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65.5k
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int64
-1
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hidden_unit_tests
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PASSED
ca7fd5d92bc0679ef75701836a83dbb1
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i < j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.math.BigInteger; import java.util.*; public class Jumper { public static void main(String[] args) { handmadeInput.FastReader in = new handmadeInput.FastReader(); StringBuilder stringBuilder = new StringBuilder(); int t = in.nextInt(); while (t-- > 0) { int n = in.nextInt(); long[] qus = new long[n + 1]; for (int i = 1; i <= n; i++) { qus[i] = in.nextInt(); } long ans = 0; for (int i = 1; i <= n; i++) { for (int j = (int) qus[i] - i; j <= n; j += qus[i]) { if (j > i) if ((qus[i] * qus[j] == i + j)) ans++; } } stringBuilder.append(ans).append(" "); } System.out.println(stringBuilder); } } // Additional Classes go here class handmadeInput { 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; } } } class UtilityFunctions { //! returns gcd of given numbers public int gcd(int a, int b) { if (b == 0) return a; return gcd(b, a % b); } public int primeFactors(int n) { HashMap<Integer, Integer> hashMap = new HashMap<>(n); int c = 0; // Print the number of 2s that divide n while (n % 2 == 0) { // if (hashMap.containsKey(2)) { // hashMap.replace(2, hashMap.get(2) + 1); // } else { // hashMap.put(2, 1); // } c++; n /= 2; } // n must be odd at this point. So we can // skip one element (Note i = i +2) for (int i = 3; i <= Math.sqrt(n); i += 2) { // While i divides n, print i and divide n while (n % i == 0) { //System.out.print(i + " "); // if (hashMap.containsKey(i)) { // hashMap.replace(i, hashMap.get(i) + 1); // } else { // hashMap.put(i, 1); // } c++; n /= i; } } // This condition is to handle the case whien // n is a prime number greater than 2 if (n > 2) { // if (hashMap.containsKey(n)) { // hashMap.replace(n, hashMap.get(n) + 1); // } else { // hashMap.put(n, 1); // } c++; } //System.out.print(n); return c; } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
7227d8b7ff45c6fe4c8fb9e7aef0a1c1
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class p4 { public static void main(String[] args) throws IOException { Scanner sc= new Scanner(System.in); long t= sc.nextLong(); for(int k=0;k<t;k++) { long n=sc.nextLong(); int ans=0; long [] a=new long[(int)n]; for(int j=0;j<n;j++) { a[j]=sc.nextLong(); } for(int i=0;i<n;i++) { int j=i+1; while(j<n) { if(a[i]*a[j]==i+j+2) { ans++; } j+=a[i]-((i+j+2)%a[i]); } } System.out.println(ans); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
825324687bf5466bde00ee63677356a9
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.StringTokenizer; import java.util.Collections; import java.util.*; public class Main { public static void main(String args[] ) throws Exception { Solve instance = Solve.getInstance(); instance.test(); } } class Solve{ static FastReader sc; static Solve instance = null; long f[]; long table[][]; int k; private Solve(){ sc = new FastReader(); } public static Solve getInstance(){ if(instance == null) instance = new Solve(); return instance; } private void input(){ } public void test() { int t = sc.nextInt(); while(t>0) { int n = sc.nextInt(); int counter = 0; Integer a[] = new Integer[n+1]; HashMap<Integer,Integer> map = new HashMap<>(); a[0] = 0; for(int i = 1;i<=n;i++){ a[i] = sc.nextInt(); map.put(a[i],i); } Arrays.sort(a); for(int i = 1;i<=n && a[i]*a[i] < 2*n ;i++) { //sout(a[i] +"\n"); for(int j = i+1;j<=n && a[j]*a[i] < 2*n;j++){ int indexI = map.get(a[i]); int IndexJ = map.get(a[j]); if((a[j]*a[i]) == (indexI+IndexJ)) counter++; } } sout(counter+"\n"); t--; } } public long re(long n,int m) { if(n == 0) return 0 ; if(n > 0 && m == 0) return (power(n,k))%(1000000007); else { if(table[(int)n][m] == 0) table[(int)n][m] = (re(n-1,m) + re(n,m-1))%(1000000007); } return (table[(int)n][m])%(1000000007); } long power(long x, int y) { if (y == 0) return 1; else if (y % 2 == 0) return power(x, y / 2) * power(x, y / 2); else return x * power(x, y / 2) * power(x, y / 2); } public void sout(Object s){ System.out.print(s); } } 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
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
c3cc3e41764af034fdd8c75244704f99
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; import java.io.*; public class PleasantPairs { public static PrintWriter out; private static final long MOD = 1000000007; private static final double INFINITY = 1e18; private static Scanner sc; public static void main(String[] args) { PleasantPairs ans = new PleasantPairs(); out = new PrintWriter(new BufferedOutputStream(System.out)); ans.solve(); out.close(); } private void solve() { sc =new Scanner(System.in); int tests = sc.nextInt(); while(tests-->0) { int N = sc.nextInt(); int []array = new int[N+1]; for(int i=1;i<=N;i++){ array[i] = sc.nextInt(); } solve(array, N); } } private void solve(int []array, int N) { int result =0; for(int i=1;i<=N;i++){ int product = (i/array[i]+1)*array[i]; int j = product-i; //System.out.printf("product: %d j: %d\n", product, j); while(j<=N) { int v1 = array[i]; int v2 = array[j]; //System.out.printf("i: %d j: %d v1: %d v2: %d\n", i+1,j+1, v1, v2); if((i!=j) && ((v1*v2) == (i+j))) result++; product += array[i]; j = product-i; } } out.println(result/2); } private int[] readIntArray(int N) { int [] array = new int[N]; for(int i=0;i<N;i++){ array[i] = sc.nextInt(); } return array; } private long[] readLongArray(int N) { long [] array = new long[N]; for(int i=0;i<N;i++){ array[i] = sc.nextLong(); } return array; } private long power(long a, long b) { if(b==0) return 1L; if(b==1) return a; long result = power(a,b/2); result*=result; if (isOdd(b)) result *=b; return result; } private boolean isOdd(long a){ return (a&1)==1; } private long[] convertToBinary(long N) { int LOGN=0; while((1L<<(LOGN))<=N) LOGN++; long []array = new long[LOGN]; for(int i=LOGN-1;i>=0;i--){ array[i] = N&1; N=N>>1; } return array; } private long[] copyToArrayFromBack(long[]to, long []from) { int j = to.length-1; for(int i=from.length-1;i>=0;i--) { to[j--] = from[i]; } return to; } private void printPrecision(double val, int precision) { out.printf("%."+precision+"f\n",val); } private boolean isBitSet(int N, int i) { return (N&(1<<i))>0; } private int setBit(int N, int i) { return N|(1<<i); } private int clearBit(int N, int i) { int mask = ~(1<<i); return N&mask; } private int updateBit(int N, int pos, int value) { clearBit(N, pos); return N|(1<<value); } private int blowLastIBits(int N, int i) { int mask = -1<<i; return N&mask; } private Equation extendedGCD(long a, long b) { if (a==0) return new Equation(b, 0, 1); Equation e = extendedGCD(b%a, a); return new Equation(e.gcd, e.y-((b/a)*e.x), e.x); } private long modularInverse(long a, long M) { Equation e = extendedGCD(a, M); return e.x%M; } private int blowBitsBetweenRange(int N, int i, int j) { int a = -1<<(i+1); int b = (1<<j)-1; int mask = a|b; return N&mask; } private long gcd(long a, long b) { if(b==0) return a; return gcd(b, a%b); } private long power(long a, long N, long MOD) { long result = 1; while(N>0) { if((N&1)>0) { result = (result*a)%MOD; } a=(a*a)%MOD; N=N>>1; } return result; } private int countOfSetBits(int N) { int result =0; while(N>0) { // blows of the last bit N=N&(N-1); result++; } return result; } private int closestLeft(long[] array, long target) { int N = array.length; int lo=0, hi=N-1; if(array[0]>target) return 0; if(array[hi]<target) return N; int ans =0; while(lo<=hi) { int mid = lo+(hi-lo)/2; if (array[mid]<=target) { ans = mid; lo= mid+1; } else { hi= mid-1; } } return ans+1; } private int closestLeftInList(List<Long> array, long target) { int N = array.size(); int lo=0, hi=N-1; if(array.get(0)>target) return 0; if(array.get(hi)<target) return N; int ans =0; while(lo<=hi) { int mid = lo+(hi-lo)/2; if (array.get(mid)<=target) { ans = mid; lo= mid+1; } else { hi= mid-1; } } return ans+1; } private int closestRightInList(List<Long> array, long target) { int N = array.size(); int lo=0, hi=N-1; if(array.get(lo)>=target) return 1; if(array.get(hi)<target) return N+1; int ans=0; while(lo<=hi) { int mid = lo+ (hi-lo)/2; if(array.get(mid)>=target) { ans=mid; hi=mid-1; } else { lo=mid+1; } } return ans+1; } private int closestRight(long[] array, long target) { int N = array.length; int lo=0, hi=N-1; if(array[lo]>=target) return 1; if(array[hi]<target) return N+1; int ans=0; while(lo<=hi) { int mid = lo+ (hi-lo)/2; if(array[mid]>=target) { ans=mid; hi=mid-1; } else { lo=mid+1; } } return ans+1; } } class Equation { long gcd,x,y; public Equation(long gcd, long x, long y) { this.gcd = gcd; this.x = x; this.y = y; } } class Point { int x,y; public Point(int x, int y){ this.x = x; this.y = y; } public double distanceFrom(Point p) { return (p.x-x)*(p.x-x)*1.0 + (p.y-y)*(p.y-y)*1.0; } public int intDistFrom(Point p) { return (p.x-x)*(p.x-x) + (p.y-y)*(p.y-y); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
c58af285f2770ffc6b475dc167e4a96d
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
//package MyPackage; import java.io.*; import java.util.*; public class MyClass { final static long mod = 1_000_000_007; static void sort(long[] a) { ArrayList<Long> l = new ArrayList<>(); for (long value : a) { l.add(value); } Collections.sort(l); for (int i = 0; i < l.size(); i++) a[i] = l.get(i); } static void sort(int[] a) { ArrayList<Integer> l = new ArrayList<>(); for (int value : a) { l.add(value); } Collections.sort(l); for (int i = 0; i < l.size(); i++) a[i] = l.get(i); } static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String n() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nint() { return Integer.parseInt(n()); } long nlong() { return Long.parseLong(n()); } double ndouble() { return Double.parseDouble(n()); } String nline() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } public static void main(String[] args) { FastReader sc = new FastReader(); PrintWriter out = new PrintWriter(System.out); int t = sc.nint(); while(t-- > 0) { int n = sc.nint(); int[] arr = new int[n + 1]; for(int i = 1; i <= n; i++) { arr[i] = sc.nint(); } out.println(solution(arr, n)); } out.flush(); out.close(); } public static int solution(int[] arr, int n) { int count = 0; for(int i = 1; i <= n; i++) { int temp = (i / arr[i] + 1) * arr[i]; while(temp - i <= n) { if(i != temp - i && arr[temp - i] == temp / arr[i]) { count++; } temp += arr[i]; } } return count / 2; } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
be25cd2a2b3a5eae416c1f4bb52562bc
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
//package MyPackage; import java.io.*; import java.util.*; public class MyClass { final static long mod = 1_000_000_007; static void sort(long[] a) { ArrayList<Long> l = new ArrayList<>(); for (long value : a) { l.add(value); } Collections.sort(l); for (int i = 0; i < l.size(); i++) a[i] = l.get(i); } static void sort(int[] a) { ArrayList<Integer> l = new ArrayList<>(); for (int value : a) { l.add(value); } Collections.sort(l); for (int i = 0; i < l.size(); i++) a[i] = l.get(i); } static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String n() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nint() { return Integer.parseInt(n()); } long nlong() { return Long.parseLong(n()); } double ndouble() { return Double.parseDouble(n()); } String nline() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } public static void main(String[] args) { FastReader sc = new FastReader(); PrintWriter out = new PrintWriter(System.out); int t = sc.nint(); while(t-- > 0) { int n = sc.nint(); int[] arr = new int[n]; for(int i = 0; i < n; i++) { arr[i] = sc.nint(); } out.println(solution(arr, n)); } out.flush(); out.close(); } public static int solution(int[] arr, int n) { int count = 0; HashMap<Integer, Integer> map = new HashMap<>(); for(int i = 0; i < n; i++) { map.put(arr[i], i + 1); } sort(arr); for (int i = 0; i < n && arr[i] * arr[i] <= 2 * n; i++) { for (int j = i + 1; j < n && arr[i] * arr[j] <= 2 * n; j++) { if (arr[i] * arr[j] == map.get(arr[i]) + map.get(arr[j])) count++; } } return count; } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
4f13066f4c16890314b5d50864c145b6
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
//package MyPackage; import java.io.*; import java.util.*; public class MyClass { final static long mod = 1_000_000_007; static void sort(long[] a) { ArrayList<Long> l = new ArrayList<>(); for (long value : a) { l.add(value); } Collections.sort(l); for (int i = 0; i < l.size(); i++) a[i] = l.get(i); } static void sort(int[] a) { ArrayList<Integer> l = new ArrayList<>(); for (int value : a) { l.add(value); } Collections.sort(l); for (int i = 0; i < l.size(); i++) a[i] = l.get(i); } static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String n() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { e.printStackTrace(); } } return st.nextToken(); } int nint() { return Integer.parseInt(n()); } long nlong() { return Long.parseLong(n()); } double ndouble() { return Double.parseDouble(n()); } String nline() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } public static void main(String[] args) { FastReader sc = new FastReader(); PrintWriter out = new PrintWriter(System.out); int t = sc.nint(); while(t-- > 0) { int n = sc.nint(); int[] arr = new int[n]; for(int i = 0; i < n; i++) { arr[i] = sc.nint(); } out.println(solution(arr, n)); } out.flush(); out.close(); } public static int solution(int[] arr, int n) { int count = 0; HashMap<Integer, Integer> map = new HashMap<>(); for(int i = 0; i < n; i++) { map.put(arr[i], i + 1); } sort(arr); for(int i = 1; i < n; i++) { if(arr[0] * arr[i] == map.get(arr[0]) + map.get(arr[i])) { count++; } } for(int i = 1; i < n; i++) { for(int j = i + 1; j < 2 * n / (i + 1); j++) { if(arr[i] * arr[j] == map.get(arr[i]) + map.get(arr[j])) { count++; } } } return count; } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
e6f8ff1b542bb5f3a50cbe076ab91a80
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.*; public class Main { public static class Pair { int key, value; public Pair(int key, int value) { this.key = key; this.value = value; } } static class Node { long index, value; public Node(long index, long value) { this.value = value; this.index = index; } } 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 { if(st.hasMoreTokens()){ str = st.nextToken("\n"); } else{ str = br.readLine(); } } catch (IOException e) { e.printStackTrace(); } return str; } } public static int gcd(int a, int b) { if (b == 0) { return a; } return gcd(b, a % b); } //BINARY EXPONENTIATION public static long binpow(long a, long b) { long res = 1; while (b > 0) { if ((b & 1) == 1) res = res * a; a = a * a; b >>= 1; } return res; } // Returns factorial of n static long fact(long n) { if (n == 0) return 1; int res = 1; for (int i = 2; i <= n; i++) res = res * i; return res; } public static void main(String[] args) { FastReader s = new FastReader(); int t = s.nextInt(); //int t = 1; while (t-- > 0) { int n = s.nextInt(); Node[] a = new Node[n]; for (int i = 0; i < n; i++) { a[i] = new Node(i + 1, s.nextInt()); } Arrays.sort(a, Comparator.comparingLong(o -> o.value)); long ans = 0; for (int i = 0; i < n; i++) { for (int j = 0; j < i; j++) { long now = a[i].value * a[j].value; if (now == a[i].index + a[j].index) { ans++; } if (now > 2L * n) { break; } } } System.out.println(ans); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
e4722c7844602e05e263a99112cbafe7
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.Scanner; public class B { public static void main(String[] args) { Scanner scan = new Scanner(System.in); long[] ar; int n = 0; int count = 0; int t = scan.nextInt(); while(t-->0){ n = scan.nextInt(); ar = new long[n+1]; for(int i=1;i<=n;i++){ ar[i] = scan.nextLong(); } for(int i=1;i<n;i++){ int x = (int)ar[i] - i; for(int j= x;j<=n;j+=ar[i]){ if(i<j){ if((long)(ar[i]*ar[j])==i+j) ++count; } } } System.out.println(count); count = 0; } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
12a4e950455c54cbe389455a1589cd72
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; import java.lang.*; import java.io.*; import java.math.*; public class GFG { 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) { FastReader sc=new FastReader(); int n=sc.nextInt(); for(int g=0;g<n;g++){ int size =sc.nextInt(); int count =0; int arr[]=new int[size+1]; for(int i=1;i<=size;i++){ arr[i]= sc.nextInt(); } for(int i=1;i<size;i++){ for(int j=arr[i]-i;j<=size;j+=arr[i]){ if(j>i&&((long)arr[i]*arr[j]==(i+j))){ count++; } } }System.out.println(count); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
a51337ea7def7ec83910437a50c18cbc
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
/*package whatever //do not write package name here */ import java.util.*; import java.lang.*; import java.io.*; import java.math.*; public class GFG { 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) { FastReader sc=new FastReader(); int n=sc.nextInt(); for(int g=0;g<n;g++){ int size =sc.nextInt(); int count =0; int arr[]=new int[size+1]; for(int i=1;i<=size;i++){ arr[i]= sc.nextInt(); } for(int i=1;i<size;i++){ for(int j=arr[i]-i;j<=size;j+=arr[i]){ if(j>=1) if(((long)arr[i]*arr[j]==i+j)&&(i<j)) count++; } }System.out.println(count); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
28a5f879349df37cdf818561924000f2
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.InputStreamReader; import java.io.PrintWriter; import java.util.*; public class Codeforces1 { public static void main (String[] args) throws java.lang.Exception { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); PrintWriter o = new PrintWriter(System.out); int t = Integer.parseInt(br.readLine()); while(t-->0) { String st[] = br.readLine().trim().split(" "); int n =Integer.parseInt(st[0]); long a[] = new long[n+1]; String st1[] = br.readLine().trim().split(" "); for(int i=0;i<n;i++) a[i+1] = Long.parseLong(st1[i]); long count=0; for(int i=1;i<=n;i++) { long temp = (i/a[i] +1)*a[i]; for( long j=temp-i;j<=n;j=j+a[i]) { if(j>i&&temp!=i&&a[(int)j]==(j+i)/a[i]) count++; } } System.out.println(count); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
317044f24fdf9579fdef0d7e9d4159d3
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; import java.io.*; public class Main { public static void main(String[] args) throws IOException { BufferedReader br = new BufferedReader( new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(br.readLine()); int i,j,n,t,p; long k,l,x; t = Integer.parseInt(st.nextToken()); for(p=1;p<=t;p++) { st = new StringTokenizer(br.readLine()); n = Integer.parseInt(st.nextToken()); long a[] = new long[n]; st = new StringTokenizer(br.readLine()); HashMap<Long,Long> m = new HashMap<Long,Long>(); for(i=0;i<n;i++) { a[i] = Long.parseLong(st.nextToken()); m.put(a[i],(long)(i+1)); } Arrays.sort(a); l = 0; for(i=0;i<n-1;i++) { k = m.get(a[i]); for(j=i+1;j<n;j++) { x = m.get(a[j]); if(a[i]*a[j] == x+k) { l++; } if(a[i]*a[j]>2*n) break; } } System.out.println(l); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
883a10a7b12aadef4884aee0ed07188d
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class Stack3 { 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(); } } static Reader sc = new Reader(); static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out)); public static void main(String[] args) throws IOException { //subsequence("abcdefghij"); /* * For integer input: int n=inputInt(); * For long input: long n=inputLong(); * For double input: double n=inputDouble(); * For String input: String s=inputString(); * Logic goes here * For printing without space: print(a+""); where a is a variable of any datatype * For printing with space: printSp(a+""); where a is a variable of any datatype * For printing with new line: println(a+""); where a is a variable of any datatype */ Scanner sc = new Scanner(System.in); int t = sc.nextInt(); for (int i = 0; i < t; i++) { int n = sc.nextInt(); boolean[] ar = new boolean[2 * n + 1]; int[] index=new int[2*n+1]; for (int j = 0; j < n; j++) { int num = sc.nextInt(); ar[num] = true; index[num]=j+1; } long ans = 0; for (int k = 3; k <= 2 * n - 1; k++) { for (int p = 1; p * p <= k; p++) { if (k % p == 0) { if (k / p != p && ar[k / p] && ar[p] ) { //System.out.println(k+" "+p+" "+k/p); double an1=(index[p]+index[k/p])/(double)k; if(an1==1) ans++; } } } } System.out.println(ans); } bw.flush(); bw.close(); } public static boolean checkPrime(int n) { if (n == 0 || n == 1) { return false; } for (int j = 2; j * j <= n; j++) { if (n % j == 0) { return false; } } return true; } public static void dfs1(List<List<Integer>> g, boolean[] visited, Stack<Integer> stack, int num) { visited[num] = true; for (Integer integer : g.get(num)) { if (!visited[integer]) { dfs1(g, visited, stack, integer); } } stack.push(num); } public static void dfs2(List<List<Integer>> g, boolean[] visited, List<Integer> list, int num, int c, int[] raj) { visited[num] = true; for (Integer integer : g.get(num)) { if (!visited[integer]) { dfs2(g, visited, list, integer, c, raj); } } raj[num] = c; list.add(num); } public static int inputInt() throws IOException { return sc.nextInt(); } public static long inputLong() throws IOException { return sc.nextLong(); } public static double inputDouble() throws IOException { return sc.nextDouble(); } public static String inputString() throws IOException { return sc.readLine(); } public static void print(String a) throws IOException { bw.write(a); } public static void printSp(String a) throws IOException { bw.write(a + " "); } public static void println(String a) throws IOException { bw.write(a + "\n"); } public static long getAns(int[] ar, int c, long[][] dp, int i, int sign) { if (i < 0) { return 1; } if (c <= 0) { return 1; } dp[i][c] = Math.max(dp[i][c], Math.max(ar[i] * getAns(ar, c - 1, dp, i - 1, sign), getAns(ar, c, dp, i - 1, 1))); return dp[i][c]; } public static long power(long a, long b, long c) { long ans = 1; while (b != 0) { if (b % 2 == 1) { ans = ans * a; ans %= c; } a = a * a; a %= c; b /= 2; } return ans; } public static long power1(long a, long b, long c) { long ans = 1; while (b != 0) { if (b % 2 == 1) { ans = multiply(ans, a, c); } a = multiply(a, a, c); b /= 2; } return ans; } public static long multiply(long a, long b, long c) { long res = 0; a %= c; while (b > 0) { if (b % 2 == 1) { res = (res + a) % c; } a = (a + a) % c; b /= 2; } return res % c; } public static long totient(long n) { long result = n; for (long i = 2; i * i <= n; i++) { if (n % i == 0) { //sum=sum+2*i; while (n % i == 0) { n /= i; // sum=sum+n; } result -= result / i; } } if (n > 1) { result -= result / n; } return result; } public static long gcd(long a, long b) { if (b == 0) { return a; } else { return gcd(b, a % b); } } public int sumOfFlooredPairs(int[] nums) { // long sum=0; long mod = (long) (1e9 + 7); Arrays.sort(nums); long[] numerator = new long[nums.length]; long[] denominator = new long[nums.length]; long[] numerator1 = new long[nums.length]; long[] denominator1 = new long[nums.length]; long num = 1; long den = nums[0]; numerator[0] = 1; denominator[0] = den; long num1 = 1; long den1 = nums[nums.length - 1]; numerator1[nums.length - 1] = 1; denominator1[nums.length - 1] = den1; for (int i = 1; i < nums.length; i++) { long gcd1 = gcd(denominator[i - 1], nums[i]); long lcm = (denominator[i - 1] * nums[i]) / gcd1; long n1 = lcm / denominator[i - 1] * numerator[i - 1] + lcm / nums[i]; numerator[i] = n1; denominator[i] = lcm; long gcd2 = gcd(denominator1[nums.length - i], nums[nums.length - 1 - i]); long lcm1 = (denominator1[nums.length - i] * nums[nums.length - 1 - i]) / gcd2; long n2 = lcm1 / denominator1[nums.length - i] * numerator1[nums.length - i] + lcm1 / nums[nums.length - 1 - i]; numerator1[nums.length - 1 - i] = n2; denominator1[nums.length - 1 - i] = lcm1; /* prefix[i]=sum; sum12+=1d/nums[nums.length-1-i]; prefix2[nums.length-1-i]=sum12;*/ } /*System.out.println(Arrays.toString(numerator)); System.out.println(Arrays.toString(denominator));*/ int sum2 = 0; for (int i = 0; i < nums.length; i++) { //float d1=(float)(numerator[i]/(double)denominator[i]); sum2 += (int) (Math.floor((numerator[i] * nums[i]) / (double) denominator[i])); sum2 %= mod; if (i + 1 < nums.length) { // float d2=(float)(numerator1[i+1]/(double)denominator1[i+1]); sum2 += (int) (Math.floor((numerator1[i + 1] * nums[i]) / (double) denominator1[i + 1])); sum2 %= mod; } } return sum2; } public static boolean[] primes(int n) { boolean[] p = new boolean[n + 1]; p[0] = false; p[1] = false; for (int i = 2; i <= n; i++) { p[i] = true; } for (int i = 2; i * i <= n; i++) { if (p[i]) { for (int j = i * i; j <= n; j += i) { p[j] = false; } } } return p; } public String LargestEven(String S) { // char[] ar=S.toCharArray(); int[] count = new int[10]; for (int i = 0; i < S.length(); i++) { count[S.charAt(i) - '0']++; } int num = -1; for (int i = 0; i <= 8; i += 2) { if (count[i] > 0) { num = i; break; } } StringBuilder ans = new StringBuilder(); for (int i = 9; i >= 0; i--) { if (i != num) { for (int j = 1; j <= count[i]; j++) { ans.append(i); } } else { for (int j = 1; j <= count[num] - 1; j++) { ans.append(num); } } } if (num != -1 && count[num] > 0) { ans.append(num); } return ans.toString(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
555a40ceca87ea94e7e3c5930b1dcd02
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; import java.math.*; import java.math.BigInteger; //import javafx.util.*; public final class B { static PrintWriter out = new PrintWriter(System.out); static StringBuilder ans=new StringBuilder(); static FastReader in=new FastReader(); static ArrayList<Integer> g[]; static long mod=(long)(1e9+7); static int D1[],D2[],par[]; static boolean set[]; static int value[]; static long INF=Long.MAX_VALUE; static int val[],tot[],max[]; static int min; static int dp[][]; static int path[][],A[]; static char X[][]; static int index[]; public static void main(String args[])throws IOException { int T=i(); outer:while(T-->0) { int N=i(); int A[]=new int[N]; int f[]=new int[2*N+5]; for(int i=0; i<N; i++) { A[i]=i(); f[A[i]]=i+1; } int c=0; for(int i=3; i<=2*N; i++) { for(int j=1; j<Math.sqrt(i); j++) { if(i%j==0) { int a=f[j],b=f[i/j]; if(a!=0 && b!=0 && j*j!=i) { if(a+b==i)c++; } } } } out.println(c); } out.close(); } static int or(int i,int j) { System.out.println("OR "+i+" "); return i(); } static int and(int i,int j) { System.out.println("AND "+i+" "+j); return i(); } static int xor(int i,int j) { System.out.println("XOR "+i+" "+j); return i(); } static String f(char X[],int d,int K) { StringBuilder sb=new StringBuilder(); StringBuilder s=new StringBuilder(); int x=K/d; String Y=""; for(int i=0; i<d; i++)s.append(X[i]); Y=s.toString(); while(x-->0) sb.append(Y); x=K%d; for(int i=0; i<x; i++)sb.append(X[i]); return sb.toString(); } static long f(long t,long x,long N,long v) { long l=0,r=N+1; while(r-l>1) { long m=(l+r)/2; if(t+m*x<=N*x)l=m; else r=m; } return l; } static void f(int dp[][],int d,int A[],int par[]) { if(A[d]==0)return ; f(dp,d+1,A,par); dp[0][d]=A[d]+Math.min(dp[0][d+1], dp[1][d+1]); if(dp[0][d+1]<dp[1][d+1]) { par[d]=1; } else par[d]=2; dp[1][d]=dp[0][d+1]; } static int [] ask(int a,int N) { System.out.println("? "+a); int A[]=input(N); return A; } static boolean isPalin(char X[]) { int l=0,r=X.length-1; while(l<=r) { if(X[l]!=X[r])return false; l++; r--; } return true; } static boolean isSorted(int A[]) { int N=A.length; for(int i=0; i<N-1; i++) { if(A[i]>A[i+1])return false; } return true; } static int f1(int x,ArrayList<Integer> A) { int l=-1,r=A.size(); while(r-l>1) { int m=(l+r)/2; int a=A.get(m); if(a<x)l=m; else r=m; } return l; } static int max(int a,int b,int c) { return Math.max(a, Math.max(c, b)); } static int value(char X[],char Y[]) { int c=0; for(int i=0; i<7; i++) { if(Y[i]=='1' && X[i]=='0')return -1; if(X[i]=='1' && Y[i]=='0')c++; } return c; } // static boolean isValid(int i,int j) // { // if(i<0 || i>=N)return false; // if(j<0 || j>=M)return false; // return true; // } 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 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[N+1]; val=new int[N+1]; for(int i=0; i<=N; i++) { g[i]=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 node implements Comparable<node> { int par,a; node(int par,int a) { this.par=par; this.a=a; } public int compareTo(node x) { return this.par-x.par; } } //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
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
91ac287e2fc62d8d9dff67d466519667
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
// 1 2 3 are easy , think of a pattern that you think can't be the answer import java.io.*; import java.util.*; import java.lang.*; public class Main{ public static void main(String[] args) throws IOException{ if (System.getProperty("ONLINE_JUDGE") == null) { PrintStream ps = new PrintStream(new File("output.txt")); InputStream is = new FileInputStream("input.txt"); System.setIn(is); System.setOut(ps); } Scanner scn = new Scanner(System.in); FastReader in = new FastReader(); PrintWriter out = new PrintWriter(System.out); int ntc = in.nextInt(); // int ntc = 1; while(ntc-- > 0){ solve(in , out , scn); } out.flush(); } public static void solve(FastReader in , PrintWriter out , Scanner scn){ int n = in.nextInt(); Pair[] arr = new Pair[n]; for (int i = 0; i < n; i++) { int curr = in.nextInt(); arr[i] = new Pair(curr, i + 1); } Arrays.sort(arr, (a, b) -> a.first - b.first); long ans = 0; int curr = 0; for (int i = 0; i < n; i++) { for (int j = i + 1; j < n; j++) { if ((arr[j].first) > (2 * n) / arr[i].first) { break; } if ((arr[i].first * arr[j].first) == arr[i].second + arr[j].second) { ans++; } } } out.println(ans); } /* *** *** *** */ public static boolean check(StringBuilder sb , int one){ HashMap<Character, Integer> map = new HashMap<>(); int cc = 0; int flag = 0; for(int i = sb.length()-1 ; i >= 0 ; i--){ if(sb.charAt(i) == '1') cc++; else flag = 1; if(flag == 0 && cc == one) return true; } return false; } static class Pair{ int first; int second; Pair( int first , int second){ this.first =first; this.second = second; } } static int gcd(int a, int b) { while (b != 0) { int t = a; a = b; b = t % b; } return a; } 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 void println(long n){System.out.println(n);} public static void print(long n){System.out.print(n);} public static void print(int n ){System.out.print(n);} public static void println(int n){System.out.println(n);} static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreTokens()) { 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().trim(); } catch (Exception e) { e.printStackTrace(); } return str; } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
bdd173c161c3fa515344833512763df9
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
// 1 2 3 are easy , think of a pattern that you think can't be the answer import java.io.*; import java.util.*; import java.lang.*; public class Main{ public static void main(String[] args) throws IOException{ if (System.getProperty("ONLINE_JUDGE") == null) { PrintStream ps = new PrintStream(new File("output.txt")); InputStream is = new FileInputStream("input.txt"); System.setIn(is); System.setOut(ps); } Scanner scn = new Scanner(System.in); FastReader in = new FastReader(); PrintWriter out = new PrintWriter(System.out); int ntc = in.nextInt(); // int ntc = 1; while(ntc-- > 0){ solve(in , out , scn); } out.flush(); } public static void solve(FastReader in , PrintWriter out , Scanner scn){ int n = in.nextInt(); Pair[] arr = new Pair[n]; for (int i = 0; i < n; i++) { int curr = in.nextInt(); arr[i] = new Pair(curr, i + 1); } Arrays.sort(arr, (a, b) -> a.first - b.first); long ans = 0; int curr = 0; for (int i = 0; i < n; i++) { for (int j = i + 1; j < n; j++) { if ((arr[j].first) > (2 * n) / (i + 1)) { break; } if ((arr[i].first * arr[j].first) == arr[i].second + arr[j].second) { ans++; } } } out.println(ans); } /* *** *** *** */ public static boolean check(StringBuilder sb , int one){ HashMap<Character, Integer> map = new HashMap<>(); int cc = 0; int flag = 0; for(int i = sb.length()-1 ; i >= 0 ; i--){ if(sb.charAt(i) == '1') cc++; else flag = 1; if(flag == 0 && cc == one) return true; } return false; } static class Pair{ int first; int second; Pair( int first , int second){ this.first =first; this.second = second; } } static int gcd(int a, int b) { while (b != 0) { int t = a; a = b; b = t % b; } return a; } 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 void println(long n){System.out.println(n);} public static void print(long n){System.out.print(n);} public static void print(int n ){System.out.print(n);} public static void println(int n){System.out.println(n);} static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { while (st == null || !st.hasMoreTokens()) { 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().trim(); } catch (Exception e) { e.printStackTrace(); } return str; } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
5f9bb33cf032a0c71247e7fb21f64733
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; //import javafx.util.*; public class Main { static PrintWriter out = new PrintWriter(System.out); static StringBuilder ans=new StringBuilder(); static FastReader in=new FastReader(); static ArrayList<Integer> g[]; //static ArrayList<ArrayList<TASK>> t; static long mod=(long)(1e9+7); static boolean set[],post[][]; static int prime[],c[]; static int par[]; // static int dp[][]; static HashMap<String,Long> mp; static long max=1; static boolean temp[][]; static int K=0; static int size[],dp[][],iv_A[],iv_B[]; static long modulo = 998244353; public static void main(String args[])throws IOException { /* * star,rope,TPST * BS,LST,MS,MQ */ int t = i(); while(t-- > 0){ int n = i(); int[] arr = new int[n+1]; for(int i = 1;i < n + 1;i++){ arr[i] = i(); } long count = 0; for(int i = 1;i < n;i++){ for(int j = arr[i] - i;j <= n;j += arr[i]){ if(j >= 1){ if(((long)arr[i]*arr[j]==i+j)&&(i<j)){ count++; } } } } System.out.println(count); } } static Boolean isSubsetSum(int n, int arr[], int sum){ // code here boolean[][] dp = new boolean[n+1][sum+1]; for(int i = 0;i < n+1;i++){ for(int j = 0;j < sum + 1;j++){ if(i == 0){ dp[i][j] = false; } if(j == 0){ dp[i][j] = true; } } } for(int i = 1;i < n+1;i++){ for(int j = 1;j < sum + 1;j++){ if(arr[i-1] <= j){ dp[i][j] = dp[i-1][j - arr[i-1]] || dp[i-1][j]; }else{ dp[i][j] = dp[i-1][j]; } } } return dp[n][sum]; } static int getmax(ArrayList<Integer> arr){ int n = arr.size(); int max = Integer.MIN_VALUE; for(int i = 0;i < n;i++){ max = Math.max(max,arr.get(i)); } return max; } static boolean check(ArrayList<Integer> arr){ int n = arr.size(); boolean flag = true; for(int i = 0;i < n-1;i++){ if(arr.get(i) != arr.get(i+1)){ flag = false; break; } } return flag; } static int MinimumFlips(String s, int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) { a[i] = (s.charAt(i) == '1' ? 1 : 0); } // Initialize prefix arrays to store // number of changes required to put // 1s at either even or odd position int[] oddone = new int[n + 1]; int[] evenone = new int[n + 1]; oddone[0] = 0; evenone[0] = 0; for (int i = 0; i < n; i++) { // If i is odd if (i % 2 != 0) { // Update the oddone // and evenone count oddone[i + 1] = oddone[i] + (a[i] == 1 ? 1 : 0); evenone[i + 1] = evenone[i] + (a[i] == 0 ? 1 : 0); } // Else i is even else { // Update the oddone // and evenone count oddone[i + 1] = oddone[i] + (a[i] == 0 ? 1 : 0); evenone[i + 1] = evenone[i] + (a[i] == 1 ? 1 : 0); } } // Initialize minimum flips return Math.min(evenone[n],oddone[n]); } static int nextPowerOf2(int n) { int count = 0; // First n in the below // condition is for the // case where n is 0 if (n > 0 && (n & (n - 1)) == 0){ while(n != 1) { n >>= 1; count += 1; } return count; }else{ while(n != 0) { n >>= 1; count += 1; } return count; } } static int length(int n){ int count = 0; while(n > 0){ n = n/10; count++; } return count; } static boolean isPrimeInt(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 int lcs(int[] nums) { int[] tails = new int[nums.length]; int size = 0; for (int x : nums) { int i = 0, j = size; while (i != j) { int m = (i + j) / 2; if (tails[m] <= x) i = m + 1; else j = m; } tails[i] = x; if (i == size) ++size; } return size; } static int CeilIndex(int A[], int l, int r, int key) { while (r - l > 1) { int m = l + (r - l) / 2; if (A[m] >= key) r = m; else l = m; } return r; } static int f(int A[], int size) { // Add boundary case, when array size is one int[] tailTable = new int[size]; int len; // always points empty slot tailTable[0] = A[0]; len = 1; for (int i = 1; i < size; i++) { if (A[i] < tailTable[0]) // new smallest value tailTable[0] = A[i]; else if (A[i] > tailTable[len - 1]) // A[i] wants to extend largest subsequence tailTable[len++] = A[i]; else // A[i] wants to be current end candidate of an existing // subsequence. It will replace ceil value in tailTable tailTable[CeilIndex(tailTable, -1, len - 1, A[i])] = A[i]; } return len; } static int containsBoth(char X[],int N) { for(int i=1; i<N; i++)if(X[i]!=X[i-1])return i-1; return -1; } static void f(char X[],int N,int A[]) { int c=0; for(int i=N-1; i>=0; i--) { if(X[i]=='1') { A[i]=c; } else c++; A[i]+=A[i+1]; } } static int f(int i,int j,char X[],char Y[],int zero) { if(i==X.length && j==Y.length)return 0; if(i==X.length)return iv_B[j]; //return inversion count here if(j==Y.length)return iv_A[i]; if(dp[i][j]==-1) { int cost_x=0,cost_y=0; if(X[i]=='1') { cost_x=zero+f(i+1,j,X,Y,zero); } else cost_x=f(i+1,j,X,Y,zero-1); if(Y[j]=='1') { cost_y=zero+f(i,j+1,X,Y,zero); } else cost_y=f(i,j+1,X,Y,zero-1); dp[i][j]=Math.min(cost_x, cost_y); } return dp[i][j]; } static boolean f(long last,long next,long l,long r,long A,long B) { while(l<=r) { long m=(l+r)/2; long s=((m)*(m-1))/2; long l1=(A*m)+s,r1=(m*B)-s; if(Math.min(next, r1)<Math.max(last, l1)) { if(l1>last)r=m-1; else l=m+1; } else return true; } return false; } static boolean isVowel(char x) { if(x=='a' || x=='e' || x=='i' ||x=='u' || x=='o')return true; return false; } static boolean f(int i,int j) { //i is no of one //j is no of ai>1 if(i==0 && j==0)return true; //this player has no pile to pick --> last move iska rha hoga if(dp[i][j]==-1) { boolean f=false; if(i>0) { if(!f(i-1,j))f=true; } if(j>0) { if(!f(i,j-1) && !f(i+1,j-1))f=true; } if(f)dp[i][j]=1; else dp[i][j]=0; } return dp[i][j]==1; } static int last=-1; static void dfs(int n,int p) { last=n; System.out.println("n--> "+n+" p--> "+p); for(int c:g[n]) { if(c!=p)dfs(c,n); } } static long abs(long a,long b) { return Math.abs(a-b); } static int lower(long A[],long x) { int l=0,r=A.length; while(r-l>1) { int m=(l+r)/2; if(A[m]<=x)l=m; else r=m; } return l; } static int f(int i,int s,int j,int N,int A[],HashMap<Integer,Integer> mp) { if(i==N) { return s; } if(dp[i][j]==-1) { if(mp.containsKey(A[i])) { int f=mp.get(A[i]); int c=0; if(f==1)c++; mp.put(A[i], f+1); HashMap<Integer,Integer> temp=new HashMap<>(); temp.put(A[i],1); return dp[i][j]=Math.min(f(i+1,s+1+c,j,N,A,mp), s+K+f(i+1,0,i,N,A,temp)); } else { mp.put(A[i],1); return dp[i][j]=f(i+1,s,j,N,A,mp); } } return dp[i][j]; } static boolean inRange(int a,int l,int r) { if(l<=a && r>=a)return true; return false; } static long f(long a,long b) { if(a%b==0)return a/b; else return (a/b)+f(b,a%b); } static void f(int index,long A[],int i,long xor) { if(index+1==A.length) { if(valid(xor^A[index],i)) { xor=xor^A[index]; max=Math.max(max, i); } return; } if(dp[index][i]==0) { dp[index][i]=1; if(valid(xor^A[index],i)) { f(index+1,A,i+1,0); f(index+1,A,i,xor^A[index]); } else { f(index+1,A,i,xor^A[index]); } } } static boolean valid(long xor,int i) { if(xor==0)return true; while(xor%2==0 ) { xor/=2; i--; } return i<=0; } static int next(int i,long pre[],long S) { int l=i,r=pre.length; while(r-l>1) { int m=(l+r)/2; if(pre[m]-pre[i-1]>S)r=m; else l=m; } return r; } static boolean lexo(long A[],long B[]) { for(int i=0; i<A.length; i++) { if(B[i]>A[i])return true; if(A[i]>B[i])return false; } return false; } static long [] f(long A[],long B[],int j) { int N=A.length; long X[]=new long[N]; for(int i=0; i<N; i++) { X[i]=(B[j]+A[i])%N; j++; j%=N; } return X; } static int find(int a) { if(par[a]<0)return a; return par[a]=find(par[a]); } static void union(int a,int b) { b=find(b); a=find(a); if(a!=b) { par[b]=a; } } 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(); } static long lower_Bound(long A[],int low,int high, long x) { if (low > high) if (x >= A[high]) return A[high]; int mid = (low + high) / 2; if (A[mid] == x) return A[mid]; if (mid > 0 && A[mid - 1] <= x && x < A[mid]) return A[mid - 1]; if (x < A[mid]) return lower_Bound( A, low, mid - 1, x); return lower_Bound(A, mid + 1, high, x); } 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) { size=new int[N+1]; // D=new int[N+1]; g=new ArrayList[N+1]; for(int i=0; i<=N; i++) { g[i]=new ArrayList<>(); } } static long pow(long a,long b) { long pow=1L; 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(int 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 ); } 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; } } //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()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str=""; try { str=br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
a36f923a5659b7adeae5b7628f56e7b9
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; //import javafx.util.*; public class Main { static PrintWriter out = new PrintWriter(System.out); static StringBuilder ans=new StringBuilder(); static FastReader in=new FastReader(); static ArrayList<Integer> g[]; //static ArrayList<ArrayList<TASK>> t; static long mod=(long)(1e9+7); static boolean set[],post[][]; static int prime[],c[]; static int par[]; // static int dp[][]; static HashMap<String,Long> mp; static long max=1; static boolean temp[][]; static int K=0; static int size[],dp[][],iv_A[],iv_B[]; static long modulo = 998244353; public static void main(String args[])throws IOException { /* * star,rope,TPST * BS,LST,MS,MQ */ Scanner sc=new Scanner(System.in); int T=sc.nextInt(); while(T-->0) { int n=sc.nextInt(); int a[]=new int[n+1]; for(int i=1;i<=n;i++) { a[i]=sc.nextInt(); } long c=0; for(int i=1;i<n;i++) { for(int j=a[i]-i;j<=n;j+=a[i]) { if(j>=1) if(((long)a[i]*a[j]==i+j)&&(i<j)) c++; } } System.out.println(c); } } static Boolean isSubsetSum(int n, int arr[], int sum){ // code here boolean[][] dp = new boolean[n+1][sum+1]; for(int i = 0;i < n+1;i++){ for(int j = 0;j < sum + 1;j++){ if(i == 0){ dp[i][j] = false; } if(j == 0){ dp[i][j] = true; } } } for(int i = 1;i < n+1;i++){ for(int j = 1;j < sum + 1;j++){ if(arr[i-1] <= j){ dp[i][j] = dp[i-1][j - arr[i-1]] || dp[i-1][j]; }else{ dp[i][j] = dp[i-1][j]; } } } return dp[n][sum]; } static int getmax(ArrayList<Integer> arr){ int n = arr.size(); int max = Integer.MIN_VALUE; for(int i = 0;i < n;i++){ max = Math.max(max,arr.get(i)); } return max; } static boolean check(ArrayList<Integer> arr){ int n = arr.size(); boolean flag = true; for(int i = 0;i < n-1;i++){ if(arr.get(i) != arr.get(i+1)){ flag = false; break; } } return flag; } static int MinimumFlips(String s, int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) { a[i] = (s.charAt(i) == '1' ? 1 : 0); } // Initialize prefix arrays to store // number of changes required to put // 1s at either even or odd position int[] oddone = new int[n + 1]; int[] evenone = new int[n + 1]; oddone[0] = 0; evenone[0] = 0; for (int i = 0; i < n; i++) { // If i is odd if (i % 2 != 0) { // Update the oddone // and evenone count oddone[i + 1] = oddone[i] + (a[i] == 1 ? 1 : 0); evenone[i + 1] = evenone[i] + (a[i] == 0 ? 1 : 0); } // Else i is even else { // Update the oddone // and evenone count oddone[i + 1] = oddone[i] + (a[i] == 0 ? 1 : 0); evenone[i + 1] = evenone[i] + (a[i] == 1 ? 1 : 0); } } // Initialize minimum flips return Math.min(evenone[n],oddone[n]); } static int nextPowerOf2(int n) { int count = 0; // First n in the below // condition is for the // case where n is 0 if (n > 0 && (n & (n - 1)) == 0){ while(n != 1) { n >>= 1; count += 1; } return count; }else{ while(n != 0) { n >>= 1; count += 1; } return count; } } static int length(int n){ int count = 0; while(n > 0){ n = n/10; count++; } return count; } static boolean isPrimeInt(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 int lcs(int[] nums) { int[] tails = new int[nums.length]; int size = 0; for (int x : nums) { int i = 0, j = size; while (i != j) { int m = (i + j) / 2; if (tails[m] <= x) i = m + 1; else j = m; } tails[i] = x; if (i == size) ++size; } return size; } static int CeilIndex(int A[], int l, int r, int key) { while (r - l > 1) { int m = l + (r - l) / 2; if (A[m] >= key) r = m; else l = m; } return r; } static int f(int A[], int size) { // Add boundary case, when array size is one int[] tailTable = new int[size]; int len; // always points empty slot tailTable[0] = A[0]; len = 1; for (int i = 1; i < size; i++) { if (A[i] < tailTable[0]) // new smallest value tailTable[0] = A[i]; else if (A[i] > tailTable[len - 1]) // A[i] wants to extend largest subsequence tailTable[len++] = A[i]; else // A[i] wants to be current end candidate of an existing // subsequence. It will replace ceil value in tailTable tailTable[CeilIndex(tailTable, -1, len - 1, A[i])] = A[i]; } return len; } static int containsBoth(char X[],int N) { for(int i=1; i<N; i++)if(X[i]!=X[i-1])return i-1; return -1; } static void f(char X[],int N,int A[]) { int c=0; for(int i=N-1; i>=0; i--) { if(X[i]=='1') { A[i]=c; } else c++; A[i]+=A[i+1]; } } static int f(int i,int j,char X[],char Y[],int zero) { if(i==X.length && j==Y.length)return 0; if(i==X.length)return iv_B[j]; //return inversion count here if(j==Y.length)return iv_A[i]; if(dp[i][j]==-1) { int cost_x=0,cost_y=0; if(X[i]=='1') { cost_x=zero+f(i+1,j,X,Y,zero); } else cost_x=f(i+1,j,X,Y,zero-1); if(Y[j]=='1') { cost_y=zero+f(i,j+1,X,Y,zero); } else cost_y=f(i,j+1,X,Y,zero-1); dp[i][j]=Math.min(cost_x, cost_y); } return dp[i][j]; } static boolean f(long last,long next,long l,long r,long A,long B) { while(l<=r) { long m=(l+r)/2; long s=((m)*(m-1))/2; long l1=(A*m)+s,r1=(m*B)-s; if(Math.min(next, r1)<Math.max(last, l1)) { if(l1>last)r=m-1; else l=m+1; } else return true; } return false; } static boolean isVowel(char x) { if(x=='a' || x=='e' || x=='i' ||x=='u' || x=='o')return true; return false; } static boolean f(int i,int j) { //i is no of one //j is no of ai>1 if(i==0 && j==0)return true; //this player has no pile to pick --> last move iska rha hoga if(dp[i][j]==-1) { boolean f=false; if(i>0) { if(!f(i-1,j))f=true; } if(j>0) { if(!f(i,j-1) && !f(i+1,j-1))f=true; } if(f)dp[i][j]=1; else dp[i][j]=0; } return dp[i][j]==1; } static int last=-1; static void dfs(int n,int p) { last=n; System.out.println("n--> "+n+" p--> "+p); for(int c:g[n]) { if(c!=p)dfs(c,n); } } static long abs(long a,long b) { return Math.abs(a-b); } static int lower(long A[],long x) { int l=0,r=A.length; while(r-l>1) { int m=(l+r)/2; if(A[m]<=x)l=m; else r=m; } return l; } static int f(int i,int s,int j,int N,int A[],HashMap<Integer,Integer> mp) { if(i==N) { return s; } if(dp[i][j]==-1) { if(mp.containsKey(A[i])) { int f=mp.get(A[i]); int c=0; if(f==1)c++; mp.put(A[i], f+1); HashMap<Integer,Integer> temp=new HashMap<>(); temp.put(A[i],1); return dp[i][j]=Math.min(f(i+1,s+1+c,j,N,A,mp), s+K+f(i+1,0,i,N,A,temp)); } else { mp.put(A[i],1); return dp[i][j]=f(i+1,s,j,N,A,mp); } } return dp[i][j]; } static boolean inRange(int a,int l,int r) { if(l<=a && r>=a)return true; return false; } static long f(long a,long b) { if(a%b==0)return a/b; else return (a/b)+f(b,a%b); } static void f(int index,long A[],int i,long xor) { if(index+1==A.length) { if(valid(xor^A[index],i)) { xor=xor^A[index]; max=Math.max(max, i); } return; } if(dp[index][i]==0) { dp[index][i]=1; if(valid(xor^A[index],i)) { f(index+1,A,i+1,0); f(index+1,A,i,xor^A[index]); } else { f(index+1,A,i,xor^A[index]); } } } static boolean valid(long xor,int i) { if(xor==0)return true; while(xor%2==0 ) { xor/=2; i--; } return i<=0; } static int next(int i,long pre[],long S) { int l=i,r=pre.length; while(r-l>1) { int m=(l+r)/2; if(pre[m]-pre[i-1]>S)r=m; else l=m; } return r; } static boolean lexo(long A[],long B[]) { for(int i=0; i<A.length; i++) { if(B[i]>A[i])return true; if(A[i]>B[i])return false; } return false; } static long [] f(long A[],long B[],int j) { int N=A.length; long X[]=new long[N]; for(int i=0; i<N; i++) { X[i]=(B[j]+A[i])%N; j++; j%=N; } return X; } static int find(int a) { if(par[a]<0)return a; return par[a]=find(par[a]); } static void union(int a,int b) { b=find(b); a=find(a); if(a!=b) { par[b]=a; } } 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(); } static long lower_Bound(long A[],int low,int high, long x) { if (low > high) if (x >= A[high]) return A[high]; int mid = (low + high) / 2; if (A[mid] == x) return A[mid]; if (mid > 0 && A[mid - 1] <= x && x < A[mid]) return A[mid - 1]; if (x < A[mid]) return lower_Bound( A, low, mid - 1, x); return lower_Bound(A, mid + 1, high, x); } 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) { size=new int[N+1]; // D=new int[N+1]; g=new ArrayList[N+1]; for(int i=0; i<=N; i++) { g[i]=new ArrayList<>(); } } static long pow(long a,long b) { long pow=1L; 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(int 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 ); } 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; } } //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()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str=""; try { str=br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
6203ba307df8b1315aa3290b7ca77f07
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.lang.reflect.AnnotatedArrayType; import java.util.*; public class Main { private static final MyWriter writer = new MyWriter(); private static final MyReader scan = new MyReader(); public static void main(String[] args) throws IOException { int q = scan.nextInt(); while (q-- > 0) solve(); writer.close(); } private static void solve() throws IOException { int n = scan.nextInt(); long[] arr = new long[n+1]; for(int i = 1; i <= n; i++){ arr[i] = scan.nextInt(); } int res = 0; for(int i = 1; i <= n; i++){ for(int j = (int)arr[i] - i ; j <= n ; j += arr[i]) { if (j <= i) continue; if (arr[i] * arr[j] == i + j) res ++; } } writer.println(res); } } class MyWriter implements Closeable { private BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(System.out)); public void print(Object object) throws IOException { writer.write(object.toString()); } public void println(Object object) throws IOException { writer.write(object.toString());writer.write(System.lineSeparator()); } public void close() throws IOException { writer.close(); } } class MyReader { private BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); private StringTokenizer tokenizer = new StringTokenizer(""); private String innerNextLine() { try { return reader.readLine(); } catch (IOException ex) { return null;}} public boolean hasNext() { while (!tokenizer.hasMoreTokens()) { String nextLine = innerNextLine();if (nextLine == null) return false;tokenizer = new StringTokenizer(nextLine); }return true; } public String nextLine() { tokenizer = new StringTokenizer("");return innerNextLine(); } public String next() { hasNext();return tokenizer.nextToken(); } public int nextInt() { return Integer.parseInt(next()); } public long nextLong() { return Long.parseLong(next()); } public double nextDouble() { return Double.parseDouble(next()); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
a317ab9a6ec21f9b41995d965ae08f96
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
//import java.util.*; //import java.lang.*; //import java.io.*; // // //public class Codeforces //{ // public static void main (String[] args) throws Exception // { // // BufferedReader read = new BufferedReader(new InputStreamReader(System.in)); // BufferedWriter write = new BufferedWriter(new OutputStreamWriter(System.out)); // // long TestCases = Long.parseLong(read.readLine().trim()); // // for (int Case = 0; Case < TestCases; Case++) { // //// String[] str = read.readLine().trim().split(" "); // int n = Integer.parseInt(read.readLine().trim()); // int array[] = Arrays.stream(read.readLine().trim().split(" ")).mapToInt(Integer::parseInt).toArray(); // // boolean[] visted = new boolean[n]; //// int[] baap = new int[n]; // HashSet<Integer> set = new HashSet<>(); // // for (int i = 0; i < n; i++) { // if(!visted[i]){ // visted[i] = true; // set.add(i); //// baap[i] = i; // } // for (int j = i+1; j < n; j++) { // if((j+1)-(i+1) != array[j]-array[i]){ // if(visted[j]){ // set.remove(i); // } // visted[j] = true; //// baap[j] = baap[i]; // } // } // } // // write.write(set.size()+"\n"); // // // } // // write.flush(); // write.close(); // read.close(); // } // // //} import java.util.*; import java.lang.*; import java.io.*; public class Codeforces { public static void main (String[] args) throws Exception { BufferedReader read = new BufferedReader(new InputStreamReader(System.in)); BufferedWriter write = new BufferedWriter(new OutputStreamWriter(System.out)); // Scanner scanner = new Scanner(System.in); long TestCases = Long.parseLong(read.readLine()); for (int Case = 0; Case < TestCases; Case++) { long n = Integer.parseInt(read.readLine().trim()); int[] array = Arrays.stream(read.readLine().trim().split(" ")).mapToInt(Integer::parseInt).toArray(); long count = 0; for (int i = 0; i < n; i++) { int j = array[i] -i-2; for (; j < n; j+=array[i]) { if(j>i && (long) array[i]*array[j] == (long)i+j+2) count++; } } write.write(count + "\n"); } write.flush(); write.close(); read.close(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
befd014606623039fc7133c489de0672
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class Practice { public static void main(String[] args) { FastReader sc = new FastReader(); int n = sc.nextInt(); while(n-->0) { int x = sc.nextInt(); pair aa[] = new pair[x]; for(int i = 0 ; i < x; i++) { int first = sc.nextInt(); int second = i+1; aa[i] = new pair(first, second); } Arrays.sort(aa); int cnt = 0; for(int j = 0 ; j < x-1; j++) { for(int i = j+1; i < x; i++) { if((long)((Integer)aa[i].first * (Integer)aa[j].first) == ((Integer)aa[i].second + (Integer)aa[j].second)) cnt++; if((long)(Integer)aa[i].first * (Integer)aa[j].first > (2*x-1)) break; } } System.out.println(cnt); } } // INPUT Class ----------> 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; } } // Pair Class -----------> static class pair<T> implements Comparable<pair>{ T first, second; pair(T first, T second) { this.first = first; this.second = second; } @Override public int compareTo(pair o) { return (Integer) this.first - (Integer) o.first; } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
8348b177596ddfac706e067df00d7ba4
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class B { public static void main(String[] args) throws IOException{ FastReader fr = new FastReader(); PrintWriter pr = new PrintWriter(new OutputStreamWriter(System.out)); int t = fr.nextInt(); while (t-- > 0) { int n = fr.nextInt(); int[] arr = new int[n+1]; int ans = 0; for (int i = 1; i < arr.length; i++) { arr[i] = fr.nextInt(); } // I mean, this is pretty much just a better way of implementing my original idea, which I am happy that I thought of for (int i = 1; i <= n; i++) { for (int j = arr[i] - (i % arr[i]); j <= n; j+=arr[i]) { if (i > j && i + j == arr[i] * arr[j]) ans++; } } pr.println(ans); } pr.close(); } static class Pair { int x, y; public Pair(int x, int y) { this.x = x; this.y = y; } } static int toInt(String s) { return Integer.parseInt(s); } static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() throws FileNotFoundException { 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
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
326ef667ba7f60c52338645816d6c3bd
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class Trials1 { public static void main(String[] args) throws NumberFormatException, IOException { BufferedReader inp=new BufferedReader(new InputStreamReader(System.in)); BufferedWriter out=new BufferedWriter(new OutputStreamWriter(System.out)); int t=Integer.parseInt(inp.readLine()); while(t-- >0) { int n=Integer.parseInt(inp.readLine()); String s[]=inp.readLine().split(" "); int a[]=new int[n+1]; for(int i=0;i<n;i++) { a[i+1]=Integer.parseInt(s[i]); } int cnt=0; for(int i=1;i<=n;i++) { for(int j=a[i]-(i%a[i]);j<=n;j+=a[i]) { if(i>j && a[i]*a[j]==i+j) cnt++; } } out.write(Integer.toString(cnt)+"\n"); } out.flush(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
335e039cda68b14ced2a8dd8ce47e0c4
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class Trials1 { public static void main(String[] args) throws NumberFormatException, IOException { BufferedReader inp=new BufferedReader(new InputStreamReader(System.in)); BufferedWriter out=new BufferedWriter(new OutputStreamWriter(System.out)); int t=Integer.parseInt(inp.readLine()); while(t-- >0) { int n=Integer.parseInt(inp.readLine()); String s[]=inp.readLine().split(" "); int a[]=new int[n+1]; for(int i=0;i<n;i++) { a[i+1]=Integer.parseInt(s[i]); } int cnt=0; for(int i=1;i<=n;i++) { for(int j=a[i]-(i%a[i]);j<=n;j+=a[i]) { if(i>j && a[i]*a[j]==i+j) cnt++; } } out.write(Integer.toString(cnt)+"\n"); } out.flush(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
3ecc91ebd098df1c8677541df5aab973
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class Trials1 { public static void main(String[] args) throws NumberFormatException, IOException { BufferedReader inp=new BufferedReader(new InputStreamReader(System.in)); BufferedWriter out=new BufferedWriter(new OutputStreamWriter(System.out)); int t=Integer.parseInt(inp.readLine()); while(t-- >0) { int n=Integer.parseInt(inp.readLine()); String s[]=inp.readLine().split(" "); int a[]=new int[n+1]; for(int i=0;i<n;i++) { a[i+1]=Integer.parseInt(s[i]); } int cnt=0; for(int i=1;i<=n;i++) { for(int j=a[i]-(i%a[i]);j<=n;j+=a[i]) { if(i>j && a[i]*a[j]==i+j) cnt++; } } out.write(Integer.toString(cnt)+"\n"); } out.flush(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
3aeaa323a2941d9ede9ffdf448f7f00d
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.StringTokenizer; public class Pleasant_Pairs { 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) { FastReader sc = new FastReader(); int t = sc.nextInt(); while(t-- > 0) { int n = sc.nextInt(); long[] A = new long[n+1]; for(int i = 1 ; i <= n ; i++) { A[i] = sc.nextLong(); } int count=0; for(int i = 1 ; i <= n ; i++) { for(long j = A[i]-i ; j <= n ; j += A[i]) { if(j > 0) { if(A[i] * A[(int)j] == i+j && i < j) { count++; } } } } System.out.println(count); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
5954a8f85403824b50cb405b1fa43041
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; public class javaTemplate { public static void main(String[] args) { Scanner s = new Scanner(System.in); int t = s.nextInt(); for (int tt = 0; tt < t; tt += 1) { int n = s.nextInt(); ArrayList<Integer> arr = new ArrayList<Integer>(); arr.add(0); for (int i = 1; i <= n; i += 1) { arr.add(s.nextInt()); } int ans = 0; ArrayList<ArrayList<Integer>> find = new ArrayList<ArrayList<Integer>>(); for (int i = 1; i <= n; i += 1) { int multi = 1; while (true) { int num = Math.abs((arr.get(i) * multi) - i); if (num <= n) { if (num > i) { find.add(new ArrayList<Integer>(Arrays.asList(multi, num))); } } else { break; } multi += 1; } } for (int i = 0; i < find.size(); i += 1) { int index = find.get(i).get(1); int num = find.get(i).get(0); if (arr.get(index) == num) { ans += 1; } } System.out.println(ans); } s.close(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
e60852a79d1b3e795e0fdc96dd99ea16
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; public class javaTemplate { public static void main(String[] args) { Scanner s = new Scanner(System.in); int t = s.nextInt(); for (int tt = 0; tt < t; tt += 1) { int n = s.nextInt(); ArrayList<Integer> arr = new ArrayList<Integer>(); arr.add(0); for (int i = 1; i <= n; i += 1) { arr.add(s.nextInt()); } int ans = 0; ArrayList<ArrayList<Integer>> find = new ArrayList<ArrayList<Integer>>(); for (int i = 1; i <= n; i += 1) { int multi = 1; while (true) { int num = Math.abs((arr.get(i) * multi) - i); if (num <= n) { if (num > i) { ArrayList<Integer> temp = new ArrayList<Integer>(); temp.add(multi); temp.add(num); find.add(temp); } } else { break; } multi += 1; } } for (int i = 0; i < find.size(); i += 1) { int index = find.get(i).get(1); int num = find.get(i).get(0); if (arr.get(index) == num) { ans += 1; } } System.out.println(ans); } s.close(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
463426c0485da7041547a8f57e7a475f
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
// import java.io.*; import java.util.*; public class javaTemplate { public static void main(String[] args) { Scanner fs = new Scanner(System.in); // StringBuilder output = new StringBuilder(); int t = fs.nextInt(); for (int tt = 0; tt < t; tt += 1) { int n = fs.nextInt(); ArrayList<Integer> arr = new ArrayList<Integer>(); arr.add(0); for (int i = 1; i <= n; i += 1) { arr.add(fs.nextInt()); } int ans = 0; ArrayList<ArrayList<Integer>> find = new ArrayList<ArrayList<Integer>>(); for (int i = 1; i <= n; i += 1) { int multi = 1; while (true) { int num = Math.abs((arr.get(i) * multi) - i); if (num <= n) { if (num > i) { ArrayList<Integer> temp = new ArrayList<Integer>(); temp.add(multi); temp.add(num); find.add(temp); } } else { break; } multi += 1; } } for (int i = 0; i < find.size(); i += 1) { int index = find.get(i).get(1); int num = find.get(i).get(0); if (arr.get(index) == num) { ans += 1; } } System.out.println(ans); // output.append(ans).append('\n'); } // System.out.println(output.toString()); fs.close(); } } // class FastScanner { // BufferedReader br; // StringTokenizer st; // public FastScanner() { // 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
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
7522a25872052878f3d664917dec14f8
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class javaTemplate { public static void main(String[] args) { FastScanner fs = new FastScanner(); StringBuilder output = new StringBuilder(); int t = fs.nextInt(); for (int tt = 0; tt < t; tt += 1) { int n = fs.nextInt(); ArrayList<Integer> arr = new ArrayList<Integer>(); arr.add(0); for (int i = 1; i <= n; i += 1) { arr.add(fs.nextInt()); } int ans = 0; ArrayList<ArrayList<Integer>> find = new ArrayList<ArrayList<Integer>>(); for (int i = 1; i <= n; i += 1) { int multi = 1; while (true) { int num = Math.abs((arr.get(i) * multi) - i); if (num <= n) { if (num > i) { ArrayList<Integer> temp = new ArrayList<Integer>(); temp.add(multi); temp.add(num); find.add(temp); } } else { break; } multi += 1; } } for (int i = 0; i < find.size(); i += 1) { int index = find.get(i).get(1); int num = find.get(i).get(0); if (arr.get(index) == num) { ans += 1; } } output.append(ans).append('\n'); } System.out.println(output.toString()); } } class FastScanner { BufferedReader br; StringTokenizer st; public FastScanner() { 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
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
c434a39d7fcf5698ef4ad27bae1770a7
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class javaTemplate { public static void main(String[] args) { FastScanner fs = new FastScanner(); StringBuilder output = new StringBuilder(); int t = fs.nextInt(); for (int tt = 0; tt < t; tt += 1) { int n = fs.nextInt(); ArrayList<Integer> arr = new ArrayList<Integer>(); arr.add(0); for (int i = 1; i <= n; i += 1) { arr.add(fs.nextInt()); } int ans = 0; ArrayList<ArrayList<Integer>> find = new ArrayList<ArrayList<Integer>>(); for (int i = 1; i <= n; i += 1) { int multi = 1; while (true) { int num = Math.abs((arr.get(i) * multi) - i); if (num <= n) { if (num > i) { ArrayList<Integer> temp = new ArrayList<Integer>(); temp.add(multi); temp.add(num); find.add(temp); } } else { break; } multi += 1; } } for (int i = 0; i < find.size(); i += 1) { int index = find.get(i).get(1); int num = find.get(i).get(0); if (arr.get(index) == num) { ans += 1; } } output.append(ans).append('\n'); } System.out.println(output.toString()); } static class FastScanner { BufferedReader br; StringTokenizer st; public FastScanner() { 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
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
5b4916d9c218cc994cb22a71a7149deb
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class javaTemplate { public static void main(String[] args) { FastScanner fs = new FastScanner(); int t = fs.nextInt(); StringBuilder allAns = new StringBuilder(); for (int tt = 0; tt < t; tt += 1) { int n = fs.nextInt(); ArrayList<Integer> arr = new ArrayList<Integer>(); arr.add(0); for (int i = 1; i <= n; i += 1) { arr.add(fs.nextInt()); } int ans = 0; ArrayList<ArrayList<Integer>> find = new ArrayList<ArrayList<Integer>>(); for (int i = 1; i <= n; i += 1) { int multi = 1; while (true) { int num = Math.abs((arr.get(i) * multi) - i); if (num <= n) { if (num > i) { ArrayList<Integer> temp = new ArrayList<Integer>(); temp.add(multi); temp.add(num); find.add(temp); } } else { break; } multi += 1; } } for (int i = 0; i < find.size(); i += 1) { // System.out.println(find.get(i)); int index = find.get(i).get(1); int num = find.get(i).get(0); if (arr.get(index) == num) { ans += 1; } } allAns.append(ans).append('\n'); } System.out.println(allAns); } static class FastScanner { BufferedReader br; StringTokenizer st; public FastScanner() { 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
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
c73b378df7d17d680405b78c9755651c
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.Scanner; public class pleasentPairs { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int t = sc.nextInt(); while (t-- > 0) { int n = sc.nextInt(); int[] a = new int[n + 1]; for (int i = 1; i <= n; i++) { a[i] = sc.nextInt(); } long res = 0; for (int i = 1; i < n; i++) { for (int j = a[i] - i; j <= n; j += a[i]) { if (j >= 1) { if (((long) a[i] * a[j] == i + j) && (i < j)) { res++; } } } } System.out.println(res); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
a4d04b2da5b0f55aabc93a7f2db1fc5c
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.Scanner; public class pleasentPairs { public static void main(String[] args) throws java.lang.Exception { Scanner sc = new Scanner(System.in); int T = sc.nextInt(); while (T-- > 0) { int n = sc.nextInt(); int a[] = new int[n + 1]; for (int i = 1; i <= n; i++) { a[i] = sc.nextInt(); } long c = 0; for (int i = 1; i < n; i++) { for (int j = a[i] - i; j <= n; j += a[i]) { if (j >= 1) if (((long) a[i] * a[j] == i + j) && (i < j)) c++; } } System.out.println(c); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
827b05ca37d3ff28bc650ee52d53558b
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.sql.SQLOutput; import java.util.*; import java.lang.*; import java.io.*; public class Main{ static StringBuilder ANS; 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 void solve(){ int n = sc.nextInt(); int[] arr = new int[n+1]; for (int i = 1; i <= n; i++) arr[i] = sc.nextInt(); int c = 0; for(int i=1;i<=n;i++){ for(int j=arr[i]-i;j<=n;j+=arr[i]){ if(i < j && ((long) arr[i] * arr[j]) == i+j) { c++; } } } ANS.append(c).append("\n"); } private static final FastReader sc = new FastReader(); public static void main (String[] args) throws java.lang.Exception { int t = sc.nextInt(); ANS = new StringBuilder(); while(t-- != 0) solve(); System.out.println(ANS); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
e8b762e9a82ddcb7bda31cccfea91bc2
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; public class Main { public static void main(String[] args) { Scanner sc=new Scanner(System.in); int t=sc.nextInt(); while(t-->0){ int n=sc.nextInt(); int[] a=new int[n]; Map<Integer,Integer> map=new HashMap<>(); for(int i=0;i<n;i++){ a[i]=sc.nextInt(); map.put(a[i],i+1); } Arrays.sort(a); int count=0; for(int i=0;i<n-1;i++) { if(a[i]*a[i+1]>2*n-1) break; for(int j=i+1;j<n;j++){ if(a[i]*a[j]>2*n-1) break; if(a[i]*a[j]==map.get(a[i])+map.get(a[j])) count++; } } System.out.println(count); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
0c9969f8bc0523de87a7be9e55031919
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.ArrayList; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.Collections; import java.util.StringTokenizer; import java.util.Arrays; import static java.lang.Math.max; import static java.lang.Math.min; import static java.lang.Math.sqrt; import static java.lang.Math.abs; import static java.lang.Math.random; import static java.lang.Integer.MAX_VALUE; import static java.lang.Integer.MIN_VALUE; import static java.util.Collections.reverseOrder; public final class Test1 { static int mod = 1000000007; static int mod1 = 998244353; public static void main(String[] args) { solve(); } static long gcd(int a, int b) {if (b == 0) return a; return gcd(b, a % b); } static long modAdd(long a, long b, long m) {a = a % m; b = b % m; return (((a + b) % m) + m) % m;} static long modMul(long a, long b, long m) {a = a % m; b = b % m; return (((a * b) % m) + m) % m;} static long modSub(long a, long b, long m) {a = a % m; b = b % m; return (((a - b) % m) + m) % m;} static long modDiv(long a, long b, long m) {a = a % m; b = b % m; return (modMul(a, mminvprime(b, m), m) + m) % m;} //only for prime m static long mminvprime(long a, long b) {return expo(a, b - 2, b);} static long expo(long a, long b, long mod) {long res = 1; while (b > 0) {if ((b & 1) != 0)res = (res * a) % mod; a = (a * a) % mod; b = b >> 1;} return res;} static long setBits(int n) {int cnt = 0; while (n != 0) { cnt++; n = n & (n - 1); } return cnt;} static int[] sieve(int n) {int[] arr = new int[n + 1]; for (int i = 2; i <= n; i++)if (arr[i] == 0) {for (int j = 2 * i; j <= n; j += i)arr[j] = 1;} return arr;} static void debug(int[] nums) { for (int i = 0; i < nums.length; i++) System.out.println(nums[i] + " "); } static void debug(long[] nums) { for (int i = 0; i < nums.length; i++) System.out.println(nums[i] + " "); } static void debug(String[] nums) { for (int i = 0; i < nums.length; i++) System.out.println(nums[i] + " "); } static void reverse(int[] nums) { int start = 0, end = nums.length - 1; while (start < end) {int temp = nums[start]; nums[start] = nums[end]; nums[end] = temp; start++; end--; } } static void reverse(char[] nums) { int start = 0, end = nums.length - 1; while (start < end) {char temp = nums[start]; nums[start] = nums[end]; nums[end] = temp; start++; end--; } } 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 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); } // <------------------------- CODE START FROM HERE --------------------------------> public static void solve() { FastScanner sc = new FastScanner(); int t = sc.nextInt(); while (t-- != 0) { int n = sc.nextInt(); int arr[] = sc.readArray(n); if (n == 2) { if ( (arr[0] * arr[1]) == 3) System.out.println(1); else System.out.println(0); } else { Pair nums[] = new Pair[n]; for (int i = 0; i < n; i++) { nums[i] = new Pair(arr[i], i + 1); } Arrays.sort(nums); // for (int i = 0; i < n; i++) // System.out.println(nums[i]); long ans = 0; int itr = 0; while ((nums[itr].val * nums[itr + 1].val ) <= (2 * n - 1)) itr++; for (int i = 0; i < itr; i++) for (int j = i + 1; j < n; j++) if ((nums[i].val * nums[j].val) == ( nums[i].index + nums[j].index) ) ans++; System.out.println(ans); } } } static class Pair implements Comparable<Pair> { long val, index; Pair(long val, long index) { this.val = val; this.index = index; } public int compareTo(Pair p) { return (int)(this.val - p.val); } public String toString() { return val + " " + index; } } // <----------------------------------CODE END HERE------------------------> // System.out.println(); // int b[] = a.clone(); }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
4ceb361398ce23104d2faa01b317a81b
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; import java.lang.Math; public class Main{ static BufferedReader reader; static StringTokenizer tokenizer; static PrintWriter writer; static int nextInt() throws IOException { return Integer.parseInt(nextToken()); } static long nextLong() throws IOException { return Long.parseLong(nextToken()); } static double nextDouble() throws IOException { return Double.parseDouble(nextToken()); } static String nextToken() throws IOException { while (tokenizer == null || !tokenizer.hasMoreTokens()) { tokenizer = new StringTokenizer(reader.readLine()); } return tokenizer.nextToken(); } static String nexts() throws IOException { tokenizer = new StringTokenizer(reader.readLine()); String s=""; while (tokenizer.hasMoreTokens()) { s+=tokenizer.nextElement()+" "; } return s; } public static int gcd(int x, int y){ if (y == 0) return x; else return gcd(y, x % y); } public static long gcd(long x, long y){ if (y == 0) return x; else return gcd(y, x % y); } static long digitSum(String x) { long a = 0; for (int i = 0; i < x.length(); i++) { a += x.charAt(i) - '0'; } return a; } static long digitSum(long x) { long a = 0; while (x > 0) { a += x % 10; x /= 10; } return a; } static int max(int x, int y) { return Math.max(x, y); } static int min(int x, int y) { return Math.min(x, y); } static int max(int x, int y, int z) { x = Math.max(x, y); x = Math.max(x, z); return x; } static int min(int x, int y, int z) { x = Math.min(x, y); x = Math.min(x, z); return x; } static long max(long x, long y) { return Math.max(x, y); } static long min(long x, long y) { return Math.min(x, y); } static long max(long x, long y, long z) { x = Math.max(x, y); x = Math.max(x, z); return x; } static long min(long x, long y, long z) { x = Math.min(x, y); x = Math.min(x, z); return x; } static double max(double x, double y) { return Math.max(x, y); } static double min(double x, double y) { return Math.min(x, y); } static double max(double x, double y, double z) { x = Math.max(x, y); x = Math.max(x, z); return x; } static double min(double x, double y, double z) { x = Math.min(x, y); x = Math.min(x, z); return x; } static void rsort(int[] ar) { Arrays.sort(ar); int len = ar.length; for (int i = 0; i < len / 2; i++) { int tmp = ar[i]; ar[i] = ar[len - 1 - i]; ar[len - 1 - i] = tmp; } } static void rsort(long[] ar) { Arrays.sort(ar); int len = ar.length; for (int i = 0; i < len / 2; i++) { long tmp = ar[i]; ar[i] = ar[len - 1 - i]; ar[len - 1 - i] = tmp; } } static void rsort(double[] ar) { Arrays.sort(ar); int len = ar.length; for (int i = 0; i < len / 2; i++) { double tmp = ar[i]; ar[i] = ar[len - 1 - i]; ar[len - 1 - i] = tmp; } } static void rsort(char[] ar) { Arrays.sort(ar); int len = ar.length; for (int i = 0; i < len / 2; i++) { char tmp = ar[i]; ar[i] = ar[len - 1 - i]; ar[len - 1 - i] = tmp; } } static long lcm(long a, long b) throws IOException { return a * b / gcd(a, b); } static int lcm(int a, int b) throws IOException { return a * b / gcd(a, b); } static int rev(int x) { int a = 0; while (x > 0) { a = a * 10 + x % 10; x /= 10; } return a; } public static boolean isPrime(int nn) { if(nn<=1)return false; if(nn<=3){return true; } if (nn%2==0||nn%3==0){return false; } for (int i=5;i*i<=nn;i=i+6){ if(nn%i==0||nn%(i+2)==0){return false; }} return true; } public static void shuffle(int[] A) { for (int i = 0; i < A.length; i++) { int j = (int)(i * Math.random()); int tmp = A[i];A[i] = A[j];A[j] = tmp; } } public static void shufflel(Long[] A) { for (int i = 0; i < A.length; i++) { int j = (int)(i * Math.random()); long tmp = A[i];A[i] = A[j];A[j] = tmp; } } public static String reverse(String input) { StringBuilder input2=new StringBuilder(); input2.append(input); input2 = input2.reverse(); return input2.toString(); } public static long power(int x, long n) { // long mod = 1000000007; if (n == 0) { return 1; } long pow = power(x, n / 2); if ((n & 1) == 1) { return (x * pow * pow); } return (pow * pow); } public static long power(long x, long y, long p) //x^y%p { long res = 1; x = x % p; while (y > 0) { if (y % 2 == 1) { res = (res * x) % p; } y = y >> 1; // y = y/2 x = (x * x) % p; } return res; } static long ncr(int n, int k) { long res = 1; // Since C(n, k) = C(n, n-k) if (k > n - k) { k = n - k; } // Calculate value of [n*(n-1)*---*(n-k+1)] / [k*(k-1)*---*1] for (int i = 0; i < k; ++i) { res *= (n - i); res /= (i + 1); } return res; } public static int inv(int a, int m) //Returns modulo inverse of a with respect to m using extended euclid algorithm { int m0=m,t,q; int x0=0,x1=1; if(m==1){ return 0; } while(a>1) { q=a/m; t=m; m=a%m;a=t; t=x0; x0=x1-q*x0; x1=t; } if(x1<0){ x1+=m0; } return x1; } static int modInverse(int n, int p) { return (int)power((long)n, (long)(p - 2),(long)p); } static int ncrmod(int n, int r, int p) { if (r == 0) // Base case return 1; int[] fac = new int[n + 1]; // Fill factorial array so that we can find all factorial of r, n and n-r fac[0] = 1; for (int i = 1; i <= n; i++) fac[i] = fac[i - 1] * i % p; return (fac[n] * modInverse(fac[r], p) % p * modInverse(fac[n - r], p) % p) % p; //IMPORTANT } static int upper(int a[], int x) //Returns rightest index of x in sorted arr else -1 { //If not present returns index of just smaller element int n=a.length; int l=0; int r=n-1; int ans=-1; while(l<=r){ int m=(r-l)/2+l; if(a[m]<=x){ ans=m; l=m+1; } else{ r=m-1; } } return ans; } static int lower(int a[], int x) //Returns leftest index of x in sorted arr else n { //If not present returns index of just greater element int n=a.length; int l=0; int r=n-1; int ans=n; while(l<=r){ int m=(r-l)/2+l; if(a[m]>=x){ ans=m; r=m-1; } else{ l=m+1; } } return ans; } public static long stringtoint(String s){ // Convert bit string to number long a = 1; long ans = 0; StringBuilder sb = new StringBuilder(); sb.append(s); sb.reverse(); s=sb.toString(); for(int i=0;i<s.length();i++){ ans = ans + a*(s.charAt(i)-'0'); a = a*2; } return ans; } String inttostring(long a,long m){ // a is number and m is length of string required String res = ""; // Convert a number in bit string representation for(int i=0;i<(int)m;i++){ if((a&(1<<i))==1){ res+='1'; }else res+='0'; } StringBuilder sb = new StringBuilder(); sb.append(res); sb.reverse(); res=sb.toString(); return res; } static final int inf = Integer.MAX_VALUE / 2; static final long linf = Long.MAX_VALUE / 3; static final long mod = (long) 1e9 + 7; static class R implements Comparable<R>{ long x, y; public R(long x, long y) { //a[i]=new R(x,y); this.x = x; this.y = y; } public int compareTo(R o) { return (int)(x-o.x); //Increasing order(Which is usually required) } } //Check if palindrome string - System.out.print(A.equals(new StringBuilder(A).reverse().toString())?"Yes":"No"); public static void main(String[] args) throws IOException { reader = new BufferedReader(new InputStreamReader(System.in)); tokenizer = null; writer = new PrintWriter(System.out); solve(); reader.close(); writer.close(); } //public static boolean check() { // // } private static void solve() throws IOException { int t = nextInt(); while(t-->0){ //String s= nextToken(); //String[] s = str.split("\\s+"); //ArrayList<Integer> ar=new ArrayList<Integer>(); //HashSet<Integer> set=new HashSet<Integer>(); // HashMap<Long,Long> h=new HashMap<Long,Long>(); //R[] a1=new R[n]; //char[] c=nextToken().toCharArray(); //PriorityQueue<Integer> pq=new PriorityQueue<Integer>(Collections.reverseOrder()); //NavigableSet<Integer> pq=new TreeSet<>(); int n = nextInt(); //long n = nextLong(); //int[] a=new int[n]; R[] a=new R[n]; //for(int i=0;i<=2*n;i++)b[i]=-1L; for(int i=0;i<n;i++){ a[i] =new R(nextLong(),i); } //for(R p:a)writer.print(p.x+" "+p.y+" "); long ans=0; //shuffle(a); //shufflel(a);rsort(); Arrays.sort(a); for(int i=0;i<n;i++){ for(int j=i+1;j<n;j++){ if((long)(a[i].y+a[j].y+2)==(a[i].x*a[j].x))ans++; if(a[i].x*a[j].x>(long)2*n)break; } } writer.println(ans); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
ff08bc7e09191d370085af8713137833
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; import java.math.*; public class Main { BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); StringTokenizer tokenizer=null; public static void main(String[] args) throws IOException { new Main().execute(); } void debug(Object...os) { System.out.println(Arrays.deepToString(os)); } int ni() throws IOException { return Integer.parseInt(ns()); } long nl() throws IOException { return Long.parseLong(ns()); } double nd() throws IOException { return Double.parseDouble(ns()); } String ns() throws IOException { while (tokenizer == null || !tokenizer.hasMoreTokens()) tokenizer = new StringTokenizer(br.readLine()); return tokenizer.nextToken(); } String nline() throws IOException { tokenizer=null; return br.readLine(); } void execute() throws IOException { int t = ni(); while(t-- > 0){ solve(); } } void solve() throws IOException { int n = ni(); int[] lookup = new int[2*n+1]; int[] arr = new int[n + 1]; int max = 0; for(int i=1;i<=n;i++){ int num = ni(); arr[i] = num; // max = Math.max(max, num); // lookup[num] = i; } int count = 0; for(int i=1;i<=n;i++){ for(int j=1;j * arr[i] <= 2*n;j++){ if(lookup[j] != 0 ){ long mul = (long)arr[i] * j; long sum = i + (long)lookup[j]; count = mul == sum ? count + 1 : count; } } lookup[arr[i]] = i; } System.out.println(count); } void swap(int[] arr, int i, int j){ int temp = arr[i]; arr[i] = arr[j]; arr[j] = temp; } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
86208dc7ab7339aeda3a8abb51c4eb16
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.*; public class ArrayQues { 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) { // TODO Auto-generated method stub FastReader sc=new FastReader(); int k=sc.nextInt(); // while(k-->0) { int n=sc.nextInt(); int A[]=new int[n+1]; HashMap<Integer,Integer> map =new HashMap<>(); for(int i=1; i<=n; i++) { A[i]=sc.nextInt(); } int res = 0; for (int i = 1; i <= n; i++) { int num = A[i]; for (int val = 1; val * num <= 2 * n; val++) { if (map.containsKey(val) && map.get(val) + i == A[i] * val) res++; } map.put(A[i],i); } System.out.println(res); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
0415c9b5bd742abbbfd026b77d4744a7
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*;import java.util.*; public class Main { static BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); static StringTokenizer st; static String next() throws IOException { while (st == null || !st.hasMoreTokens()) st = new StringTokenizer(br.readLine()); return st.nextToken(); } static int readInt() throws IOException { return Integer.parseInt(next()); } static long readLong() throws IOException { return Long.parseLong(next()); } static double readDouble() throws IOException { return Double.parseDouble(next()); } static char readChar() throws IOException { return next().charAt(0); } static String readLine() throws IOException { return br.readLine(); } static class Pair implements Comparable<Pair> { int f, s; Pair(int f, int s) { this.f = f; this.s = s; } public int compareTo(Pair other) { if (this.f != other.f) return this.f - other.f; return this.s - other.s; } } public static void main(String[] args) throws IOException { int t = readInt(); while(t-- > 0) { int n = readInt(); Pair[] p = new Pair[n]; for(int i = 0; i < n; ++i) p[i] = new Pair(readInt(),i+1); Arrays.sort(p); int ret = 0; for(int i = 0; i < n; ++i) { for(int j = i+1; j < n; ++j) { long pro = (long)p[i].f*p[j].f; if(pro >= (n<<1)) break; if(pro == p[i].s+p[j].s) ++ret; } } System.out.println(ret); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
d00fc3f67538f6cc6dbe0937765734da
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class Main { static BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); static StringTokenizer st; static String next() throws IOException { while (st == null || !st.hasMoreTokens()) st = new StringTokenizer(br.readLine()); return st.nextToken(); } static int readInt() throws IOException { return Integer.parseInt(next()); } static long readLong() throws IOException { return Long.parseLong(next()); } static double readDouble() throws IOException { return Double.parseDouble(next()); } static char readChar() throws IOException { return next().charAt(0); } static String readLine() throws IOException { return br.readLine(); } static class Pair implements Comparable<Pair> { int f, s; Pair(int f, int s) { this.f = f; this.s = s; } public int compareTo(Pair other) { if (this.f != other.f) return this.f - other.f; return this.s - other.s; } } public static void main(String[] args) throws IOException { for (int t = readInt(); t > 0; --t) { int n = readInt(); Pair p[] = new Pair[n + 1]; for (int i = 1; i <= n; ++i) p[i] = new Pair(readInt(), i); Arrays.sort(p, 1, n + 1); int ans = 0; for (int i = 1; i <= n; ++i) { for (int j = i + 1; j <= n; ++j) { long pro = (long)p[i].f*p[j].f; if (pro >= n<<1) break; if (pro == p[i].s + p[j].s) ++ans; } } System.out.println(ans); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
b3059a1a87150f5701540763cb0c2d16
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
// Piyush Nagpal import java.util.*; import java.io.*; public class C{ static int MOD=1000000007; static PrintWriter pw; static FastReader sc; 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());} public char nextChar() throws IOException {return next().charAt(0);} String nextLine(){ String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } public int[] intArr(int n) throws IOException {int[]in=new int[n];for(int i=0;i<n;i++)in[i]=nextInt();return in;} public long[] longArr(int n) throws IOException {long[]in=new long[n];for(int i=0;i<n;i++)in[i]=nextLong();return in;} } public static long gcd(long a,long b){if( b>a ){return gcd(b,a);}if( b==0 ){return a;} return gcd(b,a%b);} public static long expo( long a,long b,long M ){long result=1;while(b>0){if( b%2==1 ){result=(result*a)%M;}a=(a*a)%M;b=b/2;}return result%M;} public static ArrayList<Long> Sieve(int n){boolean [] arr= new boolean[n+1];Arrays.fill(arr, true);ArrayList<Long> list= new ArrayList<>();for(int i=2;i<=n;i++){if( arr[i]==true ){list.add((long)i);}for(int j=2*i;j<=n;j+=i){arr[j]=false;}}return list;} public static void printarr(int [] arr){for(int i=0;i<arr.length;i++){pw.print(arr[i]+" ");}} public static void printarr(long [] arr){for(int i=0;i<arr.length;i++){pw.print(arr[i]+" ");}} // int [] arr=sc.intArr(n); static void solve() throws Exception{ int n =sc.nextInt(); long [] arr= new long [n]; for(int i=0;i<n;i++){ arr[i]=sc.nextInt(); } long count=0; for(int i=1;i<=n;i++){ long x= arr[i-1]; int k=(int)(x-i); while(k<=i){ k+=x; } if(x==1){ for(int j=k;j<=n;j++){ if( arr[i-1]*arr[j-1]==i+j ){ count++; } } }else{ for(int j=k;j<=n;j+=x){ if( arr[i-1]*arr[j-1]==i+j ){ count++; } } } } pw.println(count); } public static void main(String[] args) throws Exception{ try { System.setIn(new FileInputStream("input.txt")); System.setOut(new PrintStream(new FileOutputStream("output.txt"))); } catch (Exception e) { System.err.println("Error"); } sc= new FastReader(); pw = new PrintWriter(System.out); int tc=1; tc=sc.nextInt(); for(int i=1;i<=tc;i++) { // pw.printf("Case #%d: "b, i); solve(); } pw.flush(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
ccb4ef2c25c11c54abbcc0ae29ad041c
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
// Piyush Nagpal import java.util.*; import java.io.*; public class C{ static int MOD=1000000007; static PrintWriter pw; static FastReader sc; 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());} public char nextChar() throws IOException {return next().charAt(0);} String nextLine(){ String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } public int[] intArr(int n) throws IOException {int[]in=new int[n];for(int i=0;i<n;i++)in[i]=nextInt();return in;} public long[] longArr(int n) throws IOException {long[]in=new long[n];for(int i=0;i<n;i++)in[i]=nextLong();return in;} } public static long gcd(long a,long b){if( b>a ){return gcd(b,a);}if( b==0 ){return a;} return gcd(b,a%b);} public static long expo( long a,long b,long M ){long result=1;while(b>0){if( b%2==1 ){result=(result*a)%M;}a=(a*a)%M;b=b/2;}return result%M;} public static ArrayList<Long> Sieve(int n){boolean [] arr= new boolean[n+1];Arrays.fill(arr, true);ArrayList<Long> list= new ArrayList<>();for(int i=2;i<=n;i++){if( arr[i]==true ){list.add((long)i);}for(int j=2*i;j<=n;j+=i){arr[j]=false;}}return list;} public static void printarr(int [] arr){for(int i=0;i<arr.length;i++){pw.print(arr[i]+" ");}} public static void printarr(long [] arr){for(int i=0;i<arr.length;i++){pw.print(arr[i]+" ");}} // int [] arr=sc.intArr(n); static void solve() throws Exception{ int n =sc.nextInt(); long [] arr= new long [n+1]; for(int i=1;i<=n;i++){ arr[i]=sc.nextLong(); } long count=0; for(int i=1;i<=n-1;i++){ long x= arr[i]; int j=(int)(x-i); while(j<=i){ j+=x; } for(;j<=n;j+=x){ if( arr[i]*arr[j]==(i+j) ){ count++; } } } pw.println(count); } public static void main(String[] args) throws Exception{ try { System.setIn(new FileInputStream("input.txt")); System.setOut(new PrintStream(new FileOutputStream("output.txt"))); } catch (Exception e) { System.err.println("Error"); } sc= new FastReader(); pw = new PrintWriter(System.out); int tc=1; tc=sc.nextInt(); for(int i=1;i<=tc;i++) { // pw.printf("Case #%d: "b, i); solve(); } pw.flush(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
0a4f7db88c5ec2e087bc504b345b729d
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; import java.io.BufferedReader; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStreamReader; //import java.util.*; public class Solution { static class FastScanner { BufferedReader br; StringTokenizer st ; FastScanner(){ br = new BufferedReader(new InputStreamReader(System.in)); st = new StringTokenizer(""); } FastScanner(String file) { try { br = new BufferedReader(new InputStreamReader(new FileInputStream(file))); st = new StringTokenizer(""); } catch (FileNotFoundException e) { // TODO Auto-generated catch block System.out.println("file not found"); e.printStackTrace(); } } 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()); } String readLine() throws IOException{ return br.readLine(); } } public static void main(String[] args) throws Exception { FastScanner s = new FastScanner(); int t = s.nextInt(); for(int q=0;q<t;q++){ int n = s.nextInt(); int arr[] = new int[n+1]; //Map<Integer,Integer> map = new HashMap<>(); int map1[] = new int[2*n + 1]; Arrays.fill(map1,(int)Math.pow(10,6)); for(int i=1;i<=n;i++){ arr[i] = s.nextInt(); //map.put(arr[i],i); map1[arr[i]] = i; } int count = 0; for(int i = 3;i<2*n;i++){ for(int j=1;j<=(int)(Math.sqrt(i));j++){ if((i%j==0) && (map1[j] + map1[i/j] == i) && (i!=j*j)){ count++; } } } System.out.println(count); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
92d44687dd787f4da04284f2401fada2
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedOutputStream; 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.Collections; import java.util.Comparator; import java.util.HashMap; import java.util.HashSet; import java.util.Map; import java.util.PriorityQueue; import java.util.Queue; import java.util.Scanner; import java.util.StringTokenizer; import java.util.TreeMap; public class Practice2 { static long[] sort(long[] arr) { long n=arr.length; ArrayList<Long> al=new ArrayList<>(); for(int i=0;i<n;i++) { al.add(arr[i]); } Collections.sort(al); for(int i=0;i<n;i++) { arr[i]=al.get(i); } return arr; } public static void main (String[] args) { PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out)); // out.print(); //out.println(); FastReader sc=new FastReader(); int t=sc.nextInt(); while(t-->0) { int n=sc.nextInt(); int[] arr=new int[n]; for(int i=0;i<n;i++) { arr[i]=sc.nextInt(); } long count=0; for(int i=1;i<=n;i++) { for(int j=arr[i-1]-i;j<=n;j+=arr[i-1]) { if(j-1>=0&&j>i) { if((long)arr[i-1]*(long)arr[j-1]==i+j) count++; } } } out.println(count); } 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
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
c6a6c68c4481a24f40cd8e6ada459f89
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.lang.reflect.Array; import java.math.*; import java.net.Inet4Address; import java.security.KeyStore; import java.util.*; public class sampleEditor_codeforces { static int mod=1000000007; static int mod2=1000003; static Scanner sc = new Scanner(System.in); static boolean [] sieve=new boolean[100000002]; static ArrayList<Integer> allPrimes=new ArrayList<>(); static void createSieve() { sieve[1]=true; sieve[0]=true; for(int i=2;i*i<=100000001;i++) { if(!sieve[i]) { for(int j=i*i;j<=100000001;j+=i) { sieve[j]=true; } } } // for(int i=2;i<=100000001;i++) { // if(!sieve[i]) allPrimes.add(i); // } } static class Pair implements Comparable<Pair>{ int x; int y; public Pair(int px , int py){ x = px; y = py; } @Override public int compareTo(Pair pair){ if (x > pair.x) return 1; else if (x == pair.x) return 0; else return -1; } } public static long gcd(long a,long b) { if(b==0) return a; return gcd(b,a%b); } public static long binaryToDecimal(String binary){ int n=binary.length(); int i=n-1; long sum=0; long two=1; while(i>=0){ sum+=two*(binary.charAt(i)-'0')%mod2; two*=2; i--; } return sum; } public static boolean isSorted(int[] arr) { int n = arr.length; for (int i = 0; i < n - 1; i++) { if (arr[i] > arr[i + 1]) { return false; } } return true; } public static void reverse(int[] arr) { int l = 0; int r = arr.length - 1; while (l < r) { int temp = arr[l]; arr[l] = arr[r]; arr[r] = temp; l++; r--; } } public static void reverse(int[] arr,int l,int r) { while (l < r) { int temp = arr[l]; arr[l] = arr[r]; arr[r] = temp; l++; r--; } } public static boolean isPalindrome(int n,int [] a,int x1){ int [] b=new int[n]; int m=0; for(int i=0;i<n;i++){ if(a[i]!=x1){ b[m++]=a[i]; } } for(int i=0;i<m;i++){ if(b[i]!=b[m-1-i]){ return false; } } return true; } public static long sumOfDigit(long num) { return (num<10)?num:num%10+sumOfDigit(num/10); } public static void solve(int n,int [] a) { int cnt=0; for(int i =1;i<=n;i++) { int x=a[i]; for(int j=x-i;j<=n;j+=x) { if(j>=0){ if((long)x*a[j]==i+j && i<j) cnt++; } } } System.out.println(cnt); } public static void main(String args[]) { // Scanner sc = new Scanner(System.in); int t = sc.nextInt(); while (t-- > 0) { int n=sc.nextInt(); int [] a=new int[n+1]; for(int i=1;i<=n;i++) { a[i]=sc.nextInt(); } solve(n,a); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
c7c272396d8467e9891f9db321cacdd9
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import static java.lang.Math.*; import java.io.*; import java.math.*; import java.util.*; public class cf1 { static FastReader x = new FastReader(); static OutputStream outputStream = System.out; static PrintWriter out = new PrintWriter(outputStream); /*---------------------------------------CODE STARTS HERE-------------------------*/ public static void main(String[] args) { int t = x.nextInt(); StringBuilder str = new StringBuilder(); while (t > 0) { int n= x.nextInt(); long a[] = new long[n+1]; for(int i=1;i<=n;i++) { a[i] = x.nextLong(); } long count=0; for(int i=1;i<n;i++) { long v=a[i]; for(int j=(int)v-i;j<=n;j+=v) { if(j>i&&(v*a[j])==(i+j)) { count++; } } } str.append(count); str.append("\n"); t--; } out.println(str); out.flush(); } /*--------------------------------------------FAST I/O--------------------------------*/ 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; } char nextchar() { char ch = ' '; try { ch = (char) br.read(); } catch (IOException e) { e.printStackTrace(); } return ch; } } /*--------------------------------------------BOILER PLATE---------------------------*/ static int[] readarr(int n) { int arr[] = new int[n]; for (int i = 0; i < n; i++) { arr[i] = x.nextInt(); } return arr; } static int[] sortint(int a[]) { ArrayList<Integer> al = new ArrayList<>(); for (int i : a) { al.add(i); } Collections.sort(al); for (int i = 0; i < a.length; i++) { a[i] = al.get(i); } return a; } static long[] sortlong(long a[]) { ArrayList<Long> al = new ArrayList<>(); for (long i : a) { al.add(i); } Collections.sort(al); for (int i = 0; i < al.size(); i++) { a[i] = al.get(i); } return a; } static int pow(int x, int y) { int result = 1; while (y > 0) { if (y % 2 == 0) { x = x * x; y = y / 2; } else { result = result * x; y = y - 1; } } return result; } static int[] revsort(int a[]) { ArrayList<Integer> al = new ArrayList<>(); for (int i : a) { al.add(i); } Collections.sort(al, Comparator.reverseOrder()); for (int i = 0; i < a.length; i++) { a[i] = al.get(i); } return a; } static int[] gcd(int a, int b, int ar[]) { if (b == 0) { ar[0] = a; ar[1] = 1; ar[2] = 0; return ar; } ar = gcd(b, a % b, ar); int t = ar[1]; ar[1] = ar[2]; ar[2] = t - (a / b) * ar[2]; return ar; } static boolean[] esieve(int n) { boolean p[] = new boolean[n + 1]; Arrays.fill(p, true); for (int i = 2; i * i <= n; i++) { if (p[i] == true) { for (int j = i * i; j <= n; j += i) { p[j] = false; } } } return p; } static ArrayList<Integer> primes(int n) { boolean p[] = new boolean[n + 1]; ArrayList<Integer> al = new ArrayList<>(); Arrays.fill(p, true); int i = 0; for (i = 2; i * i <= n; i++) { if (p[i] == true) { al.add(i); for (int j = i * i; j <= n; j += i) { p[j] = false; } } } for (i = i; i <= n; i++) { if (p[i] == true) { al.add(i); } } return al; } static int etf(int n) { int res = n; for (int i = 2; i * i <= n; i++) { if (n % i == 0) { res /= i; res *= (i - 1); while (n % i == 0) { n /= i; } } } if (n > 1) { res /= n; res *= (n - 1); } return res; } static int gcd(int a, int b) { if (a == 0) { return b; } return gcd(b % a, a); } static long gcd(long a, long b) { if (a == 0) { return b; } return gcd(b % a, a); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
b3015a72243856130b0a791d82af55d6
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.Scanner; public class Problem1541B { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int t = sc.nextInt(); while (t-- >= 1) { int n = sc.nextInt(); long arr[] = new long[n + 1]; for (int i = 1; i <= n; i++) { arr[i] = sc.nextInt(); } int count = 0; for (int i = 1; i <= n; i++) { for (long j = arr[i] - i; j <= n; j += arr[i]) { if (j >= 0 && i<j) { if (i + j == arr[i] * arr[(int) j]) { count++; } } } } System.out.println(count); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
0f6fee4c360480eaddacf6174ceb4018
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; import static java.lang.Math.*; import java.io.*; public class S { public static void main(String args[])throws IOException{ BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); int test = Integer.parseInt(br.readLine()); while(test > 0){ test--; int n = Integer.parseInt(br.readLine()); StringTokenizer st = new StringTokenizer(br.readLine()); int a[] = new int[n]; for(int i = 0; i < n; i++){ a[i] = Integer.parseInt(st.nextToken()); } solve(n, a); //System.out.println(s + " " + tar); //StringTokenizer st = new StringTokenizer(br.readLine()); //int n = Integer.parseInt(st.nextToken()); //int l = Integer.parseInt(st.nextToken()); //st = new StringTokenizer(br.readLine()); //int a[] = new int[n]; //for(int i = 0; i < n; i++){ // a[i] = Integer.parseInt(st.nextToken()); //} } } final static int MOD = 1000000007; public static void solve(int n, int a[]){ List<int[]> li = new ArrayList<int[]>(); for(int i = 0; i < n; i++){ li.add(new int[]{a[i], i+1}); } Collections.sort(li, new Comparator<int[]>(){ public int compare(int i1[], int i2[]){ return i1[0] - i2[0]; } }); int aa[][] = new int[n][2]; int ii = 0; for(int val[] : li){ aa[ii][0] = val[0]; aa[ii++][1] = val[1]; } int ans = 0; for(int i = 0; i < n; i++){ for(int j = i+1; j < n; j++){ long m = (long)aa[i][0] * (long)aa[j][0]; if(m == aa[i][1] + aa[j][1]){ ans++; } if(m > 2*n)break; } } System.out.println(ans); } public static int gcd(int a, int b){ if(b == 0)return a; return gcd(b, a%b); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
e85f3b1700b95eed5abcaf5e8ece18fc
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; public class _1541B { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int t = sc.nextInt(); while (t-- > 0) { int n = sc.nextInt(); int[] arr = new int[n+1]; for (int i = 1; i <=n; i++) arr[i] = sc.nextInt(); int count=0; for(int i=1;i<=n;i++){ for(int j=arr[i]-i;j<=n;j+=arr[i]) { if (j >= 0 && (long) arr[i] * arr[j] == i + j && i < j) count++; } } System.out.println(count); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
fe96ff8f155da5423f7c63afb2192620
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class solver { public static void main(String[] args) { FastScanner read = new FastScanner(); if (System.getProperty("ONLINE_JUDGE") == null) { try { System.setOut(new PrintStream(new FileOutputStream("out.txt"))); read = new FastScanner("in.txt"); } catch (Exception e) { } } // START int tc = read.nextInt(); while(tc-- > 0) { int n = read.nextInt(); int[] a = new int[n+1]; for(int i = 1; i <= n; i++) a[i] = read.nextInt(); long res = 0; for(int i = 1; i < n; i++) { for(int j = a[i]-i; j <= n; j+=a[i]) { if((j >= 1) && (j > i) && (long)a[i]*a[j] == (i+j)) res++; } } System.out.println(res); } // END } 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)); FastScanner(){} FastScanner(String file_name) throws Exception { br = new BufferedReader(new FileReader(file_name)); } 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
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
2aab6c0ed4e3f066275c2b1e1c2dba35
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; public class B_1541 { 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(); } } 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(); } } public static void main(String ar[]) throws IOException { Reader input = new Reader(); OutputWriter out = new OutputWriter(System.out); int t = input.nextInt(); while (t-- > 0) { int n = input.nextInt(); int a[] = new int[n + 1]; for (int i = 1; i <= n; i++) { a[i] = input.nextInt(); } long res = 0; for (int i = 1; i < n; i++) { for (int j = a[i] - i; j <= n; j += a[i]) { if (j >= 1) { if (((long) a[i] * a[j] == i + j) && (i < j)) { res++; } } } } out.printLine(res); } out.close(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
b57cb0c740b78828e3546941e2d7b726
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class A728B { public static void main(String[] args) { JS scan = new JS(); int t = scan.nextInt(); while(t-->0){ int n = scan.nextInt(); int[] arr =new int[n]; for(int i = 0;i<n;i++){ arr[i] = scan.nextInt(); } int count = 0; for(int i = 0;i<n;i++){ int start = (arr[i]+(i+1) / arr[i] *arr[i]) - (i+1); for(int j = start;j<=n;j+=arr[i]){ if(j-1<=i)continue; long at = arr[j-1]; if(arr[i]*at==(i+1)+j){ // System.out.println((i+1) +" "+(j)); count++; } } } System.out.println(count); } } static class JS { public int BS = 1 << 16; public char NC = (char) 0; byte[] buf = new byte[BS]; int bId = 0, size = 0; char c = NC; double num = 1; BufferedInputStream in; public JS() { in = new BufferedInputStream(System.in, BS); } public JS(String s) throws FileNotFoundException { in = new BufferedInputStream(new FileInputStream(new File(s)), BS); } public char nextChar() { 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 long nextLong() { num = 1; boolean neg = false; if (c == NC) c = nextChar(); for (; (c < '0' || c > '9'); c = nextChar()) { if (c == '-') neg = true; } long res = 0; for (; c >= '0' && c <= '9'; c = nextChar()) { res = (res << 3) + (res << 1) + c - '0'; num *= 10; } return neg ? -res : res; } public double nextDouble() { double cur = nextLong(); return c != '.' ? cur : cur + nextLong() / num; } public String next() { StringBuilder res = new StringBuilder(); while (c <= 32) c = nextChar(); while (c > 32) { res.append(c); c = nextChar(); } return res.toString(); } public String nextLine() { StringBuilder res = new StringBuilder(); while (c <= 32) c = nextChar(); while (c != '\n') { res.append(c); c = nextChar(); } return res.toString(); } public boolean hasNext() { if (c > 32) return true; while (true) { c = nextChar(); if (c == NC) return false; else if (c > 32) return true; } } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
5b1fba6e13e33326ea6f75a56850ee46
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class A728B { public static void main(String[] args) { JS scan = new JS(); int t = scan.nextInt(); while(t-->0){ int n = scan.nextInt(); long[] arr =new long[n]; for(int i = 0;i<n;i++){ arr[i] = scan.nextInt(); } int count = 0; for(int i = 0;i<n;i++){ int start = (int) ((arr[i]+(i+1) / arr[i] *arr[i]) - (i+1)); for(int j = start;j<=n;j+=arr[i]){ if(j-1<=i)continue; long at = arr[j-1]; if(arr[i]*at==(i+1)+j){ //System.out.println((i+1) +" "+(j)); count++; } } } System.out.println(count); } } static class JS { public int BS = 1 << 16; public char NC = (char) 0; byte[] buf = new byte[BS]; int bId = 0, size = 0; char c = NC; double num = 1; BufferedInputStream in; public JS() { in = new BufferedInputStream(System.in, BS); } public JS(String s) throws FileNotFoundException { in = new BufferedInputStream(new FileInputStream(new File(s)), BS); } public char nextChar() { 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 long nextLong() { num = 1; boolean neg = false; if (c == NC) c = nextChar(); for (; (c < '0' || c > '9'); c = nextChar()) { if (c == '-') neg = true; } long res = 0; for (; c >= '0' && c <= '9'; c = nextChar()) { res = (res << 3) + (res << 1) + c - '0'; num *= 10; } return neg ? -res : res; } public double nextDouble() { double cur = nextLong(); return c != '.' ? cur : cur + nextLong() / num; } public String next() { StringBuilder res = new StringBuilder(); while (c <= 32) c = nextChar(); while (c > 32) { res.append(c); c = nextChar(); } return res.toString(); } public String nextLine() { StringBuilder res = new StringBuilder(); while (c <= 32) c = nextChar(); while (c != '\n') { res.append(c); c = nextChar(); } return res.toString(); } public boolean hasNext() { if (c > 32) return true; while (true) { c = nextChar(); if (c == NC) return false; else if (c > 32) return true; } } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
cfd047da58cdfbc499a1fc702383d642
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; import java.io.*; public class A728Best { public static void main(String[] args) { JS scan = new JS(); int t = scan.nextInt(); while (t-- > 0) { int n = scan.nextInt(); element[] arr = new element[n]; for (int i = 0; i < n; i++) { arr[i] = new element(scan.nextInt(), i + 1); } Arrays.sort(arr); int count = 0; for (int i = 0; i < n; i++) { for (int j = i + 1; j < n; j++) { //System.out.println(arr[i].val*arr[j].val+" "+arr[i].idx+" "+arr[j].idx); if (arr[i].val * arr[j].val > 2 * n) break; if (arr[i].val * arr[j].val == arr[i].idx + arr[j].idx) { count++; } } } System.out.println(count); } } static class element implements Comparable<element> { long val; int idx; public element(int val, int idx) { this.val = val; this.idx = idx; } @Override public int compareTo(element o) { return Long.compare(this.val,o.val); } } static class JS { public int BS = 1 << 16; public char NC = (char) 0; byte[] buf = new byte[BS]; int bId = 0, size = 0; char c = NC; double num = 1; BufferedInputStream in; public JS() { in = new BufferedInputStream(System.in, BS); } public JS(String s) throws FileNotFoundException { in = new BufferedInputStream(new FileInputStream(new File(s)), BS); } public char nextChar() { 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 long nextLong() { num = 1; boolean neg = false; if (c == NC) c = nextChar(); for (; (c < '0' || c > '9'); c = nextChar()) { if (c == '-') neg = true; } long res = 0; for (; c >= '0' && c <= '9'; c = nextChar()) { res = (res << 3) + (res << 1) + c - '0'; num *= 10; } return neg ? -res : res; } public double nextDouble() { double cur = nextLong(); return c != '.' ? cur : cur + nextLong() / num; } public String next() { StringBuilder res = new StringBuilder(); while (c <= 32) c = nextChar(); while (c > 32) { res.append(c); c = nextChar(); } return res.toString(); } public String nextLine() { StringBuilder res = new StringBuilder(); while (c <= 32) c = nextChar(); while (c != '\n') { res.append(c); c = nextChar(); } return res.toString(); } public boolean hasNext() { if (c > 32) return true; while (true) { c = nextChar(); if (c == NC) return false; else if (c > 32) return true; } } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
6e02387079c83f289b0499f974069d61
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; public class Main { public static void main(String[] args) { Scanner scan = new Scanner(System.in); int n = scan.nextInt(); //System.out.println(n); for (int i = 0; i < n; i++) { int k = scan.nextInt(); int[] a = new int[k]; for (int ii = 0; ii < k; ii++) { a[ii] = scan.nextInt(); } System.out.println(new Finder(a).find()); } } public static class Pair implements Comparable<Pair> { int index; Integer value; public Pair(int index, int value) { this.index = index; this.value = value; } @Override public int compareTo(Pair i) { return -Integer.compare(i.value, value); } } public static class Finder { int[] a; public Finder(int[] a) { this.a = a; } public int find() { int out = 0; List<Pair> list = new ArrayList<>(a.length); for (int i = 0; i < a.length; i++) { list.add(new Pair(i, a[i])); } Collections.sort(list); for (int i = 0; i < a.length; i++) { int cur = list.get(i).value; int maxIndex = 2 * a.length /cur + 1; if (maxIndex > a.length) { maxIndex = a.length; } for(int ii = i + 1; ii < maxIndex; ii ++) { if (list.get(i).index + list.get(ii).index + 2 == list.get(i).value * list.get(ii).value) { out++; } } } return out; } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
7020d51ebc931f5ac6b71fdc1ccb8b11
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class Main { public static void main(String[] args) throws IOException { inputAndSettingData(); } static int solve(int[] arr, int N) { int cnt = 0; for (int aiaj = 3; aiaj <= 2 * N; aiaj++) { int sq = (int) Math.sqrt(aiaj); for (int ai = 1; ai <= sq; ai++) { if (aiaj % ai == 0 && aiaj != ai * ai && arr[ai] + arr[aiaj / ai] == aiaj) { cnt++; } } } return cnt; } static void inputAndSettingData() throws IOException { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(br.readLine()); StringBuilder out = new StringBuilder(); int T = Integer.parseInt(st.nextToken()); while (T-- > 0) { int N = Integer.parseInt(br.readLine()); int SZ = 2 * N + 1; int[] arr = new int[SZ]; Arrays.fill(arr, SZ); st = new StringTokenizer(br.readLine()); for (int i = 0; i < N; i++) { arr[Integer.parseInt(st.nextToken())] = i + 1; } out.append(solve(arr, N)).append("\n"); } System.out.println(out); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
9c38cc605c7bf7c38c0ee05cb8fad782
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class Main { public static void main(String[] args) throws IOException { inputAndSettingData(); } static int solve(int[] arr, int N) { int cnt = 0; for (int aiaj = 3; aiaj <= 2 * N; aiaj++) { int sq = (int) Math.sqrt(aiaj); for (int ai = 1; ai <= sq; ai++) { if (aiaj % ai == 0 && aiaj != ai * ai && arr[ai] + arr[aiaj / ai] == aiaj) { cnt++; } } } return cnt; } static void inputAndSettingData() throws IOException { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(br.readLine()); StringBuilder out = new StringBuilder(); int T = Integer.parseInt(st.nextToken()); while (T-- > 0) { int N = Integer.parseInt(br.readLine()); int[] arr = new int[2 * N + 1]; Arrays.fill(arr, (int) 1e6); st = new StringTokenizer(br.readLine()); for (int i = 0; i < N; i++) { arr[Integer.parseInt(st.nextToken())] = i + 1; } out.append(solve(arr, N)).append("\n"); } System.out.println(out); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
0241a1b2cf13c2df9e8f1a7bc1c9fa43
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class Main { public static void main(String[] args) throws IOException { inputAndSettingData(); } static int solve(int[] arr, int N) { int cnt = 0; for (int i = 3; i <= 2 * N; i++) { int sq = (int) Math.sqrt(i); for (int j = 1; j <= sq; j++) { if (i % j == 0 && i != j * j && arr[j] + arr[i / j] == i) { cnt++; } } } return cnt; } static void inputAndSettingData() throws IOException { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(br.readLine()); StringBuilder out = new StringBuilder(); int T = Integer.parseInt(st.nextToken()); while (T-- > 0) { int N = Integer.parseInt(br.readLine()); int[] arr = new int[2 * N + 1]; Arrays.fill(arr, (int) 1e6); st = new StringTokenizer(br.readLine()); for (int i = 0; i < N; i++) { arr[Integer.parseInt(st.nextToken())] = i + 1; } out.append(solve(arr, N)).append("\n"); } System.out.println(out); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
b945fd883ef321d9645f126c18f1cc34
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
//package codeforces; import java.io.*; import java.util.*; public class ProblemB { public static void main(String[] args) throws FileNotFoundException { FastReader scanner = new FastReader(false); int n = scanner.nextInt(); for (int i = 0; i < n; i++) { solve(scanner); } } public static void solve(FastReader scanner) { long n = scanner.nextLong(); long[] arr = new long[(int) (n + 1)]; for (int i = 1; i <= n; i++) { arr[i] = scanner.nextInt(); } long count = 0; for (long i = 1; i <= n; i++) { for (long j = arr[(int) i] - i; j <= n; j += arr[(int) i]) { if (j >= 0 && ((arr[(int) i] * arr[(int) j]) == (i) + (j)) && (i < j)) count++; } } System.out.println(count); } static long upperBound(long[] arr, int start, int end, long k) { int N = end; while (start < end) { int mid = start + (end - start) / 2; if (k >= arr[mid]) { start = mid + 1; } else { end = mid; } } if (start < N && arr[start] <= k) { start++; } return start; } static long lowerBound(long[] arr, int start, int end, long k) { int N = end; while (start < end) { int mid = start + (end - start) / 2; if (k <= arr[mid]) { end = mid; } else { start = mid + 1; } } if (start < N && arr[start] < k) { start++; } return start; } static int getDistance(int x1, int y1, int x2, int y2) { return Math.abs(x1 - x2) + Math.abs(y1 - y2); } static int sumOfNNaturalNumbers(int n) { return (n * (n + 1)) / 2; } static int gcd(int a, int b) { if (b == 0) return a; return gcd(b, a % b); } static class FastReader { BufferedReader br; StringTokenizer st; public FastReader(boolean fromFile) throws FileNotFoundException { if (!fromFile) { br = new BufferedReader( new InputStreamReader(System.in) ); } else { br = new BufferedReader( new InputStreamReader( new FileInputStream("src/main/java/codeforces/input.txt") ) ); } } 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
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
f02703998aca04bbc9e932fda98ef383
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; import java.io.*; public class ProbB { public static void main(String[] args) throws IOException { BufferedReader bf = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st; int cases = Integer.parseInt(bf.readLine()); for(int caseNum=0; caseNum<cases; caseNum++) { int n = Integer.parseInt(bf.readLine()); int[] arr = new int[(2*n)+1]; Arrays.fill(arr, -1); st = new StringTokenizer(bf.readLine()); for(int i=1; i<=n; i++) arr[Integer.parseInt(st.nextToken())] = i; int numPairs = 0; for(int sum=3; sum<2*n; sum++) { for(int i=1; i*i<=sum; i++) { if(sum%i==0 && i*i!=sum && arr[i]!=-1 && arr[sum/i]!=-1 && arr[i]+arr[sum/i]==sum) numPairs++; } } System.out.println(numPairs); } bf.close(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
b4c567a61c17578f81d6c2d23a6ab8ff
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
/* package codechef; // don't place package name! */ import java.util.*; import java.lang.*; import java.io.*; import java.math.BigInteger; /* Name of the class has to be "Main" only if the class is public. */ public class hello { static class FastReader { BufferedReader br; StringTokenizer st; public FastReader() { try { br=new BufferedReader(new FileReader("input.txt")); PrintStream out= new PrintStream(new FileOutputStream("output.txt")); System.setOut(out); } // Catch block to handle the exceptions catch (Exception e) { 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 java.lang.Exception { try{ FastReader sc=new FastReader(); BufferedWriter out = new BufferedWriter( new OutputStreamWriter(System.out)); int t=sc.nextInt(); while(t-->0){ int n=sc.nextInt(); long arr[]=new long[n+1]; for(int i=1;i<=n;i++){ arr[i]=sc.nextLong(); } long count=0; for(int i=1;i<=n;i++){ for(int j=(int)(arr[i]-i);j<=n;j+=arr[i]){ if(i<j&&arr[i]*arr[j]==i+j) count++; } } out.write(count+"\n"); out.flush(); } }catch(Exception e){ return; } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
b8b349df8804c7b3f678e3f9ef23a32c
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.math.BigInteger; import java.util.*; import javafx.util.Pair; public class Main { static void sort(long a[]) { Random ran = new Random(); for (int i = 0; i < a.length; i++) { int r = ran.nextInt(a.length); long temp = a[r]; a[r] = a[i]; a[i] = temp; } Arrays.sort(a); } public static void main(String[] args) { FastScanner input = new FastScanner(); int tc = input.nextInt(); while (tc-- > 0) { int n = input.nextInt(); long a[] = new long[n]; HashMap<Long,Integer> map = new HashMap<>(); for (int i = 0; i <n; i++) { a[i] = input.nextLong(); map.put(a[i], i+1); } long ans = 0; sort(a); for (int i = 0; i < n; i++) { for (int j =0; j < n; j++) { if(i==j) continue; if(a[i]*a[j]>(2*n)) break; if(a[i]*a[j]==(map.get(a[i])+map.get(a[j]))) { ans++; } } } System.out.println(ans/2); } } 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(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() throws IOException { return br.readLine(); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
c11635748043d7640a4d9378b50e6d60
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.math.BigInteger; import java.util.*; import javafx.util.Pair; public class Main { public static void main(String[] args) { FastScanner input = new FastScanner(); int tc = input.nextInt(); while (tc-- > 0) { int n = input.nextInt(); long a[] = new long[n+1]; for (int i = 1; i <=n; i++) { a[i] = input.nextLong(); } long count=0; for (int i = 1; i <=n; i++) { for (int j = (int)(a[i]-i); j <=n; j+=a[i]) { if(j>=0) { if((a[i]*a[j]==i+j)&&(i<j)) count++; } } } System.out.println(count); } } 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(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } String nextLine() throws IOException { return br.readLine(); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
3de1801e0a7c5348f44822f6094b0247
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.InputStreamReader; import java.util.*; public class Main { public static void main(String[] args) throws Exception { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(br.readLine()); int t = Integer.parseInt(st.nextToken()); StringBuilder sb = new StringBuilder(); while (t != 0) { st = new StringTokenizer(br.readLine()); int n=Integer.parseInt(st.nextToken()); List<Pair> list=new ArrayList<>(); st = new StringTokenizer(br.readLine()); for(int i=0;i<n;i++){ list.add(new Pair(i,Integer.parseInt(st.nextToken()))); } list.sort(Comparator.comparing(Pair::getY)); int count=0; for(int i=0;i<n-1;i++){ for(int j=i+1;j<n;j++){ Pair one=list.get(i); Pair two=list.get(j); long prod= (long) one.getY() *two.getY(); long sum=one.getX()+two.getX()+2; if(prod< 2L *n){ if(prod==sum){ count++; } } else{ break; } } } sb.append(count).append("\n"); t--; } System.out.println(sb); } public static class Pair{ int x; int y; Pair(int x,int y){ this.x=x; this.y=y; } public int getX(){ return x; } public int getY(){ return y; } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
360bcdb929b53fd9617157320658b82e
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.PrintWriter; import java.io.BufferedReader; import java.io.InputStreamReader; import java.io.IOException; import java.util.StringTokenizer; public class B { public static void main(String[] args) { FastReader sc = new FastReader(); PrintWriter out = new PrintWriter(System.out); int t = sc.nextInt(); for (int tt = 0; tt < t; tt++) { int n = sc.nextInt(); long[] arr = new long[n + 1]; // read array for (int i = 1; i < arr.length; i++) { arr[i] = sc.nextInt(); } solveTask2(arr, n); } out.close(); } private static void solveTask2(long[] arr, int n) { int count = 0; for (int i = 1; i <= n; i++) { for (long j = arr[i] - i; j <= n; j += arr[i]) { if (j >= 0) { if (arr[i] * arr[(int) j] == i + j && i < j) count++; } } } System.out.println(count); } static class FastReader { BufferedReader br; StringTokenizer st; 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; } int[] readArray(int n) { int[] temparr = new int[n]; for (int i = 0; i < n; i++) { temparr[i] = nextInt(); } return temparr; } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
b3054b56abb67eec6e585c98a4fa3803
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
//package Codeforces; import java.util.*; import java.io.*; public class PleasantPairs { static FastReader in=new FastReader(); static final Random random=new Random(); static long mod=1000000007L; //static HashMap<String,Integer>map=new HashMap<>(); public static void main(String args[]) throws IOException { int t=in.nextInt(); int cse=1; loop: while(t-->0) { System.out.println(solve()); } } static long solve(){ int n=in.nextInt(); int nums[]=new int[2*n+1]; Arrays.fill(nums,-1); for (int i = 0; i <n ; i++) { int no=in.nextInt(); nums[no]=i+1; } long ans=0L; for(long sum=3;sum<=2*n-1;sum++){ for(int f=1;f*f<sum;f++){ if(nums[f]!=-1 && sum%f==0){ int s=(int)sum/f; if(nums[s]!=-1) { if (nums[s] + nums[f] == sum) ans++; } } } } return ans; } static int max(int a, int b) { if(a<b) return b; return a; } static void ruffleSort(int[] a) { 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 < E > void print(E res) { System.out.println(res); } static int gcd(int a,int b) { if(b==0) { return a; } return gcd(b,a%b); } static int lcm(int a, int b) { return (a / gcd(a, b)) * b; } static int abs(int a) { if(a<0) return -1*a; return a; } 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; } int [] readintarray(int n) { int res [] = new int [n]; for(int i = 0; i<n; i++)res[i] = nextInt(); return res; } long [] readlongarray(int n) { long res [] = new long [n]; for(int i = 0; i<n; i++)res[i] = nextLong(); return res; } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
671212fc72e04f26017a8004dd3c1cb5
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.InputStreamReader; import java.io.PrintWriter; import java.util.Arrays; import java.util.HashMap; import java.util.Map; import java.util.StringTokenizer; public class PleasantPairs { public static void solution() { //TODO } public static void main(String[] args) throws Exception { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); PrintWriter writer = new PrintWriter(System.out); int tt = Integer.parseInt(reader.readLine()); // One number per line for (int t = 0; t < tt; t++) { int length = Integer.parseInt(reader.readLine()); StringTokenizer info = new StringTokenizer(reader.readLine()); // Multiple numbers per line Long[] arr = new Long[length]; Map<Long, Integer> map = new HashMap<>(); for (int i = 0; i < length; i++) { arr[i] = Long.parseLong(info.nextToken()); // For next number map.put(arr[i], i + 1); } Arrays.sort(arr); int ans = 0; for (int i = 0; i < length; i++) { for (int j = i + 1; j < length; j++) { if (arr[i] * arr[j] > 2 * length) { break; } else { //System.out.println(arr[i] * arr[j] + " " + map.get(arr[i]) + " " + map.get(arr[j])); if (arr[i] * arr[j] == map.get(arr[i]) + map.get(arr[j])) { ans++; } } } } writer.println(ans); } reader.close(); writer.close(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
8e7895ec4288804c1127fb124937f1d7
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; import java.io.*; public class CodeforcesRound728 { static FastReader sc = new FastReader(); public static void main(String[] args) throws IOException { try { int t = sc.nextInt(); while (t-- > 0) { C(); } } catch (Exception e) { return; } } static void C() { int n = sc.nextInt(); long a[] = sc.readLongArray(n); HashMap<Long,Integer> map = new HashMap<>(); for(int i=0;i<n;i++) { map.put(a[i], i); } Arrays.sort(a); long count = 0; for (int i = 0; i < n; i++) { for (int j = i + 1; j < n; j++) { long c = a[i] * a[j]; long d = (map.get(a[i]) + 1) + (map.get(a[j]) + 1); if (c == d) count++; if (c > 2 * n) break; } } System.out.println(count); } static void B() { int n = sc.nextInt(); long a[] = sc.readLongArray(n); long summ = 0, val = 0; Arrays.sort(a); for (int i = 2; i < n; i++) { summ += a[i - 2]; val -= (a[i] * (i - 1)); val += summ; } System.out.println(val); } static void A() { int n = sc.nextInt(); int a[] = new int[n]; if (n % 2 != 0) { if (n == 3) { System.out.println("3 1 2"); return; } else { System.out.print("3 1 2 "); for (int i = 3; i < n; i++) { a[i] = i + 1; } for (int i = 3; i < n - 1; i += 2) { int temp = a[i]; a[i] = a[i + 1]; a[i + 1] = temp; } for (int i = 3; i < n; i++) { System.out.print(a[i] + " "); } return; } } else { for (int i = 0; i < n; i++) { a[i] = i + 1; } for (int i = 0; i < n - 1; i += 2) { int temp = a[i]; a[i] = a[i + 1]; a[i + 1] = temp; } } for (int i : a) { System.out.print(i + " "); } System.out.println(); } static boolean[] seiveOfEratosthenes(int n) { boolean[] isPrime = new boolean[n + 1]; Arrays.fill(isPrime, true); for (int i = 2; i * i <= n; i++) { for (int j = i * i; j <= n; j += i) { isPrime[j] = false; } } return isPrime; } static boolean isPrime(long n) { if (n < 2) return false; for (int i = 2; i * i <= n; i++) { if (n % i == 0) return false; } return true; } } 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()); } int[] readIntArray(int n) { int a[] = new int[n]; for (int i = 0; i < n; i++) { a[i] = Integer.parseInt(next()); } return a; } void printIntArray(int a[]) { for (int i = 0; i < a.length; i++) { System.out.print(a[i] + " "); } } long[] readLongArray(int n) { long a[] = new long[n]; for (int i = 0; i < n; i++) { a[i] = Long.parseLong(next()); } return a; } void printLongArray(long a[]) { for (int i = 0; i < a.length; i++) { System.out.print(a[i] + " "); } } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
559ec767b31c4dd381bcf728387fc8f1
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; import java.io.*; public class CodeforcesRound728 { static FastReader sc = new FastReader(); public static void main(String[] args) throws IOException { try { int t = sc.nextInt(); while (t-- > 0) { C(); } } catch (Exception e) { return; } } static void C() { int n = sc.nextInt(); int a[] = new int[n]; int ar[] = new int[2*n+1]; Arrays.fill(ar, (int)1e6); for(int i=0;i<n;i++) { a[i] = sc.nextInt(); ar[a[i]] = i+1; } int count = 0; for (int i = 3; i < 2 * n; i++) { for (int j = 1; j <= Math.sqrt(i); j++) { if (i % j == 0 && i != j * j) { if (ar[j] + ar[i / j] == i) { count++; } } } } System.out.println(count); } static void B() { int n = sc.nextInt(); long a[] = sc.readLongArray(n); long summ = 0, val = 0; Arrays.sort(a); for (int i = 2; i < n; i++) { summ += a[i - 2]; val -= (a[i] * (i - 1)); val += summ; } System.out.println(val); } static void A() { int n = sc.nextInt(); int a[] = new int[n]; if (n % 2 != 0) { if (n == 3) { System.out.println("3 1 2"); return; } else { System.out.print("3 1 2 "); for (int i = 3; i < n; i++) { a[i] = i + 1; } for (int i = 3; i < n - 1; i += 2) { int temp = a[i]; a[i] = a[i + 1]; a[i + 1] = temp; } for (int i = 3; i < n; i++) { System.out.print(a[i] + " "); } return; } } else { for (int i = 0; i < n; i++) { a[i] = i + 1; } for (int i = 0; i < n - 1; i += 2) { int temp = a[i]; a[i] = a[i + 1]; a[i + 1] = temp; } } for (int i : a) { System.out.print(i + " "); } System.out.println(); } static boolean[] seiveOfEratosthenes(int n) { boolean[] isPrime = new boolean[n + 1]; Arrays.fill(isPrime, true); for (int i = 2; i * i <= n; i++) { for (int j = i * i; j <= n; j += i) { isPrime[j] = false; } } return isPrime; } static boolean isPrime(long n) { if (n < 2) return false; for (int i = 2; i * i <= n; i++) { if (n % i == 0) return false; } return true; } } 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()); } int[] readIntArray(int n) { int a[] = new int[n]; for (int i = 0; i < n; i++) { a[i] = Integer.parseInt(next()); } return a; } void printIntArray(int a[]) { for (int i = 0; i < a.length; i++) { System.out.print(a[i] + " "); } } long[] readLongArray(int n) { long a[] = new long[n]; for (int i = 0; i < n; i++) { a[i] = Long.parseLong(next()); } return a; } void printLongArray(long a[]) { for (int i = 0; i < a.length; i++) { System.out.print(a[i] + " "); } } double nextDouble() { return Double.parseDouble(next()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
df43384b76fde491555ab48dc63a081d
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.HashMap; import java.util.Map; import java.util.StringTokenizer; public class C { private static void sport(int[] a) { Map<Integer, Integer> map = new HashMap<>(); int n = a.length; for (int i = 0; i < n; i++) { map.put(a[i], i + 1); } int max = n + n - 1; int ans = 0; for (int i = 2; i <= max; i++) { for (int j = 1; j <= Math.sqrt(i); j++) { if (i % j == 0) { if ((i / j) == j) { continue; } Integer integer1 = map.get(j); Integer integer2 = map.get(i / j); if (integer1 == null || integer2 == null) { continue; } int val = integer1 + integer2; if (val == i) { ans++; } } } } System.out.println(ans); } public static void main(String[] args) { FastScanner sc = new FastScanner(); int t = sc.nextInt(); for (int p = 0; p < t; p++) { int n = sc.nextInt(); int[] a = sc.readArrayInt(n); sport(a); } } 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()); } long[] readArrayLong(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) { a[i] = nextLong(); } return a; } int[] readArrayInt(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
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
88fe440b328164e9b6632e83ee4d6e70
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; import java.util.function.Function; import java.util.stream.Collectors; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.*; import java.math.*; public class Solution { static StringBuilder sb; static dsu dsu; static long fact[]; static long mod=(long)(1e9+7); static ArrayList<Integer>prime; static int A[]; //static boolean visited[]; static ArrayList<Integer>adj[]; static void solve() { int n=i(); int A[]=new int[n+1]; int X[]=new int[2*n+1]; for(int i=1;i<=n;i++) { A[i]=i(); X[A[i]]=i; } int cnt=0; HashSet<Integer>hs=new HashSet<>(); for(int i=1;i<=n;i++) { int n1=A[i]; int f1=i; int j=2; while(n1*j<2*n) { int pre=n1*j; if(pre-i<=n&&pre-i>=1&&pre-i!=i) { if(A[pre-i]==j) { pair p=new pair(Math.min(i, pre-i),Math.max(i, pre-i)); cnt++; int val=p.x*100+p.y; hs.add(val); } } j++; } } //System.out.println(cnt); sb.append(hs.size()+"\n"); } public static void main(String[] args) { sb=new StringBuilder(); int test=i(); for(int tt=1;tt<=test;tt++) { solve(); } System.out.println(sb); } //*******************************************NCR%P******************************************************* static long ncr(int n, int r) { if(r>n) return (long)0; long res=fact[n]%mod; //System.out.println(res); res=((long)(res%mod)*(long)(p(fact[r],mod-2)%mod))%mod; res=((long)(res%mod)*(long)(p(fact[n-r],mod-2)%mod))%mod; //System.out.println(res); return res; } static long p(long x, long y)//POWER FXN // { if(y==0) return 1; long res=1; while(y>0) { if(y%2==1) { res=(res*x)%mod; y--; } x=(x*x)%mod; y=y/2; } return res; } static long ceil(long num, long den) { return (long)(num+den-1)/den; } //*******************************************END******************************************************* static int LowerBound(long a[], long x, int i, int j) { //X is the key value int l=i;int r=j; int lb=-1; while(l<=r) { int m=(l+r)/2; if(a[m]>=x) { lb=m; r=m-1; } else l=m+1; } return lb; } static int UpperBound(long a[], long x, int i, int j) {// x is the key or target value int l=i,r=j; int ans=-1; while(l<=r) { int m=(l+r)/2; if(a[m]<=x) { ans=m; l=m+1; } else r=m-1; } return ans; } //*********************************Disjoint set union*************************// static class dsu { int parent[]; dsu(int n) { parent=new int[n+1]; for(int i=0;i<=n;i++) parent[i]=-1; } int find(int a) { if(parent[a]<0) return a; else { int x=find(parent[a]); parent[a]=x; return x; } } void merge(int a,int b) { a=find(a); b=find(b); if(a==b) return; parent[b]=a; } } //*******************************************PRIME FACTORIZE *****************************************************************************************************// static TreeMap<Integer,Integer> prime(long n) { TreeMap<Integer,Integer>h=new TreeMap<>(); long num=n; for(int i=2;i<=Math.sqrt(num);i++) { if(n%i==0) { int nt=0; while(n%i==0) { n=n/i; nt++; } h.put(i, nt); } } if(n!=1) h.put((int)n, 1); return h; } //*************CLASS PAIR *********************************************************************************************************************************************** static class pair implements Comparable<pair> { int x; int y; pair(int x, int y) { this.x = x; this.y = y; } public int compareTo(pair o) { return(int) (y-o.y); } } //*************CLASS PAIR ***************************************************************************************************************************************************** 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 Int() { 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 String String() { 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 String(); } public interface SpaceCharFilter { public boolean isSpaceChar(int ch); } } 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 InputReader in = new InputReader(System.in); static OutputWriter out = new OutputWriter(System.out); public static int[] sort(int[] a) { int n = a.length; ArrayList<Integer> l = new ArrayList<>(); for (int i : a) l.add(i); Collections.sort(l); for (int i = 0; i < l.size(); i++) a[i] = l.get(i); return a; } public static long[] sort(long[] a) { int n = a.length; ArrayList<Long> l = new ArrayList<>(); for (long i : a) l.add(i); Collections.sort(l); for (int i = 0; i < l.size(); i++) a[i] = l.get(i); return a; } public static long pow(long x, long y) { long res = 1; while (y > 0) { if (y % 2 != 0) { res = (res * x);// % modulus; y--; } x = (x * x);// % modulus; y = y / 2; } return res; } //GCD___+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ public static long gcd(long x, long y) { if (x == 0) return y; else return gcd(y % x, x); } //****************LOWEST COMMON MULTIPLE ************************************************************************************************************************************* public static long lcm(long x, long y) { return (x * (y / gcd(x, y))); } //INPUT PATTERN****************************************************************************************************************************************************************** public static int i() { return in.Int(); } public static long l() { String s = in.String(); return Long.parseLong(s); } public static String s() { return in.String(); } public static int[] readArray(int n) { int A[] = new int[n]; for (int i = 0; i < n; i++) { A[i] = i(); } return A; } public static long[] readArray(long n) { long A[] = new long[(int) n]; for (int i = 0; i < n; i++) { A[i] = l(); } return A; } public int[][] deepCopy(int[][] matrix) { return java.util.Arrays.stream(matrix).map(el -> el.clone()).toArray($ -> matrix.clone()); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
b17199c327c94ed65bdbcb0d79f6dfeb
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class Main{ public static int Gcd(int a,int b){ if(b==0)return a; return Gcd(b,a%b); } public static void main(String[] args){ Scanner scn=new Scanner(System.in); int t=scn.nextInt(); while(t-->0){ int n=scn.nextInt(); int[] arr=new int[n+1]; for(int i=1;i<=n;i++){ arr[i]=scn.nextInt(); } int cnt=0; for(int i=1;i<=n;i++){ for(int j=arr[i]-i;j<=n;j+=arr[i]){ if(j>i&&arr[i]*1l*arr[j]==(long)(i+j))cnt++; } } System.out.println(cnt); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
3e80cf1e53bfc733e5552ff1f3e97e44
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; public class Solution { // static boolean prime[] = new boolean[10000001]; public static void main(String[] args) { Scanner sc = new Scanner(System.in); int t=sc.nextInt(); while(t-->0) { int n=sc.nextInt(); long arr[]=new long[n+1]; for (int i = 1; i < n+1; i++) { arr[i]=sc.nextLong(); } int ans=0; for(int i=1;i<=n;i++) { for(int j = (int) (arr[i]-i); j<=n; j+=arr[i]) { if(j>=0) { if ((i + j) == (arr[i] * arr[j]) && i<j) { ans++; } } // } } System.out.println(ans); } } // static void sieveOfEratosthenes(int n) // { // // // for(int i=0;i<=n;i++) // prime[i] = true; // // for(int p = 2; p*p <=n; p++) // { // // If prime[p] is not changed, then it is a prime // if(prime[p] == true) // { // // Update all multiples of p // for(int i = p*p; i <= n; i += p) // prime[i] = false; // } // } // // // Print all prime numbers //// for(int i = 2; i <= n; i++) //// { //// if(prime[i] == true) //// System.out.print(i + " "); //// } // } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
fd375abeb003b6c53b2c70f0b0b345b1
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; import java.io.*; public class Omar { static PrintWriter pw = new PrintWriter(System.out); static Scanner sc=new Scanner(System.in); public static ArrayList<pair> give(int n){ ArrayList<pair> arr=new ArrayList<>(); int end=(int)Math.sqrt(n); for(int i=1;i<=end;i++) { if(n%i==0) { if(i*i==n); else arr.add(new pair(i, n/i)); } } return arr; } public static void main(String[] args) throws IOException { ArrayList<pair>[] divisors=new ArrayList[200001]; for(int i=1;i<=200000;i++) { divisors[i]=give(i); } int t=sc.nextInt(); while(t-->0) { int n=sc.nextInt(); int []arr=new int[n+1]; HashMap<Long, Integer>hm=new HashMap<>(); for(int i=0;i<n;i++) { int x=sc.nextInt(); hm.put(1l*x, i+1); arr[i+1]=x; } long ans=0; HashSet<pair>done=new HashSet<>(); for(int i=1;i<=2*n;i++) { long sum=0; ArrayList<pair> tmp=divisors[i]; for(int j=0;j<tmp.size();j++) { if(!hm.containsKey(tmp.get(j).x) || !hm.containsKey(tmp.get(j).y))continue; int a=hm.get(tmp.get(j).x),b=hm.get(tmp.get(j).y); if(a+b==tmp.get(j).x*tmp.get(j).y) { sum++; } } ans+=sum; } pw.println(ans); } pw.flush(); } static class SegmentTree { long[] sTree, lazy; int N; public SegmentTree(int N) { this.N = N; sTree = new long[(N) << 1]; lazy = new long[(N) << 1]; } public long query(int i, int j) { return query(1, 1, N, i, j); } public long query(int node, int l, int r, int i, int j) { if (i <= l && r <= j) { return sTree[node]; } if (r < i || l > j) { return 0; } propagate(node, l, r); int leftChild = node << 1; int rightChild = node << 1 | 1; int mid = l + r >> 1; long leftQ = query(leftChild, l, mid, i, j); long rightQ = query(rightChild, mid + 1, r, i, j); return leftQ + rightQ; } public void propagate(int node, int l, int r) { if (lazy[node] == 0) { return; } int leftChild = node << 1; int rightChild = node << 1 | 1; int mid = l + r >> 1; lazy[leftChild] += lazy[node]; lazy[rightChild] += lazy[node]; sTree[leftChild] += (mid - l + 1) * lazy[node]; sTree[rightChild] += (r - (mid + 1) + 1) * lazy[node]; lazy[node] = 0; } public void updateRange(int i, int j, long val) { updateRange(1, 1, N, i, j, val); } public void updateRange(int node, int l, int r, int i, int j, long val) { if (i <= l && r <= j) { lazy[node] += val; sTree[node] += (r - l + 1) * val; return; } if (r < i || l > j) { return; } propagate(node, l, r); int leftChild = node << 1; int rightChild = node << 1 | 1; int mid = l + r >> 1; updateRange(leftChild, l, mid, i, j, val); updateRange(rightChild, mid + 1, r, i, j, val); sTree[node] = sTree[leftChild] + sTree[rightChild]; } } 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 Long(x).hashCode() * 31 + new Long(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 class Scanner { StringTokenizer st; BufferedReader br; public Scanner(InputStream s) { br = new BufferedReader(new InputStreamReader(s)); } public Scanner(String file) throws IOException { br = new BufferedReader(new FileReader(file)); } 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 String readAllLines(BufferedReader reader) throws IOException { StringBuilder content = new StringBuilder(); String line; while ((line = reader.readLine()) != null) { content.append(line); content.append(System.lineSeparator()); } return content.toString(); } 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(); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
923298bc211c2d0bf4693f791c30ace6
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.Scanner; public class PleasantPairs { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int num = sc.nextInt(); while(num-->0){ int n = sc.nextInt(); int[] res = new int[n+1]; long count = 0; for(int i = 1; i<=n; i++){ res[i] = sc.nextInt(); } for(int i = 1; i<=n; i++){ for(int j = res[i] - i; j<=n; j += res[i]){ if(j >= 1 && (i+j == ((long) res[i] *res[j])) && i<j){ count++; } } } System.out.println(count); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
6981aa8188d43019913874bc9764750a
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; public class B728{ public static void main (String args[]) throws NumberFormatException, IOException { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); int numTc = Integer.parseInt(br.readLine()); for(int tc = 0; tc <numTc; tc++) { String input1 []= br.readLine().split(" "); int n = Integer.parseInt(input1[0]); int data []= new int [n+1]; String input2 []= br.readLine().split(" "); for(int i=1; i <=n ; i++) { data[i] = Integer.parseInt(input2[i-1]); } int total=0; for(int i =1;i<=n;i++){ int j= i+1; int wantedMod =( data[i] - i%data[i])%data[i]; int currentMod = j%data[i] ; if(wantedMod!=currentMod){ j+= wantedMod>currentMod? wantedMod-currentMod : wantedMod+ data[i]-currentMod; } // while( j<=n && (j+i)%data[i]!=0) // j++; // data[i] - (data[i]-i%data[i]); while(j<=n){ // System.out.println("i:"+i+" j:"+j+" data[i]: "+data[i]); if((long)i+j==(long)data[i] * data[j]) total++; j+=data[i]; } } System.out.println(total); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
12ea3b229125ea9f55de763947582712
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; public class Solution { public static void main(String[] args) { Scanner sc = new Scanner(System.in).useLocale(Locale.US); int t = sc.nextInt(); for(int i = 0; i<t; i++) { System.out.println(solve(sc)); } } public static long solve(Scanner sc) { int n = sc.nextInt(); long[] a = new long[n]; Map<Long, Integer> m = new HashMap<>(); for (int i = 0; i<n; i++) { a[i] = sc.nextInt(); m.put(a[i], i+1); } long sum = 0; for (int i = 1; i<=n; i++) { long c = a[i-1]; for (long j = 1; j<= (2L *n)/c; j++) { if (m.containsKey(j)) { int idx = m.get(j); if (idx != i && idx + i == j*c) { sum += 1; } } } } return sum/2; } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
0099a3e4a7e9751623ab4f7466d000e5
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
//package CodeForces.RoadMap.diff1200; import java.util.Scanner; /** * @author Syed Ali. * @createdAt 08/07/2021, Thursday, 12:46 */ public class PleasantPairs { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); int testCases = scanner.nextInt(); for (int t = 0; t < testCases; t++) { int n = scanner.nextInt(); long[] arr = new long[n + 1]; for (int i = 1; i <= n; i++) { arr[i] = scanner.nextInt(); } int answer = 0; for (int i = 1; i <= n; i++) { for (int j = (int) arr[i] - i; j <= n; j += arr[i]) { if (j >= 0) { if (arr[i] * arr[j] == i + j && i < j) { ++answer; } } } } System.out.println(answer); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
9543b6c96b6956c9bf16d486e303d46b
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class B { public static void solution(BufferedReader reader, PrintWriter writer) throws IOException { In in = new In(reader); Out out = new Out(writer); int T = in.nextInt(); for (int t = 0; t < T; t++) { int n = in.nextInt(); int[] a = in.nextIntArray1(n); int rst = 0; for (int j = 2; j <= n; j++) for (int i = a[j] - j % a[j]; i < j; i += a[j]) if (a[i] * a[j] == i + j) rst++; out.println(rst); } } public static void main(String[] args) throws Exception { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); PrintWriter writer = new PrintWriter( new BufferedWriter(new OutputStreamWriter(System.out))); solution(reader, writer); writer.close(); } protected static class In { private BufferedReader reader; private StringTokenizer tokenizer = new StringTokenizer(""); public In(BufferedReader reader) { this.reader = reader; } public String next() throws IOException { while (!tokenizer.hasMoreTokens()) tokenizer = new StringTokenizer(reader.readLine()); return tokenizer.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[] nextIntArray(int n) throws IOException { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } public int[] nextIntArray1(int n) throws IOException { int[] a = new int[n + 1]; for (int i = 1; i <= n; i++) a[i] = nextInt(); return a; } public int[] nextIntArraySorted(int n) throws IOException { int[] a = nextIntArray(n); Random r = new Random(); for (int i = 0; i < n; i++) { int j = i + r.nextInt(n - i); int t = a[i]; a[i] = a[j]; a[j] = t; } Arrays.sort(a); 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 long[] nextLongArray1(int n) throws IOException { long[] a = new long[n + 1]; for (int i = 1; i <= n; i++) a[i] = nextLong(); return a; } public long[] nextLongArraySorted(int n) throws IOException { long[] a = nextLongArray(n); Random r = new Random(); for (int i = 0; i < n; i++) { int j = i + r.nextInt(n - i); long t = a[i]; a[i] = a[j]; a[j] = t; } Arrays.sort(a); return a; } } protected static class Out { private PrintWriter writer; private static boolean local = System .getProperty("ONLINE_JUDGE") == null; public Out(PrintWriter writer) { this.writer = writer; } public void print(char c) { writer.print(c); } public void print(int a) { writer.print(a); } public void printb(int a) { writer.print(a); writer.print(' '); } public void println(Object a) { writer.println(a); } public void println(Object[] os) { for (int i = 0; i < os.length; i++) { writer.print(os[i]); writer.print(' '); } writer.println(); } public void println(int[] a) { for (int i = 0; i < a.length; i++) { writer.print(a[i]); writer.print(' '); } writer.println(); } public void println(long[] a) { for (int i = 0; i < a.length; i++) { writer.print(a[i]); writer.print(' '); } writer.println(); } public void flush() { writer.flush(); } public static void db(Object... objects) { if (local) System.out.println(Arrays.deepToString(objects)); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
84f2129ad73ae4997c525b256e8a9408
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.math.BigInteger; import java.util.* ; import java.io.* ; @SuppressWarnings("unused") public class cf { static final int mod = 1000000007 ; static boolean not_prime[] = new boolean[1000001] ; static void sieve() { for(int i=2 ; i*i<1000001 ; i++) { if(not_prime[i]==false) { for(int j=2*i ; j<1000001 ; j+=i) { not_prime[j]=true ; } } }not_prime[0]=true ; not_prime[1]=true ; } public static long bexp(long base , long power) { long res=1L ; //base = base%mod ; while(power>0) { if((power&1)==1) { res=(res*base);//%mod ; power-- ; } else { base=(base*base);//%mod ; power>>=1 ; } } return res ; } static long modInverse(long n, long p) { return power(n, p - 2, p); } static long power(long x, long y, long p) { // Initialize result long res = 1; // Update x if it is more than or // equal to p x = x % p; while (y > 0) { // If y is odd, multiply x // with result if (y % 2 == 1) res = (res * x) % p; // y must be even now y = y >> 1; // y = y/2 x = (x * x) % p; } return res; } static long nCrModPFermat(int n, int r, long p) { if(n<r) return 0 ; if (r == 0) return 1; long[] fac = new long[n + 1]; fac[0] = 1; for (int i = 1; i <= n; i++) fac[i] = fac[i - 1] * i % p; return (fac[n] * modInverse(fac[r], p) % p * modInverse(fac[n - r], p) % p) % p; } private static long modular_add(long a, long b) { return ((a % mod) + (b % mod)) % mod; } private static long modular_sub(long a, long b) { return ((a % mod) - (b % mod) + mod) % mod; } private static long modular_mult(long a, long b) { return ((a % mod) * (b % mod)) % mod; } static long lcm(int a, int b) { return (a / gcd(a, b)) * b; } private static long gcd(long a, long b) { if (b == 0) { return a; } return gcd(b, a % b); } static int cbits(int num) { return (int)(Math.log(num) /Math.log(2)) + 1; } 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 HashMap<Integer , ArrayList<Integer>> map = new HashMap<>() ; static boolean vis[] ; static int parent[] , rank[] , points[] ; public static void main(String[] args)throws IOException//throws FileNotFoundException { FastReader in = new FastReader() ; StringBuilder op = new StringBuilder() ; int t = in.nextInt(); while(t-->0) { int n = in.nextInt(); long a[] = new long[n+1] ; for(int i=1 ; i<n+1 ; i++)a[i]=in.nextLong(); int res=0 ; for(int i=1 ; i<n+1 ; i++) { for(int j=(int) (a[i]-i) ; j<n+1 ; j+=a[i]) { if(j>i) { if((a[i]*a[j])==(i+j))res++; } } } op.append(res+"\n"); } System.out.println(op.toString()); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
bd87f67b3586bae1fa74c4372527c944
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.Scanner; public class PleasantPairs { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); int testcases = Integer.parseInt(scanner.nextLine()); while(testcases-- != 0) { int len = Integer.parseInt(scanner.nextLine()); int[] a = new int[len+1]; for(int i = 1; i <= len ; i++) a[i] = Integer.parseInt(scanner.next()); scanner.nextLine(); int cnt = 0; for(int i = 1 ; i <= len ; i++ ) { for(int product = a[i] ; product <= 2*len ; product += a[i] ) { int j = product - i; if( i < j && j <= len && (long)a[i]*a[j]==i+j )cnt++; } } System.out.println(cnt); } scanner.close(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
b7f07bb1fe25cae5823fec66bb2e86cd
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.Scanner; public class PleasantPairs { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); int testcases = Integer.parseInt(scanner.nextLine()); while(testcases-- != 0) { int len = Integer.parseInt(scanner.nextLine()); int[] a = new int[len]; for(int i = 0; i < len ; i++) a[i] = Integer.parseInt(scanner.next()); scanner.nextLine(); int cnt = 0; for(int i = 0 ; i < len ; i++ ) { for(int product = a[i] ; product <= 2*len ; product += a[i] ) { int j = product - i - 2; if( i < j && j < len && (long)a[i]*a[j]==i+j+2 )cnt++; } } System.out.println(cnt); } scanner.close(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
9d6dcec824ae78163cdb0490020ac254
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
//package Codeforces; import java.io.*; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; public class Solution { 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(); } } static Reader sc = new Reader(); static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out)); public static void main(String args[]) throws IOException { int t = inputInt(); while(t-->0){ int n =inputInt(); int[] a = new int[n+1]; for(int i=0;i<n;i++)a[i+1]=inputInt(); int count=0; int cnt=0; for(int i=1;i<=n;i++) { for(int j=a[i]-(i%a[i]);j<=n;j+=a[i]) { if(i>j && a[i]*a[j]==i+j) cnt++; } } System.out.println(cnt); } } public static int inputInt() throws IOException { return sc.nextInt(); } public static long inputLong() throws IOException { return sc.nextLong(); } public static double inputDouble() throws IOException { return sc.nextDouble(); } public static String inputString() throws IOException { return sc.readLine(); } public static void print(String a) throws IOException { bw.write(a); } public static void printSp(String a) throws IOException { bw.write(a + " "); } public static void println(String a) throws IOException { bw.write(a + "\n"); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
5833faa7fa2a74f45ed4ef93240c6b25
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class Trials1 { public static void main(String[] args) throws NumberFormatException, IOException { BufferedReader inp=new BufferedReader(new InputStreamReader(System.in)); BufferedWriter out=new BufferedWriter(new OutputStreamWriter(System.out)); int t=Integer.parseInt(inp.readLine()); while(t-- >0) { int n=Integer.parseInt(inp.readLine()); String s[]=inp.readLine().split(" "); int a[]=new int[n+1]; for(int i=0;i<n;i++) { a[i+1]=Integer.parseInt(s[i]); } int cnt=0; for(int i=1;i<=n;i++) { for(int j=a[i]-(i%a[i]);j<=n;j+=a[i]) { if(i>j && a[i]*a[j]==i+j) cnt++; } } out.write(Integer.toString(cnt)+"\n"); } out.flush(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
33039f19bd2d8b9ba29afa1facdeb69a
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.Scanner; public class PleasantPairs { public static void main(String[] args) { Scanner a = new Scanner(System.in); int test = a.nextInt(); for (int b = 0 ; b < test ; b++){ int n = a.nextInt() ; int[] array = new int[n]; for (int c=0 ; c < n ; c++ ) array[c] = a.nextInt(); int sum = 0 ; for (int c = 0 ; c < n ; c++ ) for (int d = ((-c - 2)%array[c] +array[c])%array[c] ; d < n ; d+=array[c] ) if ( c < d && array[d] == (d + c + 2)/array[c])sum++; System.out.println(sum); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
db7afe91544062f25eae9edc55279fdb
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
/*========================================================================== * AUTHOR: RonWonWon * CREATED: 27.06.2021 22:50:16 /*==========================================================================*/ import java.io.*; import java.util.*; public class B { public static void main(String[] args) throws IOException { /* in.ini(); PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("output.txt"))); */ long startTime = System.nanoTime(); int t = in.nextInt(), T = 1; while(t-->0) { int n = in.nextInt(); long a[] = in.readArrayL(n); int cnt = 0; for(int i=1;i<=n;i++){ for(int j=1;(a[i-1]*j-i)<=n;j++){ int y = (int)(a[i-1]*j-i); if(y<=i) continue; if(a[y-1]==j) cnt++; } } out.println(cnt); //out.println("Case #"+T+": "+ans); T++; } /* startTime = System.nanoTime() - startTime; System.err.println("Time: "+(startTime/1000000)); */ out.flush(); } static FastScanner in = new FastScanner(); static PrintWriter out = new PrintWriter(System.out); static int oo = Integer.MAX_VALUE; static class FastScanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); void ini() throws FileNotFoundException { br = new BufferedReader(new FileReader("input.txt")); } 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()); } 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()); } long[] readArrayL(int n) { long a[] = new long[n]; for(int i=0;i<n;i++) a[i] = nextLong(); return a; } double nextDouble() { return Double.parseDouble(next()); } double[] readArrayD(int n) { double a[] = new double[n]; for(int i=0;i<n;i++) a[i] = nextDouble(); 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); } static void ruffleSortL(long[] a){ int n = a.length; for(int i=0;i<n;i++){ int j = random.nextInt(n); long temp = a[j]; a[j] = a[i]; a[i] = temp; } Arrays.sort(a); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
abaee40852f7b7677b2da756fdcdb378
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; public class week4 { public static void main(String[] args) { Scanner s = new Scanner(System.in); int t = s.nextInt(); while(t-->0) { int n = s.nextInt(); long[] arr = new long[n]; Map<Long, Long> map = new HashMap<Long, Long>(); for (int i = 0; i < arr.length; i++) { arr[i] = s.nextLong(); map.put(arr[i], (long)i+1); } long ans = 0; Arrays.sort(arr); for (int i = 0; i < n-1; i++) { long x = map.get(arr[i]); for (int j = i+1; j < n; j++) { long y = map.get(arr[j]); if(x+y == arr[i]*arr[j])ans++; if(arr[i]*arr[j]>=2*n) break; } } System.out.println(ans); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
0db4e16ecfdb1036e9e0694c8a9a6459
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
//package com.cf.div2.c728; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.util.HashMap; import java.util.Map; import java.util.StringTokenizer; public class B { static PrintWriter out = new PrintWriter(System.out); 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(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } } public static void main(String[] args) { FastScanner sc = new FastScanner(); int t = sc.nextInt(); while (t-- > 0) { int n = sc.nextInt(); Map<Integer, Integer> map = new HashMap<>(); for (int i = 1; i <= n; i++) { map.put(sc.nextInt(), i); } int ans = 0; for (int i = 3; i < 2*n; i++) { for (int j = 1; j*j < i; j++) { if (i % j == 0) { if (map.containsKey(j) && map.containsKey(i / j)) { ans += map.get(j) + map.get(i / j) == i ? 1 : 0; } } } } out.println(ans); } out.close(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
e813fa875601c77dcfd06ea4daa2e6d4
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
//package com.cf.div2.c728; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.util.HashMap; import java.util.Map; import java.util.StringTokenizer; public class B { static PrintWriter out = new PrintWriter(System.out); 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(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } } public static void main(String[] args) { FastScanner sc = new FastScanner(); int t = sc.nextInt(); while (t-- > 0) { int n = sc.nextInt(); Map<Integer, Integer> map = new HashMap<>(); for (int i = 1; i <= n; i++) { map.put(sc.nextInt(), i); } int ans = 0; for (int i = 3; i < 2*n; i++) { for (int j = 1; j < Math.sqrt(i); j++) { if (i % j == 0) { if (map.containsKey(j) && map.containsKey(i / j)) { ans += map.get(j) + map.get(i / j) == i ? 1 : 0; } } } } out.println(ans); } out.close(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
0e7d73f0bcff6803fa8abc2265cd3f39
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.StringTokenizer; public class Main7 { public static void main(String[] args) { FastScanner sc=new FastScanner(); int t=sc.nextInt(); while(t-->0) { int n=sc.nextInt(); long arr[]=new long[n+1]; for(int i=1;i<n+1;i++) arr[i]=sc.nextInt(); int count=0; for(int i=1;i<=n;i++) { for(int j=(int)arr[i]-i;j<=n;j+=arr[i]) { if(j>=0) if(arr[i]*arr[j]==i+j&&i<j) count++; } } System.out.println(count); } } 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()); } String nextLine() { String str = ""; try { str = br.readLine(); } catch (IOException e) { e.printStackTrace(); } return str; } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
cbdba4fadd32904e0df9aa816a2833fc
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; public class CodeForces1541A{ public static void main(String[] args) { Scanner input = new Scanner(System.in); int t = input.nextInt(); for(int tt = 0;tt<t;tt++){ int n = input.nextInt(); int[] a = new int[n+1]; for(int i = 1;i<=n;i++){ a[i] = input.nextInt(); } int count = 0; for(int i = 1;i<=n;i++){ int remain = i % a[i]; int start = i - 2 * remain + a[i]; if(start >= i){ start -= a[i]; } for(int j = start; j > 0; j -= a[i]){ if(j < i && i + j == a[i] * a[j]){ count++; } } } System.out.println(count); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
a3e8281ec048a2f56977d9ab2fabe06b
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class C { public static void main(String[] args) throws java.lang.Exception{ Scanner sc=new Scanner(System.in); int T=sc.nextInt(); while(T-->0) { int n=sc.nextInt(); int a[]=new int[n+1]; for(int i=1;i<=n;i++) { a[i]=sc.nextInt(); } long c=0; for(int i=1;i<=n;i++) { for(int j=a[i]-i;j<=n;j+=a[i]) { if(j>=1) if(((long)a[i]*a[j]==i+j)&&(i<j)) c++; } } System.out.println(c); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
c166312c0c3ee78757f334ce1fb93fa2
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.util.*; import java.io.*; import java.math.*; public class Solution implements Runnable { public static void solve() { int t = i(); while(t-->0){ int n = i(); int[] arr = new int[n+1]; TreeSet<Integer> hs = new TreeSet(); for(int i=1;i<=n;i++){ arr[i] = i(); hs.add(arr[i]); } int count =0; for(int i=1;i<=n;i++){ for(int x: hs){ int y = x * arr[i] - i ; if((y<=n && y>i) && arr[y] ==x){ count++; } if(y>n)break; } } System.out.println(count); } } public static boolean isVowel(char c) { if(c=='a'||c=='e'||c=='i'||c=='o'||c=='u')return true; return false; } public static int upperbound(int[] a,int low,int high,int key) { while(low<high) { int mid=(low+high)>>1; if(a[mid]>key) { high=mid; } else { low=mid+1; } } return low; } public static int lowerbound(int[] a,int low,int high,int key) { while(low<high) { int mid=(low+high)>>1; if(a[mid]>=key) { high=mid; } else { low=mid+1; } } return low; } public void run() { solve(); out.close(); } public static void main(String[] args) throws IOException { new Thread(null, new Solution(), "whatever", 1<<26).start(); } static class Pair implements Comparable<Pair> { long a; int b; Pair(){} Pair(long a,int b) { this.a=a; this.b=b; } public int compareTo(Pair x) { return Long.compare(x.a,this.a); } } ////////////////////////////////////////////////////// Merge Sort //////////////////////////////////////////////////////////////////////// static class Merge { public static void sort(long inputArr[]) { int length = inputArr.length; doMergeSort(inputArr,0, length - 1); } private static void doMergeSort(long[] arr,int lowerIndex, int higherIndex) { if (lowerIndex < higherIndex) { int middle = lowerIndex + (higherIndex - lowerIndex) / 2; doMergeSort(arr,lowerIndex, middle); doMergeSort(arr,middle + 1, higherIndex); mergeParts(arr,lowerIndex, middle, higherIndex); } } private static void mergeParts(long[]array,int lowerIndex, int middle, int higherIndex) { long[] temp=new long[higherIndex-lowerIndex+1]; for (int i = lowerIndex; i <= higherIndex; i++) { temp[i-lowerIndex] = array[i]; } int i = lowerIndex; int j = middle + 1; int k = lowerIndex; while (i <= middle && j <= higherIndex) { if (temp[i-lowerIndex] < temp[j-lowerIndex]) { array[k] = temp[i-lowerIndex]; i++; } else { array[k] = temp[j-lowerIndex]; j++; } k++; } while (i <= middle) { array[k] = temp[i-lowerIndex]; k++; i++; } while(j<=higherIndex) { array[k]=temp[j-lowerIndex]; k++; j++; } } } /////////////////////////////////////////////////////////// Methods //////////////////////////////////////////////////////////////////////// static boolean isPal(String s) { for(int i=0, j=s.length()-1;i<=j;i++,j--) { if(s.charAt(i)!=s.charAt(j)) return false; } return true; } static String rev(String s) { StringBuilder sb=new StringBuilder(s); sb.reverse(); return sb.toString(); } static int gcd(int a,int b){return (a==0)?b:gcd(b%a,a);} static long gcdExtended(long a,long b,long[] x) { if(a==0){ x[0]=0; x[1]=1; return b; } long[] y=new long[2]; long gcd=gcdExtended(b%a, a, y); x[0]=y[1]-(b/a)*y[0]; x[1]=y[0]; return gcd; } boolean findSum(int set[], int n, long sum) { if (sum == 0) return true; if (n == 0 && sum != 0) return false; if (set[n-1] > sum) return findSum(set, n-1, sum); return findSum(set, n-1, sum) ||findSum(set, n-1, sum-set[n-1]); } public static long modPow(long base, long exp, long mod) { base = base % mod; long result = 1; while (exp > 0) { if (exp % 2 == 1) { result = (result * base) % mod; } base = (base * base) % mod; exp = exp >> 1; } return result; } static long[] fac; static long[] inv; static long mod=(long)1e9+7; public static void cal() { fac = new long[1000005]; inv = new long[1000005]; fac[0] = 1; inv[0] = 1; for (int i = 1; i <= 1000000; i++) { fac[i] = (fac[i - 1] * i) % mod; inv[i] = (inv[i - 1] * modPow(i, mod - 2, mod)) % mod; } } public static long ncr(int n, int r) { return (((fac[n] * inv[r]) % mod) * inv[n - r]) % mod; } ////////////////////////////////////////// Input Reader //////////////////////////////////////////////////////////////////////////////////////////////////// static InputReader sc = new InputReader(System.in); static PrintWriter out= new PrintWriter(System.out); static class InputReader { private final InputStream stream; private final byte[] buf = new byte[8192]; private int curChar, snumChars; private SpaceCharFilter filter; public InputReader(InputStream stream) { this.stream = stream; } public int snext() { if (snumChars == -1) throw new InputMismatchException(); if (curChar >= snumChars) { curChar = 0; try { snumChars = stream.read(buf); } catch (IOException e) { throw new InputMismatchException(); } if (snumChars <= 0) return -1; } return buf[curChar++]; } public int nextInt() { int c = snext(); while (isSpaceChar(c)) { c = snext(); } int sgn = 1; if (c == '-') { sgn = -1; c = snext(); } int res = 0; do { if (c < '0' || c > '9') throw new InputMismatchException(); res *= 10; res += c - '0'; c = snext(); } while (!isSpaceChar(c)); return res * sgn; } public long nextLong() { int c = snext(); while (isSpaceChar(c)) { c = snext(); } int sgn = 1; if (c == '-') { sgn = -1; c = snext(); } long res = 0; do { if (c < '0' || c > '9') throw new InputMismatchException(); res *= 10; res += c - '0'; c = snext(); } while (!isSpaceChar(c)); return res * sgn; } 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; } public String nextLine() { int c = snext(); while (isSpaceChar(c)) c = snext(); StringBuilder res = new StringBuilder(); do { res.appendCodePoint(c); c = snext(); } while (!isEndOfLine(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; } private boolean isEndOfLine(int c) { return c == '\n' || c == '\r' || c == -1; } public interface SpaceCharFilter { public boolean isSpaceChar(int ch); } } static int i() { return sc.nextInt(); } static long l(){ return sc.nextLong(); } static int[] iarr(int n) { return sc.nextIntArray(n); } static long[] larr(int n) { return sc.nextLongArray(n); } static String s(){ return sc.nextLine(); } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
5b84570d7910f30f6f031defa2fb4ea0
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.OutputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.List; import java.util.Arrays; import java.util.StringTokenizer; import java.io.IOException; import java.io.BufferedReader; import java.io.InputStreamReader; import java.io.InputStream; import java.util.ArrayList; /** * Built using CHelper plug-in * Actual solution is at the top */ public class PleasantPairs { public static void main(String[] args) { InputStream inputStream = System.in; OutputStream outputStream = System.out; InputReader in = new InputReader(inputStream); PrintWriter out = new PrintWriter(outputStream); TaskA solver = new TaskA(); solver.solve(1, in, out); out.close(); } static class TaskA { static StringBuilder sb; public void solve(int testNumber, InputReader in, PrintWriter out) { //solution int t = 1; t = in.nextInt(); while (t-- > 0) { function(in,out); } } static void function(InputReader in,PrintWriter out){ int n = in.nextInt(); int[] arr = new int[n + 1]; for (int i = 1; i <= n; i++) { arr[i] = in.nextInt(); } long ans = 0L; for (int i = 1; i <= n; i++) { int skip = arr[i]; int st = skip - i; int moves = 1; while (st <= n) { if (st > i && arr[st] == moves) { ans++; } st += skip; moves++; } } out.println(ans); } } 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()); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
a1c7e58481668056bc68330e93d34424
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
/* package codechef; // don't place package name! */ import java.util.*; import java.lang.*; import java.io.*; import java.math.*; /* Name of the class has to be "Main" only if the class is public. */ public final class Solution { public static void main (String[] args) throws java.lang.Exception { // your code goes here BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); int k=Integer.parseInt(br.readLine()); while(k-- >0){ int n=Integer.parseInt(br.readLine()); int[] arr= new int[n]; String[]a= br.readLine().split(" "); Map<Integer,Integer> res= new HashMap<>(); for(int i=0;i<n;i++){ arr[i]=Integer.parseInt(a[i]); res.put(arr[i],i+1); } int count=0; for(int i=3;i<2*n;i++){ count+=check(res,i,n); } System.out.println(count); } } public static int check(Map<Integer,Integer> res,int a,int n){ int count=0; for(int i=1;i*i<=a;i++){ if(a%i==0 &&i*i!=a&& res.containsKey(i)&&res.containsKey(a/i)&&res.get(i)+res.get(a/i)==a)count++; } return count; } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
63eaf9aea2c991e80b4cc2957124bcbd
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class pleasantpairs { public static void main(String[] args) throws IOException { BufferedReader f = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(f.readLine()); long t = Long.parseLong(st.nextToken()); while(t > 0) { t --; long n = Long.parseLong(f.readLine()); st = new StringTokenizer(f.readLine()); long[] arr = new long[(int) n + 2]; for(int i = 1; i <= n; i ++) arr[i] = Long.parseLong(st.nextToken()); int count = 0; for(int i = 1; i < n; i ++) { long startingIndex = arr[i] - (i) % arr[i]; while(startingIndex <= i) startingIndex += arr[i]; for(int j = (int) startingIndex; j <= n; j += arr[i]) { if(i < j && (long) arr[i] * (long) arr[j] == i + j) count ++; } } System.out.println(count); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output
PASSED
d5b70f21037720be1dc0d3af6d898007
train_107.jsonl
1624635300
You are given an array $$$a_1, a_2, \dots, a_n$$$ consisting of $$$n$$$ distinct integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
256 megabytes
import java.io.*; import java.util.*; public class pleasantPairs { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(new BufferedReader(new InputStreamReader(System.in))); int t = sc.nextInt(); while (t-- > 0) { int n = sc.nextInt(); int[] a = new int[n]; for(int i=0;i<n;i++){ a[i] = sc.nextInt(); } int out = 0; for(int i=0;i<n;i++){ int val = a[i]; int temp = val; while(temp<=(i+1)){ temp += val; } int j = temp-(i+1); while(j<=n){ if(a[j-1]==((i+1)+j)/val && i!=(j-1)){ // System.out.println(i+" "+(j-1)); out++; } temp +=val; j=temp-(i+1); } } System.out.println(out/2); } } }
Java
["3\n2\n3 1\n3\n6 1 5\n5\n3 1 5 9 2"]
2 seconds
["1\n1\n3"]
NoteFor the first test case, the only pair that satisfies the constraints is $$$(1, 2)$$$, as $$$a_1 \cdot a_2 = 1 + 2 = 3$$$For the second test case, the only pair that satisfies the constraints is $$$(2, 3)$$$.For the third test case, the pairs that satisfy the constraints are $$$(1, 2)$$$, $$$(1, 5)$$$, and $$$(2, 3)$$$.
Java 8
standard input
[ "brute force", "implementation", "math", "number theory" ]
0ce05499cd28f0825580ff48dae9e7a9
The first line contains one integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. Then $$$t$$$ cases follow. The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 10^5$$$) — the length of array $$$a$$$. The second line of each test case contains $$$n$$$ space separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2 \cdot n$$$) — the array $$$a$$$. It is guaranteed that all elements are distinct. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
1,200
For each test case, output the number of pairs of indices $$$(i, j)$$$ such that $$$i &lt; j$$$ and $$$a_i \cdot a_j = i + j$$$.
standard output