp = b; b = a%b; a = tmp; } return a; } public static long gcd(long a, long b) { long tmp = 0; while(b != 0) { tmp = b; b = a%b; a = tmp; } return a; } public static int random(int min, int max) { return random.nextInt(max-min+1)+min; } public static void dbg(Object... o) { System.out.println(Arrays.deepToString(o)); } public static void reverse(int[] s, int l , int r) { for(int i = l; i<=(l+r)/2; i++) { int tmp = s[i]; s[i] = s[r+l-i]; s[r+l-i] = tmp; } } public static void reverse(int[] s) { reverse(s, 0, s.length-1); } public static void reverse(long[] s, int l , int r) { for(int i = l; i<=(l+r)/2; i++) { long tmp = s[i]; s[i] = s[r+l-i]; s[r+l-i] = tmp; } } public static void reverse(long[] s) { reverse(s, 0, s.length-1); } public static void reverse(float[] s, int l , int r) { for(int i = l; i<=(l+r)/2; i++) { float tmp = s[i]; s[i] = s[r+l-i]; s[r+l-i] = tmp; } } public static void reverse(float[] s) { reverse(s, 0, s.length-1); } public static void reverse(double[] s, int l , int r) { for(int i = l; i<=(l+r)/2; i++) { double tmp = s[i]; s[i] = s[r+l-i]; s[r+l-i] = tmp; } } public static void reverse(double[] s) { reverse(s, 0, s.length-1); } public static void reverse(char[] s, int l , int r) { for(int i = l; i<=(l+r)/2; i++) { char tmp = s[i]; s[i] = s[r+l-i]; s[r+l-i] = tmp; } } public static void reverse(char[] s) { reverse(s, 0, s.length-1); } public static <T> void reverse(T[] s, int l , int r) { for(int i = l; i<=(l+r)/2; i++) { T tmp = s[i]; s[i] = s[r+l-i]; s[r+l-i] = tmp; } } public static <T> void reverse(T[] s) { reverse(s, 0, s.length-1); } public static void shuffle(int[] s) { for (int i = 0; i < s.length; ++i) { int j = random.nextInt(i + 1); int t = s[i]; s[i] = s[j]; s[j] = t; } } public static void shuffle(long[] s) { for (int i = 0; i < s.length; ++i) { int j = random.nextInt(i + 1); long t = s[i]; s[i] = s[j]; s[j] = t; } } public static void shuffle(float[] s) { for (int i = 0; i < s.length; ++i) { int j = random.nextInt(i + 1); float t = s[i]; s[i] = s[j]; s[j] = t; } } public static void shuffle(double[] s) { for (int i = 0; i < s.length; ++i) { int j = random.nextInt(i + 1); double t = s[i]; s[i] = s[j]; s[j] = t; } } public static void shuffle(char[] s) { for (int i = 0; i < s.length; ++i) { int j = random.nextInt(i + 1); char t = s[i]; s[i] = s[j]; s[j] = t; } } public static <T> void shuffle(T[] s) { for (int i = 0; i < s.length; ++i) { int j = random.nextInt(i + 1); T t = s[i]; s[i] = s[j]; s[j] = t; } } public static void sortArray(int[] a) { shuffle(a); Arrays.sort(a); } public static void sortArray(long[] a) { shuffle(a); Arrays.sort(a); } public static void sortArray(float[] a) { shuffle(a); Arrays.sort(a); } public static void sortArray(double[] a) { shuffle(a); Arrays.sort(a); } public static void sortArray(char[] a) { shuffle(a); Arrays.sort(a); } public static <T extends Comparable<T>> void sortArray(T[] a) { Arrays.sort(a); } } static class Writer { private PrintWriter pw; public Writer(){ pw = new PrintWriter(System.out); } public Writer(String f){ try { pw = new PrintWriter(new FileWriter(f)); } catch (IOException e) { e.printStackTrace(); } } public void printArray(int[] a) { for(int i = 0; i<a.length; i++) print(a[i]+" "); } public void printlnArray(int[] a) { for(int i = 0; i<a.length; i++) print(a[i]+" "); pw.println(); } public void printArray(long[] a) { for(int i = 0; i<a.length; i++) print(a[i]+" "); } public void printlnArray(long[] a) { for(int i = 0; i<a.length; i++) print(a[i]+" "); pw.println(); } public void print(Object o) { pw.print(o.toString()); } public void println(Object o) { pw.println(o.toString()); } public void println() { pw.println(); } public void flush() { pw.flush(); } public void exit() { pw.close(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
626161a2cf0dbc556602229d4a8e92ee
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.awt.*; import java.io.*; import java.util.*; import java.util.List; public class Hell { public static void main(String[] args) throws Exception { FastReader sc = new FastReader(); int n=sc.nextInt(); System.out.println("? 1 "+n); System.out.flush(); int x=sc.nextInt(); boolean f=false; if (x!=1) { f=true; System.out.println("? 1 " + x); } System.out.flush(); int newX=-1; if (f) newX = sc.nextInt(); if (newX==x){ int l=1, r=x; int ans=-1; while (l<=r){ int m=(l+r)/2; if (m==x){ System.out.println("! "+(m-1)); System.out.flush(); return; } System.out.println("? "+m+" "+x); System.out.flush(); newX=sc.nextInt(); if (newX==x){ ans=m; l=m+1; }else { r=m-1; } } System.out.println("! "+(ans)); System.out.flush(); }else { int r=n,l=x; int ans=-1; while (l<=r){ int m=(l+r)/2; if (m==x){ System.out.println("! "+(m+1)); System.out.flush(); return; } System.out.println("? "+x+" "+m); System.out.flush(); newX=sc.nextInt(); if (newX==x){ r=m-1; }else { l=m+1; } } System.out.println("! "+(l)); System.out.flush(); } } public static long maximumArea(int arr[]){ int n=arr.length; long suf[]=new long[n]; suf[n-1]=arr[n-1]; for (int i=n-2;i>=0;i--){ suf[i]=arr[i]*(n-i); } for(int i=n-2;i>=0;i--){ suf[i]=Math.max(suf[i], suf[i+1]); } long ans=0; for (int i=0;i<n-1;i++){ ans=Math.max((long) arr[i]*(i+1)+suf[i+1], ans); } return ans; } public static int[] itemsCollected(int t[]){ int n = t.length; int i=0, j=n-1; long sumi=0, sumj=0; while (i<=j){ while (i<=j && sumi<=sumj){ sumi+=t[i]; i++; } while (i<=j && sumi>sumj){ sumj+=t[j]; j--; } } return new int[]{i, n-j-1}; } public static long minimumCost(int c[], int q[]){ PriorityQueue<Point> pq=new PriorityQueue<Point>(new Comparator<Point>() { @Override public int compare(Point o1, Point o2) { return o1.c-o2.c; } }); int n=c.length; long ans=0; for (int i=0;i<n;i++){ pq.add(new Point(c[i], q[i])); Point pop=pq.poll(); ans+=pop.c; if (pop.q-1==0)continue; pq.add(new Point(pop.c, pop.q-1)); } return ans; } static class Point{ int c, q; Point(int c, int q){ this.c=c; this.q=q; } } static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
b89bcd2c6131f19217c4762746a623a6
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.HashSet; import java.util.Random; import java.util.Stack; import java.util.StringTokenizer; import java.util.TreeMap; // CFPS -> CodeForcesProblemSet public final class CFPS { static FastReader fr = new FastReader(); static PrintWriter out = new PrintWriter(System.out); static final int gigamod = 1000000007; static final int mod = 998244353; static int t = 1; static double epsilon = 0.00000001; static boolean[] isPrime; static int[] smallestFactorOf; @SuppressWarnings("unused") public static void main(String[] args) { OUTER: for (int tc = 0; tc < t; tc++) { int n = fr.nextInt(); // Observations: // 1. The task is to determine the maximum element from the array using the // queries. int smIdx = query(0, n - 1); // first, we will find out whether the element lies on the left side or on the // right int lqsmIdx = -54; if (smIdx != 0) lqsmIdx = query(0, smIdx); if (lqsmIdx == smIdx) { // [0, smIdx] contains the largest element // we will use binary search to find the largest index, the exclusion // of which, changes smIdx int lo = 0, hi = smIdx - 2; int largest = -1; while (lo <= hi) { int mid = lo + (hi - lo) / 2; // mid will be excluded // [mid + 1, smIdx] is the range int qsmIdx = query(mid + 1, smIdx); if (qsmIdx == smIdx) { // largest is not excluded yet, at mid // we will exclude some larger idx lo = mid + 1; } else { // largest got excluded at mid, it lies // to the left of mid hi = mid - 1; largest = mid; } } if (largest != -1) out.println("! " + ++largest); else out.println("! " + (smIdx)); } else { // [smIdx + 1, n - 1] contains the largest element int lo = smIdx + 2, hi = n - 1; int largest = n; while (lo <= hi) { int mid = lo + (hi - lo) / 2; // mid will be excluded // [smIdx, mid - 1] is the range int qsmIdx = query(smIdx, mid - 1); if (qsmIdx == smIdx) { // largest is not excluded yet hi = mid - 1; } else { lo = mid + 1; largest = mid; } } if (largest != n) out.println("! " + ++largest); else out.println("! " + (smIdx + 2)); } } out.close(); } static int query(int l, int r) { out.println("? " + (l + 1) + " " + (r + 1)); out.flush(); return fr.nextInt() - 1; } static class LCA { int[] height, first, segtree; ArrayList<Integer> euler; boolean[] visited; int n; LCA(UGraph ug, int root) { n = ug.V(); height = new int[n]; first = new int[n]; euler = new ArrayList<>(); visited = new boolean[n]; dfs(ug, root, 0); int m = euler.size(); segtree = new int[m * 4]; build(1, 0, m - 1); } void dfs(UGraph ug, int node, int h) { visited[node] = true; height[node] = h; first[node] = euler.size(); euler.add(node); for (int adj : ug.adj(node)) { if (!visited[adj]) { dfs(ug, adj, h + 1); euler.add(node); } } } void build(int node, int b, int e) { if (b == e) { segtree[node] = euler.get(b); } else { int mid = (b + e) / 2; build(node << 1, b, mid); build(node << 1 | 1, mid + 1, e); int l = segtree[node << 1], r = segtree[node << 1 | 1]; segtree[node] = (height[l] < height[r]) ? l : r; } } int query(int node, int b, int e, int L, int R) { if (b > R || e < L) return -1; if (b >= L && e <= R) return segtree[node]; int mid = (b + e) >> 1; int left = query(node << 1, b, mid, L, R); int right = query(node << 1 | 1, mid + 1, e, L, R); if (left == -1) return right; if (right == -1) return left; return height[left] < height[right] ? left : right; } int lca(int u, int v) { int left = first[u], right = first[v]; if (left > right) { int temp = left; left = right; right = temp; } return query(1, 0, euler.size() - 1, left, right); } } static class FenwickTree { long[] array; // 1-indexed array, In this array We save cumulative information to perform efficient range queries and updates public FenwickTree(int size) { array = new long[size + 1]; } public long rsq(int ind) { assert ind > 0; long sum = 0; while (ind > 0) { sum += array[ind]; //Extracting the portion up to the first significant one of the binary representation of 'ind' and decrementing ind by that number ind -= ind & (-ind); } return sum; } public long rsq(int a, int b) { assert b >= a && a > 0 && b > 0; return rsq(b) - rsq(a - 1); } public void update(int ind, long value) { assert ind > 0; while (ind < array.length) { array[ind] += value; //Extracting the portion up to the first significant one of the binary representation of 'ind' and incrementing ind by that number ind += ind & (-ind); } } public int size() { return array.length - 1; } } static boolean[] prefMatchesSuff(char[] s) { int n = s.length; boolean[] res = new boolean[n + 1]; int[] pi = prefixFunction(s); res[0] = true; for (int p = n; p != 0; p = pi[p]) res[p] = true; return res; } static int[] prefixFunction(char[] s) { int k = s.length; int[] pfunc = new int[k + 1]; pfunc[0] = pfunc[1] = 0; for (int i = 2; i <= k; i++) { pfunc[i] = 0; for (int p = pfunc[i - 1]; p != 0; p = pfunc[p]) if (s[p] == s[i - 1]) { pfunc[i] = p + 1; break; } if (pfunc[i] == 0 && s[i - 1] == s[0]) pfunc[i] = 1; } return pfunc; } static class Edge implements Comparable<Edge> { int from, to; long weight; int id; // int hash; Edge(int fro, int t, long weigh, int i) { from = fro; to = t; weight = weigh; id = i; // hash = Objects.hash(from, to, weight); } /*public int hashCode() { return hash; }*/ public int compareTo(Edge that) { return Long.compare(this.id, that.id); } } public static long[][] sparseTable(long[] a) { int n = a.length; int b = 32-Integer.numberOfLeadingZeros(n); long[][] ret = new long[b][]; for(int i = 0, l = 1;i < b;i++, l*=2) { if(i == 0) { ret[i] = a; }else { ret[i] = new long[n-l+1]; for(int j = 0;j < n-l+1;j++) { ret[i][j] = Math.min(ret[i-1][j], ret[i-1][j+l/2]); } } } return ret; } public static long sparseRMQ(long[][] table, int l, int r) { // [a,b) assert l <= r; if(l >= r)return Integer.MAX_VALUE; // 1:0, 2:1, 3:1, 4:2, 5:2, 6:2, 7:2, 8:3 int t = 31-Integer.numberOfLeadingZeros(r-l); return Math.min(table[t][l], table[t][r-(1<<t)]); } static class Point implements Comparable<Point> { long x; long y; long z; long id; // private int hashCode; Point() { x = z = y = 0; // this.hashCode = Objects.hash(x, y, cost); } Point(Point p) { this.x = p.x; this.y = p.y; this.z = p.z; this.id = p.id; // this.hashCode = Objects.hash(x, y, cost); } Point(long x, long y, long z, long id) { this.x = x; this.y = y; this.z = z; this.id = id; // this.hashCode = Objects.hash(x, y, id); } Point(long a, long b) { this.x = a; this.y = b; this.z = 0; // this.hashCode = Objects.hash(a, b); } Point(long x, long y, long id) { this.x = x; this.y = y; this.id = id; } @Override public int compareTo(Point o) { if (this.x < o.x) return -1; if (this.x > o.x) return 1; if (this.y < o.y) return -1; if (this.y > o.y) return 1; if (this.z < o.z) return -1; if (this.z > o.z) return 1; return 0; } @Override public boolean equals(Object that) { return this.compareTo((Point) that) == 0; } /*@Override public int hashCode() { return this.hashCode; }*/ } static class BinaryLift { // FUNCTIONS: k-th ancestor and LCA in log(n) int[] parentOf; int maxJmpPow; int[][] binAncestorOf; int n; int[] lvlOf; // How this works? // a. For every node, we store the b-ancestor for b in {1, 2, 4, 8, .. log(n)}. // b. When we need k-ancestor, we represent 'k' in binary and for each set bit, we // lift level in the tree. public BinaryLift(UGraph tree) { n = tree.V(); maxJmpPow = logk(n, 2) + 1; parentOf = new int[n]; binAncestorOf = new int[n][maxJmpPow]; lvlOf = new int[n]; for (int i = 0; i < n; i++) Arrays.fill(binAncestorOf[i], -1); parentConstruct(0, -1, tree, 0); binConstruct(); } // TODO: Implement lvlOf[] initialization public BinaryLift(int[] parentOf) { this.parentOf = parentOf; n = parentOf.length; maxJmpPow = logk(n, 2) + 1; binAncestorOf = new int[n][maxJmpPow]; lvlOf = new int[n]; for (int i = 0; i < n; i++) Arrays.fill(binAncestorOf[i], -1); UGraph tree = new UGraph(n); for (int i = 1; i < n; i++) tree.addEdge(i, parentOf[i]); binConstruct(); parentConstruct(0, -1, tree, 0); } private void parentConstruct(int current, int from, UGraph tree, int depth) { parentOf[current] = from; lvlOf[current] = depth; for (int adj : tree.adj(current)) if (adj != from) parentConstruct(adj, current, tree, depth + 1); } private void binConstruct() { for (int node = 0; node < n; node++) for (int lvl = 0; lvl < maxJmpPow; lvl++) binConstruct(node, lvl); } private int binConstruct(int node, int lvl) { if (node < 0) return -1; if (lvl == 0) return binAncestorOf[node][lvl] = parentOf[node]; if (node == 0) return binAncestorOf[node][lvl] = -1; if (binAncestorOf[node][lvl] != -1) return binAncestorOf[node][lvl]; return binAncestorOf[node][lvl] = binConstruct(binConstruct(node, lvl - 1), lvl - 1); } // return ancestor which is 'k' levels above this one public int ancestor(int node, int k) { if (node < 0) return -1; if (node == 0) if (k == 0) return node; else return -1; if (k > (1 << maxJmpPow) - 1) return -1; if (k == 0) return node; int ancestor = node; int highestBit = Integer.highestOneBit(k); while (k > 0 && ancestor != -1) { ancestor = binAncestorOf[ancestor][logk(highestBit, 2)]; k -= highestBit; highestBit = Integer.highestOneBit(k); } return ancestor; } public int lca(int u, int v) { if (u == v) return u; // The invariant will be that 'u' is below 'v' initially. if (lvlOf[u] < lvlOf[v]) { int temp = u; u = v; v = temp; } // Equalizing the levels. u = ancestor(u, lvlOf[u] - lvlOf[v]); if (u == v) return u; // We will now raise level by largest fitting power of two until possible. for (int power = maxJmpPow - 1; power > -1; power--) if (binAncestorOf[u][power] != binAncestorOf[v][power]) { u = binAncestorOf[u][power]; v = binAncestorOf[v][power]; } return ancestor(u, 1); } } static class DFSTree { // NOTE: The thing is made keeping in mind that the whole // input graph is connected. UGraph tree; UGraph backUG; int hasBridge; int n; DFSTree(UGraph ug) { this.n = ug.V(); tree = new UGraph(n); hasBridge = -1; backUG = new UGraph(n); treeCalc(0, -1, new boolean[n], ug); } private void treeCalc(int current, int from, boolean[] marked, UGraph ug) { if (marked[current]) { // This is a backEdge. backUG.addEdge(from, current); return; } if (from != -1) tree.addEdge(from, current); marked[current] = true; for (int adj : ug.adj(current)) if (adj != from) treeCalc(adj, current, marked, ug); } public boolean hasBridge() { if (hasBridge != -1) return (hasBridge == 1); // We have to determine the bridge. bridgeFinder(); return (hasBridge == 1); } int[] levelOf; int[] dp; private void bridgeFinder() { // Finding the level of each node. levelOf = new int[n]; // Applying DP solution. // dp[i] -> Highest level reachable from subtree of 'i' using // some backEdge. dp = new int[n]; Arrays.fill(dp, Integer.MAX_VALUE / 100); dpDFS(0, -1, 0); // Now, we will check each edge and determine whether its a // bridge. for (int i = 0; i < n; i++) for (int adj : tree.adj(i)) { // (i -> adj) is the edge. if (dp[adj] > levelOf[i]) hasBridge = 1; } if (hasBridge != 1) hasBridge = 0; } private int dpDFS(int current, int from, int lvl) { levelOf[current] = lvl; dp[current] = levelOf[current]; for (int back : backUG.adj(current)) dp[current] = Math.min(dp[current], levelOf[back]); for (int adj : tree.adj(current)) if (adj != from) dp[current] = Math.min(dp[current], dpDFS(adj, current, lvl + 1)); return dp[current]; } } static class UnionFind { // Uses weighted quick-union with path compression. private int[] parent; // parent[i] = parent of i private int[] size; // size[i] = number of sites in tree rooted at i // Note: not necessarily correct if i is not a root node private int count; // number of components public UnionFind(int n) { count = n; parent = new int[n]; size = new int[n]; for (int i = 0; i < n; i++) { parent[i] = i; size[i] = 1; } } // Number of connected components. public int count() { return count; } // Find the root of p. public int find(int p) { while (p != parent[p]) p = parent[p]; return p; } public boolean connected(int p, int q) { return find(p) == find(q); } public int numConnectedTo(int node) { return size[find(node)]; } // Weighted union. public void union(int p, int q) { int rootP = find(p); int rootQ = find(q); if (rootP == rootQ) return; // make smaller root point to larger one if (size[rootP] < size[rootQ]) { parent[rootP] = rootQ; size[rootQ] += size[rootP]; } else { parent[rootQ] = rootP; size[rootP] += size[rootQ]; } count--; } public static int[] connectedComponents(UnionFind uf) { // We can do this in nlogn. int n = uf.size.length; int[] compoColors = new int[n]; for (int i = 0; i < n; i++) compoColors[i] = uf.find(i); HashMap<Integer, Integer> oldToNew = new HashMap<>(); int newCtr = 0; for (int i = 0; i < n; i++) { int thisOldColor = compoColors[i]; Integer thisNewColor = oldToNew.get(thisOldColor); if (thisNewColor == null) thisNewColor = newCtr++; oldToNew.put(thisOldColor, thisNewColor); compoColors[i] = thisNewColor; } return compoColors; } } static class UGraph { // Adjacency list. private HashSet<Integer>[] adj; private static final String NEWLINE = "\n"; private int E; @SuppressWarnings("unchecked") public UGraph(int V) { adj = (HashSet<Integer>[]) new HashSet[V]; E = 0; for (int i = 0; i < V; i++) adj[i] = new HashSet<Integer>(); } public void addEdge(int from, int to) { if (adj[from].contains(to)) return; E++; adj[from].add(to); adj[to].add(from); } public HashSet<Integer> adj(int from) { return adj[from]; } public int degree(int v) { return adj[v].size(); } public int V() { return adj.length; } public int E() { return E; } public String toString() { StringBuilder s = new StringBuilder(); s.append(V() + " vertices, " + E() + " edges " + NEWLINE); for (int v = 0; v < V(); v++) { s.append(v + ": "); for (int w : adj[v]) { s.append(w + " "); } s.append(NEWLINE); } return s.toString(); } public static void dfsMark(int current, boolean[] marked, UGraph g) { if (marked[current]) return; marked[current] = true; Iterable<Integer> adj = g.adj(current); for (int adjc : adj) dfsMark(adjc, marked, g); } public static void dfsMark(int current, int from, long[] distTo, boolean[] marked, UGraph g, ArrayList<Integer> endPoints) { if (marked[current]) return; marked[current] = true; if (from != -1) distTo[current] = distTo[from] + 1; HashSet<Integer> adj = g.adj(current); int alreadyMarkedCtr = 0; for (int adjc : adj) { if (marked[adjc]) alreadyMarkedCtr++; dfsMark(adjc, current, distTo, marked, g, endPoints); } if (alreadyMarkedCtr == adj.size()) endPoints.add(current); } public static void bfsOrder(int current, UGraph g) { } public static void dfsMark(int current, int[] colorIds, int color, UGraph g) { if (colorIds[current] != -1) return; colorIds[current] = color; Iterable<Integer> adj = g.adj(current); for (int adjc : adj) dfsMark(adjc, colorIds, color, g); } public static int[] connectedComponents(UGraph g) { int n = g.V(); int[] componentId = new int[n]; Arrays.fill(componentId, -1); int colorCtr = 0; for (int i = 0; i < n; i++) { if (componentId[i] != -1) continue; dfsMark(i, componentId, colorCtr, g); colorCtr++; } return componentId; } public static boolean hasCycle(UGraph ug) { int n = ug.V(); boolean[] marked = new boolean[n]; boolean[] hasCycleFirst = new boolean[1]; for (int i = 0; i < n; i++) { if (marked[i]) continue; hcDfsMark(i, ug, marked, hasCycleFirst, -1); } return hasCycleFirst[0]; } // Helper for hasCycle. private static void hcDfsMark(int current, UGraph ug, boolean[] marked, boolean[] hasCycleFirst, int parent) { if (marked[current]) return; if (hasCycleFirst[0]) return; marked[current] = true; HashSet<Integer> adjc = ug.adj(current); for (int adj : adjc) { if (marked[adj] && adj != parent && parent != -1) { hasCycleFirst[0] = true; return; } hcDfsMark(adj, ug, marked, hasCycleFirst, current); } } } static class Digraph { // Adjacency list. private HashSet<Integer>[] adj; private static final String NEWLINE = "\n"; private int E; @SuppressWarnings("unchecked") public Digraph(int V) { adj = (HashSet<Integer>[]) new HashSet[V]; E = 0; for (int i = 0; i < V; i++) adj[i] = new HashSet<Integer>(); } public void addEdge(int from, int to) { if (adj[from].contains(to)) return; E++; adj[from].add(to); } public HashSet<Integer> adj(int from) { return adj[from]; } public int V() { return adj.length; } public int E() { return E; } public Digraph reversed() { Digraph dg = new Digraph(V()); for (int i = 0; i < V(); i++) for (int adjVert : adj(i)) dg.addEdge(adjVert, i); return dg; } public String toString() { StringBuilder s = new StringBuilder(); s.append(V() + " vertices, " + E() + " edges " + NEWLINE); for (int v = 0; v < V(); v++) { s.append(v + ": "); for (int w : adj[v]) { s.append(w + " "); } s.append(NEWLINE); } return s.toString(); } public static int[] KosarajuSharirSCC(Digraph dg) { int[] id = new int[dg.V()]; Digraph reversed = dg.reversed(); // Gotta perform topological sort on this one to get the stack. Stack<Integer> revStack = Digraph.topologicalSort(reversed); // Initializing id and idCtr. id = new int[dg.V()]; int idCtr = -1; // Creating a 'marked' array. boolean[] marked = new boolean[dg.V()]; while (!revStack.isEmpty()) { int vertex = revStack.pop(); if (!marked[vertex]) sccDFS(dg, vertex, marked, ++idCtr, id); } return id; } private static void sccDFS(Digraph dg, int source, boolean[] marked, int idCtr, int[] id) { marked[source] = true; id[source] = idCtr; for (Integer adjVertex : dg.adj(source)) if (!marked[adjVertex]) sccDFS(dg, adjVertex, marked, idCtr, id); } public static Stack<Integer> topologicalSort(Digraph dg) { // dg has to be a directed acyclic graph. // We'll have to run dfs on the digraph and push the deepest nodes on stack first. // We'll need a Stack<Integer> and a int[] marked. Stack<Integer> topologicalStack = new Stack<Integer>(); boolean[] marked = new boolean[dg.V()]; // Calling dfs for (int i = 0; i < dg.V(); i++) if (!marked[i]) runDfs(dg, topologicalStack, marked, i); return topologicalStack; } static void runDfs(Digraph dg, Stack<Integer> topologicalStack, boolean[] marked, int source) { marked[source] = true; for (Integer adjVertex : dg.adj(source)) if (!marked[adjVertex]) runDfs(dg, topologicalStack, marked, adjVertex); topologicalStack.add(source); } } static class FastReader { private BufferedReader bfr; private StringTokenizer st; public FastReader() { bfr = new BufferedReader(new InputStreamReader(System.in)); } String next() { if (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(bfr.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } char nextChar() { return next().toCharArray()[0]; } String nextString() { return next(); } int[] nextIntArray(int n) { int[] arr = new int[n]; for (int i = 0; i < n; i++) arr[i] = nextInt(); return arr; } double[] nextDoubleArray(int n) { double[] arr = new double[n]; for (int i = 0; i < arr.length; i++) arr[i] = nextDouble(); return arr; } long[] nextLongArray(int n) { long[] arr = new long[n]; for (int i = 0; i < n; i++) arr[i] = nextLong(); return arr; } int[][] nextIntGrid(int n, int m) { int[][] grid = new int[n][m]; for (int i = 0; i < n; i++) { for (int j = 0; j < m; j++) grid[i][j] = fr.nextInt(); } return grid; } } static class SegmentTree { private Node[] heap; private long[] array; private int size; public SegmentTree(long[] array) { this.array = Arrays.copyOf(array, array.length); //The max size of this array is about 2 * 2 ^ log2(n) + 1 size = (int) (2 * Math.pow(2.0, Math.floor((Math.log((double) array.length) / Math.log(2.0)) + 1))); heap = new Node[size]; build(1, 0, array.length); } public int size() { return array.length; } //Initialize the Nodes of the Segment tree private void build(int v, int from, int size) { heap[v] = new Node(); heap[v].from = from; heap[v].to = from + size - 1; if (size == 1) { heap[v].sum = array[from]; heap[v].min = array[from]; heap[v].max = array[from]; } else { //Build childs build(2 * v, from, size / 2); build(2 * v + 1, from + size / 2, size - size / 2); heap[v].sum = heap[2 * v].sum + heap[2 * v + 1].sum; //min = min of the children heap[v].min = Math.min(heap[2 * v].min, heap[2 * v + 1].min); heap[v].max = Math.max(heap[2 * v].max, heap[2 * v + 1].max); } } public long rsq(int from, int to) { return rsq(1, from, to); } private long rsq(int v, int from, int to) { Node n = heap[v]; //If you did a range update that contained this node, you can infer the Sum without going down the tree if (n.pendingVal != null && contains(n.from, n.to, from, to)) { return (to - from + 1) * n.pendingVal; } if (contains(from, to, n.from, n.to)) { return heap[v].sum; } if (intersects(from, to, n.from, n.to)) { propagate(v); long leftSum = rsq(2 * v, from, to); long rightSum = rsq(2 * v + 1, from, to); return leftSum + rightSum; } return 0; } public long rMinQ(int from, int to) { return rMinQ(1, from, to); } private long rMinQ(int v, int from, int to) { Node n = heap[v]; //If you did a range update that contained this node, you can infer the Min value without going down the tree if (n.pendingVal != null && contains(n.from, n.to, from, to)) { return n.pendingVal; } if (contains(from, to, n.from, n.to)) { return heap[v].min; } if (intersects(from, to, n.from, n.to)) { propagate(v); long leftMin = rMinQ(2 * v, from, to); long rightMin = rMinQ(2 * v + 1, from, to); return Math.min(leftMin, rightMin); } return Integer.MAX_VALUE; } public long rMaxQ(int from, int to) { return rMaxQ(1, from, to); } private long rMaxQ(int v, int from, int to) { Node n = heap[v]; //If you did a range update that contained this node, you can infer the Min value without going down the tree if (n.pendingVal != null && contains(n.from, n.to, from, to)) { return n.pendingVal; } if (contains(from, to, n.from, n.to)) { return heap[v].max; } if (intersects(from, to, n.from, n.to)) { propagate(v); long leftMax = rMaxQ(2 * v, from, to); long rightMax = rMaxQ(2 * v + 1, from, to); return Math.max(leftMax, rightMax); } return Integer.MIN_VALUE; } public void update(int from, int to, long value) { update(1, from, to, value); } private void update(int v, int from, int to, long value) { //The Node of the heap tree represents a range of the array with bounds: [n.from, n.to] Node n = heap[v]; if (contains(from, to, n.from, n.to)) { change(n, value); } if (n.size() == 1) return; if (intersects(from, to, n.from, n.to)) { propagate(v); update(2 * v, from, to, value); update(2 * v + 1, from, to, value); n.sum = heap[2 * v].sum + heap[2 * v + 1].sum; n.min = Math.min(heap[2 * v].min, heap[2 * v + 1].min); n.max = Math.max(heap[2 * v].max, heap[2 * v + 1].max); } } //Propagate temporal values to children private void propagate(int v) { Node n = heap[v]; if (n.pendingVal != null) { change(heap[2 * v], n.pendingVal); change(heap[2 * v + 1], n.pendingVal); n.pendingVal = null; //unset the pending propagation value } } //Save the temporal values that will be propagated lazily private void change(Node n, long value) { n.pendingVal = value; n.sum = n.size() * value; n.min = value; n.max = value; array[n.from] = value; } //Test if the range1 contains range2 private boolean contains(int from1, int to1, int from2, int to2) { return from2 >= from1 && to2 <= to1; } //check inclusive intersection, test if range1[from1, to1] intersects range2[from2, to2] private boolean intersects(int from1, int to1, int from2, int to2) { return from1 <= from2 && to1 >= from2 // (.[..)..] or (.[...]..) || from1 >= from2 && from1 <= to2; // [.(..]..) or [..(..).. } //The Node class represents a partition range of the array. static class Node { long sum; long min; long max; //Here we store the value that will be propagated lazily Long pendingVal = null; int from; int to; int size() { return to - from + 1; } } } @SuppressWarnings("serial") static class CountMap<T> extends TreeMap<T, Integer>{ CountMap() { } CountMap(T[] arr) { this.putCM(arr); } public Integer putCM(T key) { return super.put(key, super.getOrDefault(key, 0) + 1); } public Integer removeCM(T key) { int count = super.getOrDefault(key, -1); if (count == -1) return -1; if (count == 1) return super.remove(key); else return super.put(key, count - 1); } public Integer getCM(T key) { return super.getOrDefault(key, 0); } public void putCM(T[] arr) { for (T l : arr) this.putCM(l); } } static long dioGCD(long a, long b, long[] x0, long[] y0) { if (b == 0) { x0[0] = 1; y0[0] = 0; return a; } long[] x1 = new long[1], y1 = new long[1]; long d = dioGCD(b, a % b, x1, y1); x0[0] = y1[0]; y0[0] = x1[0] - y1[0] * (a / b); return d; } static boolean diophantine(long a, long b, long c, long[] x0, long[] y0, long[] g) { g[0] = dioGCD(Math.abs(a), Math.abs(b), x0, y0); if (c % g[0] > 0) { return false; } x0[0] *= c / g[0]; y0[0] *= c / g[0]; if (a < 0) x0[0] = -x0[0]; if (b < 0) y0[0] = -y0[0]; return true; } static long[][] prod(long[][] mat1, long[][] mat2) { int n = mat1.length; long[][] prod = new long[n][n]; for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) // determining prod[i][j] // it will be the dot product of mat1[i][] and mat2[][i] for (int k = 0; k < n; k++) prod[i][j] += mat1[i][k] * mat2[k][j]; return prod; } static long[][] matExpo(long[][] mat, long power) { int n = mat.length; long[][] ans = new long[n][n]; if (power == 0) return null; if (power == 1) return mat; long[][] half = matExpo(mat, power / 2); ans = prod(half, half); if (power % 2 == 1) { ans = prod(ans, mat); } return ans; } static int KMPNumOcc(char[] text, char[] pat) { int n = text.length; int m = pat.length; char[] patPlusText = new char[n + m + 1]; for (int i = 0; i < m; i++) patPlusText[i] = pat[i]; patPlusText[m] = '^'; // Seperator for (int i = 0; i < n; i++) patPlusText[m + i] = text[i]; int[] fullPi = piCalcKMP(patPlusText); int answer = 0; for (int i = 0; i < n + m + 1; i++) if (fullPi[i] == m) answer++; return answer; } static int[] piCalcKMP(char[] s) { int n = s.length; int[] pi = new int[n]; for (int i = 1; i < n; i++) { int j = pi[i - 1]; while (j > 0 && s[i] != s[j]) j = pi[j - 1]; if (s[i] == s[j]) j++; pi[i] = j; } return pi; } static long hash(long key) { long h = Long.hashCode(key); h ^= (h >>> 20) ^ (h >>> 12) ^ (h >>> 7) ^ (h >>> 4); return h & (gigamod-1); } static int mapTo1D(int row, int col, int n, int m) { // Maps elements in a 2D matrix serially to elements in // a 1D array. return row * m + col; } static int[] mapTo2D(int idx, int n, int m) { // Inverse of what the one above does. int[] rnc = new int[2]; rnc[0] = idx / m; rnc[1] = idx % m; return rnc; } static boolean[] primeGenerator(int upto) { // Sieve of Eratosthenes: isPrime = new boolean[upto + 1]; smallestFactorOf = new int[upto + 1]; Arrays.fill(smallestFactorOf, 1); Arrays.fill(isPrime, true); isPrime[1] = isPrime[0] = false; for (long i = 2; i < upto + 1; i++) if (isPrime[(int) i]) { smallestFactorOf[(int) i] = (int) i; // Mark all the multiples greater than or equal // to the square of i to be false. for (long j = i; j * i < upto + 1; j++) { if (isPrime[(int) j * (int) i]) { isPrime[(int) j * (int) i] = false; smallestFactorOf[(int) j * (int) i] = (int) i; } } } return isPrime; } static HashMap<Integer, Integer> smolNumPrimeFactorization(int num) { if (smallestFactorOf == null) primeGenerator(num + 1); HashMap<Integer, Integer> fnps = new HashMap<>(); while (num != 1) { fnps.put(smallestFactorOf[num], fnps.getOrDefault(smallestFactorOf[num], 0) + 1); num /= smallestFactorOf[num]; } return fnps; } static HashMap<Long, Integer> primeFactorization(long num) { // Returns map of factor and its power in the number. HashMap<Long, Integer> map = new HashMap<>(); while (num % 2 == 0) { num /= 2; Integer pwrCnt = map.get(2L); map.put(2L, pwrCnt != null ? pwrCnt + 1 : 1); } for (long i = 3; i * i <= num; i += 2) { while (num % i == 0) { num /= i; Integer pwrCnt = map.get(i); map.put(i, pwrCnt != null ? pwrCnt + 1 : 1); } } // If the number is prime, we have to add it to the // map. if (num != 1) map.put(num, 1); return map; } static HashSet<Long> divisors(long num) { HashSet<Long> divisors = new HashSet<Long>(); divisors.add(1L); divisors.add(num); for (long i = 2; i * i <= num; i++) { if (num % i == 0) { divisors.add(num/i); divisors.add(i); } } return divisors; } static void coprimeGenerator(int m, int n, ArrayList<Point> coprimes, int limit, int numCoprimes) { if (m > limit) return; if (m <= limit && n <= limit) coprimes.add(new Point(m, n)); if (coprimes.size() > numCoprimes) return; coprimeGenerator(2 * m - n, m, coprimes, limit, numCoprimes); coprimeGenerator(2 * m + n, m, coprimes, limit, numCoprimes); coprimeGenerator(m + 2 * n, n, coprimes, limit, numCoprimes); } static int bsearch(int[] arr, int val, int lo, int hi) { // Returns the index of the first element // larger than or equal to val. int idx = -1; while (lo <= hi) { int mid = lo + (hi - lo)/2; if (arr[mid] >= val) { idx = mid; hi = mid - 1; } else lo = mid + 1; } return idx; } static int bsearch(long[] arr, long val, int lo, int hi) { // Returns the index of the first element // larger than or equal to val. int idx = -1; while (lo <= hi) { int mid = lo + (hi - lo)/2; if (arr[mid] >= val) { idx = mid; hi = mid - 1; } else lo = mid + 1; } return idx; } static int bsearch(long[] arr, long val, int lo, int hi, boolean sMode) { // Returns the index of the last element // smaller than or equal to val. int idx = -1; while (lo <= hi) { int mid = lo + (hi - lo)/2; if (arr[mid] > val) { hi = mid - 1; } else { idx = mid; lo = mid + 1; } } return idx; } static int bsearch(int[] arr, long val, int lo, int hi, boolean sMode) { int idx = -1; while (lo <= hi) { int mid = lo + (hi - lo)/2; if (arr[mid] > val) { hi = mid - 1; } else { idx = mid; lo = mid + 1; } } return idx; } static long nCr(long n, long r, long[] fac) { long p = mod; if (r == 0) return 1; return (fac[(int)n] * modInverse(fac[(int)r], p) % p * modInverse(fac[(int)n - (int)r], p) % p) % p; } static long modInverse(long n, long p) { return power(n, p - 2, p); } static long modDiv(long a, long b){return mod(a * power(b, gigamod - 2, gigamod));} static long power(long x, long y, long p) { long res = 1; x = x % p; while (y > 0) { if ((y & 1)==1) res = (res * x) % p; y = y >> 1; x = (x * x) % p; } return res; } static int logk(long n, long k) { return (int)(Math.log(n) / Math.log(k)); } static long gcd(long a, long b) { if (b == 0) { return a; } else { return gcd(b, a % b); } } static int gcd(int a, int b) { if (b == 0) { return a; } else { return gcd(b, a % b); } } static long gcd(long[] arr) { int n = arr.length; long gcd = arr[0]; for (int i = 1; i < n; i++) { gcd = gcd(gcd, arr[i]); } return gcd; } static int gcd(int[] arr) { int n = arr.length; int gcd = arr[0]; for (int i = 1; i < n; i++) { gcd = gcd(gcd, arr[i]); } return gcd; } static long lcm(long[] arr) { long lcm = arr[0]; int n = arr.length; for (int i = 1; i < n; i++) { lcm = (lcm * arr[i]) / gcd(lcm, arr[i]); } return lcm; } static long lcm(long a, long b) { return (a * b)/gcd(a, b); } static boolean less(int a, int b) { return a < b ? true : false; } static boolean isSorted(int[] a) { for (int i = 1; i < a.length; i++) { if (less(a[i], a[i - 1])) return false; } return true; } static boolean isSorted(long[] a) { for (int i = 1; i < a.length; i++) { if (a[i] < a[i - 1]) return false; } return true; } static void swap(int[] a, int i, int j) { int temp = a[i]; a[i] = a[j]; a[j] = temp; } static void swap(long[] a, int i, int j) { long temp = a[i]; a[i] = a[j]; a[j] = temp; } static void swap(double[] a, int i, int j) { double temp = a[i]; a[i] = a[j]; a[j] = temp; } static void swap(char[] a, int i, int j) { char temp = a[i]; a[i] = a[j]; a[j] = temp; } static void sort(int[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); } static void sort(char[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); } static void sort(long[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); } static void sort(double[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); } static void reverseSort(int[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); int n = arr.length; for (int i = 0; i < n/2; i++) swap(arr, i, n - 1 - i); } static void reverseSort(char[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); int n = arr.length; for (int i = 0; i < n/2; i++) swap(arr, i, n - 1 - i); } static void reverse(char[] arr) { int n = arr.length; for (int i = 0; i < n / 2; i++) swap(arr, i, n - 1 - i); } static void reverseSort(long[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); int n = arr.length; for (int i = 0; i < n/2; i++) swap(arr, i, n - 1 - i); } static void reverseSort(double[] arr) { shuffleArray(arr, 0, arr.length - 1); Arrays.sort(arr); int n = arr.length; for (int i = 0; i < n/2; i++) swap(arr, i, n - 1 - i); } static void shuffleArray(long[] arr, int startPos, int endPos) { Random rnd = new Random(); for (int i = startPos; i < endPos; ++i) { long tmp = arr[i]; int randomPos = i + rnd.nextInt(endPos - i); arr[i] = arr[randomPos]; arr[randomPos] = tmp; } } static void shuffleArray(int[] arr, int startPos, int endPos) { Random rnd = new Random(); for (int i = startPos; i < endPos; ++i) { int tmp = arr[i]; int randomPos = i + rnd.nextInt(endPos - i); arr[i] = arr[randomPos]; arr[randomPos] = tmp; } } static void shuffleArray(double[] arr, int startPos, int endPos) { Random rnd = new Random(); for (int i = startPos; i < endPos; ++i) { double tmp = arr[i]; int randomPos = i + rnd.nextInt(endPos - i); arr[i] = arr[randomPos]; arr[randomPos] = tmp; } } static void shuffleArray(char[] arr, int startPos, int endPos) { Random rnd = new Random(); for (int i = startPos; i < endPos; ++i) { char tmp = arr[i]; int randomPos = i + rnd.nextInt(endPos - i); arr[i] = arr[randomPos]; arr[randomPos] = tmp; } } static boolean isPrime(long n) {if (n<=1)return false;if(n<=3)return true;if(n%2==0||n%3==0)return false;for(long i=5;i*i<=n;i=i+6)if(n%i==0||n%(i+2)==0)return false;return true;} static String toString(int[] dp){StringBuilder sb=new StringBuilder();for(int i=0;i<dp.length;i++)sb.append(dp[i]+" ");return sb.toString();} static String toString(boolean[] dp){StringBuilder sb=new StringBuilder();for(int i=0;i<dp.length;i++)sb.append(dp[i]+" ");return sb.toString();} static String toString(long[] dp){StringBuilder sb=new StringBuilder();for(int i=0;i<dp.length;i++)sb.append(dp[i]+" ");return sb.toString();} static String toString(char[] dp){StringBuilder sb=new StringBuilder();for(int i=0;i<dp.length;i++)sb.append(dp[i]+"");return sb.toString();} static String toString(int[][] dp){StringBuilder sb=new StringBuilder();for(int i=0;i<dp.length;i++){for(int j=0;j<dp[i].length;j++){sb.append(dp[i][j]+" ");}sb.append('\n');}return sb.toString();} static String toString(long[][] dp){StringBuilder sb=new StringBuilder();for(int i=0;i<dp.length;i++){for(int j=0;j<dp[i].length;j++) {sb.append(dp[i][j]+" ");}sb.append('\n');}return sb.toString();} static String toString(double[][] dp){StringBuilder sb=new StringBuilder();for(int i = 0;i<dp.length;i++){for(int j = 0;j<dp[i].length;j++){sb.append(dp[i][j]+" ");}sb.append('\n');}return sb.toString();} static String toString(char[][] dp){StringBuilder sb = new StringBuilder();for(int i = 0;i<dp.length;i++){for(int j = 0;j<dp[i].length;j++){sb.append(dp[i][j]+"");}sb.append('\n');}return sb.toString();} static long mod(long a, long m){return(a%m+1000000L*m)%m;} static long mod(long num){return(num%gigamod+gigamod)%gigamod;} } // NOTES: // ASCII VALUE OF 'A': 65 // ASCII VALUE OF 'a': 97 // Range of long: 9 * 10^18 // ASCII VALUE OF '0': 48 // Primes upto 'n' can be given by (n / (logn)).
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
786a8ea4dc2913466f380e5e45b70231
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class Codeforces { public static void main(String[] args) throws IOException { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); //int cases = Integer.parseInt(br.readLine()); //o:while(cases-- > 0) { String[] str = br.readLine().split(" "); int n = Integer.parseInt(str[0]); int h2 = q(1, n); int left = 1; int right = h2; boolean isleft = true; if(h2 == 1 || q(1, h2) != h2) { isleft = false; left = h2; right = n; } while(isleft && left+1 < right) { int mid = left + (right - left)/2; int rep = q(Math.min(mid, h2), Math.max(mid, h2)); if(rep == h2) { left = mid; }else { right = mid; } } while(!isleft && left+1 < right) { int mid = left + (right - left)/2; int rep = q(Math.min(mid, h2), Math.max(mid, h2)); if(rep == h2) { right = mid; }else { left = mid; } } if(isleft) { System.out.println("! "+left); }else{ System.out.println("! "+right); } //} } public static int q(int left, int right) throws IOException{ System.out.println("? "+left+" "+right); System.out.flush(); BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); int reply = Integer.parseInt(br.readLine()); return reply; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
3a4ac6df4d35c6d94daaa8e1b43d7415
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.DataInputStream; import java.io.IOException; import java.io.OutputStreamWriter; import java.io.PrintWriter; import java.util.Arrays; import java.util.Map; import java.util.TreeMap; public class Main { private static void run() throws IOException { int n = in.nextInt(); // TreeMap<Double, Integer> map = new TreeMap<>(); // for (int i = 1; i <= n; i++) { // map.put(Math.random(), i); // } // a = new int[n]; // int index = 0; // for (Map.Entry<Double, Integer> now : map.entrySet()) { // a[index++] = now.getValue(); // } //// print_array(a); // System.err.flush(); query_with_second(1, n, query(1, n)); } private static void query_with_second(int left, int right, int second) throws IOException { if (left == right) { out.printf("! %d \n", left); out.flush(); // check(left); return; } int mid = (left + right) >> 1; if (second <= mid) { int query_left = query(Math.min(left, second), mid); if (query_left == second) { query_with_second(left, mid, second); } else { query_with_second(mid + 1, right, second); } } else { int query_right = query(mid + 1, Math.max(right, second)); if (query_right == second) { query_with_second(mid + 1, right, second); } else { query_with_second(left, mid, second); } } } // static int[] a; // static int count = 0; // // private static void check(int ans) { // int[] tmp = new int[a.length]; // System.arraycopy(a, 0, tmp, 0, a.length); // Arrays.sort(tmp); // System.err.println(tmp[a.length - 1] + " " + a[ans - 1] + " " + (tmp[a.length - 1] == a[ans - 1])); // System.err.println("count: " + count); // System.err.flush(); // if (tmp[a.length - 1] != a[ans - 1] || count > 20) { // System.exit(0); // } // // count = 0; // } private static int query(int left, int right) throws IOException { if (left == right) return -1; out.printf("? %d %d\n", left, right); out.flush(); return in.nextInt(); // count++; // int[] tmp = new int[right - left + 1]; // for (int i = 0; i < right - left + 1; i++) { // tmp[i] = a[left + i - 1]; // } // Arrays.sort(tmp); // for (int i = left; i <= right; i++) { // if (a[i - 1] == tmp[right - left - 1]) { // System.err.println("input: " + i); // System.err.flush(); // return i; // } // } // System.err.println("input error"); // System.err.flush(); // throw new RuntimeException(); } public static void main(String[] args) throws IOException { in = new Reader(); out = new PrintWriter(new OutputStreamWriter(System.out)); // int t = in.nextInt(); // for (int i = 0; i < t; i++) { // } run(); out.flush(); in.close(); out.close(); } private static int gcd(int a, int b) { if (a == 0 || b == 0) return 0; while (b != 0) { int tmp; tmp = a % b; a = b; b = tmp; } return a; } static final long mod = 1000000007; static long pow_mod(long a, long b) { long result = 1; while (b != 0) { if ((b & 1) != 0) result = (result * a) % mod; a = (a * a) % mod; b >>= 1; } return result; } private static long multiplied_mod(long... longs) { long ans = 1; for (long now : longs) { ans = (ans * now) % mod; } return ans; } @SuppressWarnings("FieldCanBeLocal") private static Reader in; private static PrintWriter out; private static void print_array(int[] array) { for (int now : array) { System.err.print(now); System.err.print(' '); } System.err.println(); } private static void print_array(long[] array) { for (long now : array) { out.print(now); out.print(' '); } out.println(); } static class Reader { private static final int BUFFER_SIZE = 1 << 16; private final DataInputStream din; private final byte[] buffer; private int bufferPointer, bytesRead; Reader() { din = new DataInputStream(System.in); buffer = new byte[BUFFER_SIZE]; bufferPointer = bytesRead = 0; } public String readLine() throws IOException { final byte[] buf = new byte[1024]; // line length int cnt = 0, c; while ((c = read()) != -1) { if (c == '\n') { break; } buf[cnt++] = (byte) c; } return new String(buf, 0, cnt); } public int nextSign() throws IOException { byte c = read(); while ('+' != c && '-' != c) { c = read(); } return '+' == c ? 0 : 1; } private static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); } public int skip() throws IOException { int b; // noinspection ALL while ((b = read()) != -1 && isSpaceChar(b)) { ; } return b; } public char nc() throws IOException { return (char) skip(); } public String next() throws IOException { int b = skip(); final StringBuilder sb = new StringBuilder(); while (!isSpaceChar(b)) { // when nextLine, (isSpaceChar(b) && b != ' ') sb.appendCodePoint(b); b = read(); } return sb.toString(); } public int nextInt() throws IOException { int ret = 0; byte c = read(); while (c <= ' ') { c = read(); } final boolean neg = c == '-'; if (neg) { c = read(); } do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); if (neg) { return -ret; } return ret; } public long nextLong() throws IOException { long ret = 0; byte c = read(); while (c <= ' ') { c = read(); } final boolean neg = c == '-'; if (neg) { c = read(); } do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); if (neg) { return -ret; } return ret; } public double nextDouble() throws IOException { double ret = 0, div = 1; byte c = read(); while (c <= ' ') { c = read(); } final boolean neg = c == '-'; if (neg) { c = read(); } do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); if (c == '.') { while ((c = read()) >= '0' && c <= '9') { ret += (c - '0') / (div *= 10); } } if (neg) { return -ret; } return ret; } private void fillBuffer() throws IOException { bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); if (bytesRead == -1) { buffer[0] = -1; } } private byte read() throws IOException { if (bufferPointer == bytesRead) { fillBuffer(); } return buffer[bufferPointer++]; } public void close() throws IOException { din.close(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
2da146aef2fe1ac1b76d4b98d7005856
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; @SuppressWarnings("unchecked") public class GuessingTheGreatestHard implements Runnable { void solve() throws IOException { int l = 1, h = read.intNext(); int dmax = ask(l, h); if (ask(l, dmax) == dmax) { h = dmax; while (h - l > 1) { int m = (l + h) / 2; if (ask(m, dmax) == dmax) { l = m; } else { h = m; } } int q = ask(l, h); if (q == h) { println("! " + l); } else { println("! " + h); } } else { l = dmax; while (h - l > 1) { int m = (l + h) / 2; if (ask(dmax, m) == dmax) { h = m; } else { l = m; } } int q = ask(l, h); if (q == h) { println("! " + l); } else { println("! " + h); } } } int ask(int l, int h) throws IOException { if (l >= h) return -1; System.out.println("? " + l + " " + h); return read.intNext(); } /************************************************************************************************************************************************/ public static void main(String[] args) throws IOException { new Thread(null, new GuessingTheGreatestHard(), "1").start(); } static PrintWriter out = new PrintWriter(System.out); static Reader read = new Reader(); static StringBuilder sbr = new StringBuilder(); static int mod = (int) 1e9 + 7; static int dmax = Integer.MAX_VALUE; static long lmax = Long.MAX_VALUE; static int dmin = Integer.MIN_VALUE; static long lmin = Long.MIN_VALUE; @Override public void run() { try { solve(); out.close(); } catch (IOException e) { e.printStackTrace(); System.exit(1); } } static class Reader { private byte[] buf = new byte[1024]; private int index; private InputStream in; private int total; public Reader() { in = System.in; } public int scan() throws IOException { if (total < 0) throw new InputMismatchException(); if (index >= total) { index = 0; total = in.read(buf); if (total <= 0) return -1; } return buf[index++]; } public int intNext() throws IOException { int integer = 0; int n = scan(); while (isWhiteSpace(n)) n = scan(); int neg = 1; if (n == '-') { neg = -1; n = scan(); } while (!isWhiteSpace(n)) { if (n >= '0' && n <= '9') { integer *= 10; integer += n - '0'; n = scan(); } else throw new InputMismatchException(); } return neg * integer; } public double doubleNext() throws IOException { double doub = 0; int n = scan(); while (isWhiteSpace(n)) n = scan(); int neg = 1; if (n == '-') { neg = -1; n = scan(); } while (!isWhiteSpace(n) && n != '.') { if (n >= '0' && n <= '9') { doub *= 10; doub += n - '0'; n = scan(); } else throw new InputMismatchException(); } if (n == '.') { n = scan(); double temp = 1; while (!isWhiteSpace(n)) { if (n >= '0' && n <= '9') { temp /= 10; doub += (n - '0') * temp; n = scan(); } else throw new InputMismatchException(); } } return doub * neg; } public String read() throws IOException { StringBuilder sb = new StringBuilder(); int n = scan(); while (isWhiteSpace(n)) n = scan(); while (!isWhiteSpace(n)) { sb.append((char) n); n = scan(); } return sb.toString(); } private boolean isWhiteSpace(int n) { if (n == ' ' || n == '\n' || n == '\r' || n == '\t' || n == -1) return true; return false; } } static void shuffle(int[] aa) { int n = aa.length; Random rand = new Random(); for (int i = 1; i < n; i++) { int j = rand.nextInt(i + 1); int tmp = aa[i]; aa[i] = aa[j]; aa[j] = tmp; } } static void shuffle(int[][] aa) { int n = aa.length; Random rand = new Random(); for (int i = 1; i < n; i++) { int j = rand.nextInt(i + 1); int first = aa[i][0]; int second = aa[i][1]; aa[i][0] = aa[j][0]; aa[i][1] = aa[j][1]; aa[j][0] = first; aa[j][1] = second; } } static final class Comparators { public static final Comparator<int[]> pairIntArr = (x, y) -> x[0] == y[0] ? compare(x[1], y[1]) : compare(x[0], y[0]); private static final int compare(final int x, final int y) { return Integer.compare(x, y); } } static void print(Object object) { out.print(object); } static void println(Object object) { out.println(object); } static int[] iArr(int len) { return new int[len]; } static long[] lArr(int len) { return new long[len]; } static long min(long a, long b) { return Math.min(a, b); } static int min(int a, int b) { return Math.min(a, b); } static long max(Long a, Long b) { return Math.max(a, b); } static int max(int a, int b) { return Math.max(a, b); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
07f5fcd77f5ad1f37d35d530924ff0cb
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; public class C2 { public static class FastIO { BufferedReader br; BufferedWriter bw, be; StringTokenizer st; public FastIO() { br = new BufferedReader(new InputStreamReader(System.in)); bw = new BufferedWriter(new OutputStreamWriter(System.out)); be = new BufferedWriter(new OutputStreamWriter(System.err)); st = new StringTokenizer(""); } private void read() throws IOException { st = new StringTokenizer(br.readLine()); } public String ns() throws IOException { while(!st.hasMoreTokens()) read(); return st.nextToken(); } public int ni() throws IOException { return Integer.parseInt(ns()); } public long nl() throws IOException { return Long.parseLong(ns()); } public float nf() throws IOException { return Float.parseFloat(ns()); } public double nd() throws IOException { return Double.parseDouble(ns()); } public char nc() throws IOException { return ns().charAt(0); } public int[] nia(int n) throws IOException { int[] a = new int[n]; for(int i = 0; i < n; i++) a[i] = ni(); return a; } public long[] nla(int n) throws IOException { long[] a = new long[n]; for(int i = 0; i < n; i++) a[i] = nl(); return a; } public char[] nca() throws IOException { return f.ns().toCharArray(); } public void out(String s) throws IOException { bw.write(s); bw.flush(); } public void flush() throws IOException { bw.flush(); be.flush(); } public void err(String s) throws IOException { be.write(s); be.flush(); } } static class Pair { int a, b; Pair(int x, int y) { a = x; b = y; } public int hashCode() { return a^b; } public boolean equals(Object obj) { Pair that = (Pair)obj; return a == that.a && b == that.b; } } static FastIO f; static HashMap<Pair, Integer> h; public static void main(String args[]) throws IOException { f = new FastIO(); int n, ans, smax; h = new HashMap<>(); n = f.ni(); smax = getSMax(1, n); ans = (n == 2) ? (smax == 1) ? 2 : 1 : (smax == 1 || (smax != n && smax == getSMax(smax, n))) ? getRB(smax+1, n, smax) : getLB(1, smax-1, smax); f.out("! " + ans + "\n"); } public static int getLB(int s, int e, int sm) throws IOException { if(e == s) return s; if(e == s+1) return (getSMax(e, sm) == sm) ? e : s; int mid = s + (e-s)/2; int s1 = getSMax(mid+1, sm); if(s1 == sm) return getLB(mid+1, e, sm); return getLB(s, mid, sm); } public static int getRB(int s, int e, int sm) throws IOException { if(e == s) return s; if(e == s+1) return (getSMax(sm, s) == sm) ? s : e; int mid = s + (e-s)/2; int s1 = getSMax(sm, mid); if(s1 == sm) return getRB(s, mid, sm); return getRB(mid+1, e, sm); } public static int getMax(int l, int r, int sm) throws IOException { if(r == l+1) return (sm == l) ? r : l; if(r == l+2) { int a = getMax(l, l+1, getSMax(l, l+1)), b = getMax(l+1, r, getSMax(l+1, r)); return (a == b || b == sm) ? a : b; } int mid = l + (r-l)/2; if(sm <= mid) { int sm1 = getSMax(l, mid); if(sm1 == sm) return getMax(l, mid, sm1); return getMax(mid+1, r, getSMax(mid+1, r)); } else { int sm2 = getSMax(mid+1, r); if(sm2 == sm) return getMax(mid+1, r, sm2); return getMax(l, mid, getSMax(l, mid)); } } public static int getSMax(int l, int r) throws IOException { Pair p = new Pair(l, r); if(h.containsKey(p)) return h.get(p); f.out("? " + l + " " + r + "\n"); int ans = f.ni(); h.put(p, ans); return ans; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
78512d563b13354ac83aa58e285c9fc6
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import static java.lang.Math.max; import static java.lang.Math.min; import static java.lang.Math.abs; import java.io.*; import java.util.*; public class B { static int n; static int[] arr; static char[] s; public static void main(String[] args) throws IOException { f = new Flash(); out = new PrintWriter(System.out); int T = 1; //ni(); for(int tc = 1; tc <= T; tc++){ n = ni(); fn(); } out.flush(); out.close(); } static void fn() { //we cannot query [L, L] or [R, R] int pos = query(1, n); int left = 1; if(pos > 1) left = query(1, pos); int right = n; if(pos < n) right = query(pos, n); if(left == pos && pos > 1) { int l = 1, r = pos-1; while(l < r) { int mid = l + (r - l + 1) / 2; if(query(mid, pos) == pos) l = mid; else r = mid - 1; } sop("! " + l); } else { int l = pos+1, r = n; while(l < r) { int mid = l + (r - l) / 2; if(query(pos, mid) == pos) r = mid; else l = mid + 1; } sop("! " + l); } } static int query(int l, int r) { sop("? " + l + " " + r); out.flush(); return ni(); } static Flash f; static PrintWriter out; static final long mod = (long)1e9+7; static final long inf = Long.MAX_VALUE; static final int _inf = Integer.MAX_VALUE; static final int maxN = (int)5e5+5; static long[] fact, inv; static void sort(int[] a){ List<Integer> A = new ArrayList<>(); for(int i : a) A.add(i); Collections.sort(A); for(int i = 0; i < A.size(); i++) a[i] = A.get(i); } static void sort(long[] a){ List<Long> A = new ArrayList<>(); for(long i : a) A.add(i); Collections.sort(A); for(int i = 0; i < A.size(); i++) a[i] = A.get(i); } static void print(int[] a){ StringBuilder sb = new StringBuilder(); for(int i = 0; i < a.length; i++) sb.append(a[i] + " "); sop(sb); } static void print(long[] a){ StringBuilder sb = new StringBuilder(); for(int i = 0; i < a.length; i++) sb.append(a[i] + " "); sop(sb); } static int swap(int itself, int dummy){return itself;} static long swap(long itself, long dummy){return itself;} static void sop(Object o){out.println(o);} static int ni(){return f.ni();} static long nl(){return f.nl();} static double nd(){return f.nd();} static String next(){return f.next();} static String ns(){return f.ns();} static char[] nc(){return f.nc();} static int[] arr(int len){return f.arr(len);} static int gcd(int a, int b){if(b == 0) return a; return gcd(b, a%b);} static long gcd(long a, long b){if(b == 0) return a; return gcd(b, a%b);} static int lcm(int a, int b){return (a*b)/gcd(a, b);} static long lcm(long a, long b){return (a*b)/gcd(a, b);} static class Flash { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); String next(){ while(!st.hasMoreTokens()){ try{ st = new StringTokenizer(br.readLine()); }catch(IOException e){ e.printStackTrace(); } } return st.nextToken(); } String ns(){ String s = new String(); try{ s = br.readLine().trim(); }catch(IOException e){ e.printStackTrace(); } return s; } int[] arr(int n){ int[] a = new int[n]; for(int i = 0; i < n; i++) a[i] = ni(); return a; } char[] nc(){return ns().toCharArray();} int ni(){return Integer.parseInt(next());} long nl(){return Long.parseLong(next());} double nd(){return Double.parseDouble(next());} } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
56792dbec1d9d5217b8b4a8a7b30a43e
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; public class cf { static Reader sc = new Reader(); // static Scanner sc = new Scanner(System.in); static PrintWriter out = new PrintWriter(System.out); public static void main(String[] args) { int n = sc.nextInt(); int ans = -1; int index = query(1, n); if (index == 1 || query(1, index) != index) { ans = n; // binary search int l = index, r = n; while (l < r) { int mid = l + (r - l) / 2; if (l + 1 == r) { if (l > index && query(index, l) == index) { ans = l; } else { ans = r; } break; } if (index == mid) break; if (query(index, mid) == index) { ans = mid; r = mid; } else { l = mid; } } } else { ans = 1; // binary search int l = 1, r = index; while (l < r) { int mid = l + (r - l) / 2; if (l + 1 == r) { if (r < index && query(r, index) == index) { ans = r; } else { ans = l; } break; } if (index == mid) break; if (query(mid, index) == index) { ans = mid; l = mid; } else { r = mid; } } } out.println("! " + ans); out.close(); } private static int query(int x, int y) { out.println("? " + x + " " + y); out.flush(); return sc.nextInt(); } static class Reader { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); String next() { while (!st.hasMoreTokens()) try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
489c8a9ee001a1f90d7a7160e4db2131
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.Arrays; import java.util.Random; import java.util.StringTokenizer; public final class C { public static void main(String[] args) { final FastScanner fs = new FastScanner(); final int n = fs.nextInt(); final int res1 = query(0, n - 1, fs); final boolean left = query(0, res1, fs) == res1; int lo, hi; if (left) { lo = 0; hi = res1; // upperBound while (lo < hi) { final int mid = lo + hi + 1 >>> 1; if (query(mid, res1, fs) == res1) { lo = mid; } else { hi = mid - 1; } } } else { lo = res1; hi = n - 1; // lowerBound while (lo < hi) { final int mid = lo + hi >>> 1; if (query(res1, mid, fs) != res1) { lo = mid + 1; } else { hi = mid; } } } System.out.println("! " + (lo + 1)); System.out.close(); } private static int query(int low, int high, FastScanner fs) { if (low == high) { return -1; } low++; high++; System.out.println("? " + low + ' ' + high); return fs.nextInt() - 1; } static final class Utils { public static void shuffleSort(int[] x) { shuffle(x); Arrays.sort(x); } public static void shuffleSort(long[] x) { shuffle(x); Arrays.sort(x); } public static void shuffle(int[] x) { final Random r = new Random(); for (int i = 0; i <= x.length - 2; i++) { final int j = i + r.nextInt(x.length - i); swap(x, i, j); } } public static void shuffle(long[] x) { final Random r = new Random(); for (int i = 0; i <= x.length - 2; i++) { final int j = i + r.nextInt(x.length - i); swap(x, i, j); } } public static void swap(int[] x, int i, int j) { final int t = x[i]; x[i] = x[j]; x[j] = t; } public static void swap(long[] x, int i, int j) { final long t = x[i]; x[i] = x[j]; x[j] = t; } private Utils() {} } static class FastScanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); private String next() { while (!st.hasMoreTokens()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { //noinspection CallToPrintStackTrace e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } int[] nextIntArray(int n) { final int[] a = new int[n]; for (int i = 0; i < n; i++) { a[i] = nextInt(); } return a; } long[] nextLongArray(int n) { final long[] a = new long[n]; for (int i = 0; i < n; i++) { a[i] = nextLong(); } return a; } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
6a6aa473b68ecb135f8cd6de7c6263ff
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.Arrays; import java.util.Random; import java.util.StringTokenizer; public final class C1 { public static void main(String[] args) { final FastScanner fs = new FastScanner(); final int n = fs.nextInt(); final int res1 = query(0, n - 1, fs); final int res2 = query(0, res1, fs); int lo; int hi; if (res2 == res1) { lo = 0; hi = res1; while (lo < hi) { final int mid = lo + hi + 1 >>> 1; if (query(mid, res1, fs) == res1) { lo = mid; } else { hi = mid - 1; } } } else { lo = res1; hi = n - 1; while (lo < hi) { final int mid = lo + hi >>> 1; if (query(res1, mid, fs) != res1) { lo = mid + 1; } else { hi = mid; } } } System.out.println("! " + (lo + 1)); System.out.close(); } private static int query(int low, int high, FastScanner fs) { if (low == high) { return -1; } low++; high++; System.out.println("? " + low + ' ' + high); return fs.nextInt() - 1; } static final class Utils { public static void shuffleSort(int[] x) { shuffle(x); Arrays.sort(x); } public static void shuffleSort(long[] x) { shuffle(x); Arrays.sort(x); } public static void shuffle(int[] x) { final Random r = new Random(); for (int i = 0; i <= x.length - 2; i++) { final int j = i + r.nextInt(x.length - i); swap(x, i, j); } } public static void shuffle(long[] x) { final Random r = new Random(); for (int i = 0; i <= x.length - 2; i++) { final int j = i + r.nextInt(x.length - i); swap(x, i, j); } } public static void swap(int[] x, int i, int j) { final int t = x[i]; x[i] = x[j]; x[j] = t; } public static void swap(long[] x, int i, int j) { final long t = x[i]; x[i] = x[j]; x[j] = t; } private Utils() {} } static class FastScanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); private String next() { while (!st.hasMoreTokens()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { //noinspection CallToPrintStackTrace e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } int[] nextIntArray(int n) { final int[] a = new int[n]; for (int i = 0; i < n; i++) { a[i] = nextInt(); } return a; } long[] nextLongArray(int n) { final long[] a = new long[n]; for (int i = 0; i < n; i++) { a[i] = nextLong(); } return a; } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
4dd362e68aaaf512ce74ff315d1c794f
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; import java.math.*; public class Solution{ public static void main(String[] args) { TaskA solver = new TaskA(); // int t = in.nextInt(); // for (int i = 1; i <= t ; i++) { // solver.solve(i, in, out); // } solver.solve(1, in, out); out.flush(); out.close(); } static class TaskA { public void solve(int testNumber, InputReader in, PrintWriter out) { int n= in.nextInt();boolean isL=false;boolean isR=false; int smax=query(1,n); if(smax==1) { isR=true; } else { int x=query(1,smax); if(x==smax) { isL=true; } else { isR=true; } } if(isL) { int l=1;int r=smax; while(r>l) { if(l==smax-1) { System.out.println("! "+(l));return; } int mid=(r+l)/2; int x=query(mid,smax); if(x==smax) { l=mid+1; } else { r=mid; } } System.out.println("! "+(l-1));return; } else { int l=smax;int r=n; while(r>l) { if(r==smax+1) { System.out.println("! "+(r));return; } int mid=(r+l)/2; int x=query(smax,mid); if(x==smax) { r=mid; } else { l=mid+1; } } System.out.println("! "+(r));return; } } } static int query(int l,int r) { System.out.println("? "+l+" "+r); System.out.print ("\n"); int x=in.nextInt(); return x; } static boolean check(Pair[]arr,int mid,int n) { int c=0; for(int i=0;i<n;i++) { if(mid-1-arr[i].first<=c&&c<=arr[i].second) { c++; } } return c>=mid; } static long sum(int[]arr) { long s=0; for(int x:arr) { s+=x; } return s; } static long sum(long[]arr) { long s=0; for(long x:arr) { s+=x; } return s; } static int gcd(int a, int b) { if (b == 0) return a; return gcd(b, a % b); } static void sort(int[] a) { ArrayList<Integer> q = new ArrayList<>(); for (int i : a) q.add(i); Collections.sort(q); for (int i = 0; i < a.length; i++) a[i] = q.get(i); } static void sort(long[] a) { ArrayList<Long> q = new ArrayList<>(); for (long i : a) q.add(i); Collections.sort(q); for (int i = 0; i < a.length; i++) a[i] = q.get(i); } static void println(int[][]arr) { for(int i=0;i<arr.length;i++) { for(int j=0;j<arr[0].length;j++) { print(arr[i][j]+" "); } print("\n"); } } static void println(long[][]arr) { for(int i=0;i<arr.length;i++) { for(int j=0;j<arr[0].length;j++) { print(arr[i][j]+" "); } print("\n"); } } static void println(int[]arr){ for(int i=0;i<arr.length;i++) { print(arr[i]+" "); } print("\n"); } static void println(long[]arr){ for(int i=0;i<arr.length;i++) { print(arr[i]+" "); } print("\n"); } static long[]input(int n){ long[]arr=new long[n]; for(int i=0;i<n;i++) { arr[i]=in.nextInt(); } return arr; } static long[]input(){ long n= in.nextInt(); long[]arr=new long[(int)n]; for(int i=0;i<n;i++) { arr[i]=in.nextLong(); } return arr; } //////////////////////////////////////////////////////// static class Pair { long first; long second; Pair(long x, long y) { this.first = x; this.second = y; } } static void sortS(Pair arr[]) { Arrays.sort(arr, new Comparator<Pair>() { @Override public int compare(Pair p1, Pair p2) { return (int)(p1.second - p2.second); } }); } static void sortF(Pair arr[]) { Arrays.sort(arr, new Comparator<Pair>() { @Override public int compare(Pair p1, Pair p2) { return (int)(p1.first - p2.first); } }); } ///////////////////////////////////////////////////////////// static InputStream inputStream = System.in; static OutputStream outputStream = System.out; static InputReader in = new InputReader(inputStream); static PrintWriter out = new PrintWriter(outputStream); static void println(long c) { out.println(c); } static void print(long c) { out.print(c); } static void print(int c) { out.print(c); } static void println(int x) { out.println(x); } static void print(String s) { out.print(s); } static void println(String s) { out.println(s); } static void println(boolean b) { out.println(b); } static class InputReader { public BufferedReader reader; public StringTokenizer tokenizer; public InputReader(InputStream stream) { reader = new BufferedReader(new InputStreamReader(stream), 32768); tokenizer = null; } public String next() { while (tokenizer == null || !tokenizer.hasMoreTokens()) { try { tokenizer = new StringTokenizer(reader.readLine()); } catch (IOException e) { throw new RuntimeException(e); } } return tokenizer.nextToken(); } public int nextInt() { return Integer.parseInt(next()); } public long nextLong() { return Long.parseLong(next()); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
f2b017bd4d6000e0be09525df5b0fbf5
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; public class Main { public static int[] a = new int[]{0, 4, 3, 2, 1, 5}; public static void main(String[] args) throws Exception{ BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); int testCase = Integer.parseInt(in.readLine().trim()); int l = 1; int r = testCase; int smax = seclarge(in, l, r); if (smax == l) { l++; } else if (smax == r) { r--; } else { int smax2 = seclarge(in, smax, r); if (smax2 == smax) { l = smax + 1; } else { r = smax - 1; } } while (l + 1 < r) { int m = l + (r - l)/2; int smax2 = 0; if (smax <= m) { smax2 = seclarge(in, smax, m); if (smax2 == smax) { r = m; } else { l = m + 1; } } else { smax2 = seclarge(in, m, smax); if (smax2 == smax) { l = m; } else { r = m - 1; } } } int largest = 0; if (smax < l) { largest = seclarge(in, smax, l) == smax ? l : r; } else { largest = seclarge(in, r, smax) == smax ? r : l; } System.out.println("! " + largest); System.out.flush(); } public static int seclarge(BufferedReader in, int l, int r) throws Exception{ System.out.println("? " + l + " " + r); System.out.flush(); int sec = Integer.parseInt(in.readLine().trim()); return sec; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
4c8b93b0877a77391d74ea47d9912a76
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class Solution { static class FastReader { BufferedReader br; StringTokenizer st; public FastReader(String s) { try { br = new BufferedReader(new FileReader(s)); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String nextToken() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(nextToken()); } String nextLine() throws IOException { return br.readLine(); } long nextLong() { return Long.parseLong(nextToken()); } double nextDouble() { return Double.parseDouble(nextToken()); } float nextFloat() { return Float.parseFloat(nextToken()); } } static FastReader f = new FastReader(); static BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); static StringTokenizer st; static StringBuilder sb = new StringBuilder(); private static final int mod = (int) (1e9 + 7); static int MAX = 500005; static long[] fact; static int[] inputArray(int n) throws IOException { int[] a = new int[n]; for(int i = 0 ; i < n ; i++) { // a[i] = (int) (Math.random()*1e5 + 1); a[i] = f.nextInt(); } return a; } static long[] inputLongArray(int n) throws IOException { long[] a = new long[n]; for(int i = 0 ; i < n ; i++) { a[i] = f.nextLong(); // a[i] = (long) (Math.random() * 1e9 + 1); } return a; } static long gcd(long a , long b) { if(a == 0 || b == 0) { return Math.max(a , b); } //System.out.println("a - " + a + " b - " + b); if(a % b == 0) { return b; } return gcd(b , a % b); } static void initializeFact() { fact = new long[MAX]; for(int i = 0 ; i < fact.length ; i++) { if(i == 0) { fact[i] = 1; } else { fact[i] = fact[i-1] * i % mod; } } } static long longModulus(long x , long m) { if(x < m) { return x; } long d = x / m; return x - d * m; } static boolean[] sieveOfEratosthenes(int n) { boolean[] isPrime = new boolean[n+1]; Arrays.fill(isPrime , true); isPrime[0] = false; isPrime[1] = false; for(int i = 2; i * i <= n ; i++) { for(int j = 2 * i ; j <= n; j += i) isPrime[j] = false; } return isPrime; } static long moduloInversePrime(long a) { //System.out.println("modulo inverse of " + a + " -> " + ans); return modPow(a , mod - 2); } static long mult(long a, long b) { return (a * b % mod); } static long modPow(long a, int step) { long ans = 1; while(step != 0) { if((step & 1) != 0) ans = mult(ans , a); a = mult(a , a); step >>= 1; } return ans; } static boolean isPrime(int n) { if(n == 1) { return false; } for(int i = 2 ; i <= Math.sqrt(n) ; i++) { if(n % i == 0) { return false; } } return true; } static int query(int l , int r) { System.out.println("? " + l + " " + r); System.out.flush(); return f.nextInt(); } public static void main(String[] args) throws IOException { int t = 1; for(int test = 0 ; test < t ; test++) { int n = f.nextInt(); int l = 1, r = n; int m = query(l, r); boolean left = false; if(m != 1) { int x = query(l, m); if(x == m) { r = m - 1; left = true; } else { l = m + 1; } } else { l = 2; } int ans = -1; while(l <= r) { int mid = (l+r) / 2; // System.out.println("l: " + l + ", r: " + r + ", mid: " + mid); if(left) { int q = query(mid, m); if(q == m) { ans = mid; l = mid + 1; } else { r = mid - 1; } } else { int q = query(m, mid); if(q == m) { ans = mid; r = mid - 1; } else { l = mid + 1; } } } System.out.println("! " + ans); System.out.flush(); } } private static int split(int[] a, int l, int r, long[] preSum) { int low = l, high = r - 1; while(low <= high) { int mid = (low + high) / 2; if(preSum[mid+1] - preSum[l] == preSum[r+1] - preSum[mid+1]) { return mid; } else if(preSum[mid+1] - preSum[l] > preSum[r+1] - preSum[mid+1]) { high = mid - 1; } else { low = mid + 1; } } return -1; } } /* */
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
034b06b58dd0ac9ba2a6caeee50ac6d6
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.util.StringTokenizer; public class C { void solve() throws IOException { int n = nextInt(); int begin = 1; int end = n; /* 5 1 3 4 2 1 2 3 4 5 2 1 3 5 1 4 2 3 5 4 3 2 1 */ writer.println("? " + begin + " " + end); writer.flush(); int secMax = nextInt(); boolean beginChanging = true; if (secMax == 1) { begin = 2; end = n; beginChanging = false; } else if (secMax == n) { begin = 1; end = secMax - 1; } else { writer.println("? " + 1 + " " + secMax); writer.flush(); int leftSecMax = nextInt(); if (leftSecMax == secMax) { begin = 1; end = secMax - 1; } else { beginChanging = false; begin = secMax + 1; end = n; } } if (beginChanging) { int lastGood = 0; while (begin <= end) { int mid = begin + (end - begin) / 2; writer.println("? " + mid + " " + secMax); writer.flush(); int newSecMax = nextInt(); if (secMax == newSecMax) { lastGood = mid; begin = mid + 1; } else { end = mid - 1; } } writer.println("! " + lastGood); } else { int lastGood = 0; while (begin <= end) { int mid = begin + (end - begin) / 2; writer.println("? " + secMax + " " + mid); writer.flush(); int newSecMax = nextInt(); if (newSecMax == secMax) { lastGood = mid; end = mid - 1; } else { begin = mid + 1; } } writer.println("! " + lastGood); } } String nextToken() throws IOException { while (tokenizer == null || !tokenizer.hasMoreTokens()) { tokenizer = new StringTokenizer(reader.readLine()); } return tokenizer.nextToken(); } int nextInt() throws IOException { return Integer.parseInt(nextToken()); } StringTokenizer tokenizer; PrintWriter writer; BufferedReader reader; public void run() { try { writer = new PrintWriter(System.out); reader = new BufferedReader(new InputStreamReader(System.in)); solve(); reader.close(); writer.close(); } catch (Exception e) { e.printStackTrace(); } } public static void main(String[] args) { new C().run(); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
d6ffb983be6e26cb0d1e0474db26706e
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.*; public class CodeForces { public static void main(String[] args) { // TODO Auto-generated method stub FastScanner fs=new FastScanner(); int n=fs.nextInt(); int pos=solve(n); System.out.println("! "+(pos+1)); // System.out.println("No of queery = "+count); } private static int solve(int n) { int smallx=query(0,n-1); if(smallx==0||query(0,smallx)!=smallx) { int l=smallx,r=n-1; while(r-l>1) { int mid=(l+r)/2; if(query(smallx,mid)==smallx) { r=mid; } else l=mid; } return r; } else { int l=0,r=smallx; while(r-l>1) { int mid=(l+r)/2; if(query(mid,smallx)==smallx) { l=mid; } else r=mid; } return l; } } private static int query(int l,int r) { if(l>=r) return -1; System.out.println("? "+(l+1)+" "+(r+1)); FastScanner fs=new FastScanner(); int pos=fs.nextInt(); return pos-1; } static void mysort(int[] a) { //ruffle int n=a.length; Random r=new Random(); for (int i=0; i<a.length; i++) { int oi=r.nextInt(n), temp=a[i]; a[i]=a[oi]; a[oi]=temp; } //then sort Arrays.sort(a); } // Use this to input code since it is faster than a Scanner static class FastScanner { BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st=new StringTokenizer(""); String next() { while (!st.hasMoreTokens()) try { st=new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } int[] readArray(int n) { int[] a=new int[n]; for (int i=0; i<n; i++) a[i]=nextInt(); return a; } long nextLong() { return Long.parseLong(next()); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
62098d7f6649049ae99a01475f85f6f4
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
// c1 import java.util.*; // import java.lang.*; import java.io.*; // THIS TEMPLATE MADE BY AKSH BANSAL. public class Solution { static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } public static void main(String[] args) throws IOException { FastReader sc = new FastReader(); PrintWriter out = new PrintWriter(System.out); // ________________________________ int n= sc.nextInt(); if(n==1){ out.println("! 1"); out.flush(); return; } int start = 1, end = n; int pos = query(start, end, out, sc); if(pos>1 && query(1,pos,out,sc)==pos){ end = pos-1; }else{ start = pos+1; } while(start<end){ int mid = start+(end-start)/2; if(start+1==end){ pos = query(start,end,out,sc); if(pos==start){ start = end; } break; } // checking sub section if(pos>=mid){ int cur = query(mid, pos, out, sc); if(cur==pos){ start = mid; } else { end = mid-1; } } else{ int cur = query(pos, mid, out, sc); if(cur==pos){ end = mid; } else { start = mid+1; } } } out.println("! "+start); out.flush(); } private static int query(int start, int end, PrintWriter out, FastReader sc) { out.println("? "+start+" "+end); out.flush(); int res= sc.nextInt(); return res; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
99c47dc4a57585d46d7081ee4841c137
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; public class Q1486C { static Scanner s = new Scanner(System.in); public static void main(String args[]) { int r = s.nextInt(); System.out.println("? 1 " + r); System.out.flush(); int k = s.nextInt(); if(r==2) { System.out.println("! " + (3-k)); return; } if(k!=1) { System.out.println("? 1 " + k); System.out.flush(); if(s.nextInt()==k) solvel(1,k-1,k); else solver(k+1,r,k); } else solver(1,r,1); } public static void solvel(int l, int r, int k) { if(l==r) { System.out.println("! " + l); return; } int m = (l+r+1)/2; System.out.println("? " + m + " " + k); System.out.flush(); if(s.nextInt()==k) { solvel(m,r,k); } else { solvel(l,m-1,k); } } public static void solver(int l, int r, int k) { if(l==r) { System.out.println("! " + l); return; } int m = (l+r)/2; System.out.println("? " + k + " " + m); System.out.flush(); if(s.nextInt()==k) { solver(l,m,k); } else { solver(m+1,r,k); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
045aeed6392a7eaeba45774544f7c5c8
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class GuessingTheGreatest2 { static FastScanner fs; static FastWriter fw; static boolean checkOnlineJudge = System.getProperty("ONLINE_JUDGE") == null; private static final int iMax = (int) (1e9), iMin = (int) (-1e9); private static final long lMax = (int) (1e15), lMin = (int) (-1e15); private static final int mod = (int) (1e9 + 7); public static void main(String[] args) throws IOException { fs = new FastScanner(); fw = new FastWriter(); int t = 1; //t = fs.nextInt(); while (t-- > 0) { solve(); } fw.out.close(); } private static void solve() { int n = fs.nextInt(); int l = 1, r = n; char side; int idx = ask(1, n); if (idx == 1) { side = 'l'; } else if (idx == n) { side = 'r'; } else { int temp = ask(1, idx); if (temp == idx) { r = idx; side = 'r'; } else { l = idx; side = 'l'; } } while (r - l > 1) { int mid = l + ((r - l) / 2); if (side == 'r') { int temp = ask(mid, idx); if (temp == idx) l = mid; else r = mid; } else { int temp = ask(idx, mid); if (temp == idx) r = mid; else l = mid; } } int temp = ask(l, r); if (temp == l) fw.out.println("! " + r); else fw.out.println("! " + l); } private static int ask(int l, int r) { fw.out.println("? " + l + " " + r); fw.out.flush(); return fs.nextInt(); } private static class UnionFind { private final int[] parent; UnionFind(int n) { parent = new int[n]; for (int i = 0; i < n; i++) parent[i] = i; } private int getParent(int i) { if (parent[i] == i) return i; return parent[i] = getParent(parent[i]); } private void unify(int i, int j) { int p1 = getParent(i); int p2 = getParent(j); if (p1 != p2) parent[p1] = p2; } } private static int gcd(int a, int b) { return (b == 0 ? a : gcd(b, a % b)); } private static long pow(long a, long b) { long result = 1; while (b > 0) { if ((b & 1L) == 1) { result = (result * a) % mod; } a = (a * a) % mod; b >>= 1; } return result; } private static int ceilDiv(int a, int b) { return ((a + b - 1) / b); } private static List<Integer> primes(int n) { boolean[] primeArr = new boolean[n + 5]; Arrays.fill(primeArr, true); for (int i = 2; (i * i) <= n; i++) { if (primeArr[i]) { for (int j = i * i; j <= n; j += i) { primeArr[j] = false; } } } List<Integer> primeList = new ArrayList<>(); for (int i = 2; i <= n; i++) { if (primeArr[i]) primeList.add(i); } return primeList; } private static class Pair<U, V> { private final U first; private final V second; @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Pair<?, ?> pair = (Pair<?, ?>) o; return first.equals(pair.first) && second.equals(pair.second); } @Override public int hashCode() { return Objects.hash(first, second); } @Override public String toString() { return "(" + first + ", " + second + ")"; } private Pair(U ff, V ss) { this.first = ff; this.second = ss; } } private static <T> void randomizeArr(T[] arr, int n) { Random r = new Random(); for (int i = (n - 1); i > 0; i--) { int j = r.nextInt(i + 1); swap(arr, i, j); } } private static Integer[] readIntArray(int n) { Integer[] arr = new Integer[n]; for (int i = 0; i < n; i++) arr[i] = fs.nextInt(); return arr; } private static List<Integer> readIntList(int n) { List<Integer> list = new ArrayList<>(); for (int i = 0; i < n; i++) list.add(fs.nextInt()); return list; } private static <T> void swap(T[] arr, int i, int j) { T temp = arr[i]; arr[i] = arr[j]; arr[j] = temp; } private static <T> void displayArr(T[] arr) { for (T x : arr) fw.out.print(x + " "); fw.out.println(); } private static <T> void displayList(List<T> list) { for (T x : list) fw.out.print(x + " "); fw.out.println(); } private static class FastScanner { BufferedReader br; StringTokenizer st; FastScanner() throws IOException { if (checkOnlineJudge) this.br = new BufferedReader(new FileReader("src/input.txt")); else this.br = new BufferedReader(new InputStreamReader(System.in)); this.st = new StringTokenizer(""); } public String next() { while (!st.hasMoreTokens()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException err) { err.printStackTrace(); } } return st.nextToken(); } public String nextLine() { if (st.hasMoreTokens()) { return st.nextToken("").trim(); } try { return br.readLine().trim(); } catch (IOException err) { err.printStackTrace(); } return ""; } public int nextInt() { return Integer.parseInt(next()); } public long nextLong() { return Long.parseLong(next()); } public double nextDouble() { return Double.parseDouble(next()); } } private static class FastWriter { PrintWriter out; FastWriter() throws IOException { if (checkOnlineJudge) out = new PrintWriter(new FileWriter("src/output.txt")); else out = new PrintWriter(System.out); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
880fa225b71690a8d64c7f5215a9d1c5
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
/* TO LEARN 2-euler tour */ /* TO SOLVE codeforces 722 kavi on pairing duty */ /* bit manipulation shit 1-Computer Systems: A Programmer's Perspective 2-hacker's delight 3-(02-03-bits-ints) 4-machine-basics 5-Bits Manipulation tutorialspoint */ /* TO WATCH */ import java.util.*; import java.math.*; import java.io.*; import java.util.stream.Collectors; public class B{ static FastScanner scan=new FastScanner(); public static PrintWriter out = new PrintWriter (new BufferedOutputStream(System.out)); static int ask(int l,int r) { System.out.println("? "+l+" "+r); return scan.nextInt(); } public static void main(String[] args) throws Exception { // scan=new FastScanner("D:\\usaco test data\\W.txt"); // out = new PrintWriter("D:\\usaco test data\\WW.txt"); /* READING 3-Introduction to DP with Bitmasking codefoces 4-Bit Manipulation hackerearth 5-read more about mobious and inculsion-exclusion */ /* if it has no Xs or Os then the answer is 0 */ int tt=1; //tt=scan.nextInt(); int T=1; //System.out.println(8|9); outer:while(tt-->0) { int n=scan.nextInt(); int idx=ask(1,n); int second=-1,first=-1; if(idx!=n) first=ask(idx,n); if(1!=idx) second=ask(1,idx); int l=-1,r=-1; if(first==idx) { l=idx; r=n; l++; int ans=-1; while(l<=r) { int mid=(l+r)/2; int as=ask(idx,mid); if(as==idx) { ans=mid; r=mid-1; } else l=mid+1; } out.println("! "+ans); } else { l=1; r=idx; r--; int ans=-1; while(l<=r) { int mid=(l+r)/2; int as=ask(mid,idx); if(as==idx) { ans=mid; l=mid+1; } else r=mid-1; } out.println("! "+ans); } } out.close(); } static long binexp(long a,long n) { if(n==0) return 1; long res=binexp(a,n/2); if(n%2==1) return res*res*a; else return res*res; } static long powMod(long base, long exp, long mod) { if (base == 0 || base == 1) return base; if (exp == 0) return 1; if (exp == 1) return (base % mod+mod)%mod; long R = (powMod(base, exp/2, mod) % mod+mod)%mod; R *= R; R %= mod; if ((exp & 1) == 1) { return (base * R % mod+mod)%mod; } else return (R %mod+mod)%mod; } static double dis(double x1,double y1,double x2,double y2) { return Math.sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)); } static long mod(long x,long y) { if(x<0) x=x+(-x/y+1)*y; return x%y; } public static long pow(long b, long e) { long r = 1; while (e > 0) { if (e % 2 == 1) r = r * b ; b = b * b; e >>= 1; } return r; } private static void sort(long[] arr) { List<Long> list = new ArrayList<>(); for (long object : arr) list.add(object); Collections.sort(list); //Collections.reverse(list); for (int i = 0; i < list.size(); ++i) arr[i] = list.get(i); } private static void sort2(long[] arr) { List<Long> list = new ArrayList<>(); for (Long object : arr) list.add(object); Collections.sort(list); Collections.reverse(list); for (int i = 0; i < list.size(); ++i) arr[i] = list.get(i); } static class FastScanner { private int BS = 1 << 16; private char NC = (char) 0; private byte[] buf = new byte[BS]; private int bId = 0, size = 0; private char c = NC; private double cnt = 1; private BufferedInputStream in; public FastScanner() { in = new BufferedInputStream(System.in, BS); } public FastScanner(String s) { try { in = new BufferedInputStream(new FileInputStream(new File(s)), BS); } catch (Exception e) { in = new BufferedInputStream(System.in, BS); } } private char getChar() { while (bId == size) { try { size = in.read(buf); } catch (Exception e) { return NC; } if (size == -1) return NC; bId = 0; } return (char) buf[bId++]; } public int nextInt() { return (int) nextLong(); } public int[] nextInts(int N) { int[] res = new int[N]; for (int i = 0; i < N; i++) { res[i] = (int) nextLong(); } return res; } public long[] nextLongs(int N) { long[] res = new long[N]; for (int i = 0; i < N; i++) { res[i] = nextLong(); } return res; } public long nextLong() { cnt = 1; boolean neg = false; if (c == NC) c = getChar(); for (; (c < '0' || c > '9'); c = getChar()) { if (c == '-') neg = true; } long res = 0; for (; c >= '0' && c <= '9'; c = getChar()) { res = (res << 3) + (res << 1) + c - '0'; cnt *= 10; } return neg ? -res : res; } public double nextDouble() { double cur = nextLong(); return c != '.' ? cur : cur + nextLong() / cnt; } public double[] nextDoubles(int N) { double[] res = new double[N]; for (int i = 0; i < N; i++) { res[i] = nextDouble(); } return res; } public String next() { StringBuilder res = new StringBuilder(); while (c <= 32) c = getChar(); while (c > 32) { res.append(c); c = getChar(); } return res.toString(); } public String nextLine() { StringBuilder res = new StringBuilder(); while (c <= 32) c = getChar(); while (c != '\n') { res.append(c); c = getChar(); } return res.toString(); } public boolean hasNext() { if (c > 32) return true; while (true) { c = getChar(); if (c == NC) return false; else if (c > 32) return true; } } } static class Pair implements Comparable<Pair>{ public long x, y,z; public Pair(long x1, long y1,long z1) { x=x1; y=y1; z=z1; } public Pair(long x1, long y1) { x=x1; y=y1; } @Override public int hashCode() { return (int)(x + 31 * y); } public String toString() { return x + " " + y+" "+z; } @Override public boolean equals(Object o){ if (o == this) return true; if (o.getClass() != getClass()) return false; Pair t = (Pair)o; return t.x == x && t.y == y&&t.z==z; } public int compareTo(Pair o) { return (int)(z-o.z); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
dc9938aa6b7b91356b061aa85ec25da3
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
//https://codeforces.com/contest/1486/problem/C2 //C2. Guessing the Greatest (hard version) import java.util.*; import java.io.*; public class CF_1486_C2{ static BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); static PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out)); static int ask(int l, int r) throws Exception{ if(l==r) return -1; pw.print("? "+l+" "+r+"\n"); pw.flush(); return Integer.parseInt(br.readLine()); } public static void main(String[] args) throws Exception{ int n = Integer.parseInt(br.readLine()); int l = 1, r = n; int sm = ask(l, r); if(sm==ask(l, sm)) r = sm-1; else l = sm+1; while(r-l>1){ int mid = (r+l)>>1; if(mid>sm){ if(ask(sm, mid)==sm) r = mid; else l = mid+1; } else{ if(ask(mid, sm)==sm) l = mid; else r = mid-1; } } int ans = l; if(r-l==1){ if(sm>r){ if(ask(r, sm)==sm) ans = r; else ans = l; } else{ if(ask(sm, l)==sm) ans = l; else ans = r; } } pw.print("! "+ans); pw.flush(); pw.close(); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
0293554d38b5805c08a841e21596d726
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
/*input */ import java.util.*; import java.lang.*; import java.io.*; public class Main { static PrintWriter out; static int MOD = 1000000007; static FastReader scan; /*-------- I/O using short named function ---------*/ public static String ns(){return scan.next();} public static int ni(){return scan.nextInt();} public static long nl(){return scan.nextLong();} public static double nd(){return scan.nextDouble();} public static String nln(){return scan.nextLine();} public static void p(Object o){out.print(o);} public static void ps(Object o){out.print(o + " ");} public static void pn(Object o){out.println(o);} /*-------- for output of an array ---------------------*/ static void iPA(int arr []){ StringBuilder output = new StringBuilder(); for(int i=0; i<arr.length; i++)output.append(arr[i] + " ");out.println(output); } static void lPA(long arr []){ StringBuilder output = new StringBuilder(); for(int i=0; i<arr.length; i++)output.append(arr[i] + " ");out.println(output); } static void sPA(String arr []){ StringBuilder output = new StringBuilder(); for(int i=0; i<arr.length; i++)output.append(arr[i] + " ");out.println(output); } static void dPA(double arr []){ StringBuilder output = new StringBuilder(); for(int i=0; i<arr.length; i++)output.append(arr[i] + " ");out.println(output); } /*-------------- for input in an array ---------------------*/ static void iIA(int arr[]){ for(int i=0; i<arr.length; i++)arr[i] = ni(); } static void lIA(long arr[]){ for(int i=0; i<arr.length; i++)arr[i] = nl(); } static void sIA(String arr[]){ for(int i=0; i<arr.length; i++)arr[i] = ns(); } static void dIA(double arr[]){ for(int i=0; i<arr.length; i++)arr[i] = nd(); } /*------------ for taking input faster ----------------*/ static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } // Method to check if x is power of 2 static boolean isPowerOfTwo (int x) { return x!=0 && ((x&(x-1)) == 0);} //Method to return lcm of two numbers static int gcd(int a, int b){return a==0?b:gcd(b % a, a); } //Method to count digit of a number static int countDigit(long n){return (int)Math.floor(Math.log10(n) + 1);} //Method for sorting static void ruffle_sort(int[] a) { //shandom_ruffle Random r=new Random(); int n=a.length; for (int i=0; i<n; i++) { int oi=r.nextInt(n); int temp=a[i]; a[i]=a[oi]; a[oi]=temp; } //sort Arrays.sort(a); } //Method for checking if a number is prime or not static boolean isPrime(int n) { if (n <= 1) return false; if (n <= 3) return true; if (n % 2 == 0 || n % 3 == 0) return false; for (int i = 5; i * i <= n; i = i + 6) if (n % i == 0 || n % (i + 2) == 0) return false; return true; } public static void main (String[] args) throws java.lang.Exception { OutputStream outputStream =System.out; out =new PrintWriter(outputStream); scan =new FastReader(); //for fast output sometimes StringBuilder sb = new StringBuilder(); int t = 1; while(t-->0){ int n = ni(); int smax = askQuery(1, n); if(smax == 1 || askQuery(1, smax) != smax){ int l = smax, r = n; while(r - l > 1){ int mid = (l + r)/2; if(askQuery(smax, mid) == smax){ r = mid; }else{ l = mid; } } pn("! " + r); }else{ int l = 1, r = smax; while(r - l > 1){ int mid = (l + r)/2; if(askQuery(mid, smax) == smax){ l = mid; }else{ r = mid; } } pn("! " + l); } } out.flush(); out.close(); } static int askQuery(int l, int r){ pn("? " + l + " " + r); out.flush(); return ni(); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
ee39c86d4a1355d5e628d2d2fd8b1070
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class Solution { public static void main(String args[]) throws Exception { BufferedReader Rb = new BufferedReader(new InputStreamReader(System.in)); int n = Integer.valueOf(Rb.readLine()); int l = 1, r = n; System.out.println("? " + l + " " + r); System.out.flush(); int pos = Integer.valueOf(Rb.readLine()); System.out.println("? " + (pos!=l?l:pos) + " " + (pos!=l?pos:r)); System.out.flush(); int n_pos = Integer.valueOf(Rb.readLine()); boolean flag = true; if(n_pos == pos) { if(pos == l) {l = pos + 1;} else {r = pos - 1; flag = false;} } else { if(pos == l) {r = pos - 1; flag = false;} else {l = pos + 1;} } int last = -1; while(l <= r) { int m = (l + r) / 2; int s = (m < pos)?m:pos; int e = (m < pos)?pos:m; System.out.println("? " + s + " " + e); System.out.flush(); n_pos = Integer.valueOf(Rb.readLine()); if(n_pos == pos) { last = m; if(!flag) {l = (l + r)/2 + 1;} else {r = (l + r)/2 - 1;} } else { if(flag) {l = (l + r)/2 + 1;} else {r = (l + r)/2 - 1;} } } System.out.println("! " + last); System.out.flush(); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
9c615e36ba3f6135a956c80322a3a0b3
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.util.*; public class GuessingTheGreatestHard { static FastScanner fs = new FastScanner(); static int query(int left, int right) { System.out.println("? " + left + " " + right); return fs.nextInt(); } public static void main(String[] args) { PrintWriter out = new PrintWriter(System.out); int n = fs.nextInt(); int secondMax = query(1, n); int left = 1, right = n; if(secondMax == 1 || query(1, secondMax) != secondMax) { left = secondMax; right = n; while(left + 1 < right) { int mid = (left + right) / 2; if(query(secondMax, mid) == secondMax) right = mid; else left = mid; } } else { left = 1; right = secondMax; while(left + 1 < right) { int mid = (left + right) / 2; if(query(mid, secondMax) == secondMax) left = mid; else right = mid; } } int myAns = query(left, right) == left ? right : left; System.out.println("! " + myAns); } static void ruffleSort(int[] a) { int n = a.length; Random r = new Random(); for(int i = 0; i < a.length; ++i) { int oi = r.nextInt(n), t = a[i]; a[i] = a[oi]; a[oi] = t; } Arrays.sort(a); } static void sort(int[] a) { ArrayList<Integer> l = new ArrayList<>(); for(int i : a) l.add(i); Collections.sort(l); for(int i = 0; i < a.length; ++i) a[i] = l.get(i); } static class FastScanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); String next() { while(!st.hasMoreTokens()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } int[] readArray(int n) { int[] a = new int[n]; for(int i = 0; i < n; ++i) a[i] = nextInt(); return a; } long nextLong() { return Long.parseLong(next()); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
06aaefedf0ab46f8a1ecf1d8b95f0184
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.lang.*; import java.io.*; import java.math.BigInteger; public class C { static Scanner in; public static void main(String[] args) { in = new Scanner(System.in); int n = in.nextInt(); int l=1, r= n; int s = query(l, r); if(query(1, s) == s) { l = 1; r = s-1; while(l<r) { int m = (l+r+1)/2; if(query(m, s) == s) l = m; else r = m-1; } solve(l); } else { l = s+1; r = n; while(l<r) { int m = (l+r)/2; if(query(s, m) == s) r = m; else l = m+1; } solve(l); } } static int query(int l, int r) { if(l>=r) return -1; System.out.println("? " + l + " " + r); System.out.flush(); return in.nextInt(); } static void solve(int s) { System.out.println("! " + s); System.out.flush(); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
fa886e682a579512869f47c28ca75a56
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.StringTokenizer; public class Solution { static Reader input; public static void main(String[] args) throws IOException { input = new Reader(); int n = input.nextInt(); int secondMax = ask(1, n), temp; int max; if(secondMax == n) { max = leftBinarySearch(1, n-1, secondMax); } else if(secondMax == 1) { max = rightBinarySearch(2, n, secondMax); } else { temp = ask(secondMax, n); if(temp != secondMax) { max = leftBinarySearch(1, secondMax-1, secondMax); } else { max = rightBinarySearch(secondMax+1, n, secondMax); } } System.out.println("! " + max); } static int leftBinarySearch(int l, int r, int secondMax) throws IOException { int temp, middle, left = l, right = r, answer = l; while(left <= right) { middle = left+right>>1; temp = ask(middle, secondMax); if(temp == secondMax) { answer = middle; left = middle+1; } else { right = middle-1; } } return answer; } static int rightBinarySearch(int l, int r, int secondMax) throws IOException { int temp, middle, left = l, right = r, answer = r; while(left <= right) { middle = left+right>>1; temp = ask(secondMax, middle); if(temp == secondMax) { answer = middle; right = middle-1; } else { left = middle+1; } } return answer; } static int ask(int l, int r) throws IOException { System.out.println("? " + l + " " + r); System.out.flush(); return input.nextInt(); } static class Reader { BufferedReader bufferedReader; StringTokenizer string; public Reader() { InputStreamReader inr = new InputStreamReader(System.in); bufferedReader = new BufferedReader(inr); } public String next() throws IOException { while(string == null || ! string.hasMoreElements()) { string = new StringTokenizer(bufferedReader.readLine()); } return string.nextToken(); } public int nextInt() throws IOException { return Integer.parseInt(next()); } public long nextLong() throws IOException { return Long.parseLong(next()); } public double nextDouble() throws IOException { return Double.parseDouble(next()); } public String nextLine() throws IOException { return bufferedReader.readLine(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
4be74713a3a09e5566a712f754dcd408
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; import java.lang.*; public class cf719 { public static int query(int l,int r) throws Exception{ if(l>=r)return -1; InputStreamReader ip=new InputStreamReader(System.in); BufferedReader br = new BufferedReader(ip); System.out.println("? "+(l+1)+" "+(r+1)); int ans=Integer.parseInt(br.readLine()); return ans-1; } //For HardVersion the resulting number of queries is 2+⌈𝑙𝑜𝑔(base2)10^5⌉=19. //For EasyVersion the resulting number of queries is 2⋅⌈𝑙𝑜𝑔2105⌉=34. public static void HardVersion() throws Exception{ InputStreamReader ip=new InputStreamReader(System.in); BufferedReader br = new BufferedReader(ip); int n =Integer.parseInt(br.readLine()); // String[] strs=(br.readLine()).trim().split(" "); int l=0,r=n; //so that segment divide equally by mid [l,mid) [mid,r) int smax=query(l, r-1); //segment max int ans=0; if(smax==0 || query(0, smax)!=smax){ l=smax; r=n-1; //Max lie in right segment while((r-l)>1){ int mid=l+(r-l)/2; if(query(smax,mid)==smax){ r=mid; }else{ l=mid; } } System.out.println("! "+(r+1)); //+r+" " }else{ l=0; r=smax; //Max lie in left segment while((r-l)>1){ int mid=l+(r-l)/2; if(query(mid,smax)==smax){ l=mid; }else{ r=mid; } } System.out.println("! "+(l+1)); } } public static void EasyVersion() throws Exception{ InputStreamReader ip=new InputStreamReader(System.in); BufferedReader br = new BufferedReader(ip); int n =Integer.parseInt(br.readLine()); // String[] strs=(br.readLine()).trim().split(" "); int l=0,r=n; //so that segment divide equally by mid [l,mid) [mid,r) int ans=0; while((r-l)>1){ // query possible for segment of size >1 int mid=l+(r-l)/2; int smax=query(l, r-1); //segment max if(smax<mid){ if(query(l, mid-1)==smax){ r=mid; }else{ l=mid; } }else{ if(query(mid, r-1)==smax){ l=mid; }else{ r=mid; } } // System.out.println(l+" "+r); } System.out.println("! "+r); //+r+" " } //******************************************************************************************************************** */ public static void main(String[] args) throws Exception{ HardVersion(); } public static void solve3() throws Exception{ InputStreamReader ip=new InputStreamReader(System.in); BufferedReader br = new BufferedReader(ip); int t = Integer.parseInt(br.readLine()); StringBuilder asb=new StringBuilder(); while(t-->0){ int n =Integer.parseInt(br.readLine()); String[] strs=(br.readLine()).trim().split(" "); // int n=Integer.parseInt(strs[0]),k=Integer.parseInt(strs[1]),r=Integer.parseInt(strs[2]),s=Integer.parseInt(strs[3]); // String str=(br.readLine()).trim(); //Rearrange Given Expression- a𝑗−a𝑖=𝑗−𝑖 => aj-j == ai-i int[] arr=new int[n]; HashMap<Integer,Integer> hm=new HashMap<>(); for(int i=0;i<n;i++){ arr[i]=Integer.parseInt(strs[i]); hm.put((arr[i]-i), hm.getOrDefault((arr[i]-i), 0)+1); } long ans=0; for(int key:hm.keySet()){ long ct=hm.get(key); ans+=(ct*(ct-1))/2; } // System.out.println(ans+" ct "+ct); System.out.println(ans); } } //******************************************************************************************************************** */ public static long modInverse1(long a, long m){ // int g = gcd(a, m); // if(g!=1) {System.out.println("Inverse Doesnot Exist");} return binexp(a, m - 2, m); } public static long binexp(long a, long b, long m){ if (b == 0)return 1; long res = binexp(a, b / 2, m); if (b % 2 == 1) return (( (res*res)%m )*a) % m; else return (res*res)%m; } //binexp public static long binexp(long a,long b){ if(b==0)return 1; long res=binexp(a, b/2); if(b%2==1){ return (((res*res))*a); }else return (res*res); } //Comparator Interface public static class comp implements Comparator<int[]>{ public int compare(int[] a,int[] b){ return a[0]-b[0]; } } //gcd using Euclid's Division Algorithm public static long gcd(long a,long b){ if(b==0)return a; else return gcd(b, a%b); } //check prime in root(n) public static int isprime(int n){ for(int i=2;i<=Math.sqrt(n);i++){ if(n%i==0)return i; } return -1; //means n is prime } //SOE static int[] sieve; public static void SOE(int n){ sieve=new int[n+1]; // System.out.println("All prime number from 1 to n:-"); for(int x=2;x<=n;x++){ if(sieve[x]!=0){ //Not prime number continue; } // System.out.print(x+" "); for(int u=2*x;u<=n;u+=x){ sieve[u]=x; } } //If sieve[i]=0 means 'i' is primr else 'i' is not prime } //sort public static void sort(long[] arr) { int n = arr.length; for (int i = 0; i < n; i++) { int idx = (int) Math.random() * n; long temp = arr[i]; arr[i] = arr[idx]; arr[idx] = temp; //swap } Arrays.sort(arr); } public static void sort(int[] arr) { int n = arr.length; for (int i = 0; i < n; i++) { int idx = (int) Math.random() * n; int temp = arr[i]; arr[i] = arr[idx]; arr[idx] = temp; //swap } Arrays.sort(arr); } //1d print public static void print(int[] dp) { for (int val : dp) { System.out.print(val + " "); } System.out.println(); } public static void print(long[] dp) {//Method Overloading for (long val : dp) { System.out.print(val + " "); } System.out.println(); } //2d print public static void print(long[][] dp) {//Method Overloading for (long[] a : dp) { for (long val : a) { System.out.print(val + " "); } System.out.println(); } } public static void print(int[][] dp) { for (int[] a : dp) { for (int val : a) { System.out.print(val + " "); } System.out.println(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
cfb2527a128e02373c62ca80ddaf87ff
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; import java.lang.*; public class cf719 { public static int query(int l,int r) throws Exception{ if(l>=r)return -1; InputStreamReader ip=new InputStreamReader(System.in); BufferedReader br = new BufferedReader(ip); System.out.println("? "+(l+1)+" "+(r+1)); int ans=Integer.parseInt(br.readLine()); return ans-1; } public static void Hard() throws Exception{ InputStreamReader ip=new InputStreamReader(System.in); BufferedReader br = new BufferedReader(ip); int n =Integer.parseInt(br.readLine()); // String[] strs=(br.readLine()).trim().split(" "); int l=0,r=n; //so that segment divide equally by mid [l,mid) [mid,r) int smax=query(l, r-1); //segment max int ans=0; if(smax==0 || query(0, smax)!=smax){ l=smax; r=n-1; //Max lie in right segment while((r-l)>1){ int mid=l+(r-l)/2; if(query(smax,mid)==smax){ r=mid; }else{ l=mid; } } System.out.println("! "+(r+1)); //+r+" " }else{ l=0; r=smax; //Max lie in left segment while((r-l)>1){ int mid=l+(r-l)/2; if(query(mid,smax)==smax){ l=mid; }else{ r=mid; } } System.out.println("! "+(l+1)); } } public static void Easy() throws Exception{ InputStreamReader ip=new InputStreamReader(System.in); BufferedReader br = new BufferedReader(ip); int n =Integer.parseInt(br.readLine()); // String[] strs=(br.readLine()).trim().split(" "); int l=0,r=n; //so that segment divide equally by mid [l,mid) [mid,r) int ans=0; while((r-l)>1){ // query possible for segment of size >1 int mid=l+(r-l)/2; // if(l==mid){ // last segment of size 2 This condition is mandatory otherwise loop goes in infinite loop // if(query(l, r)==l){ ans=r;} // else{ ans=l; } break; // } int smax=query(l, r-1); //segment max if(smax<mid){ if(query(l, mid-1)==smax){ r=mid; }else{ l=mid; } }else{ if(query(mid, r-1)==smax){ l=mid; }else{ r=mid; } } // System.out.println(l+" "+r); } System.out.println("! "+r); //+r+" " } //******************************************************************************************************************** */ public static void main(String[] args) throws Exception{ Hard(); } public static void solve3() throws Exception{ InputStreamReader ip=new InputStreamReader(System.in); BufferedReader br = new BufferedReader(ip); int t = Integer.parseInt(br.readLine()); StringBuilder asb=new StringBuilder(); while(t-->0){ int n =Integer.parseInt(br.readLine()); String[] strs=(br.readLine()).trim().split(" "); // int n=Integer.parseInt(strs[0]),k=Integer.parseInt(strs[1]),r=Integer.parseInt(strs[2]),s=Integer.parseInt(strs[3]); // String str=(br.readLine()).trim(); //Rearrange Given Expression- a𝑗−a𝑖=𝑗−𝑖 => aj-j == ai-i int[] arr=new int[n]; HashMap<Integer,Integer> hm=new HashMap<>(); for(int i=0;i<n;i++){ arr[i]=Integer.parseInt(strs[i]); hm.put((arr[i]-i), hm.getOrDefault((arr[i]-i), 0)+1); } long ans=0; for(int key:hm.keySet()){ long ct=hm.get(key); ans+=(ct*(ct-1))/2; } // System.out.println(ans+" ct "+ct); System.out.println(ans); } } //******************************************************************************************************************** */ public static long modInverse1(long a, long m){ // int g = gcd(a, m); // if(g!=1) {System.out.println("Inverse Doesnot Exist");} return binexp(a, m - 2, m); } public static long binexp(long a, long b, long m){ if (b == 0)return 1; long res = binexp(a, b / 2, m); if (b % 2 == 1) return (( (res*res)%m )*a) % m; else return (res*res)%m; } //binexp public static long binexp(long a,long b){ if(b==0)return 1; long res=binexp(a, b/2); if(b%2==1){ return (((res*res))*a); }else return (res*res); } //Comparator Interface public static class comp implements Comparator<int[]>{ public int compare(int[] a,int[] b){ return a[0]-b[0]; } } //gcd using Euclid's Division Algorithm public static long gcd(long a,long b){ if(b==0)return a; else return gcd(b, a%b); } //check prime in root(n) public static int isprime(int n){ for(int i=2;i<=Math.sqrt(n);i++){ if(n%i==0)return i; } return -1; //means n is prime } //SOE static int[] sieve; public static void SOE(int n){ sieve=new int[n+1]; // System.out.println("All prime number from 1 to n:-"); for(int x=2;x<=n;x++){ if(sieve[x]!=0){ //Not prime number continue; } // System.out.print(x+" "); for(int u=2*x;u<=n;u+=x){ sieve[u]=x; } } //If sieve[i]=0 means 'i' is primr else 'i' is not prime } //sort public static void sort(long[] arr) { int n = arr.length; for (int i = 0; i < n; i++) { int idx = (int) Math.random() * n; long temp = arr[i]; arr[i] = arr[idx]; arr[idx] = temp; //swap } Arrays.sort(arr); } public static void sort(int[] arr) { int n = arr.length; for (int i = 0; i < n; i++) { int idx = (int) Math.random() * n; int temp = arr[i]; arr[i] = arr[idx]; arr[idx] = temp; //swap } Arrays.sort(arr); } //1d print public static void print(int[] dp) { for (int val : dp) { System.out.print(val + " "); } System.out.println(); } public static void print(long[] dp) {//Method Overloading for (long val : dp) { System.out.print(val + " "); } System.out.println(); } //2d print public static void print(long[][] dp) {//Method Overloading for (long[] a : dp) { for (long val : a) { System.out.print(val + " "); } System.out.println(); } } public static void print(int[][] dp) { for (int[] a : dp) { for (int val : a) { System.out.print(val + " "); } System.out.println(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
3d89019bec7646237b7ed3cf73055123
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.Scanner; public class D { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); int mid = ask(1, n, sc); if (mid < n && ask(mid, n, sc) == mid) { solve(mid, n, false, sc, mid); } else { solve(1, mid, true, sc, mid); } } public static void solve(int a, int b, boolean isRight, Scanner sc, int mid) { int l = a, r = b; if (isRight) r--; else l++; int ans = 0; while (l <= r) { int m = (l+r)/2; // System.out.println("l, m, r: "+l+","+m+","+r); if (isRight) { int res = ask(m, b, sc); // System.out.println("res: "+res); if (res == mid) { ans = m; l = m+1; } else r = m-1; } else { int res = ask(a, m, sc); // System.out.println("res: "+res); if (res == mid) { ans = m; r = m-1; } else l = m+1; } } System.out.println("! "+ans); } public static int ask(int l, int r, Scanner sc) { System.out.println("? "+l+" "+r); System.out.flush(); return sc.nextInt(); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
e06562fa1e915b201b735a54ffc876ee
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.*; public class Main { static class DisjointUnionSets { int[] rank, parent; int n; // Constructor public DisjointUnionSets(int n) { rank = new int[n]; parent = new int[n]; this.n = n; makeSet(); } // Creates n sets with single item in each void makeSet() { for (int i = 0; i < n; i++) { // Initially, all elements are in // their own set. parent[i] = i; } } // Returns representative of x's set int find(int x) { // Finds the representative of the set // that x is an element of if (parent[x] != x) { // if x is not the parent of itself // Then x is not the representative of // his set, parent[x] = find(parent[x]); // so we recursively call Find on its parent // and move i's node directly under the // representative of this set } return parent[x]; } // Unites the set that includes x and the set // that includes x void union(int x, int y) { // Find representatives of two sets int xRoot = find(x), yRoot = find(y); // Elements are in the same set, no need // to unite anything. if (xRoot == yRoot) return; // If x's rank is less than y's rank if (rank[xRoot] < rank[yRoot]) // Then move x under y so that depth // of tree remains less parent[xRoot] = yRoot; // Else if y's rank is less than x's rank else if (rank[yRoot] < rank[xRoot]) // Then move y under x so that depth of // tree remains less parent[yRoot] = xRoot; else // if ranks are the same { // Then move y under x (doesn't matter // which one goes where) parent[yRoot] = xRoot; // And increment the result tree's // rank by 1 rank[xRoot] = rank[xRoot] + 1; } } } static class MyScanner { BufferedReader br; StringTokenizer st; public MyScanner() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine(){ String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } static class HashMultiSet<T> implements Iterable<T> { private final HashMap<T,Integer> map; private int size; public HashMultiSet(){map=new HashMap<>(); size=0;} public void clear(){map.clear(); size=0;} public int size(){return size;} public int setSize(){return map.size();} public boolean contains(T a){return map.containsKey(a);} public boolean isEmpty(){return size==0;} public Integer get(T a){return map.getOrDefault(a,0);} public void add(T a, int count) { int cur=get(a);map.put(a,cur+count); size+=count; if(cur+count==0) map.remove(a); } public void addOne(T a){add(a,1);} public void remove(T a, int count){add(a,Math.max(-get(a),-count));} public void removeOne(T a){remove(a,1);} public void removeAll(T a){remove(a,Integer.MAX_VALUE-10);} public Iterator<T> iterator() { return new Iterator<>() { private final Iterator<T> iter = map.keySet().iterator(); private int count = 0; private T curElement; public boolean hasNext(){return iter.hasNext()||count>0;} public T next() { if(count==0) { curElement=iter.next(); count=get(curElement); } count--; return curElement; } }; } } private static long abs(long x){ if(x < 0) x*=-1l;return x; } private static int abs(int x){ if(x < 0) x*=-1;return x; } // public static int get(HashMap<Integer, Deque<Integer> > a, int key ){ // return a.get(key).getLast(); // } // public static void removeLast (HashMap<Integer,Deque<Integer> > a, int key){ // if(a.containsKey(key)){ // a.get(key).removeLast(); // if(a.get(key).size() == 0) a.remove(key); // } // } // public static void add(HashMap<Integer,Deque<Integer>> a, int key, int val){ // if(a.containsKey(key)){ // a.get(key).addLast(val); // }else{ // Deque<Integer> b = new LinkedList<>(); // b.addLast(val); // a.put(key,b); // } // } private static int askRange(int l ,int r){ if(l == r) return l; MyScanner sc = new MyScanner(); System.out.println("? "+l+" "+r); System.out.flush(); return sc.nextInt(); } private static int binr(int l ,int r,int v){ if(l > r) return Integer.MAX_VALUE; int mid = (r+l) /2; if(askRange(v,mid) == v){ int x = binr(l,mid-1,v); return Math.min(x,mid); }else{ int x = binr(mid+1,r,v); return x; } } private static int binl(int l,int r,int v){ if (l > r) return Integer.MIN_VALUE; int mid = (l+r) /2; if(askRange(mid,v) == v){ int x = binl(mid+1,r,v); return Math.max(x,mid); }else{ int x = binl(l,mid-1,v); return x; } } public static void main(String[] args) { MyScanner sc = new MyScanner(); int n = sc.nextInt(); int v = askRange(1,n); int v1 = askRange(v,n); if(v == v1 && v != n){ System.out.println("! " +binr(v+1,n,v)); }else{ System.out.println("! "+binl(1,v-1,v)); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
8fba1039c9eccaa33fe71b3cac378871
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; public class C2_Rnd703_Div2 { static int n; public static void main(String[] args) throws NumberFormatException, IOException { BufferedReader scan = new BufferedReader(new InputStreamReader(System.in)); PrintWriter out = new PrintWriter(System.out); n = Integer.parseInt(scan.readLine()); int ans = solve(n, scan, out); out.println("! " + (ans+1)); out.flush(); } public static int parse(String num) { return Integer.parseInt(num); } public static int solve(int n, BufferedReader scan, PrintWriter out) throws IOException { int smax = query(0, n-1, scan, out); if(smax == 0) return binSearchRight(smax, scan, out); else if(smax == n-1) return binSearchLeft(smax, scan, out); else if(query(0, smax, scan, out) == smax) return binSearchLeft(smax, scan, out); else return binSearchRight(smax, scan, out); } public static int binSearchLeft(int smax, BufferedReader scan, PrintWriter out) throws IOException { int low = 1, high = smax - 1, mid; int index = 0; while(low <= high) { mid = (low + high) / 2; // smax is in this range if(sendQuery(mid, smax, scan, out) == smax) { low = mid + 1; if(index < mid) index = mid; } else { high = mid - 1; } } return index; } // need to make sure this doesn't make a query of length 1 private static int binSearchRight(int smax, BufferedReader scan, PrintWriter out) throws IOException { int low = smax + 1, high = n - 2, mid; int index = n - 1; while(low <= high) { mid = (low + high) / 2; // smax is in that range if(sendQuery(mid, smax, scan, out) == smax) { high = mid - 1; if(index > mid) index = mid; } else { low = mid + 1; } } return index; } private static int sendQuery(int a, int b, BufferedReader scan, PrintWriter out) throws IOException { if(a > b) return query(b, a, scan, out); else return query(a, b, scan, out); } public static int query(int l, int r, BufferedReader scan, PrintWriter out) throws IOException { out.println("? " + (l+1) + " " + (r+1)); out.flush(); return parse(scan.readLine()) - 1; } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
a8e79cf35441397f7e59bb38802cef69
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.ArrayList; import java.util.Arrays; import java.util.Scanner; import java.io.*; import java.util.*; public class CFEd { public static void main(String[] args) { Scanner us = new Scanner(System.in); int n = us.nextInt(); ask(1, n); int response = us.nextInt(); if(response == 1) { searchRight(response, us, n); } else if(response == n) { searchLeft(response, us); } else { ask(1, response); int res2 = us.nextInt(); if(res2 == response) { searchLeft(response, us); } else { searchRight(response, us, n); } } } static void ask(int i, int j) { System.out.println("? " + i + " " + j); System.out.flush(); } static void searchLeft(int start, Scanner us) { int ubnd = start - 1; int lbnd = 1; while(ubnd - lbnd > 1) { int mid = (ubnd + lbnd)/2; ask(mid, start); int response = us.nextInt(); if(response == start) { lbnd = mid; } else { ubnd = mid - 1; } } if(ubnd == lbnd) { System.out.println("! " + ubnd); } else { ask(ubnd, start); int response = us.nextInt(); if(response == start) { System.out.println("! " + ubnd); } else { System.out.println("! " + lbnd); } } } static void searchRight(int start, Scanner us, int n) { int ubnd = n; int lbnd = start + 1; while(ubnd - lbnd > 1) { int mid = (ubnd + lbnd)/2; ask(start, mid); int response = us.nextInt(); if(response == start) { ubnd = mid; } else { lbnd = mid + 1; } } if(ubnd == lbnd) { System.out.println("! " + ubnd); } else { ask(start, lbnd); int response = us.nextInt(); if(response == start) { System.out.println("! " + lbnd); } else { System.out.println("! " + ubnd); } } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
b003e7e51359aa907fd0a33a55ff3b01
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; public class tank { //static StringBuilder IO = new StringBuilder(); //static final Scanner scan = new Scanner(System.in); static final FastScanner fs = new FastScanner(); public static void main(String[] args) { // int t = fs.nextInt(); // while(t-->0){ // SLV(); // } SLV(); //System.out.println(IO); } static void SLV(){ int n = fs.nextInt(); int smax = ask(1, n), ans; if(smax == 1) { ans = fn(2, n, 1); }else if(smax == n){ ans = fn(1, n-1, n); }else{ if(ask(1, smax) == smax){ ans = fn(1, smax - 1, smax); }else ans = fn(smax + 1, n, smax); } System.out.println("! " + ans); } static int fn(int l ,int r, int smax){ int mid = (l + r)/2; if(r == l) return l; if(smax > r){ if(l == r-1){ if(ask(r, smax) == smax) return r; else return l; } if(ask(mid , smax) == smax) return fn(mid, r, smax); else return fn(l, mid - 1, smax); }else{ if(l == r - 1){ if(ask(smax, l) == smax) return l; else return r; } if(smax == ask(smax, mid)) return fn(l, mid, smax); else return fn(mid + 1,r, smax); } } static int ask(int l, int r){ if(l == r) return l; System.out.println("? " + l + " " + r); int num = fs.nextInt(); System.out.flush(); return num; } static class FastScanner { BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st=new StringTokenizer(""); String next() { while (!st.hasMoreTokens()) try { st=new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } int[] readArray(int n) { int[] a=new int[n]; for (int i=0; i<n; i++) a[i]=nextInt(); return a; } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
f06170ea3badab724a5648976d47a03c
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.Scanner; public class Index { static Scanner scan = new Scanner(System.in); static int query(int l, int r) { if(l>=r)return 0; System.out.printf("? %d %d\n", l, r); System.out.flush(); return scan.nextInt(); } public static void main(String[] args) { int l = 1, r = scan.nextInt(), mid, x; int second_max = query(l, r); while (l < r) { mid = (l + r) / 2; if (second_max <= mid) { x = query(Math.min(l, second_max), mid); if (x == second_max) r = mid; else l = mid + 1; } else { x = query(mid + 1, Math.max(second_max, r)); if (x == second_max) l = mid + 1; else r = mid; } } System.out.printf("! %d\n", l); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
34b21000f7c478f4520c3c8da2608be0
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n=sc.nextInt(); System.out.println("? 1 "+n); System.out.flush(); int x=sc.nextInt(); boolean f=false; if (x!=1) { f=true; System.out.println("? 1 " + x); } System.out.flush(); int newX=-1; if (f) newX = sc.nextInt(); if (newX==x){ int l=1, r=x; int ans=-1; while (l<=r){ int m=(l+r)/2; if (m==x){ System.out.println("! "+(m-1)); System.out.flush(); return; } System.out.println("? "+m+" "+x); System.out.flush(); newX=sc.nextInt(); if (newX==x){ ans=m; l=m+1; }else { r=m-1; } } System.out.println("! "+(ans)); System.out.flush(); }else { int r=n,l=x; int ans=-1; while (l<=r){ int m=(l+r)/2; if (m==x){ System.out.println("! "+(m+1)); System.out.flush(); return; } System.out.println("? "+x+" "+m); System.out.flush(); newX=sc.nextInt(); if (newX==x){ r=m-1; }else { l=m+1; } } System.out.println("! "+(l)); System.out.flush(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
fbf599dbfcacc1a1ab7eaa02158c974c
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; //My life seems to be a joke. But, one day I will conquer. public class B{ public static Scanner sc = new Scanner(System.in); public static int query(int l, int r) { if(l>=r)return -1; System.out.println("? "+l+" "+r); int a = sc.nextInt(); return a; } public static void main(String[] args) { FastScanner fs = new FastScanner(); PrintWriter out = new PrintWriter(System.out); int n = fs.nextInt(); int l = 1; int r = n; int pos = query(l,r); if(pos==1 || query(1,pos)!=pos) { int left = pos; int right = n; while(left+1<right) { int mid = (left+right)/2; if(query(pos,mid)==pos) { right = mid; } else{ left = mid; } } System.out.println("! "+right); } else { int left = 1; int right = pos; while(left+1<right) { int mid = (left+right)/2; if(query(mid,pos)==pos) { left = mid; } else { right = mid; } } System.out.println("! "+left); } out.close(); } static class FastScanner { BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st=new StringTokenizer(""); String next() { while (!st.hasMoreTokens()) try { st=new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } int[] readArray(int n) { int[] a=new int[n]; for (int i=0; i<n; i++) a[i]=nextInt(); return a; } long nextLong() { return Long.parseLong(next()); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
5706ccef4ac2d203215fc656bed96eb9
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.io.*; public class Main { static class Scan { private byte[] buf=new byte[1024]; private int index; private InputStream in; private int total; public Scan() { in=System.in; } public int scan()throws IOException { if(total<0) throw new InputMismatchException(); if(index>=total) { index=0; total=in.read(buf); if(total<=0) return -1; } return buf[index++]; } public int scanInt()throws IOException { int integer=0; int n=scan(); while(isWhiteSpace(n)) n=scan(); int neg=1; if(n=='-') { neg=-1; n=scan(); } while(!isWhiteSpace(n)) { if(n>='0'&&n<='9') { integer*=10; integer+=n-'0'; n=scan(); } else throw new InputMismatchException(); } return neg*integer; } public double scanDouble()throws IOException { double doub=0; int n=scan(); while(isWhiteSpace(n)) n=scan(); int neg=1; if(n=='-') { neg=-1; n=scan(); } while(!isWhiteSpace(n)&&n!='.') { if(n>='0'&&n<='9') { doub*=10; doub+=n-'0'; n=scan(); } else throw new InputMismatchException(); } if(n=='.') { n=scan(); double temp=1; while(!isWhiteSpace(n)) { if(n>='0'&&n<='9') { temp/=10; doub+=(n-'0')*temp; n=scan(); } else throw new InputMismatchException(); } } return doub*neg; } public String scanString()throws IOException { StringBuilder sb=new StringBuilder(); int n=scan(); while(isWhiteSpace(n)) n=scan(); while(!isWhiteSpace(n)) { sb.append((char)n); n=scan(); } return sb.toString(); } private boolean isWhiteSpace(int n) { if(n==' '||n=='\n'||n=='\r'||n=='\t'||n==-1) return true; return false; } } public static void sort(int arr[],int l,int r) { //sort(arr,0,n-1); if(l==r) { return; } int mid=(l+r)/2; sort(arr,l,mid); sort(arr,mid+1,r); merge(arr,l,mid,mid+1,r); } public static void merge(int arr[],int l1,int r1,int l2,int r2) { int tmp[]=new int[r2-l1+1]; int indx1=l1,indx2=l2; //sorting the two halves using a tmp array for(int i=0;i<tmp.length;i++) { if(indx1>r1) { tmp[i]=arr[indx2]; indx2++; continue; } if(indx2>r2) { tmp[i]=arr[indx1]; indx1++; continue; } if(arr[indx1]<arr[indx2]) { tmp[i]=arr[indx1]; indx1++; continue; } tmp[i]=arr[indx2]; indx2++; } //Copying the elements of tmp into the main array for(int i=0,j=l1;i<tmp.length;i++,j++) { arr[j]=tmp[i]; } } public static void sort(long arr[],int l,int r) { //sort(arr,0,n-1); if(l==r) { return; } int mid=(l+r)/2; sort(arr,l,mid); sort(arr,mid+1,r); merge(arr,l,mid,mid+1,r); } public static void merge(long arr[],int l1,int r1,int l2,int r2) { long tmp[]=new long[r2-l1+1]; int indx1=l1,indx2=l2; //sorting the two halves using a tmp array for(int i=0;i<tmp.length;i++) { if(indx1>r1) { tmp[i]=arr[indx2]; indx2++; continue; } if(indx2>r2) { tmp[i]=arr[indx1]; indx1++; continue; } if(arr[indx1]<arr[indx2]) { tmp[i]=arr[indx1]; indx1++; continue; } tmp[i]=arr[indx2]; indx2++; } //Copying the elements of tmp into the main array for(int i=0,j=l1;i<tmp.length;i++,j++) { arr[j]=tmp[i]; } } public static void main(String args[]) throws IOException { Scan input=new Scan(); int n=input.scanInt(); if(n==1) { System.out.println("! 1"); return; } System.out.println("? "+1+" "+n); System.out.flush(); int indx=input.scanInt(); int ans=-1; int lft=-1; if(indx!=1) { System.out.println("? "+1+" "+indx); System.out.flush(); lft=input.scanInt(); } int l,r; //Right if(lft!=indx) { l=indx+1; r=n; while(l<=r) { int mid=(l+r)/2; System.out.println("? "+indx+" "+mid); System.out.flush(); int idx=input.scanInt(); if(idx==indx) { ans=mid; r=mid-1; } else { l=mid+1; } } } if(lft==indx) { //left l=1; r=indx-1; while(l<=r) { int mid=(l+r)/2; System.out.println("? "+mid+" "+indx); System.out.flush(); int idx=input.scanInt(); if(idx==indx) { ans=mid; l=mid+1; } else { r=mid-1; } } } System.out.println("! "+ans); } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
8c6e20e0b7a3d6fca28df6a3d410d715
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.*; import java.util.*; import java.math.*; public class Solution{ public static void main(String[] args) { TaskA solver = new TaskA(); // int t = in.nextInt(); // for (int i = 1; i <= t ; i++) { // solver.solve(i, in, out); // } solver.solve(1, in, out); out.flush(); out.close(); } static class TaskA { public void solve(int testNumber, InputReader in, PrintWriter out) { int n= in.nextInt();boolean isL=false;boolean isR=false; int smax=query(1,n); if(smax==1) { isR=true; } else { int x=query(1,smax); if(x==smax) { isL=true; } else { isR=true; } } if(isL) { int l=1;int r=smax; while(r>l) { if(l==smax-1) { System.out.println("! "+(l));return; } int mid=(r+l)/2; int x=query(mid,smax); if(x==smax) { l=mid+1; } else { r=mid; } } System.out.println("! "+(l-1));return; } else { int l=smax;int r=n; while(r>l) { if(r==smax+1) { System.out.println("! "+(r));return; } int mid=(r+l)/2; int x=query(smax,mid); if(x==smax) { r=mid; } else { l=mid+1; } } System.out.println("! "+(r));return; } } } static int query(int l,int r) { System.out.println("? "+l+" "+r); System.out.print ("\n"); int x=in.nextInt(); return x; } static boolean check(Pair[]arr,int mid,int n) { int c=0; for(int i=0;i<n;i++) { if(mid-1-arr[i].first<=c&&c<=arr[i].second) { c++; } } return c>=mid; } static long sum(int[]arr) { long s=0; for(int x:arr) { s+=x; } return s; } static long sum(long[]arr) { long s=0; for(long x:arr) { s+=x; } return s; } static int gcd(int a, int b) { if (b == 0) return a; return gcd(b, a % b); } static void sort(int[] a) { ArrayList<Integer> q = new ArrayList<>(); for (int i : a) q.add(i); Collections.sort(q); for (int i = 0; i < a.length; i++) a[i] = q.get(i); } static void sort(long[] a) { ArrayList<Long> q = new ArrayList<>(); for (long i : a) q.add(i); Collections.sort(q); for (int i = 0; i < a.length; i++) a[i] = q.get(i); } static void println(int[][]arr) { for(int i=0;i<arr.length;i++) { for(int j=0;j<arr[0].length;j++) { print(arr[i][j]+" "); } print("\n"); } } static void println(long[][]arr) { for(int i=0;i<arr.length;i++) { for(int j=0;j<arr[0].length;j++) { print(arr[i][j]+" "); } print("\n"); } } static void println(int[]arr){ for(int i=0;i<arr.length;i++) { print(arr[i]+" "); } print("\n"); } static void println(long[]arr){ for(int i=0;i<arr.length;i++) { print(arr[i]+" "); } print("\n"); } static long[]input(int n){ long[]arr=new long[n]; for(int i=0;i<n;i++) { arr[i]=in.nextInt(); } return arr; } static long[]input(){ long n= in.nextInt(); long[]arr=new long[(int)n]; for(int i=0;i<n;i++) { arr[i]=in.nextLong(); } return arr; } //////////////////////////////////////////////////////// static class Pair { long first; long second; Pair(long x, long y) { this.first = x; this.second = y; } } static void sortS(Pair arr[]) { Arrays.sort(arr, new Comparator<Pair>() { @Override public int compare(Pair p1, Pair p2) { return (int)(p1.second - p2.second); } }); } static void sortF(Pair arr[]) { Arrays.sort(arr, new Comparator<Pair>() { @Override public int compare(Pair p1, Pair p2) { return (int)(p1.first - p2.first); } }); } ///////////////////////////////////////////////////////////// static InputStream inputStream = System.in; static OutputStream outputStream = System.out; static InputReader in = new InputReader(inputStream); static PrintWriter out = new PrintWriter(outputStream); static void println(long c) { out.println(c); } static void print(long c) { out.print(c); } static void print(int c) { out.print(c); } static void println(int x) { out.println(x); } static void print(String s) { out.print(s); } static void println(String s) { out.println(s); } static void println(boolean b) { out.println(b); } static class InputReader { public BufferedReader reader; public StringTokenizer tokenizer; public InputReader(InputStream stream) { reader = new BufferedReader(new InputStreamReader(stream), 32768); tokenizer = null; } public String next() { while (tokenizer == null || !tokenizer.hasMoreTokens()) { try { tokenizer = new StringTokenizer(reader.readLine()); } catch (IOException e) { throw new RuntimeException(e); } } return tokenizer.nextToken(); } public int nextInt() { return Integer.parseInt(next()); } public long nextLong() { return Long.parseLong(next()); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
ed1f8929d3f8468ca750027982e162ef
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
/* "Everything in the universe is balanced. Every disappointment you face in life will be balanced by something good for you! Keep going, never give up." Just have Patience + 1... */ import java.util.*; import java.lang.*; import java.io.*; public class Solution { public static void main(String[] args) throws java.lang.Exception { out = new PrintWriter(new BufferedOutputStream(System.out)); sc = new FastReader(); int test = 1; for (int t = 1; t <= test; t++) { solve(); } out.close(); } private static void solve() { int n = sc.nextInt(); int smax = interact(0, n - 1); if (smax == 0 || interact(0, smax) != smax) { int l = smax, r = n - 1; while (r - l > 1) { int mid = (l + r) / 2; if (interact(smax, mid) == smax) { r = mid; }else { l = mid; } } out.println("! " + (r + 1)); }else { int l = 0, r = smax; while (r - l > 1) { int mid = (l + r) / 2; if (interact(mid, smax) == smax) { l = mid; }else { r = mid; } } out.println("! " + (l + 1)); } } private static int interact(int l, int r) { if (l >= r) { return -1; } out.println("? " + (l + 1) + " " + (r + 1)); out.flush(); int index = sc.nextInt(); return index - 1; } public static FastReader sc; public static PrintWriter out; static class FastReader { BufferedReader br; StringTokenizer str; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (str == null || !str.hasMoreElements()) { try { str = new StringTokenizer(br.readLine()); } catch (IOException lastMonthOfVacation) { lastMonthOfVacation.printStackTrace(); } } return str.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException lastMonthOfVacation) { lastMonthOfVacation.printStackTrace(); } return str; } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
497e598cd8560d002e7357b9bd19ba1f
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.util.ArrayList; import java.util.Arrays; import java.util.Random; import java.util.StringTokenizer; public class Solution { static ArrayList<String> list; public static void main(String[] args) { PrintWriter out = new PrintWriter(System.out); FastScanner fs = new FastScanner(); int ti = 1; outer: while (ti-- > 0) { int n = fs.nextInt(); int l = 0; int r = n; int s = ck(0, n - 1); if (s == 0 || ck(0, s) != s) { l = s; r = n - 1; while (r - l > 1) { int m = (l + r) / 2; if (ck(s, m) == s) r = m; else l = m; } System.out.println("! " + (r + 1)); return; } else { l = 0; r = s; while (r - l > 1) { int m = (l + r) / 2; if (ck(m, s) == s) l = m; else r = m; } System.out.println("! " + (l + 1)); return; } } out.close(); } private static int ck(int l, int r) { if (l >= r) return -1; l++; r++; System.out.println("? " + l + " " + r); FastScanner fs = new FastScanner(); int k = fs.nextInt(); return k - 1; } static final int mod = 1_000_000_007; static void sort(long[] a) { Random random = new Random(); int n = a.length; for (int i = 0; i < n; i++) { int oi = random.nextInt(n); long temp = a[oi]; a[oi] = a[i]; a[i] = temp; } Arrays.sort(a); } static void sort(int[] a) { Random random = new Random(); int n = a.length; for (int i = 0; i < n; i++) { int oi = random.nextInt(n), temp = a[oi]; a[oi] = a[i]; a[i] = temp; } Arrays.sort(a); } static long add(long a, long b) { return (a + b) % mod; } static long sub(long a, long b) { return ((a - b) % mod + mod) % mod; } static long mul(long a, long b) { return (a * b) % mod; } static long exp(long base, long exp) { if (exp == 0) return 1; long half = exp(base, exp / 2); if (exp % 2 == 0) return mul(half, half); return mul(half, mul(half, base)); } static long[] factorials = new long[2_000_001]; static long[] invFactorials = new long[2_000_001]; static void precompFacts() { factorials[0] = invFactorials[0] = 1; for (int i = 1; i < factorials.length; i++) factorials[i] = mul(factorials[i - 1], i); invFactorials[factorials.length - 1] = exp(factorials[factorials.length - 1], mod - 2); for (int i = invFactorials.length - 2; i >= 0; i--) invFactorials[i] = mul(invFactorials[i + 1], i + 1); } static long nCk(int n, int k) { return mul(factorials[n], mul(invFactorials[k], invFactorials[n - k])); } static boolean isPrime(int n) { if (n <= 1) return false; else if (n == 2) return true; else if (n % 2 == 0) return false; for (int i = 3; i <= Math.sqrt(n); i += 2) { if (n % i == 0) return false; } return true; } static int gcd(int a, int b) { if (b == 0) return a; return gcd(b, a % b); } static long gcd(long a, long b) { if (b == 0) return a; return gcd(b, a % b); } static long binpow(long a, long b, long m) { a %= m; long res = 1; while (b > 0) { if (b % 2 == 1) res = res * a % m; a = a * a % m; b >>= 1; } return res; } static int divCount(int n) { boolean hash[] = new boolean[n + 1]; Arrays.fill(hash, true); for (int p = 2; p * p < n; p++) if (hash[p] == true) for (int i = p * 2; i < n; i += p) hash[i] = false; int total = 1; for (int p = 2; p <= n; p++) { if (hash[p]) { int count = 0; if (n % p == 0) { while (n % p == 0) { n = n / p; count++; } total = total * (count + 1); } } } return total; } static class FastScanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); String next() { while (!st.hasMoreTokens()) try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } int[] readArray(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } long nextLong() { return Long.parseLong(next()); } } static class Pair { int a; int b; public Pair(int a, int b) { this.a = a; this.b = b; } } static class ST { int leftmost, rightmost; ST lChild, rChild; int sum; public ST(ST cur) { this.leftmost = cur.leftmost; this.rightmost = cur.rightmost; this.lChild = cur.lChild; this.rChild = cur.rChild; } public ST(int leftmost, int rightmost) { this.leftmost = leftmost; this.rightmost = rightmost; if (leftmost != rightmost) { int mid = (leftmost + rightmost) / 2; lChild = new ST(leftmost, mid); rChild = new ST(mid + 1, rightmost); recalc(); } } void recalc() { if (leftmost == rightmost) return; sum = lChild.sum + rChild.sum; } ST pointUpdate(int index, int val) { if (leftmost == rightmost) { ST cur = new ST(index, index); cur.sum += 1; return cur; } ST cur = new ST(this); int mid = (leftmost + rightmost) / 2; if (index <= mid) { cur.lChild = lChild.pointUpdate(index, val); } else cur.rChild = rChild.pointUpdate(index, val); cur.recalc(); return cur; } int rangeSum(int l, int r) { if (l > rightmost || r < leftmost) return 0; if (l <= leftmost && r >= rightmost) return sum; return lChild.rangeSum(l, r) + rChild.rangeSum(l, r); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
328378c45afc83312e2ebc6183bc634d
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.util.*; import java.lang.*; import java.io.*; public class Main { void solve() { int n = in.nextInt(); int low = 1; int high = n; int secondLast = query(1, n); if (secondLast == 1) { low = 2; } else if (secondLast == n) { high = n - 1; } else { int onLeft = query(1, secondLast); if (onLeft == secondLast) { high = secondLast - 1; } else { low = secondLast + 1; } } int res = 0; while (low <= high) { int mid = (low + high) / 2; int l = secondLast; int r = mid; if (mid < secondLast) { l = mid; r = secondLast; } int val = query(l, r); if (val != secondLast) { if (r == secondLast) { high = mid - 1; } else { low = mid + 1; } } else { res = mid; if (r == secondLast) { low = mid + 1; } else { high = mid - 1; } } } System.out.println("! " + res); } int query(int l, int r) { System.out.println("? " + l + " " + r); int val = in.nextInt(); System.out.flush(); return val; } public static void main (String[] args) { // It happens - Syed Mizbahuddin Main sol = new Main(); int t = 1; // t = in.nextInt(); while (t-- != 0) { sol.solve(); } System.out.print(out); } <T> void println(T[] s) { if (err == null)return; err.println(Arrays.toString(s)); } <T> void println(T s) { if (err == null)return; err.println(s); } void println(int s) { if (err == null)return; err.println(s); } void println(int[] a) { if (err == null)return; println(Arrays.toString(a)); } int[] array(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) { a[i] = in.nextInt(); } return a; } int[] array1(int n) { int[] a = new int[n + 1]; for (int i = 1; i <= n; i++) { a[i] = in.nextInt(); } return a; } int max(int[] a) { int max = a[0]; for (int i = 0; i < a.length; i++)max = Math.max(max, a[i]); return max; } int min(int[] a) { int min = a[0]; for (int i = 0; i < a.length; i++)min = Math.min(min, a[i]); return min; } int count(int[] a, int x) { int count = 0; for (int i = 0; i < a.length; i++)if (x == a[i])count++; return count; } void printArray(int[] a) { for (int ele : a)out.append(ele + " "); out.append("\n"); } static { try { // System.setIn(new FileInputStream("input.txt")); // System.setOut(new PrintStream(new FileOutputStream("output.txt"))); // err = new PrintStream(new FileOutputStream("error.txt")); } catch (Exception e) {} } static FastReader in; static StringBuilder out; static PrintStream err; static String yes , no , endl; final int MAX; final int MIN; int mod ; Main() { in = new FastReader(); out = new StringBuilder(); MAX = Integer.MAX_VALUE; MIN = Integer.MIN_VALUE; mod = (int)1e9 + 7; yes = "YES\n"; no = "NO\n"; endl = "\n"; } class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader( new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } class Pair implements Comparable<Pair> { int first , second; Pair(int first, int second) { this.first = first; this.second = second; } public int compareTo(Pair b) { return this.first - b.first; } public String toString() { String s = "{ " + Integer.toString(first) + " , " + Integer.toString(second) + " }"; return s; } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output
PASSED
8cbada4c6d2e0e7fc686fcecaaa2ecf3
train_109.jsonl
1613658900
The only difference between the easy and the hard version is the limit to the number of queries.This is an interactive problem.There is an array $$$a$$$ of $$$n$$$ different numbers. In one query you can ask the position of the second maximum element in a subsegment $$$a[l..r]$$$. Find the position of the maximum element in the array in no more than 20 queries.A subsegment $$$a[l..r]$$$ is all the elements $$$a_l, a_{l + 1}, ..., a_r$$$. After asking this subsegment you will be given the position of the second maximum from this subsegment in the whole array.
256 megabytes
import java.io.DataInputStream; import java.io.IOException; import java.io.OutputStreamWriter; import java.io.PrintWriter; import java.util.Arrays; import java.util.Map; import java.util.TreeMap; public class Main { private static void run() throws IOException { int n = in.nextInt(); // TreeMap<Double, Integer> map = new TreeMap<>(); // for (int i = 1; i <= n; i++) { // map.put(Math.random(), i); // } // a = new int[n]; // int index = 0; // for (Map.Entry<Double, Integer> now : map.entrySet()) { // a[index++] = now.getValue(); // } //// print_array(a); // System.err.flush(); query_with_second(1, n, query(1, n)); } private static void query_with_second(int left, int right, int second) throws IOException { if (left == right) { out.printf("! %d \n", left); out.flush(); // check(left); return; } int mid = (left + right) >> 1; if (second <= mid) { int query_left = query(Math.min(left, second), mid); if (query_left == second) { query_with_second(left, mid, second); } else { query_with_second(mid + 1, right, second); } } else { int query_right = query(mid + 1, Math.max(right, second)); if (query_right == second) { query_with_second(mid + 1, right, second); } else { query_with_second(left, mid, second); } } } // static int[] a; // static int count = 0; // // private static void check(int ans) { // int[] tmp = new int[a.length]; // System.arraycopy(a, 0, tmp, 0, a.length); // Arrays.sort(tmp); // System.err.println(tmp[a.length - 1] + " " + a[ans - 1] + " " + (tmp[a.length - 1] == a[ans - 1])); // System.err.println("count: " + count); // System.err.flush(); // if (tmp[a.length - 1] != a[ans - 1] || count > 20) { // System.exit(0); // } // // count = 0; // } private static int query(int left, int right) throws IOException { if (left == right) return -1; out.printf("? %d %d\n", left, right); out.flush(); return in.nextInt(); // count++; // int[] tmp = new int[right - left + 1]; // for (int i = 0; i < right - left + 1; i++) { // tmp[i] = a[left + i - 1]; // } // Arrays.sort(tmp); // for (int i = left; i <= right; i++) { // if (a[i - 1] == tmp[right - left - 1]) { // System.err.println("input: " + i); // System.err.flush(); // return i; // } // } // System.err.println("input error"); // System.err.flush(); // throw new RuntimeException(); } public static void main(String[] args) throws IOException { in = new Reader(); out = new PrintWriter(new OutputStreamWriter(System.out)); // int t = in.nextInt(); // for (int i = 0; i < t; i++) { // } run(); out.flush(); in.close(); out.close(); } private static int gcd(int a, int b) { if (a == 0 || b == 0) return 0; while (b != 0) { int tmp; tmp = a % b; a = b; b = tmp; } return a; } static final long mod = 1000000007; static long pow_mod(long a, long b) { long result = 1; while (b != 0) { if ((b & 1) != 0) result = (result * a) % mod; a = (a * a) % mod; b >>= 1; } return result; } private static long multiplied_mod(long... longs) { long ans = 1; for (long now : longs) { ans = (ans * now) % mod; } return ans; } @SuppressWarnings("FieldCanBeLocal") private static Reader in; private static PrintWriter out; private static void print_array(int[] array) { for (int now : array) { System.err.print(now); System.err.print(' '); } System.err.println(); } private static void print_array(long[] array) { for (long now : array) { out.print(now); out.print(' '); } out.println(); } static class Reader { private static final int BUFFER_SIZE = 1 << 16; private final DataInputStream din; private final byte[] buffer; private int bufferPointer, bytesRead; Reader() { din = new DataInputStream(System.in); buffer = new byte[BUFFER_SIZE]; bufferPointer = bytesRead = 0; } public String readLine() throws IOException { final byte[] buf = new byte[1024]; // line length int cnt = 0, c; while ((c = read()) != -1) { if (c == '\n') { break; } buf[cnt++] = (byte) c; } return new String(buf, 0, cnt); } public int nextSign() throws IOException { byte c = read(); while ('+' != c && '-' != c) { c = read(); } return '+' == c ? 0 : 1; } private static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); } public int skip() throws IOException { int b; // noinspection ALL while ((b = read()) != -1 && isSpaceChar(b)) { ; } return b; } public char nc() throws IOException { return (char) skip(); } public String next() throws IOException { int b = skip(); final StringBuilder sb = new StringBuilder(); while (!isSpaceChar(b)) { // when nextLine, (isSpaceChar(b) && b != ' ') sb.appendCodePoint(b); b = read(); } return sb.toString(); } public int nextInt() throws IOException { int ret = 0; byte c = read(); while (c <= ' ') { c = read(); } final boolean neg = c == '-'; if (neg) { c = read(); } do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); if (neg) { return -ret; } return ret; } public long nextLong() throws IOException { long ret = 0; byte c = read(); while (c <= ' ') { c = read(); } final boolean neg = c == '-'; if (neg) { c = read(); } do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); if (neg) { return -ret; } return ret; } public double nextDouble() throws IOException { double ret = 0, div = 1; byte c = read(); while (c <= ' ') { c = read(); } final boolean neg = c == '-'; if (neg) { c = read(); } do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); if (c == '.') { while ((c = read()) >= '0' && c <= '9') { ret += (c - '0') / (div *= 10); } } if (neg) { return -ret; } return ret; } private void fillBuffer() throws IOException { bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); if (bytesRead == -1) { buffer[0] = -1; } } private byte read() throws IOException { if (bufferPointer == bytesRead) { fillBuffer(); } return buffer[bufferPointer++]; } public void close() throws IOException { din.close(); } } }
Java
["5\n\n3\n\n4"]
1 second
["? 1 5\n\n? 4 5\n\n! 1"]
NoteIn the sample suppose $$$a$$$ is $$$[5, 1, 4, 2, 3]$$$. So after asking the $$$[1..5]$$$ subsegment $$$4$$$ is second to max value, and it's position is $$$3$$$. After asking the $$$[4..5]$$$ subsegment $$$2$$$ is second to max value and it's position in the whole array is $$$4$$$.Note that there are other arrays $$$a$$$ that would produce the same interaction, and the answer for them might be different. Example output is given in purpose of understanding the interaction.
Java 11
standard input
[ "binary search", "interactive" ]
eb660c470760117dfd0b95acc10eee3b
The first line contains a single integer $$$n$$$ $$$(2 \leq n \leq 10^5)$$$ — the number of elements in the array.
1,900
null
standard output