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http://rosettacode.org/wiki/Permutations_by_swapping
Permutations by swapping
Task Generate permutations of n items in which successive permutations differ from each other by the swapping of any two items. Also generate the sign of the permutation which is +1 when the permutation is generated from an even number of swaps from the initial state, and -1 for odd. Show the permutations and signs of three items, in order of generation here. Such data are of use in generating the determinant of a square matrix and any functions created should bear this in mind. Note: The Steinhaus–Johnson–Trotter algorithm generates successive permutations where adjacent items are swapped, but from this discussion adjacency is not a requirement. References Steinhaus–Johnson–Trotter algorithm Johnson-Trotter Algorithm Listing All Permutations Heap's algorithm [1] Tintinnalogia Related tasks   Matrix arithmetic   Gray code
#ALGOL_68
ALGOL 68
BEGIN # Heap's algorithm for generating permutations - from the pseudo-code on the Wikipedia page # # generate permutations of a # PROC generate = ( INT k, REF[]INT a, REF INT swap count )VOID: IF k = 1 THEN output permutation( a, swap count ) ELSE # Generate permutations with kth unaltered # # Initially k = length a # generate( k - 1, a, swap count ); # Generate permutations for kth swapped with each k-1 initial # FOR i FROM 0 TO k - 2 DO # Swap choice dependent on parity of k (even or odd) # swap count +:= 1; INT swap item = IF ODD k THEN 0 ELSE i FI; INT t = a[ swap item ]; a[ swap item ] := a[ k - 1 ]; a[ k - 1 ] := t; generate( k - 1, a, swap count ) OD FI # generate # ; # generate permutations of a # PROC permute = ( REF[]INT a )VOID: BEGIN INT swap count := 0; generate( ( UPB a + 1 ) - LWB a, a[ AT 0 ], swap count ) END # permute # ;   # handle a permutation # PROC output permutation = ( REF[]INT a, INT swap count )VOID: BEGIN print( ( "[" ) ); FOR i FROM LWB a TO UPB a DO print( ( whole( a[ i ], 0 ) ) ); IF i = UPB a THEN print( ( "]" ) ) ELSE print( ( ", " ) ) FI OD; print( ( " sign: ", IF ODD swap count THEN "-1" ELSE " 1" FI, newline ) ) END # output permutation # ;   [ 1 : 3 ]INT a := ( 1, 2, 3 ); permute( a )   END
http://rosettacode.org/wiki/Permutation_test
Permutation test
Permutation test You are encouraged to solve this task according to the task description, using any language you may know. A new medical treatment was tested on a population of n + m {\displaystyle n+m} volunteers, with each volunteer randomly assigned either to a group of n {\displaystyle n} treatment subjects, or to a group of m {\displaystyle m} control subjects. Members of the treatment group were given the treatment, and members of the control group were given a placebo. The effect of the treatment or placebo on each volunteer was measured and reported in this table. Table of experimental results Treatment group Control group 85 68 88 41 75 10 66 49 25 16 29 65 83 32 39 92 97 28 98 Write a program that performs a permutation test to judge whether the treatment had a significantly stronger effect than the placebo. Do this by considering every possible alternative assignment from the same pool of volunteers to a treatment group of size n {\displaystyle n} and a control group of size m {\displaystyle m} (i.e., the same group sizes used in the actual experiment but with the group members chosen differently), while assuming that each volunteer's effect remains constant regardless. Note that the number of alternatives will be the binomial coefficient ( n + m n ) {\displaystyle {\tbinom {n+m}{n}}} . Compute the mean effect for each group and the difference in means between the groups in every case by subtracting the mean of the control group from the mean of the treatment group. Report the percentage of alternative groupings for which the difference in means is less or equal to the actual experimentally observed difference in means, and the percentage for which it is greater. Note that they should sum to 100%. Extremely dissimilar values are evidence of an effect not entirely due to chance, but your program need not draw any conclusions. You may assume the experimental data are known at compile time if that's easier than loading them at run time. Test your solution on the data given above.
#Ada
Ada
with Ada.Text_IO; with Iterate_Subsets;   procedure Permutation_Test is   type Group_Type is array(Positive range <>) of Positive;   Treat_Group: constant Group_Type := (85, 88, 75, 66, 25, 29, 83, 39, 97); Ctrl_Group: constant Group_Type := (68, 41, 10, 49, 16, 65, 32, 92, 28, 98);   package Iter is new Iterate_Subsets(Treat_Group'Length, Ctrl_Group'Length);   Full_Group: constant Group_Type(1 .. Iter.All_Elements)  := Treat_Group & Ctrl_Group;   function Mean(S: Iter.Subset) return Float is Sum: Natural := 0; begin for I in S'Range loop Sum := Sum + Full_Group(S(I)); end loop; return Float(Sum)/Float(S'Length); end Mean;   package FIO is new Ada.Text_IO.Float_IO(Float);   T_Avg: Float := Mean(Iter.First); S_Avg: Float; S: Iter.Subset := Iter.First; Equal: Positive := 1; -- Mean(Iter'First) = Mean(Iter'First) Higher: Natural  := 0; Lower: Natural  := 0;   begin -- Permutation_Test; -- first, count the subsets with a higher, an equal or a lower mean loop Iter.Next(S); S_Avg := Mean(S); if S_Avg = T_Avg then Equal := Equal + 1; elsif S_Avg >= T_Avg then Higher := Higher + 1; else Lower := Lower + 1; end if; exit when Iter.Last(S); end loop;   -- second, output the results declare use Ada.Text_IO; Sum: Float := Float(Higher + Equal + Lower); begin Put("Less or Equal: "); FIO.Put(100.0*Float(Lower+Equal) / Sum, Fore=>3, Aft=>1, Exp=>0); Put(Integer'Image(Lower+Equal)); New_Line; Put("More: "); FIO.Put(100.0*Float(Higher) / Sum, Fore=>3, Aft=>1, Exp=>0); Put(Integer'Image(Higher)); New_Line; end; end Permutation_Test;
http://rosettacode.org/wiki/Peripheral_drift_illusion
Peripheral drift illusion
Task Generate and display a Peripheral Drift Illusion The image appears to be moving even though it is perfectly static. Provide a link to show the output, either by running the code online or a screenshot uploaded to a suitable image host. References Codepen demo.
#Perl
Perl
use strict; use warnings;   my $svg = <<'EOD'; <svg xmlns="http://www.w3.org/2000/svg" xmlns:svg="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="1200" height="825"> <rect width="100%" height="100%" fill="#d3d004" /> <defs> <g id="block"> <polygon points="-25,-25,-25,25,25,25" fill="white" /> <polygon points="25,25,25,-25,-25,-25" fill="black" /> <rect x="-20" y="-20" width="40" height="40" fill="#3250ff" /> </g> </defs> EOD   for my $X (1..15) { for my $Y (1..10) { my $r = int(($X + $Y) / 2) % 4 * 90; my $x = $X * 75; my $y = $Y * 75; my $a = $r > 0 ? "rotate($r,$x,$y) " : ''; $svg .= qq{<use xlink:href="#block" transform="$a translate($x,$y)" />\n} } } $svg .= '</svg>';   open my $fh, '>', 'peripheral-drift.svg'; print $fh $svg; close $fh;
http://rosettacode.org/wiki/Peripheral_drift_illusion
Peripheral drift illusion
Task Generate and display a Peripheral Drift Illusion The image appears to be moving even though it is perfectly static. Provide a link to show the output, either by running the code online or a screenshot uploaded to a suitable image host. References Codepen demo.
#Phix
Phix
-- -- demo\rosetta\Peripheral_Drift_Illusion.exw -- ========================================== -- -- converted from https://codepen.io/josetxu/pen/rNmXjrq -- with javascript_semantics include pGUI.e Ihandle dlg, canvas cdCanvas cdcanvas constant title = "Peripheral Drift Illusion", CD_LIGHT_OLIVE = #d3d004, CD_PALE_BLUE = #3250ff, dxy = {{45,45},{0,45},{0,0},{45,0},{45,45},{0,45}} function redraw_cb(Ihandle /*ih*/, integer /*posx*/, /*posy*/) integer {width, height} = IupGetIntInt(canvas, "DRAWSIZE") cdCanvasActivate(cdcanvas) cdCanvasSetBackground(cdcanvas, CD_LIGHT_OLIVE) cdCanvasClear(cdcanvas) integer c = 0, cy = floor(height/2)*2-81 while cy>100 do integer d = c, cx = 81 while cx<width-100 do cdCanvasSetForeground(cdcanvas, CD_WHITE) cdCanvasBox(cdcanvas, cx, cx+45, cy, cy-45) cdCanvasSetForeground(cdcanvas, CD_BLACK) cdCanvasBegin(cdcanvas, CD_FILL) for i=4 to 6 do integer {dy,dx} = dxy[i-d] cdCanvasVertex(cdcanvas, cx+dx, cy-dy) end for cdCanvasEnd(cdcanvas) cdCanvasSetForeground(cdcanvas, CD_PALE_BLUE) cdCanvasBox(cdcanvas, cx+4, cx+41, cy-4, cy-41) d = remainder(d+(odd(cx)==odd(cy)),4) cx += 63 end while c = remainder(c+4-even(cy),4) cy -= 63 end while cdCanvasFlush(cdcanvas) return IUP_DEFAULT end function function map_cb(Ihandle ih) atom res = IupGetDouble(NULL, "SCREENDPI")/25.4 IupGLMakeCurrent(canvas) if platform()=JS then cdcanvas = cdCreateCanvas(CD_IUP, canvas) else cdcanvas = cdCreateCanvas(CD_GL, "10x10 %g", {res}) end if cdCanvasSetBackground(cdcanvas, CD_PARCHMENT) return IUP_DEFAULT end function function canvas_resize_cb(Ihandle /*canvas*/) integer {cw, ch} = IupGetIntInt(canvas, "DRAWSIZE") atom res = IupGetDouble(NULL, "SCREENDPI")/25.4 cdCanvasSetAttribute(cdcanvas, "SIZE", "%dx%d %g", {cw, ch, res}) return IUP_DEFAULT end function procedure main() IupOpen() canvas = IupGLCanvas("RASTERSIZE=780x600") -- (sensible restore size) sequence cb = {"MAP_CB", Icallback("map_cb"), "ACTION", Icallback("redraw_cb"), "RESIZE_CB", Icallback("canvas_resize_cb")} IupSetCallbacks(canvas, cb) dlg = IupDialog(canvas,`TITLE="%s",PLACEMENT=MAXIMIZED`,{title}) IupShow(dlg) if platform()!=JS then IupMainLoop() IupClose() end if end procedure main()
http://rosettacode.org/wiki/Playing_cards
Playing cards
Task Create a data structure and the associated methods to define and manipulate a deck of   playing cards. The deck should contain 52 unique cards. The methods must include the ability to:   make a new deck   shuffle (randomize) the deck   deal from the deck   print the current contents of a deck Each card must have a pip value and a suit value which constitute the unique value of the card. Related tasks: Card shuffles Deal cards_for_FreeCell War Card_Game Poker hand_analyser Go Fish
#C.23
C#
using System; using System.Linq; using System.Collections.Generic;   public struct Card { public Card(string rank, string suit) : this() { Rank = rank; Suit = suit; }   public string Rank { get; } public string Suit { get; }   public override string ToString() => $"{Rank} of {Suit}"; }   public class Deck : IEnumerable<Card> { static readonly string[] ranks = { "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten", "Jack", "Queen", "King", "Ace" }; static readonly string[] suits = { "Clubs", "Diamonds", "Hearts", "Spades" }; readonly List<Card> cards;   public Deck() { cards = (from suit in suits from rank in ranks select new Card(rank, suit)).ToList(); }   public int Count => cards.Count;   public void Shuffle() { // using Knuth Shuffle (see at http://rosettacode.org/wiki/Knuth_shuffle) var random = new Random(); for (int i = 0; i < cards.Count; i++) { int r = random.Next(i, cards.Count); var temp = cards[i]; cards[i] = cards[r]; cards[r] = temp; } }   public Card Deal() { int last = cards.Count - 1; Card card = cards[last]; //Removing from the front will shift the other items back 1 spot, //so that would be an O(n) operation. Removing from the back is O(1). cards.RemoveAt(last); return card; }   public IEnumerator<Card> GetEnumerator() { //Reverse enumeration of the list so that they are returned in the order they would be dealt. //LINQ's Reverse() copies the entire list. Let's avoid that. for (int i = cards.Count - 1; i >= 0; i--) yield return cards[i]; }   System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => GetEnumerator(); }
http://rosettacode.org/wiki/Pi
Pi
Create a program to continually calculate and output the next decimal digit of   π {\displaystyle \pi }   (pi). The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession. The output should be a decimal sequence beginning   3.14159265 ... Note: this task is about   calculating   pi.   For information on built-in pi constants see Real constants and functions. Related Task Arithmetic-geometric mean/Calculate Pi
#BASIC
BASIC
10 REM ADOPTED FROM COMMODORE BASIC 20 N = 100: REM N MAY BE INCREASED, BUT WILL SLOW EXECUTION 30 LN = INT(10*N/3)+16 40 ND = 1 50 DIM A(LN) 60 N9 = 0 70 PD = 0:REM FIRST PRE-DIGIT IS A 0 80 REM 90 FOR J = 1 TO LN 100 A(J-1) = 2:REM START WITH 2S 110 NEXT J 120 REM 130 FOR J = 1 TO N 140 Q = 0 150 FOR I = LN TO 1 STEP -1:REM WORK BACKWARDS 160 X = 10*A(I-1) + Q*I 170 A(I-1) = X - (2*I-1)*INT(X/(2*I-1)):REM X - INT ( X / Y) * Y 180 Q = INT(X/(2*I - 1)) 190 NEXT I 200 A(0) = Q-10*INT(Q/10) 210 Q = INT(Q/10) 220 IF Q=9 THEN N9 = N9 + 1: GOTO 450 240 IF Q<>10 THEN GOTO 350 250 REM Q == 10 260 D = PD+1: GOSUB 500 270 IF N9 <= 0 THEN GOTO 320 280 FOR K = 1 TO N9 290 D = 0: GOSUB 500 300 NEXT K 310 REM END IF 320 PD = 0 330 N9 = 0 335 GOTO 450 340 REM Q <> 10 350 D = PD: GOSUB 500 360 PD = Q 370 IF N9 = 0 THEN GOTO 450 380 FOR K = 1 TO N9 390 D = 9: GOSUB 500 400 NEXT K 410 N9 = 0 450 NEXT J 460 PRINT PD 470 END 480 REM 490 REM OUTPUT DIGITS 500 IF ND=0 THEN PRINT D;: RETURN 510 IF D=0 THEN RETURN 520 PRINT D;"."; 530 ND = 0 550 RETURN    
http://rosettacode.org/wiki/Periodic_table
Periodic table
Task Display the row and column in the periodic table of the given atomic number. The periodic table Let us consider the following periodic table representation. __________________________________________________________________________ | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | | | |1 H He | | | |2 Li Be B C N O F Ne | | | |3 Na Mg Al Si P S Cl Ar | | | |4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr | | | |5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe | | | |6 Cs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn | | | |7 Fr Ra ° Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og | |__________________________________________________________________________| | | | | |8 Lantanoidi* La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu | | | |9 Aktinoidi° Ak Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr | |__________________________________________________________________________| Example test cases;   1 -> 1 1   2 -> 1 18   29 -> 4 11   42 -> 5 6   57 -> 8 4   58 -> 8 5   72 -> 6 4   89 -> 9 4 Details; The representation of the periodic table may be represented in various way. The one presented in this challenge does have the following property : Lantanides and Aktinoides are all in a dedicated row, hence there is no element that is placed at 6, 3 nor 7, 3. You may take a look at the atomic number repartitions here. The atomic number is at least 1, at most 118. See also   the periodic table   This task was an idea from CompSciFact   The periodic table in ascii that was used as template
#6502_Assembly
6502 Assembly
Lookup:  ;INPUT: X = atomic number of the element of interest. LDA PeriodicTable_Column,x STA $20  ;store column number in memory (I chose $20 arbitrarily, you can store it anywhere) LDA PeriodicTable_Row,x STA $21  ;store row number in memory RTS   PeriodicTable_Column: db $ff,$01,$18,$01,$02,$13,$14,$15,$16,$17,$18,...  ;I don't need to write them all out, the concept is self-explanatory enough. PeriodicTable_Row: db $ff,$01,$01,$02,$02,$02,$02,$02,$02,$02,$02,...
http://rosettacode.org/wiki/Pig_the_dice_game
Pig the dice game
The   game of Pig   is a multiplayer game played with a single six-sided die.   The object of the game is to reach   100   points or more.   Play is taken in turns.   On each person's turn that person has the option of either: Rolling the dice:   where a roll of two to six is added to their score for that turn and the player's turn continues as the player is given the same choice again;   or a roll of   1   loses the player's total points   for that turn   and their turn finishes with play passing to the next player. Holding:   the player's score for that round is added to their total and becomes safe from the effects of throwing a   1   (one).   The player's turn finishes with play passing to the next player. Task Create a program to score for, and simulate dice throws for, a two-person game. Related task   Pig the dice game/Player
#FOCAL
FOCAL
01.10 T "GAME OF PIG"! 01.20 S S(1)=0;S S(2)=0;S P=1 01.30 T !"PLAYER",%1,P," TURN BEGINS"! 01.40 D 3;I (99-S(P))1.7 01.50 S P=3-P 01.60 G 1.3 01.70 T !"THE WINNER IS PLAYER",%1,P,! 01.80 Q   02.10 S A=10*FRAN();S A=1+FITR(6*(A-FITR(A)))   03.10 S T=0 03.20 T "PLAYER",%1,P," SCORE",%3,S(P)," TURN",%3,T 03.25 D 2;T " ROLL",%1,A," " 03.30 I (A-2)3.55;S T=T+A 03.35 A "- R)OLL OR H)OLD",C 03.40 I (C-0R)3.45,3.2,3.45 03.45 I (C-0H)3.5,3.6,3.5 03.50 T "INVALID INPUT ";G 3.35 03.55 T "- TOO BAD!"!;S T=0 03.60 S S(P)=S(P)+T 03.65 T "PLAYER",%1,P," SCORE",%3,S(P)," TURN FINISHED"!
http://rosettacode.org/wiki/Pernicious_numbers
Pernicious numbers
A   pernicious number   is a positive integer whose   population count   is a prime. The   population count   is the number of   ones   in the binary representation of a non-negative integer. Example 22   (which is   10110   in binary)   has a population count of   3,   which is prime,   and therefore 22   is a pernicious number. Task display the first   25   pernicious numbers   (in decimal). display all pernicious numbers between   888,888,877   and   888,888,888   (inclusive). display each list of integers on one line   (which may or may not include a title). See also Sequence   A052294 pernicious numbers on The On-Line Encyclopedia of Integer Sequences. Rosetta Code entry   population count, evil numbers, odious numbers.
#AWK
AWK
  # syntax: GAWK -f PERNICIOUS_NUMBERS.AWK BEGIN { pernicious(25) pernicious(888888877,888888888) exit(0) } function pernicious(x,y, count,n) { if (y == "") { # print first X pernicious numbers while (count < x) { if (is_prime(pop_count(++n)) == 1) { printf("%d ",n) count++ } } } else { # print pernicious numbers in X-Y range for (n=x; n<=y; n++) { if (is_prime(pop_count(n)) == 1) { printf("%d ",n) } } } print("") } function dec2bin(n, str) { while (n) { if (n%2 == 0) { str = "0" str } else { str = "1" str } n = int(n/2) } if (str == "") { str = "0" } return(str) } function is_prime(x, i) { if (x <= 1) { return(0) } for (i=2; i<=int(sqrt(x)); i++) { if (x % i == 0) { return(0) } } return(1) } function pop_count(n) { n = dec2bin(n) return gsub(/1/,"&",n) }  
http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation
Permutations/Rank of a permutation
A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items. For our purposes the ranking will assign integers 0.. ( n ! − 1 ) {\displaystyle 0..(n!-1)} to an ordering of all the permutations of the integers 0.. ( n − 1 ) {\displaystyle 0..(n-1)} . For example, the permutations of the digits zero to 3 arranged lexicographically have the following rank: PERMUTATION RANK (0, 1, 2, 3) -> 0 (0, 1, 3, 2) -> 1 (0, 2, 1, 3) -> 2 (0, 2, 3, 1) -> 3 (0, 3, 1, 2) -> 4 (0, 3, 2, 1) -> 5 (1, 0, 2, 3) -> 6 (1, 0, 3, 2) -> 7 (1, 2, 0, 3) -> 8 (1, 2, 3, 0) -> 9 (1, 3, 0, 2) -> 10 (1, 3, 2, 0) -> 11 (2, 0, 1, 3) -> 12 (2, 0, 3, 1) -> 13 (2, 1, 0, 3) -> 14 (2, 1, 3, 0) -> 15 (2, 3, 0, 1) -> 16 (2, 3, 1, 0) -> 17 (3, 0, 1, 2) -> 18 (3, 0, 2, 1) -> 19 (3, 1, 0, 2) -> 20 (3, 1, 2, 0) -> 21 (3, 2, 0, 1) -> 22 (3, 2, 1, 0) -> 23 Algorithms exist that can generate a rank from a permutation for some particular ordering of permutations, and that can generate the same rank from the given individual permutation (i.e. given a rank of 17 produce (2, 3, 1, 0) in the example above). One use of such algorithms could be in generating a small, random, sample of permutations of n {\displaystyle n} items without duplicates when the total number of permutations is large. Remember that the total number of permutations of n {\displaystyle n} items is given by n ! {\displaystyle n!} which grows large very quickly: A 32 bit integer can only hold 12 ! {\displaystyle 12!} , a 64 bit integer only 20 ! {\displaystyle 20!} . It becomes difficult to take the straight-forward approach of generating all permutations then taking a random sample of them. A question on the Stack Overflow site asked how to generate one million random and indivudual permutations of 144 items. Task Create a function to generate a permutation from a rank. Create the inverse function that given the permutation generates its rank. Show that for n = 3 {\displaystyle n=3} the two functions are indeed inverses of each other. Compute and show here 4 random, individual, samples of permutations of 12 objects. Stretch goal State how reasonable it would be to use your program to address the limits of the Stack Overflow question. References Ranking and Unranking Permutations in Linear Time by Myrvold & Ruskey. (Also available via Google here). Ranks on the DevData site. Another answer on Stack Overflow to a different question that explains its algorithm in detail. Related tasks Factorial_base_numbers_indexing_permutations_of_a_collection
#Kotlin
Kotlin
// version 1.1.2   import java.util.Random   fun IntArray.swap(i: Int, j: Int) { val temp = this[i] this[i] = this[j] this[j] = temp }   tailrec fun mrUnrank1(rank: Int, n: Int, vec: IntArray) { if (n < 1) return val q = rank / n val r = rank % n vec.swap(r, n - 1) mrUnrank1(q, n - 1, vec) }   fun mrRank1(n: Int, vec: IntArray, inv: IntArray): Int { if (n < 2) return 0 val s = vec[n - 1] vec.swap(n - 1, inv[n - 1]) inv.swap(s, n - 1) return s + n * mrRank1(n - 1, vec, inv) }   fun getPermutation(rank: Int, n: Int, vec: IntArray) { for (i in 0 until n) vec[i] = i mrUnrank1(rank, n, vec) }   fun getRank(n: Int, vec: IntArray): Int { val v = IntArray(n) val inv = IntArray(n) for (i in 0 until n) { v[i] = vec[i] inv[vec[i]] = i } return mrRank1(n, v, inv) }   fun main(args: Array<String>) { var tv = IntArray(3) for (r in 0..5) { getPermutation(r, 3, tv) System.out.printf("%2d -> %s -> %d\n", r, tv.contentToString(), getRank(3, tv)) } println() tv = IntArray(4) for (r in 0..23) { getPermutation(r, 4, tv) System.out.printf("%2d -> %s -> %d\n", r, tv.contentToString(), getRank(4, tv)) }   println() tv = IntArray(12) val a = IntArray(4) val rand = Random() val fact12 = (2..12).fold(1) { acc, i -> acc * i } for (i in 0..3) a[i] = rand.nextInt(fact12) for (r in a) { getPermutation(r, 12, tv) System.out.printf("%9d -> %s -> %d\n", r, tv.contentToString(), getRank(12, tv)) } }
http://rosettacode.org/wiki/Pierpont_primes
Pierpont primes
A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v . A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v . The term "Pierpont primes" is generally understood to mean the first definition, but will be called "Pierpont primes of the first kind" on this page to distinguish them. Task Write a routine (function, procedure, whatever) to find Pierpont primes of the first & second kinds. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the first kind. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the second kind If your language supports large integers, find and display here, on this page, the 250th Pierpont prime of the first kind and the 250th Pierpont prime of the second kind. See also Wikipedia - Pierpont primes OEIS:A005109 - Class 1 -, or Pierpont primes OEIS:A005105 - Class 1 +, or Pierpont primes of the second kind
#Java
Java
  import java.math.BigInteger; import java.text.NumberFormat; import java.util.ArrayList; import java.util.List;   public class PierpontPrimes {   public static void main(String[] args) { NumberFormat nf = NumberFormat.getNumberInstance(); display("First 50 Pierpont primes of the first kind:", pierpontPrimes(50, true)); display("First 50 Pierpont primes of the second kind:", pierpontPrimes(50, false)); System.out.printf("250th Pierpont prime of the first kind:  %s%n%n", nf.format(pierpontPrimes(250, true).get(249))); System.out.printf("250th Pierpont prime of the second kind: %s%n%n", nf.format(pierpontPrimes(250, false).get(249))); }   private static void display(String message, List<BigInteger> primes) { NumberFormat nf = NumberFormat.getNumberInstance(); System.out.printf("%s%n", message); for ( int i = 1 ; i <= primes.size() ; i++ ) { System.out.printf("%10s ", nf.format(primes.get(i-1))); if ( i % 10 == 0 ) { System.out.printf("%n"); } } System.out.printf("%n"); }   public static List<BigInteger> pierpontPrimes(int n, boolean first) { List<BigInteger> primes = new ArrayList<BigInteger>(); if ( first ) { primes.add(BigInteger.valueOf(2)); n -= 1; }   BigInteger two = BigInteger.valueOf(2); BigInteger twoTest = two; BigInteger three = BigInteger.valueOf(3); BigInteger threeTest = three; int twoIndex = 0, threeIndex = 0; List<BigInteger> twoSmooth = new ArrayList<BigInteger>();   BigInteger one = BigInteger.ONE; BigInteger mOne = BigInteger.valueOf(-1); int count = 0; while ( count < n ) { BigInteger min = twoTest.min(threeTest); twoSmooth.add(min); if ( min.compareTo(twoTest) == 0 ) { twoTest = two.multiply(twoSmooth.get(twoIndex)); twoIndex++; } if ( min.compareTo(threeTest) == 0 ) { threeTest = three.multiply(twoSmooth.get(threeIndex)); threeIndex++; } BigInteger test = min.add(first ? one : mOne); if ( test.isProbablePrime(10) ) { primes.add(test); count++; } } return primes; }   }  
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#CoffeeScript
CoffeeScript
array = [1,2,3] console.log array[Math.floor(Math.random() * array.length)]
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#Common_Lisp
Common Lisp
(defvar *list* '(one two three four five))   (print (nth (random (length *list*)) *list*)) (print (nth (random (length *list*)) *list*)) (print (nth (random (length *list*)) *list*))
http://rosettacode.org/wiki/Primality_by_trial_division
Primality by trial division
Task Write a boolean function that tells whether a given integer is prime. Remember that   1   and all non-positive numbers are not prime. Use trial division. Even numbers greater than   2   may be eliminated right away. A loop from   3   to   √ n    will suffice,   but other loops are allowed. Related tasks   count in factors   prime decomposition   AKS test for primes   factors of an integer   Sieve of Eratosthenes   factors of a Mersenne number   trial factoring of a Mersenne number   partition an integer X into N primes   sequence of primes by Trial Division
#Standard_ML
Standard ML
fun is_prime n = if n = 2 then true else if n < 2 orelse n mod 2 = 0 then false else let fun loop k = if k * k > n then true else if n mod k = 0 then false else loop (k+2) in loop 3 end
http://rosettacode.org/wiki/Phrase_reversals
Phrase reversals
Task Given a string of space separated words containing the following phrase: rosetta code phrase reversal Reverse the characters of the string. Reverse the characters of each individual word in the string, maintaining original word order within the string. Reverse the order of each word of the string, maintaining the order of characters in each word. Show your output here. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#Clojure
Clojure
(use '[clojure.string :only (join split)]) (def phrase "rosetta code phrase reversal") (defn str-reverse [s] (apply str (reverse s)))   ; Reverse string (str-reverse phrase) ; Words reversed (join " " (map str-reverse (split phrase #" "))) ; Word order reversed (apply str (interpose " " (reverse (split phrase #" "))))  
http://rosettacode.org/wiki/Permutations/Derangements
Permutations/Derangements
A derangement is a permutation of the order of distinct items in which no item appears in its original place. For example, the only two derangements of the three items (0, 1, 2) are (1, 2, 0), and (2, 0, 1). The number of derangements of n distinct items is known as the subfactorial of n, sometimes written as !n. There are various ways to calculate !n. Task Create a named function/method/subroutine/... to generate derangements of the integers 0..n-1, (or 1..n if you prefer). Generate and show all the derangements of 4 integers using the above routine. Create a function that calculates the subfactorial of n, !n. Print and show a table of the counted number of derangements of n vs. the calculated !n for n from 0..9 inclusive. Optional stretch goal   Calculate    !20 Related tasks   Anagrams/Deranged anagrams   Best shuffle   Left_factorials Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#Ada
Ada
with Ada.Text_IO; use Ada.Text_IO; procedure DePermute is type U64 is mod 2**64; type Num is range 0 .. 20; type NumList is array (Natural range <>) of Num; type PtNumList is access all NumList; package IO is new Ada.Text_IO.Integer_IO (Num); package UIO is new Ada.Text_IO.Modular_IO (U64);   function deranged (depth : Natural; list : PtNumList; show : Boolean) return U64 is tmp : Num; count : U64 := 0; begin if depth = list'Length then if show then for i in list'Range loop IO.Put (list (i), 2); end loop; New_Line; end if; return 1; end if; for i in reverse depth .. list'Last loop if Num (i + 1) /= list (depth) then tmp := list (i); list (i) := list (depth); list (depth) := tmp; count := count + deranged (depth + 1, list, show); tmp := list (i); list (i) := list (depth); list (depth) := tmp; end if; end loop; return count; end deranged;   function gen_n (len : Natural; show : Boolean) return U64 is list : PtNumList; begin list := new NumList (0 .. len - 1); for i in list'Range loop list (i) := Num (i + 1); end loop; return deranged (0, list, show); end gen_n;   function sub_fact (n : Natural) return U64 is begin if n < 2 then return U64 (1 - n); else return (sub_fact (n - 1) + sub_fact (n - 2)) * U64 (n - 1); end if; end sub_fact;   count : U64; begin Put_Line ("Deranged 4:"); count := gen_n (4, True); Put_Line ("List vs. calc:"); for i in Natural range 0 .. 9 loop IO.Put (Num (i), 1); UIO.Put (gen_n (i, False), 7); UIO.Put (sub_fact (i), 7); New_Line; end loop; Put_Line ("!20 = " & U64'Image (sub_fact (20))); end DePermute;
http://rosettacode.org/wiki/Permutations_by_swapping
Permutations by swapping
Task Generate permutations of n items in which successive permutations differ from each other by the swapping of any two items. Also generate the sign of the permutation which is +1 when the permutation is generated from an even number of swaps from the initial state, and -1 for odd. Show the permutations and signs of three items, in order of generation here. Such data are of use in generating the determinant of a square matrix and any functions created should bear this in mind. Note: The Steinhaus–Johnson–Trotter algorithm generates successive permutations where adjacent items are swapped, but from this discussion adjacency is not a requirement. References Steinhaus–Johnson–Trotter algorithm Johnson-Trotter Algorithm Listing All Permutations Heap's algorithm [1] Tintinnalogia Related tasks   Matrix arithmetic   Gray code
#Arturo
Arturo
permutations: function [arr][ d: 1 c: array.of: size arr 0 xs: new arr sign: 1   ret: new @[@[xs, sign]]   while [true][ while [d > 1][ d: d-1 c\[d]: 0 ]   while [c\[d] >= d][ d: d+1 if d >= size arr -> return ret ]   i: (1 = and d 1)? -> c\[d] -> 0 tmp: xs\[i] xs\[i]: xs\[d] xs\[d]: tmp   sign: neg sign 'ret ++ @[new @[xs, sign]] c\[d]: c\[d] + 1 ]   return ret ]   loop permutations 0..2 'row -> print [row\0 "-> sign:" row\1]   print ""   loop permutations 0..3 'row -> print [row\0 "-> sign:" row\1]
http://rosettacode.org/wiki/Permutation_test
Permutation test
Permutation test You are encouraged to solve this task according to the task description, using any language you may know. A new medical treatment was tested on a population of n + m {\displaystyle n+m} volunteers, with each volunteer randomly assigned either to a group of n {\displaystyle n} treatment subjects, or to a group of m {\displaystyle m} control subjects. Members of the treatment group were given the treatment, and members of the control group were given a placebo. The effect of the treatment or placebo on each volunteer was measured and reported in this table. Table of experimental results Treatment group Control group 85 68 88 41 75 10 66 49 25 16 29 65 83 32 39 92 97 28 98 Write a program that performs a permutation test to judge whether the treatment had a significantly stronger effect than the placebo. Do this by considering every possible alternative assignment from the same pool of volunteers to a treatment group of size n {\displaystyle n} and a control group of size m {\displaystyle m} (i.e., the same group sizes used in the actual experiment but with the group members chosen differently), while assuming that each volunteer's effect remains constant regardless. Note that the number of alternatives will be the binomial coefficient ( n + m n ) {\displaystyle {\tbinom {n+m}{n}}} . Compute the mean effect for each group and the difference in means between the groups in every case by subtracting the mean of the control group from the mean of the treatment group. Report the percentage of alternative groupings for which the difference in means is less or equal to the actual experimentally observed difference in means, and the percentage for which it is greater. Note that they should sum to 100%. Extremely dissimilar values are evidence of an effect not entirely due to chance, but your program need not draw any conclusions. You may assume the experimental data are known at compile time if that's easier than loading them at run time. Test your solution on the data given above.
#AWK
AWK
  # syntax: GAWK -f PERMUTATION_TEST.AWK # converted from C BEGIN { # "treatment..................control......................" n = split("85,88,75,66,25,29,83,39,97,68,41,10,49,16,65,32,92,28,98",data,",") for (i=1; i<=n; i++) { # make AWK array look like a C array data[i-1] = data[i] } delete data[n] total = 1 for (i=0; i<9; i++) { treat += data[i] } for (i=19; i>10; i--) { total *= i } for (i=9; i>0; i--) { total /= i } gt = pick(19,9,0,treat) le = total - gt printf("<= : %9.6f%% %6d\n",100*le/total,le) printf(" > : %9.6f%% %6d\n",100*gt/total,gt) exit(0) } function pick(at,remain,accu,treat) { if (!remain) { return (accu > treat) ? 1 : 0 } return pick(at-1,remain-1,accu+data[at-1],treat) + ( (at > remain) ? pick(at-1,remain,accu,treat) : 0 ) }  
http://rosettacode.org/wiki/Peripheral_drift_illusion
Peripheral drift illusion
Task Generate and display a Peripheral Drift Illusion The image appears to be moving even though it is perfectly static. Provide a link to show the output, either by running the code online or a screenshot uploaded to a suitable image host. References Codepen demo.
#Raku
Raku
use SVG;   my @blocks = (1..15 X 1..10).map: -> ($X, $Y) { my $x = $X * 75; my $y = $Y * 75; my $a = (my $r = ($X + $Y) div 2 % 4 * 90) > 0 ?? "rotate($r,$x,$y) " !! ''; :use['xlink:href'=>'#block', 'transform'=>"{$a}translate($x,$y)"] }   'peripheral-drift-raku.svg'.IO.spurt: SVG.serialize( svg => [ :1200width, :825height, :rect[:width<100%>, :height<100%>, :fill<#d3d004>], :defs[ :g[ :id<block>, :polygon[:points<-25,-25,-25,25,25,25>, :fill<white>], :polygon[:points<25,25,25,-25,-25,-25>, :fill<black>], :rect[:x<-20>, :y<-20>, :width<40>, :height<40>, :fill<#3250ff>] ] ], |@blocks, ] )
http://rosettacode.org/wiki/Playing_cards
Playing cards
Task Create a data structure and the associated methods to define and manipulate a deck of   playing cards. The deck should contain 52 unique cards. The methods must include the ability to:   make a new deck   shuffle (randomize) the deck   deal from the deck   print the current contents of a deck Each card must have a pip value and a suit value which constitute the unique value of the card. Related tasks: Card shuffles Deal cards_for_FreeCell War Card_Game Poker hand_analyser Go Fish
#C.2B.2B
C++
#include <deque> #include <algorithm> #include <ostream> #include <iterator>   namespace cards { class card { public: enum pip_type { two, three, four, five, six, seven, eight, nine, ten, jack, queen, king, ace, pip_count }; enum suite_type { hearts, spades, diamonds, clubs, suite_count }; enum { unique_count = pip_count * suite_count };   card(suite_type s, pip_type p): value(s + suite_count * p) {}   explicit card(unsigned char v = 0): value(v) {}   pip_type pip() { return pip_type(value / suite_count); }   suite_type suite() { return suite_type(value % suite_count); }   private: unsigned char value; };   const char* const pip_names[] = { "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "jack", "queen", "king", "ace" };   std::ostream& operator<<(std::ostream& os, card::pip_type pip) { return os << pip_names[pip]; }   const char* const suite_names[] = { "hearts", "spades", "diamonds", "clubs" };   std::ostream& operator<<(std::ostream& os, card::suite_type suite) { return os << suite_names[suite]; }   std::ostream& operator<<(std::ostream& os, card c) { return os << c.pip() << " of " << c.suite(); }   class deck { public: deck() { for (int i = 0; i < card::unique_count; ++i) { cards.push_back(card(i)); } }   void shuffle() { std::random_shuffle(cards.begin(), cards.end()); }   card deal() { card c = cards.front(); cards.pop_front(); return c; }   typedef std::deque<card>::const_iterator const_iterator; const_iterator begin() const { return cards.cbegin(); } const_iterator end() const { return cards.cend(); } private: std::deque<card> cards; };   inline std::ostream& operator<<(std::ostream& os, const deck& d) { std::copy(d.begin(), d.end(), std::ostream_iterator<card>(os, "\n")); return os; } }
http://rosettacode.org/wiki/Pi
Pi
Create a program to continually calculate and output the next decimal digit of   π {\displaystyle \pi }   (pi). The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession. The output should be a decimal sequence beginning   3.14159265 ... Note: this task is about   calculating   pi.   For information on built-in pi constants see Real constants and functions. Related Task Arithmetic-geometric mean/Calculate Pi
#BBC_BASIC
BBC BASIC
WIDTH 80 M% = (HIMEM-END-1000) / 4 DIM B%(M%) FOR I% = 0 TO M% : B%(I%) = 20 : NEXT E% = 0 L% = 2 FOR C% = M% TO 14 STEP -7 D% = 0 A% = C%*2-1 FOR P% = C% TO 1 STEP -1 D% = D%*P% + B%(P%)*&64 B%(P%) = D% MOD A% D% DIV= A% A% -= 2 NEXT CASE TRUE OF WHEN D% = 99: E% = E% * 100 + D% : L% += 2 WHEN C% = M%: PRINT ;(D% DIV 100) / 10; : E% = D% MOD 100 OTHERWISE: PRINT RIGHT$(STRING$(L%,"0") + STR$(E% + D% DIV 100),L%); E% = D% MOD 100 : L% = 2 ENDCASE NEXT
http://rosettacode.org/wiki/Periodic_table
Periodic table
Task Display the row and column in the periodic table of the given atomic number. The periodic table Let us consider the following periodic table representation. __________________________________________________________________________ | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | | | |1 H He | | | |2 Li Be B C N O F Ne | | | |3 Na Mg Al Si P S Cl Ar | | | |4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr | | | |5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe | | | |6 Cs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn | | | |7 Fr Ra ° Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og | |__________________________________________________________________________| | | | | |8 Lantanoidi* La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu | | | |9 Aktinoidi° Ak Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr | |__________________________________________________________________________| Example test cases;   1 -> 1 1   2 -> 1 18   29 -> 4 11   42 -> 5 6   57 -> 8 4   58 -> 8 5   72 -> 6 4   89 -> 9 4 Details; The representation of the periodic table may be represented in various way. The one presented in this challenge does have the following property : Lantanides and Aktinoides are all in a dedicated row, hence there is no element that is placed at 6, 3 nor 7, 3. You may take a look at the atomic number repartitions here. The atomic number is at least 1, at most 118. See also   the periodic table   This task was an idea from CompSciFact   The periodic table in ascii that was used as template
#68000_Assembly
68000 Assembly
Lookup: ;input: D0.W = the atomic number of interest. LEA PeriodicTable,A0 ADD.W D0,D0 ;we're indexing a table of words, so double the index. MOVE.W (A0,D0),D0 ;D0.W contains row number in the high byte and column number in the low byte. RTS   PeriodicTable: DC.W $FFFF ;padding since arrays start at zero in assembly. DC.W $0101 ;HYDROGEN DC.W $0118 ;HELIUM DC.W $0201 ;LITHIUM DC.W $0202 ;BERYLLIUM DC.W $0213 ;BORON DC.W $0214 ;CARBON DC.W $0215 ;NITROGEN DC.W $0216 ;OXYGEN DC.W $0217 ;FLUORINE DC.W $0218 ;NEON ;etc.
http://rosettacode.org/wiki/Pig_the_dice_game
Pig the dice game
The   game of Pig   is a multiplayer game played with a single six-sided die.   The object of the game is to reach   100   points or more.   Play is taken in turns.   On each person's turn that person has the option of either: Rolling the dice:   where a roll of two to six is added to their score for that turn and the player's turn continues as the player is given the same choice again;   or a roll of   1   loses the player's total points   for that turn   and their turn finishes with play passing to the next player. Holding:   the player's score for that round is added to their total and becomes safe from the effects of throwing a   1   (one).   The player's turn finishes with play passing to the next player. Task Create a program to score for, and simulate dice throws for, a two-person game. Related task   Pig the dice game/Player
#Forth
Forth
include lib/choose.4th include lib/yesorno.4th   : turn ( n1 -- n2) ." Player " . ." is up" cr \ which player is up 0 begin \ nothing so far s" Rolling" yes/no? \ stand or roll? while \ now roll the dice 6 choose 1+ dup ." Rolling " . dup 1 = if drop drop 0 else + ." (" dup 0 .r ." )" then cr dup 0= until \ until player stands or 1 is rolled ;   : pigthedice ( --) 2 0 1 over \ setup players begin over turn + dup ." Total score: " . cr cr dup 100 < while 2swap repeat ." Player " swap . ." won with " . ." points." cr ." Player " swap . ." lost with " . ." points." cr ; \ show the results   pigthedice
http://rosettacode.org/wiki/Pernicious_numbers
Pernicious numbers
A   pernicious number   is a positive integer whose   population count   is a prime. The   population count   is the number of   ones   in the binary representation of a non-negative integer. Example 22   (which is   10110   in binary)   has a population count of   3,   which is prime,   and therefore 22   is a pernicious number. Task display the first   25   pernicious numbers   (in decimal). display all pernicious numbers between   888,888,877   and   888,888,888   (inclusive). display each list of integers on one line   (which may or may not include a title). See also Sequence   A052294 pernicious numbers on The On-Line Encyclopedia of Integer Sequences. Rosetta Code entry   population count, evil numbers, odious numbers.
#Befunge
Befunge
55*00p1>:"ZOA>/"***7-*>\:2>/\v >8**`!#^_$@\<(^v^)>/#2^#\<2 2 ^+**"X^yYo":+1<_:.48*,00v|: <% v".D}Tx"$,+55_^#!p00:-1g<v |< > * + : * * + ^^ ! % 2 $ <^ <^
http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation
Permutations/Rank of a permutation
A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items. For our purposes the ranking will assign integers 0.. ( n ! − 1 ) {\displaystyle 0..(n!-1)} to an ordering of all the permutations of the integers 0.. ( n − 1 ) {\displaystyle 0..(n-1)} . For example, the permutations of the digits zero to 3 arranged lexicographically have the following rank: PERMUTATION RANK (0, 1, 2, 3) -> 0 (0, 1, 3, 2) -> 1 (0, 2, 1, 3) -> 2 (0, 2, 3, 1) -> 3 (0, 3, 1, 2) -> 4 (0, 3, 2, 1) -> 5 (1, 0, 2, 3) -> 6 (1, 0, 3, 2) -> 7 (1, 2, 0, 3) -> 8 (1, 2, 3, 0) -> 9 (1, 3, 0, 2) -> 10 (1, 3, 2, 0) -> 11 (2, 0, 1, 3) -> 12 (2, 0, 3, 1) -> 13 (2, 1, 0, 3) -> 14 (2, 1, 3, 0) -> 15 (2, 3, 0, 1) -> 16 (2, 3, 1, 0) -> 17 (3, 0, 1, 2) -> 18 (3, 0, 2, 1) -> 19 (3, 1, 0, 2) -> 20 (3, 1, 2, 0) -> 21 (3, 2, 0, 1) -> 22 (3, 2, 1, 0) -> 23 Algorithms exist that can generate a rank from a permutation for some particular ordering of permutations, and that can generate the same rank from the given individual permutation (i.e. given a rank of 17 produce (2, 3, 1, 0) in the example above). One use of such algorithms could be in generating a small, random, sample of permutations of n {\displaystyle n} items without duplicates when the total number of permutations is large. Remember that the total number of permutations of n {\displaystyle n} items is given by n ! {\displaystyle n!} which grows large very quickly: A 32 bit integer can only hold 12 ! {\displaystyle 12!} , a 64 bit integer only 20 ! {\displaystyle 20!} . It becomes difficult to take the straight-forward approach of generating all permutations then taking a random sample of them. A question on the Stack Overflow site asked how to generate one million random and indivudual permutations of 144 items. Task Create a function to generate a permutation from a rank. Create the inverse function that given the permutation generates its rank. Show that for n = 3 {\displaystyle n=3} the two functions are indeed inverses of each other. Compute and show here 4 random, individual, samples of permutations of 12 objects. Stretch goal State how reasonable it would be to use your program to address the limits of the Stack Overflow question. References Ranking and Unranking Permutations in Linear Time by Myrvold & Ruskey. (Also available via Google here). Ranks on the DevData site. Another answer on Stack Overflow to a different question that explains its algorithm in detail. Related tasks Factorial_base_numbers_indexing_permutations_of_a_collection
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
fromrank[list_, 0] := list; fromrank[list_, n_] := Prepend[fromrank[DeleteCases[list, #], Mod[n, (Length@list - 1)!]], #] &@ RankedMin[list, Quotient[n, (Length@list - 1)!] + 1];   rank[{}] = 0; rank[{x_, y___}] := Count[{y}, _?(# < x &)] Length@{y}! + rank[{y}];   Print /@ Table[{n, fromrank[{0, 1, 2, 3}, n], rank@fromrank[{0, 1, 2, 3}, n]}, {n, 0, 23}];   Do[Print@fromrank[Range[0, 12 - 1], RandomInteger[12!]], {4}]; Do[Print@fromrank[Range[0, 144 - 1], RandomInteger[144!]], {4}];
http://rosettacode.org/wiki/Pierpont_primes
Pierpont primes
A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v . A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v . The term "Pierpont primes" is generally understood to mean the first definition, but will be called "Pierpont primes of the first kind" on this page to distinguish them. Task Write a routine (function, procedure, whatever) to find Pierpont primes of the first & second kinds. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the first kind. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the second kind If your language supports large integers, find and display here, on this page, the 250th Pierpont prime of the first kind and the 250th Pierpont prime of the second kind. See also Wikipedia - Pierpont primes OEIS:A005109 - Class 1 -, or Pierpont primes OEIS:A005105 - Class 1 +, or Pierpont primes of the second kind
#jq
jq
def is_prime: . as $n | if ($n < 2) then false elif ($n % 2 == 0) then $n == 2 elif ($n % 3 == 0) then $n == 3 elif ($n % 5 == 0) then $n == 5 elif ($n % 7 == 0) then $n == 7 elif ($n % 11 == 0) then $n == 11 elif ($n % 13 == 0) then $n == 13 elif ($n % 17 == 0) then $n == 17 elif ($n % 19 == 0) then $n == 19 else {i:23} | until( (.i * .i) > $n or ($n % .i == 0); .i += 2) | .i * .i > $n end;   # pretty-printing def lpad($len): tostring | ($len - length) as $l | (" " * $l)[:$l] + .;   def nwise($n): def n: if length <= $n then . else .[0:$n] , (.[$n:] | n) end; n;   def table($ncols; $colwidth): nwise($ncols) | map(lpad($colwidth)) | join(" ");
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#Crystal
Crystal
  puts [1, 2, 3, 4, 5].sample(1)  
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#D
D
import std.stdio, std.random;   void main() { const items = ["foo", "bar", "baz"]; items[uniform(0, $)].writeln; }
http://rosettacode.org/wiki/Primality_by_trial_division
Primality by trial division
Task Write a boolean function that tells whether a given integer is prime. Remember that   1   and all non-positive numbers are not prime. Use trial division. Even numbers greater than   2   may be eliminated right away. A loop from   3   to   √ n    will suffice,   but other loops are allowed. Related tasks   count in factors   prime decomposition   AKS test for primes   factors of an integer   Sieve of Eratosthenes   factors of a Mersenne number   trial factoring of a Mersenne number   partition an integer X into N primes   sequence of primes by Trial Division
#Swift
Swift
import Foundation   extension Int { func isPrime() -> Bool {   switch self { case let x where x < 2: return false case 2: return true default: return self % 2 != 0 &&  !stride(from: 3, through: Int(sqrt(Double(self))), by: 2).contains {self % $0 == 0} } } }
http://rosettacode.org/wiki/Phrase_reversals
Phrase reversals
Task Given a string of space separated words containing the following phrase: rosetta code phrase reversal Reverse the characters of the string. Reverse the characters of each individual word in the string, maintaining original word order within the string. Reverse the order of each word of the string, maintaining the order of characters in each word. Show your output here. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#COBOL
COBOL
  program-id. phra-rev. data division. working-storage section. 1 phrase pic x(28) value "rosetta code phrase reversal". 1 wk-str pic x(16). 1 binary. 2 phrase-len pic 9(4). 2 pos pic 9(4). 2 cnt pic 9(4). procedure division. compute phrase-len = function length (phrase) display phrase display function reverse (phrase) perform display-words move function reverse (phrase) to phrase perform display-words stop run .   display-words. move 1 to pos perform until pos > phrase-len unstring phrase delimited space into wk-str count in cnt with pointer pos end-unstring display function reverse (wk-str (1:cnt)) with no advancing if pos < phrase-len display space with no advancing end-if end-perform display space . end program phra-rev.  
http://rosettacode.org/wiki/Permutations/Derangements
Permutations/Derangements
A derangement is a permutation of the order of distinct items in which no item appears in its original place. For example, the only two derangements of the three items (0, 1, 2) are (1, 2, 0), and (2, 0, 1). The number of derangements of n distinct items is known as the subfactorial of n, sometimes written as !n. There are various ways to calculate !n. Task Create a named function/method/subroutine/... to generate derangements of the integers 0..n-1, (or 1..n if you prefer). Generate and show all the derangements of 4 integers using the above routine. Create a function that calculates the subfactorial of n, !n. Print and show a table of the counted number of derangements of n vs. the calculated !n for n from 0..9 inclusive. Optional stretch goal   Calculate    !20 Related tasks   Anagrams/Deranged anagrams   Best shuffle   Left_factorials Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#Arturo
Arturo
isClean?: function [s,o][ loop.with:'i s 'a [ if a = o\[i] -> return false ] return true ]   derangements: function [n][ original: 1..n select permutate original 'x -> isClean? x original ]   subfactorial: function [n].memoize[ (n =< 1)? -> 1 - n -> (n-1) * (add subfactorial n-1 subfactorial n-2) ]   print "Derangements of 1 2 3 4:" loop derangements 4 'x [ print x ]   print "\nNumber of derangements:" print [pad "n" 5 pad "counted" 15 pad "calculated" 15] print repeat "-" 39 loop 0..9 'z [ counted: size derangements z calculated: subfactorial z print [pad to :string z 5 pad to :string counted 15 pad to :string calculated 15] ]   print ~"\n!20 = |subfactorial 20|"
http://rosettacode.org/wiki/Permutations_by_swapping
Permutations by swapping
Task Generate permutations of n items in which successive permutations differ from each other by the swapping of any two items. Also generate the sign of the permutation which is +1 when the permutation is generated from an even number of swaps from the initial state, and -1 for odd. Show the permutations and signs of three items, in order of generation here. Such data are of use in generating the determinant of a square matrix and any functions created should bear this in mind. Note: The Steinhaus–Johnson–Trotter algorithm generates successive permutations where adjacent items are swapped, but from this discussion adjacency is not a requirement. References Steinhaus–Johnson–Trotter algorithm Johnson-Trotter Algorithm Listing All Permutations Heap's algorithm [1] Tintinnalogia Related tasks   Matrix arithmetic   Gray code
#AutoHotkey
AutoHotkey
Permutations_By_Swapping(str, list:=""){ ch := SubStr(str, 1, 1) ; get left-most charachter of str for i, line in StrSplit(list, "`n") ; for each line in list loop % StrLen(line) + 1 ; loop each possible position Newlist .= RegExReplace(line, mod(i,2) ? "(?=.{" A_Index-1 "}$)" : "^.{" A_Index-1 "}\K", ch) "`n" list := Newlist ? Trim(Newlist, "`n") : ch ; recreate list if !str := SubStr(str, 2) ; remove charachter from left hand side return list ; done if str is empty return Permutations_By_Swapping(str, list) ; else recurse }
http://rosettacode.org/wiki/Permutation_test
Permutation test
Permutation test You are encouraged to solve this task according to the task description, using any language you may know. A new medical treatment was tested on a population of n + m {\displaystyle n+m} volunteers, with each volunteer randomly assigned either to a group of n {\displaystyle n} treatment subjects, or to a group of m {\displaystyle m} control subjects. Members of the treatment group were given the treatment, and members of the control group were given a placebo. The effect of the treatment or placebo on each volunteer was measured and reported in this table. Table of experimental results Treatment group Control group 85 68 88 41 75 10 66 49 25 16 29 65 83 32 39 92 97 28 98 Write a program that performs a permutation test to judge whether the treatment had a significantly stronger effect than the placebo. Do this by considering every possible alternative assignment from the same pool of volunteers to a treatment group of size n {\displaystyle n} and a control group of size m {\displaystyle m} (i.e., the same group sizes used in the actual experiment but with the group members chosen differently), while assuming that each volunteer's effect remains constant regardless. Note that the number of alternatives will be the binomial coefficient ( n + m n ) {\displaystyle {\tbinom {n+m}{n}}} . Compute the mean effect for each group and the difference in means between the groups in every case by subtracting the mean of the control group from the mean of the treatment group. Report the percentage of alternative groupings for which the difference in means is less or equal to the actual experimentally observed difference in means, and the percentage for which it is greater. Note that they should sum to 100%. Extremely dissimilar values are evidence of an effect not entirely due to chance, but your program need not draw any conclusions. You may assume the experimental data are known at compile time if that's easier than loading them at run time. Test your solution on the data given above.
#BBC_BASIC
BBC BASIC
ntreated% = 9 nplacebo% = 10 DIM results%(ntreated% + nplacebo% - 1) results%() = 85, 88, 75, 66, 25, 29, 83, 39, 97, \ REM treated group \ 68, 41, 10, 49, 16, 65, 32, 92, 28, 98 : REM placebo group   greater% = 0 FOR comb% = 0 TO 2^(ntreated%+nplacebo%)-1 IF FNnbits(comb%) = ntreated% THEN tsum% = 0 : psum% = 0 FOR b% = 0 TO ntreated%+nplacebo%-1 IF comb% AND 2^b% THEN tsum% += results%(b%) ELSE psum% += results%(b%) ENDIF NEXT meandiff = tsum%/ntreated% - psum%/nplacebo% IF comb% = 2^ntreated% - 1 THEN actual = meandiff ELSE greater% -= meandiff > actual groups% += 1 ENDIF ENDIF NEXT   percent = 100 * greater%/groups% PRINT "Percentage groupings <= actual experiment: "; 100 - percent PRINT "Percentage groupings > actual experiment: "; percent END   DEF FNnbits(N%) N% -= N% >>> 1 AND &55555555 N% = (N% AND &33333333) + (N% >>> 2 AND &33333333) N% = (N% + (N% >>> 4)) AND &0F0F0F0F N% += N% >>> 8 : N% += N% >>> 16 = N% AND &7F
http://rosettacode.org/wiki/Permutation_test
Permutation test
Permutation test You are encouraged to solve this task according to the task description, using any language you may know. A new medical treatment was tested on a population of n + m {\displaystyle n+m} volunteers, with each volunteer randomly assigned either to a group of n {\displaystyle n} treatment subjects, or to a group of m {\displaystyle m} control subjects. Members of the treatment group were given the treatment, and members of the control group were given a placebo. The effect of the treatment or placebo on each volunteer was measured and reported in this table. Table of experimental results Treatment group Control group 85 68 88 41 75 10 66 49 25 16 29 65 83 32 39 92 97 28 98 Write a program that performs a permutation test to judge whether the treatment had a significantly stronger effect than the placebo. Do this by considering every possible alternative assignment from the same pool of volunteers to a treatment group of size n {\displaystyle n} and a control group of size m {\displaystyle m} (i.e., the same group sizes used in the actual experiment but with the group members chosen differently), while assuming that each volunteer's effect remains constant regardless. Note that the number of alternatives will be the binomial coefficient ( n + m n ) {\displaystyle {\tbinom {n+m}{n}}} . Compute the mean effect for each group and the difference in means between the groups in every case by subtracting the mean of the control group from the mean of the treatment group. Report the percentage of alternative groupings for which the difference in means is less or equal to the actual experimentally observed difference in means, and the percentage for which it is greater. Note that they should sum to 100%. Extremely dissimilar values are evidence of an effect not entirely due to chance, but your program need not draw any conclusions. You may assume the experimental data are known at compile time if that's easier than loading them at run time. Test your solution on the data given above.
#C
C
#include <stdio.h>   int data[] = { 85, 88, 75, 66, 25, 29, 83, 39, 97, 68, 41, 10, 49, 16, 65, 32, 92, 28, 98 };   int pick(int at, int remain, int accu, int treat) { if (!remain) return (accu > treat) ? 1 : 0;   return pick(at - 1, remain - 1, accu + data[at - 1], treat) + ( at > remain ? pick(at - 1, remain, accu, treat) : 0 ); }   int main() { int treat = 0, i; int le, gt; double total = 1; for (i = 0; i < 9; i++) treat += data[i]; for (i = 19; i > 10; i--) total *= i; for (i = 9; i > 0; i--) total /= i;   gt = pick(19, 9, 0, treat); le = total - gt;   printf("<= : %f%%  %d\n > : %f%%  %d\n", 100 * le / total, le, 100 * gt / total, gt); return 0; }
http://rosettacode.org/wiki/Peripheral_drift_illusion
Peripheral drift illusion
Task Generate and display a Peripheral Drift Illusion The image appears to be moving even though it is perfectly static. Provide a link to show the output, either by running the code online or a screenshot uploaded to a suitable image host. References Codepen demo.
#Wren
Wren
import "dome" for Window import "graphics" for Canvas, Color   // signifies the white edges on the blue squares var LT = 0 var TR = 1 var RB = 2 var BL = 3   var Edges = [ [LT, BL, BL, RB, RB, TR, TR, LT, LT, BL, BL, RB], [LT, LT, BL, BL, RB, RB, TR, TR, LT, LT, BL, BL], [TR, LT, LT, BL, BL, RB, RB, TR, TR, LT, LT, BL], [TR, TR, LT, LT, BL, BL, RB, RB, TR, TR, LT, LT], [RB, TR, TR, LT, LT, BL, BL, RB, RB, TR, TR, LT], [RB, RB, TR, TR, LT, LT, BL, BL, RB, RB, TR, TR], [BL, RB, RB, TR, TR, LT, LT, BL, BL, RB, RB, TR], [BL, BL, RB, RB, TR, TR, LT, LT, BL, BL, RB, RB], [LT, BL, BL, RB, RB, TR, TR, LT, LT, BL, BL, RB], [LT, LT, BL, BL, RB, RB, TR, TR, LT, LT, BL, BL], [TR, LT, LT, BL, BL, RB, RB, TR, TR, LT, LT, BL], [TR, TR, LT, LT, BL, BL, RB, RB, TR, TR, LT, LT] ]   var Light_olive = Color.hex("#d3d004") var Pale_blue = Color.hex("#3250ff")   var W = Color.white var B = Color.black   var Colors = [ [W, B, B, W], [W, W, B, B], [B, W, W, B], [B, B, W, W] ]   class PeripheralDrift { construct new() { Window.resize(1000, 1000) Canvas.resize(1000, 1000) Window.title = "Peripheral drift illusion" }   init() { Canvas.cls(Light_olive) for (x in 0..11) { var px = 90 + x * 70 for (y in 0..11) { var py = 90 + y * 70 Canvas.rectfill(px, py, 50, 50, Pale_blue) drawEdge(px, py, Edges[y][x]) } } }   drawEdge(px, py, edge) { var c = Colors[edge] Canvas.line(px, py, px + 46, py, c[0], 4) Canvas.line(px + 46, py, px + 46, py + 46, c[1], 4) Canvas.line(px, py + 46, px + 46, py + 46, c[2], 4) Canvas.line(px, py + 46, px, py, c[3], 4) }   update() {}   draw(alpha) {} }   var Game = PeripheralDrift.new()
http://rosettacode.org/wiki/Playing_cards
Playing cards
Task Create a data structure and the associated methods to define and manipulate a deck of   playing cards. The deck should contain 52 unique cards. The methods must include the ability to:   make a new deck   shuffle (randomize) the deck   deal from the deck   print the current contents of a deck Each card must have a pip value and a suit value which constitute the unique value of the card. Related tasks: Card shuffles Deal cards_for_FreeCell War Card_Game Poker hand_analyser Go Fish
#Ceylon
Ceylon
import com.vasileff.ceylon.random.api { ... }   """Run the example code for Rosetta Code ["Playing cards" task] (http://rosettacode.org/wiki/Playing_cards).""" shared void run() { variable value deck = Deck(); print("New deck (``deck.size`` cards): ``deck`` ");   deck = deck.shuffle(); print("Shuffeled deck (``deck.size`` cards): ``deck`` ");   print("Deal three hands: "); for (i in 1..3) { value [hand, _deck] = deck.deal(); print("- Dealt ``hand.size`` cards to hand ``i`` : ``join(hand)``"); deck = _deck; }   print(" Deck (``deck.size`` cards) after dealing three hands: ``deck``");   }   abstract class Suit() of clubs | hearts | spades | diamonds {}   object clubs extends Suit() { string = "♣"; } object hearts extends Suit() { string = "♥"; } object spades extends Suit() { string = "♠"; } object diamonds extends Suit() { string = "♦"; }   abstract class Pip() of two | three | four | five | six | seven | eight | nine | ten | jack | queen | king | ace {} object two extends Pip() { string = "2"; } object three extends Pip() { string = "3"; } object four extends Pip() { string = "4"; } object five extends Pip() { string = "5"; } object six extends Pip() { string = "6"; } object seven extends Pip() { string = "7"; } object eight extends Pip() { string = "8"; } object nine extends Pip() { string = "9"; } object ten extends Pip() { string = "10"; } object jack extends Pip() { string = "J"; } object queen extends Pip() { string = "Q"; } object king extends Pip() { string = "K"; } object ace extends Pip() { string = "A"; }   class Card(shared Pip pip, shared Suit suit) { string = "``pip`` of ``suit``"; }     String join(Card[] cards) => ", ".join { *cards };   class Deck (cards = [ for (suit in `Suit`.caseValues) for (pip in `Pip`.caseValues) Card(pip, suit) ]) { shared Card[] cards;   shared Deck shuffle(Random rnd = platformRandom()) => if (nonempty cards) then Deck( [*randomize(cards, rnd)] ) else this;   shared Integer size => cards.size;   shared Boolean empty => cards.empty;   string => if (size > 13) then "\n " + "\n ". join { *cards.partition(13).map((cards) => join(cards)) } else join(cards);   shared [Card[], Deck] deal(Integer handSize = 5) { if (handSize >= cards.size) { return [cards, Deck([])]; } else { return [ cards.initial(handSize), Deck(cards.skip(handSize).sequence()) ]; } } }
http://rosettacode.org/wiki/Pi
Pi
Create a program to continually calculate and output the next decimal digit of   π {\displaystyle \pi }   (pi). The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession. The output should be a decimal sequence beginning   3.14159265 ... Note: this task is about   calculating   pi.   For information on built-in pi constants see Real constants and functions. Related Task Arithmetic-geometric mean/Calculate Pi
#bc
bc
#!/usr/bin/bc -l   scaleinc= 20   define zeropad ( n ) { auto m for ( m= scaleinc - 1; m > 0; --m ) { if ( n < 10^m ) { print "0" } } return ( n ) }   wantscale= scaleinc - 2 scale= wantscale + 2 oldpi= 4*a(1) scale= wantscale oldpi= oldpi / 1 oldpi while( 1 ) { wantscale= wantscale + scaleinc scale= wantscale + 2 pi= 4*a(1) scale= 0 digits= ((pi - oldpi) * 10^wantscale) / 1 zeropad( digits ) scale= wantscale oldpi= pi / 1 }
http://rosettacode.org/wiki/Periodic_table
Periodic table
Task Display the row and column in the periodic table of the given atomic number. The periodic table Let us consider the following periodic table representation. __________________________________________________________________________ | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | | | |1 H He | | | |2 Li Be B C N O F Ne | | | |3 Na Mg Al Si P S Cl Ar | | | |4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr | | | |5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe | | | |6 Cs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn | | | |7 Fr Ra ° Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og | |__________________________________________________________________________| | | | | |8 Lantanoidi* La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu | | | |9 Aktinoidi° Ak Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr | |__________________________________________________________________________| Example test cases;   1 -> 1 1   2 -> 1 18   29 -> 4 11   42 -> 5 6   57 -> 8 4   58 -> 8 5   72 -> 6 4   89 -> 9 4 Details; The representation of the periodic table may be represented in various way. The one presented in this challenge does have the following property : Lantanides and Aktinoides are all in a dedicated row, hence there is no element that is placed at 6, 3 nor 7, 3. You may take a look at the atomic number repartitions here. The atomic number is at least 1, at most 118. See also   the periodic table   This task was an idea from CompSciFact   The periodic table in ascii that was used as template
#ALGOL_68
ALGOL 68
BEGIN # display the period and group number of an element, # # given its atomic number # INT max atomic number = 118; # highest known element # # the positions are stored as: # # ( group number * group multiplier ) + period # INT group multiplier = 100; [ 1 : max atomic number ]INT position; # construct the positions of the elements in the table # BEGIN STRING periodic table = "- =" + "-- -----=" + "-- -----=" + "-----------------=" + "-----------------=" + "--8--------------=" + "--9--------------=" ; INT period := 1; INT group := 1; INT element := 1; FOR t FROM LWB periodic table TO UPB periodic table DO CHAR p = periodic table[ t ]; IF p = "8" OR p = "9" THEN # lantanoids or actinoids # INT series period = IF p = "8" THEN 8 ELSE 9 FI; INT series group := 4; FOR e TO 15 DO position[ element ] := ( group multiplier * series group ) + series period; element +:= 1; series group +:= 1 OD ELIF p /= " " THEN # there is a single element here # position[ element ] := ( group multiplier * group ) + period; element +:= 1; IF p = "=" THEN # final element of the period # period +:= 1; group := 0 FI FI; group +:= 1 OD END; # display the period and group numbers of test elements # []INT test = ( 1, 2, 29, 42, 57, 58, 59, 71, 72, 89, 90, 103, 113 ); FOR t FROM LWB test TO UPB test DO INT e = test[ t ]; IF e < LWB position OR e > UPB position THEN print( ( "Invalid element: ", whole( e, 0 ), newline ) ) ELSE INT period = position[ e ] MOD group multiplier; INT group = position[ e ] OVER group multiplier; print( ( "Element ", whole( e, -3 ) , " -> ", whole( period, 0 ), ", ", whole( group, -2 ) , newline ) ) FI OD END
http://rosettacode.org/wiki/Pig_the_dice_game
Pig the dice game
The   game of Pig   is a multiplayer game played with a single six-sided die.   The object of the game is to reach   100   points or more.   Play is taken in turns.   On each person's turn that person has the option of either: Rolling the dice:   where a roll of two to six is added to their score for that turn and the player's turn continues as the player is given the same choice again;   or a roll of   1   loses the player's total points   for that turn   and their turn finishes with play passing to the next player. Holding:   the player's score for that round is added to their total and becomes safe from the effects of throwing a   1   (one).   The player's turn finishes with play passing to the next player. Task Create a program to score for, and simulate dice throws for, a two-person game. Related task   Pig the dice game/Player
#FreeBASIC
FreeBASIC
  Const numjugadores = 2 Const maxpuntos = 100 Dim As Byte almacenpuntos(numjugadores), jugador, puntos, tirada Dim As String nuevotiro   Cls: Color 15: Print "The game of PIG" Print String(15, "=") + Chr(13) + Chr(10): Color 7 Print "Si jugador saca un 1, no anota nada y se convierte en el turno del oponente." Print "Si jugador saca 2-6, se agrega al total del turno y su turno continúa." Print "Si jugador elige 'mantener', su total de puntos se añade a su puntuación, " Print " y se convierte en el turno del siguiente jugador." + Chr(10) Print "El primer jugador en anotar 100 o más puntos gana." + Chr(13) + Chr(10): Color 7   Do For jugador = 1 To numjugadores puntos = 0   While almacenpuntos(jugador) <= maxpuntos Color 15: Print Print Using "Jugador #: (&_, &)"; jugador;almacenpuntos(jugador);puntos;: Color 11 Input " ¿Tirada? (Sn) ", nuevotiro If Ucase(nuevotiro) = "S" Then tirada = Int(Rnd* 5) + 1 Print " Tirada:"; tirada If tirada = 1 Then Color 11: Print Chr(10) + "­¡Pierdes tu turno! jugador"; jugador; Print " pero mantienes tu puntuación anterior de "; almacenpuntos(jugador): Color 7 Exit While End If puntos = puntos + tirada Else almacenpuntos(jugador) = almacenpuntos(jugador) + puntos Print " Te quedas con:"; almacenpuntos(jugador) If almacenpuntos(jugador) >= maxpuntos Then Color 14: Print Chr(10) + "Gana el jugador"; jugador; " con"; almacenpuntos(jugador); " puntos." Sleep: End End If Exit While End If Wend Next jugador Loop  
http://rosettacode.org/wiki/Pernicious_numbers
Pernicious numbers
A   pernicious number   is a positive integer whose   population count   is a prime. The   population count   is the number of   ones   in the binary representation of a non-negative integer. Example 22   (which is   10110   in binary)   has a population count of   3,   which is prime,   and therefore 22   is a pernicious number. Task display the first   25   pernicious numbers   (in decimal). display all pernicious numbers between   888,888,877   and   888,888,888   (inclusive). display each list of integers on one line   (which may or may not include a title). See also Sequence   A052294 pernicious numbers on The On-Line Encyclopedia of Integer Sequences. Rosetta Code entry   population count, evil numbers, odious numbers.
#C
C
#include <stdio.h>   typedef unsigned uint; uint is_pern(uint n) { uint c = 2693408940u; // int with all prime-th bits set while (n) c >>= 1, n &= (n - 1); // take out lowerest set bit one by one return c & 1; }   int main(void) { uint i, c; for (i = c = 0; c < 25; i++) if (is_pern(i)) printf("%u ", i), ++c; putchar('\n');   for (i = 888888877u; i <= 888888888u; i++) if (is_pern(i)) printf("%u ", i); putchar('\n');   return 0; }
http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation
Permutations/Rank of a permutation
A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items. For our purposes the ranking will assign integers 0.. ( n ! − 1 ) {\displaystyle 0..(n!-1)} to an ordering of all the permutations of the integers 0.. ( n − 1 ) {\displaystyle 0..(n-1)} . For example, the permutations of the digits zero to 3 arranged lexicographically have the following rank: PERMUTATION RANK (0, 1, 2, 3) -> 0 (0, 1, 3, 2) -> 1 (0, 2, 1, 3) -> 2 (0, 2, 3, 1) -> 3 (0, 3, 1, 2) -> 4 (0, 3, 2, 1) -> 5 (1, 0, 2, 3) -> 6 (1, 0, 3, 2) -> 7 (1, 2, 0, 3) -> 8 (1, 2, 3, 0) -> 9 (1, 3, 0, 2) -> 10 (1, 3, 2, 0) -> 11 (2, 0, 1, 3) -> 12 (2, 0, 3, 1) -> 13 (2, 1, 0, 3) -> 14 (2, 1, 3, 0) -> 15 (2, 3, 0, 1) -> 16 (2, 3, 1, 0) -> 17 (3, 0, 1, 2) -> 18 (3, 0, 2, 1) -> 19 (3, 1, 0, 2) -> 20 (3, 1, 2, 0) -> 21 (3, 2, 0, 1) -> 22 (3, 2, 1, 0) -> 23 Algorithms exist that can generate a rank from a permutation for some particular ordering of permutations, and that can generate the same rank from the given individual permutation (i.e. given a rank of 17 produce (2, 3, 1, 0) in the example above). One use of such algorithms could be in generating a small, random, sample of permutations of n {\displaystyle n} items without duplicates when the total number of permutations is large. Remember that the total number of permutations of n {\displaystyle n} items is given by n ! {\displaystyle n!} which grows large very quickly: A 32 bit integer can only hold 12 ! {\displaystyle 12!} , a 64 bit integer only 20 ! {\displaystyle 20!} . It becomes difficult to take the straight-forward approach of generating all permutations then taking a random sample of them. A question on the Stack Overflow site asked how to generate one million random and indivudual permutations of 144 items. Task Create a function to generate a permutation from a rank. Create the inverse function that given the permutation generates its rank. Show that for n = 3 {\displaystyle n=3} the two functions are indeed inverses of each other. Compute and show here 4 random, individual, samples of permutations of 12 objects. Stretch goal State how reasonable it would be to use your program to address the limits of the Stack Overflow question. References Ranking and Unranking Permutations in Linear Time by Myrvold & Ruskey. (Also available via Google here). Ranks on the DevData site. Another answer on Stack Overflow to a different question that explains its algorithm in detail. Related tasks Factorial_base_numbers_indexing_permutations_of_a_collection
#Nim
Nim
func mrUnrank1(vec: var openArray[int]; rank, n: int) = if n < 1: return let q = rank div n let r = rank mod n swap vec[r], vec[n - 1] vec.mrUnrank1(q, n - 1)   func mrRank1(vec, inv: var openArray[int]; n: int): int = if n < 2: return 0 let s = vec[n - 1] swap vec[n - 1], vec[inv[n - 1]] swap inv[s], inv[n - 1] result = s + n * vec.mrRank1(inv, n - 1)   func getPermutation(vec: var openArray[int]; rank: int) = for i in 0..vec.high: vec[i] = i vec.mrUnrank1(rank, vec.len)   func getRank(vec: openArray[int]): int = var v, inv = newSeq[int](vec.len) for i, val in vec: v[i] = val inv[val] = i result = v.mrRank1(inv, vec.len)     when isMainModule:   import math, random, sequtils, strformat   randomize()   var tv3: array[3, int] for r in 0..5: tv3.getPermutation(r) echo &"{r:>2} → {tv3} → {tv3.getRank()}"   echo "" var tv4: array[4, int] for r in 0..23: tv4.getPermutation(r) echo &"{r:>2} → {tv4} → {tv4.getRank()}"   echo "" var tv12: array[12, int] for r in newSeqWith(4, rand(fac(12))): tv12.getPermutation(r) echo &"{r:>9} → {tv12} → {tv12.getRank()}"
http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation
Permutations/Rank of a permutation
A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items. For our purposes the ranking will assign integers 0.. ( n ! − 1 ) {\displaystyle 0..(n!-1)} to an ordering of all the permutations of the integers 0.. ( n − 1 ) {\displaystyle 0..(n-1)} . For example, the permutations of the digits zero to 3 arranged lexicographically have the following rank: PERMUTATION RANK (0, 1, 2, 3) -> 0 (0, 1, 3, 2) -> 1 (0, 2, 1, 3) -> 2 (0, 2, 3, 1) -> 3 (0, 3, 1, 2) -> 4 (0, 3, 2, 1) -> 5 (1, 0, 2, 3) -> 6 (1, 0, 3, 2) -> 7 (1, 2, 0, 3) -> 8 (1, 2, 3, 0) -> 9 (1, 3, 0, 2) -> 10 (1, 3, 2, 0) -> 11 (2, 0, 1, 3) -> 12 (2, 0, 3, 1) -> 13 (2, 1, 0, 3) -> 14 (2, 1, 3, 0) -> 15 (2, 3, 0, 1) -> 16 (2, 3, 1, 0) -> 17 (3, 0, 1, 2) -> 18 (3, 0, 2, 1) -> 19 (3, 1, 0, 2) -> 20 (3, 1, 2, 0) -> 21 (3, 2, 0, 1) -> 22 (3, 2, 1, 0) -> 23 Algorithms exist that can generate a rank from a permutation for some particular ordering of permutations, and that can generate the same rank from the given individual permutation (i.e. given a rank of 17 produce (2, 3, 1, 0) in the example above). One use of such algorithms could be in generating a small, random, sample of permutations of n {\displaystyle n} items without duplicates when the total number of permutations is large. Remember that the total number of permutations of n {\displaystyle n} items is given by n ! {\displaystyle n!} which grows large very quickly: A 32 bit integer can only hold 12 ! {\displaystyle 12!} , a 64 bit integer only 20 ! {\displaystyle 20!} . It becomes difficult to take the straight-forward approach of generating all permutations then taking a random sample of them. A question on the Stack Overflow site asked how to generate one million random and indivudual permutations of 144 items. Task Create a function to generate a permutation from a rank. Create the inverse function that given the permutation generates its rank. Show that for n = 3 {\displaystyle n=3} the two functions are indeed inverses of each other. Compute and show here 4 random, individual, samples of permutations of 12 objects. Stretch goal State how reasonable it would be to use your program to address the limits of the Stack Overflow question. References Ranking and Unranking Permutations in Linear Time by Myrvold & Ruskey. (Also available via Google here). Ranks on the DevData site. Another answer on Stack Overflow to a different question that explains its algorithm in detail. Related tasks Factorial_base_numbers_indexing_permutations_of_a_collection
#PARI.2FGP
PARI/GP
vector(3!,i,permtonum(numtoperm(3,i-1)))==vector(3!,i,i-1) vector(4,i,numtoperm(12,random(12!))) for(i=1,1e6,numtoperm(144,random(144!)))
http://rosettacode.org/wiki/Pierpont_primes
Pierpont primes
A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v . A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v . The term "Pierpont primes" is generally understood to mean the first definition, but will be called "Pierpont primes of the first kind" on this page to distinguish them. Task Write a routine (function, procedure, whatever) to find Pierpont primes of the first & second kinds. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the first kind. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the second kind If your language supports large integers, find and display here, on this page, the 250th Pierpont prime of the first kind and the 250th Pierpont prime of the second kind. See also Wikipedia - Pierpont primes OEIS:A005109 - Class 1 -, or Pierpont primes OEIS:A005105 - Class 1 +, or Pierpont primes of the second kind
#Julia
Julia
using Primes   function pierponts(N, firstkind = true) ret, incdec = BigInt[], firstkind ? 1 : -1 for k2 in 0:10000, k3 in 0:k2, switch in false:true i, j = switch ? (k3, k2) : (k2, k3) n = BigInt(2)^i * BigInt(3)^j + incdec if isprime(n) && !(n in ret) push!(ret, n) if length(ret) == N * 2 return sort(ret)[1:N] end end end throw("Failed to find $(N * 2) primes") end   println("The first 50 Pierpont primes (first kind) are: ", pierponts(50))   println("\nThe first 50 Pierpont primes (second kind) are: ", pierponts(50, false))   println("\nThe 250th Pierpont prime (first kind) is: ", pierponts(250)[250])   println("\nThe 250th Pierpont prime (second kind) is: ", pierponts(250, false)[250])   println("\nThe 1000th Pierpont prime (first kind) is: ", pierponts(1000)[1000])   println("\nThe 1000th Pierpont prime (second kind) is: ", pierponts(1000, false)[1000])   println("\nThe 2000th Pierpont prime (first kind) is: ", pierponts(2000)[2000])   println("\nThe 2000th Pierpont prime (second kind) is: ", pierponts(2000, false)[2000])  
http://rosettacode.org/wiki/Pierpont_primes
Pierpont primes
A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v . A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v . The term "Pierpont primes" is generally understood to mean the first definition, but will be called "Pierpont primes of the first kind" on this page to distinguish them. Task Write a routine (function, procedure, whatever) to find Pierpont primes of the first & second kinds. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the first kind. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the second kind If your language supports large integers, find and display here, on this page, the 250th Pierpont prime of the first kind and the 250th Pierpont prime of the second kind. See also Wikipedia - Pierpont primes OEIS:A005109 - Class 1 -, or Pierpont primes OEIS:A005105 - Class 1 +, or Pierpont primes of the second kind
#Kotlin
Kotlin
import java.math.BigInteger import kotlin.math.min   val one: BigInteger = BigInteger.ONE val two: BigInteger = BigInteger.valueOf(2) val three: BigInteger = BigInteger.valueOf(3)   fun pierpont(n: Int): List<List<BigInteger>> { val p = List(2) { MutableList(n) { BigInteger.ZERO } } p[0][0] = two var count = 0 var count1 = 1 var count2 = 0 val s = mutableListOf<BigInteger>() s.add(one) var i2 = 0 var i3 = 0 var k = 1 var n2: BigInteger var n3: BigInteger var t: BigInteger while (count < n) { n2 = s[i2] * two n3 = s[i3] * three if (n2 < n3) { t = n2 i2++ } else { t = n3 i3++ } if (t > s[k - 1]) { s.add(t) k++ t += one if (count1 < n && t.isProbablePrime(10)) { p[0][count1] = t count1++ } t -= two if (count2 < n && t.isProbablePrime(10)) { p[1][count2] = t count2++ } count = min(count1, count2) } } return p }   fun main() { val p = pierpont(2000)   println("First 50 Pierpont primes of the first kind:") for (i in 0 until 50) { print("%8d ".format(p[0][i])) if ((i - 9) % 10 == 0) { println() } }   println("\nFirst 50 Pierpont primes of the second kind:") for (i in 0 until 50) { print("%8d ".format(p[1][i])) if ((i - 9) % 10 == 0) { println() } }   println("\n250th Pierpont prime of the first kind: ${p[0][249]}") println("\n250th Pierpont prime of the first kind: ${p[1][249]}")   println("\n1000th Pierpont prime of the first kind: ${p[0][999]}") println("\n1000th Pierpont prime of the first kind: ${p[1][999]}")   println("\n2000th Pierpont prime of the first kind: ${p[0][1999]}") println("\n2000th Pierpont prime of the first kind: ${p[1][1999]}") }
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#Delphi
Delphi
!print choose [ "one" "two" "chicken" ]
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#D.C3.A9j.C3.A0_Vu
Déjà Vu
!print choose [ "one" "two" "chicken" ]
http://rosettacode.org/wiki/Primality_by_trial_division
Primality by trial division
Task Write a boolean function that tells whether a given integer is prime. Remember that   1   and all non-positive numbers are not prime. Use trial division. Even numbers greater than   2   may be eliminated right away. A loop from   3   to   √ n    will suffice,   but other loops are allowed. Related tasks   count in factors   prime decomposition   AKS test for primes   factors of an integer   Sieve of Eratosthenes   factors of a Mersenne number   trial factoring of a Mersenne number   partition an integer X into N primes   sequence of primes by Trial Division
#Tcl
Tcl
proc is_prime n { if {$n <= 1} {return false} if {$n == 2} {return true} if {$n % 2 == 0} {return false} for {set i 3} {$i <= sqrt($n)} {incr i 2} { if {$n % $i == 0} {return false} } return true }
http://rosettacode.org/wiki/Phrase_reversals
Phrase reversals
Task Given a string of space separated words containing the following phrase: rosetta code phrase reversal Reverse the characters of the string. Reverse the characters of each individual word in the string, maintaining original word order within the string. Reverse the order of each word of the string, maintaining the order of characters in each word. Show your output here. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#Common_Lisp
Common Lisp
  (defun split-string (str) "Split a string into space separated words including spaces" (do* ((lst nil) (i (position-if #'alphanumericp str) (position-if #'alphanumericp str :start j)) (j (when i (position #\Space str :start i)) (when i (position #\Space str :start i))) ) ((null j) (nreverse (push (subseq str i nil) lst))) (push (subseq str i j) lst) (push " " lst) ))     (defun task (str) (print (reverse str)) (let ((lst (split-string str))) (print (apply #'concatenate 'string (mapcar #'reverse lst))) (print (apply #'concatenate 'string (reverse lst))) ) nil )    
http://rosettacode.org/wiki/Permutations/Derangements
Permutations/Derangements
A derangement is a permutation of the order of distinct items in which no item appears in its original place. For example, the only two derangements of the three items (0, 1, 2) are (1, 2, 0), and (2, 0, 1). The number of derangements of n distinct items is known as the subfactorial of n, sometimes written as !n. There are various ways to calculate !n. Task Create a named function/method/subroutine/... to generate derangements of the integers 0..n-1, (or 1..n if you prefer). Generate and show all the derangements of 4 integers using the above routine. Create a function that calculates the subfactorial of n, !n. Print and show a table of the counted number of derangements of n vs. the calculated !n for n from 0..9 inclusive. Optional stretch goal   Calculate    !20 Related tasks   Anagrams/Deranged anagrams   Best shuffle   Left_factorials Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#AutoHotkey
AutoHotkey
#NoEnv SetBatchLines -1 Process, Priority,, high   output := "Derangements for 1, 2, 3, 4:`n"   obj := [1, 2, 3, 4], objS := obj.Clone() Loop ; permute 4 { obj := perm_NextObj(Obj) If !obj break For k, v in obj if ( objS[k] = v ) continue 2 output .= ObjDisp(obj) "`n" } output .= "`nTable of n, counted, calculated derangements:`n"   Loop 10 ; Count !n { obj := [] count := 0 output .= A_Tab . (i := A_Index-1) . A_Tab Loop % i obj[A_Index] := A_Index objS := obj.Clone() Loop { obj := perm_NextObj(Obj) If !obj break For k, v in obj if ( objS[k] = v ) continue 2 count++ } output .= count . A_Tab . cd(i) . "`n" } output .= "`nApproximation of !20: " . cd(20) MsgBox % Clipboard := output   perm_NextObj(obj){ ; next lexicographic permutation p := 0, objM := ObjMaxIndex(obj) Loop % objM { If A_Index=1 continue t := obj[objM+1-A_Index] n := obj[objM+2-A_Index] If ( t < n ) { p := objM+1-A_Index, pC := obj[p] break } } If !p return false Loop { t := obj[objM+1-A_Index] If ( t > pC ) { n := objM+1-A_Index, nC := obj[n] break } }   obj[n] := pC, obj[p] := nC return ObjReverse(obj, objM-p) }   ObjReverse(Obj, tail){ o := ObjClone(Obj), ObjM := ObjMaxIndex(O) Loop % tail o[ObjM-A_Index+1] := Obj[ObjM+A_Index-tail] return o }   ObjDisp(obj){ For k, v in obj s .= v ", " return SubStr(s, 1, strLen(s)-2) }     cd(n){ ; Count Derangements static e := 2.71828182845904523536028747135 return n ? floor(ft(n)/e + 1/2) : 1 } ft(n){ ; FacTorial a := 1 Loop % n a *= A_Index return a }
http://rosettacode.org/wiki/Permutations_by_swapping
Permutations by swapping
Task Generate permutations of n items in which successive permutations differ from each other by the swapping of any two items. Also generate the sign of the permutation which is +1 when the permutation is generated from an even number of swaps from the initial state, and -1 for odd. Show the permutations and signs of three items, in order of generation here. Such data are of use in generating the determinant of a square matrix and any functions created should bear this in mind. Note: The Steinhaus–Johnson–Trotter algorithm generates successive permutations where adjacent items are swapped, but from this discussion adjacency is not a requirement. References Steinhaus–Johnson–Trotter algorithm Johnson-Trotter Algorithm Listing All Permutations Heap's algorithm [1] Tintinnalogia Related tasks   Matrix arithmetic   Gray code
#BASIC
BASIC
call perms(3) print call perms(4) end   subroutine perms(n) dim p((n+1)*4) for i = 1 to n p[i] = -i next i s = 1   do print "Perm: [ "; for i = 1 to n print abs(p[i]); " "; next i print "] Sign: "; s   k = 0 for i = 2 to n if p[i] < 0 and (abs(p[i]) > abs(p[i-1])) and (abs(p[i]) > abs(p[k])) then k = i next i for i = 1 to n-1 if p[i] > 0 and (abs(p[i]) > abs(p[i+1])) and (abs(p[i]) > abs(p[k])) then k = i next i if k then for i = 1 to n #reverse elements > k if abs(p[i]) > abs(p[k]) then p[i] = -p[i] next i if p[k] < 0 then i = k-1 else i = k+1 temp = p[k] p[k] = p[i] p[i] = temp s = -s end if until k = 0 end subroutine
http://rosettacode.org/wiki/Permutations_by_swapping
Permutations by swapping
Task Generate permutations of n items in which successive permutations differ from each other by the swapping of any two items. Also generate the sign of the permutation which is +1 when the permutation is generated from an even number of swaps from the initial state, and -1 for odd. Show the permutations and signs of three items, in order of generation here. Such data are of use in generating the determinant of a square matrix and any functions created should bear this in mind. Note: The Steinhaus–Johnson–Trotter algorithm generates successive permutations where adjacent items are swapped, but from this discussion adjacency is not a requirement. References Steinhaus–Johnson–Trotter algorithm Johnson-Trotter Algorithm Listing All Permutations Heap's algorithm [1] Tintinnalogia Related tasks   Matrix arithmetic   Gray code
#BBC_BASIC
BBC BASIC
PROCperms(3) PRINT PROCperms(4) END   DEF PROCperms(n%) LOCAL p%(), i%, k%, s% DIM p%(n%) FOR i% = 1 TO n% p%(i%) = -i% NEXT s% = 1 REPEAT PRINT "Perm: [ "; FOR i% = 1 TO n% PRINT ;ABSp%(i%) " "; NEXT PRINT "] Sign: ";s% k% = 0 FOR i% = 2 TO n% IF p%(i%)<0 IF ABSp%(i%)>ABSp%(i%-1) IF ABSp%(i%)>ABSp%(k%) k% = i% NEXT FOR i% = 1 TO n%-1 IF p%(i%)>0 IF ABSp%(i%)>ABSp%(i%+1) IF ABSp%(i%)>ABSp%(k%) k% = i% NEXT IF k% THEN FOR i% = 1 TO n% IF ABSp%(i%)>ABSp%(k%) p%(i%) *= -1 NEXT i% = k%+SGNp%(k%) SWAP p%(k%),p%(i%) s% = -s% ENDIF UNTIL k% = 0 ENDPROC
http://rosettacode.org/wiki/Permutation_test
Permutation test
Permutation test You are encouraged to solve this task according to the task description, using any language you may know. A new medical treatment was tested on a population of n + m {\displaystyle n+m} volunteers, with each volunteer randomly assigned either to a group of n {\displaystyle n} treatment subjects, or to a group of m {\displaystyle m} control subjects. Members of the treatment group were given the treatment, and members of the control group were given a placebo. The effect of the treatment or placebo on each volunteer was measured and reported in this table. Table of experimental results Treatment group Control group 85 68 88 41 75 10 66 49 25 16 29 65 83 32 39 92 97 28 98 Write a program that performs a permutation test to judge whether the treatment had a significantly stronger effect than the placebo. Do this by considering every possible alternative assignment from the same pool of volunteers to a treatment group of size n {\displaystyle n} and a control group of size m {\displaystyle m} (i.e., the same group sizes used in the actual experiment but with the group members chosen differently), while assuming that each volunteer's effect remains constant regardless. Note that the number of alternatives will be the binomial coefficient ( n + m n ) {\displaystyle {\tbinom {n+m}{n}}} . Compute the mean effect for each group and the difference in means between the groups in every case by subtracting the mean of the control group from the mean of the treatment group. Report the percentage of alternative groupings for which the difference in means is less or equal to the actual experimentally observed difference in means, and the percentage for which it is greater. Note that they should sum to 100%. Extremely dissimilar values are evidence of an effect not entirely due to chance, but your program need not draw any conclusions. You may assume the experimental data are known at compile time if that's easier than loading them at run time. Test your solution on the data given above.
#C.23
C#
using System; using System.Collections.Generic;   namespace PermutationTest { class Program { static readonly List<int> DATA = new List<int>{ 85, 88, 75, 66, 25, 29, 83, 39, 97, 68, 41, 10, 49, 16, 65, 32, 92, 28, 98 };   static int Pick(int at, int remain, int accu, int treat) { if (remain == 0) { return (accu > treat) ? 1 : 0; } return Pick(at - 1, remain - 1, accu + DATA[at - 1], treat) + ((at > remain) ? Pick(at - 1, remain, accu, treat) : 0); }   static void Main() { int treat = 0; double total = 1.0; for (int i = 0; i <= 8; i++) { treat += DATA[i]; } for (int i = 19; i >= 11; i--) { total *= i; } for (int i = 9; i >= 1; --i) { total /= i; } int gt = Pick(19, 9, 0, treat); int le = (int) (total - gt); Console.WriteLine("<= {0}% {1}", 100.0 * le / total, le); Console.WriteLine(" > {0}% {1}", 100.0 * gt / total, gt); } } }
http://rosettacode.org/wiki/Permutation_test
Permutation test
Permutation test You are encouraged to solve this task according to the task description, using any language you may know. A new medical treatment was tested on a population of n + m {\displaystyle n+m} volunteers, with each volunteer randomly assigned either to a group of n {\displaystyle n} treatment subjects, or to a group of m {\displaystyle m} control subjects. Members of the treatment group were given the treatment, and members of the control group were given a placebo. The effect of the treatment or placebo on each volunteer was measured and reported in this table. Table of experimental results Treatment group Control group 85 68 88 41 75 10 66 49 25 16 29 65 83 32 39 92 97 28 98 Write a program that performs a permutation test to judge whether the treatment had a significantly stronger effect than the placebo. Do this by considering every possible alternative assignment from the same pool of volunteers to a treatment group of size n {\displaystyle n} and a control group of size m {\displaystyle m} (i.e., the same group sizes used in the actual experiment but with the group members chosen differently), while assuming that each volunteer's effect remains constant regardless. Note that the number of alternatives will be the binomial coefficient ( n + m n ) {\displaystyle {\tbinom {n+m}{n}}} . Compute the mean effect for each group and the difference in means between the groups in every case by subtracting the mean of the control group from the mean of the treatment group. Report the percentage of alternative groupings for which the difference in means is less or equal to the actual experimentally observed difference in means, and the percentage for which it is greater. Note that they should sum to 100%. Extremely dissimilar values are evidence of an effect not entirely due to chance, but your program need not draw any conclusions. You may assume the experimental data are known at compile time if that's easier than loading them at run time. Test your solution on the data given above.
#C.2B.2B
C++
#include<iostream> #include<vector> #include<numeric> #include<functional>   class { public: int64_t operator()(int n, int k){ return partial_factorial(n, k) / factorial(n - k);} private: int64_t partial_factorial(int from, int to) { return from == to ? 1 : from * partial_factorial(from - 1, to); } int64_t factorial(int n) { return n == 0 ? 1 : n * factorial(n - 1);} }combinations;   int main() { static constexpr int treatment = 9; const std::vector<int> data{ 85, 88, 75, 66, 25, 29, 83, 39, 97, 68, 41, 10, 49, 16, 65, 32, 92, 28, 98 };   int treated = std::accumulate(data.begin(), data.begin() + treatment, 0);   std::function<int (int, int, int)> pick; pick = [&](int n, int from, int accumulated) { if(n == 0) return accumulated > treated ? 1 : 0; else return pick(n - 1, from - 1, accumulated + data[from - 1]) + (from > n ? pick(n, from - 1, accumulated) : 0); };   int total = combinations(data.size(), treatment); int greater = pick(treatment, data.size(), 0); int lesser = total - greater;   std::cout << "<= : " << 100.0 * lesser / total << "% " << lesser << std::endl << " > : " << 100.0 * greater / total << "% " << greater << std::endl; }
http://rosettacode.org/wiki/Perfect_totient_numbers
Perfect totient numbers
Generate and show here, the first twenty Perfect totient numbers. Related task   Totient function Also see   the OEIS entry for   perfect totient numbers.   mrob   list of the first 54
#11l
11l
F φ(n) R sum((1..n).filter(k -> gcd(@n, k) == 1).map(k -> 1))   F perfect_totient(cnt) [Int] r   L(n0) 1.. V parts = 0 V n = n0 L n != 1 n = φ(n) parts += n I parts == n0 r [+]= n0 I r.len == cnt R r   print(perfect_totient(20))
http://rosettacode.org/wiki/Playing_cards
Playing cards
Task Create a data structure and the associated methods to define and manipulate a deck of   playing cards. The deck should contain 52 unique cards. The methods must include the ability to:   make a new deck   shuffle (randomize) the deck   deal from the deck   print the current contents of a deck Each card must have a pip value and a suit value which constitute the unique value of the card. Related tasks: Card shuffles Deal cards_for_FreeCell War Card_Game Poker hand_analyser Go Fish
#Clojure
Clojure
(def suits [:club :diamond :heart :spade]) (def pips [:ace 2 3 4 5 6 7 8 9 10 :jack :queen :king])   (defn deck [] (for [s suits p pips] [s p]))   (def shuffle clojure.core/shuffle) (def deal first) (defn output [deck] (doseq [[suit pip] deck] (println (format "%s of %ss" (if (keyword? pip) (name pip) pip) (name suit)))))
http://rosettacode.org/wiki/Pi
Pi
Create a program to continually calculate and output the next decimal digit of   π {\displaystyle \pi }   (pi). The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession. The output should be a decimal sequence beginning   3.14159265 ... Note: this task is about   calculating   pi.   For information on built-in pi constants see Real constants and functions. Related Task Arithmetic-geometric mean/Calculate Pi
#Bracmat
Bracmat
( pi = f,q r t k n l,first .  !arg:((=?f),?q,?r,?t,?k,?n,?l) & yes:?first & whl ' ( 4*!q+!r+-1*!t+-1*!n*!t:<0 & f$!n & (  !first:yes & f$"." & no:?first | ) & "compute and update variables for next cycle" & 10*(!r+-1*!n*!t):?nr & div$(10*(3*!q+!r).!t)+-10*!n:?n & !q*10:?q & !nr:?r | "compute and update variables for next cycle" & (2*!q+!r)*!l:?nr & div$(!q*(7*!k+2)+!r*!l.!t*!l):?nn & !q*!k:?q & !t*!l:?t & !l+2:?l & !k+1:?k & !nn:?n & !nr:?r ) ) & pi$((=.put$!arg),1,0,1,1,3,3)
http://rosettacode.org/wiki/Periodic_table
Periodic table
Task Display the row and column in the periodic table of the given atomic number. The periodic table Let us consider the following periodic table representation. __________________________________________________________________________ | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | | | |1 H He | | | |2 Li Be B C N O F Ne | | | |3 Na Mg Al Si P S Cl Ar | | | |4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr | | | |5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe | | | |6 Cs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn | | | |7 Fr Ra ° Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og | |__________________________________________________________________________| | | | | |8 Lantanoidi* La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu | | | |9 Aktinoidi° Ak Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr | |__________________________________________________________________________| Example test cases;   1 -> 1 1   2 -> 1 18   29 -> 4 11   42 -> 5 6   57 -> 8 4   58 -> 8 5   72 -> 6 4   89 -> 9 4 Details; The representation of the periodic table may be represented in various way. The one presented in this challenge does have the following property : Lantanides and Aktinoides are all in a dedicated row, hence there is no element that is placed at 6, 3 nor 7, 3. You may take a look at the atomic number repartitions here. The atomic number is at least 1, at most 118. See also   the periodic table   This task was an idea from CompSciFact   The periodic table in ascii that was used as template
#Applesoft_BASIC
Applesoft BASIC
0 GR:HOME:COLOR=11:FORR=1TO7:FORC=1TO2:GOSUB7:NEXTC,R:COLOR=7:FORR=4TO7:FORC=3+(R>5)TO12:GOSUB7:NEXTC,R:COLOR=13:FORR=2TO7:FORC=13TO18:GOSUB7:NEXTC,R 1 forr=2to7:forc=13to18:GOSUB7:NEXTC,R:COLOR=14:R=8:FORC=4TO18:GOSUB7:NEXTC:COLOR=12:R=9:FORC=4TO18:GOSUB7:NEXTC:R=9:FORC=4TO18:GOSUB7:NEXTC:Z=2:R=7:C=3:GOSUB7:COLOR=14:R=6:C=3:GOSUB7:COLOR=15 2 S=14:W=18:FORI=1TO7:READN(I),I(I):NEXT:DATA2,0,10,0,18,0,36,0,54,0,86,57,118,89,1,1,1,2,1,18,29,4,11,42,5,6,57,8,4,58,8,5,72,6,4,89,9,4,59,8,6,71,8,18,90,9,5,103,9,18 3 FORT=1TO8:READA,Y,X:GOSUB4:PRINTRIGHT$(" "+STR$(A),3)"->"R" "LEFT$(STR$(C)+" ",3);:GOSUB7:NEXTT:VTAB23:END 4 N=0:FORR=1TO7:P=N:N=N(R):IFA>NTHEN:NEXTR 5 E=N-P:K=A-P:IFI(R)AND(I(R)<=AANDA<=I(R)+S)THENR=R+2:C=K+1:RETURN 6 E=W-E:L=1+(N>2):C=K+E*(K>L):RETURN 7 K=C+(R=1ANDC=2)*16:VLINR*4+Z,R*4+2ATK*2+1:RETURN
http://rosettacode.org/wiki/Pig_the_dice_game
Pig the dice game
The   game of Pig   is a multiplayer game played with a single six-sided die.   The object of the game is to reach   100   points or more.   Play is taken in turns.   On each person's turn that person has the option of either: Rolling the dice:   where a roll of two to six is added to their score for that turn and the player's turn continues as the player is given the same choice again;   or a roll of   1   loses the player's total points   for that turn   and their turn finishes with play passing to the next player. Holding:   the player's score for that round is added to their total and becomes safe from the effects of throwing a   1   (one).   The player's turn finishes with play passing to the next player. Task Create a program to score for, and simulate dice throws for, a two-person game. Related task   Pig the dice game/Player
#Go
Go
package main   import ( "fmt" "math/rand" "strings" "time" )   func main() { rand.Seed(time.Now().UnixNano()) //Set seed to current time   playerScores := [...]int{0, 0} turn := 0 currentScore := 0   for { player := turn % len(playerScores)   fmt.Printf("Player %v [%v, %v], (H)old, (R)oll or (Q)uit: ", player, playerScores[player], currentScore)   var answer string fmt.Scanf("%v", &answer) switch strings.ToLower(answer) { case "h": //Hold playerScores[player] += currentScore fmt.Printf(" Player %v now has a score of %v.\n\n", player, playerScores[player])   if playerScores[player] >= 100 { fmt.Printf(" Player %v wins!!!\n", player) return }   currentScore = 0 turn += 1 case "r": //Roll roll := rand.Intn(6) + 1   if roll == 1 { fmt.Printf(" Rolled a 1. Bust!\n\n") currentScore = 0 turn += 1 } else { fmt.Printf(" Rolled a %v.\n", roll) currentScore += roll } case "q": //Quit return default: //Incorrent input fmt.Print(" Please enter one of the given inputs.\n") } } fmt.Printf("Player %v wins!!!\n", (turn-1)%len(playerScores)) }
http://rosettacode.org/wiki/Pernicious_numbers
Pernicious numbers
A   pernicious number   is a positive integer whose   population count   is a prime. The   population count   is the number of   ones   in the binary representation of a non-negative integer. Example 22   (which is   10110   in binary)   has a population count of   3,   which is prime,   and therefore 22   is a pernicious number. Task display the first   25   pernicious numbers   (in decimal). display all pernicious numbers between   888,888,877   and   888,888,888   (inclusive). display each list of integers on one line   (which may or may not include a title). See also Sequence   A052294 pernicious numbers on The On-Line Encyclopedia of Integer Sequences. Rosetta Code entry   population count, evil numbers, odious numbers.
#C.23
C#
using System; using System.Linq;   namespace PerniciousNumbers { class Program { public static int PopulationCount(long n) { int cnt = 0; do { if ((n & 1) != 0) { cnt++; } } while ((n >>= 1) > 0);   return cnt; }   public static bool isPrime(int x) { if (x <= 2 || (x & 1) == 0) { return x == 2; }   var limit = Math.Sqrt(x); for (int i = 3; i <= limit; i += 2) { if (x % i == 0) { return false; } }   return true; }   private static IEnumerable<int> Pernicious(int start, int count, int take) { return Enumerable.Range(start, count).Where(n => isPrime(PopulationCount(n))).Take(take); }   static void Main(string[] args) { foreach (var n in Pernicious(0, int.MaxValue, 25)) { Console.Write("{0} ", n); }   Console.WriteLine();   foreach (var n in Pernicious(888888877, 11, 11)) { Console.Write("{0} ", n); }   Console.ReadKey(); } } }
http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation
Permutations/Rank of a permutation
A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items. For our purposes the ranking will assign integers 0.. ( n ! − 1 ) {\displaystyle 0..(n!-1)} to an ordering of all the permutations of the integers 0.. ( n − 1 ) {\displaystyle 0..(n-1)} . For example, the permutations of the digits zero to 3 arranged lexicographically have the following rank: PERMUTATION RANK (0, 1, 2, 3) -> 0 (0, 1, 3, 2) -> 1 (0, 2, 1, 3) -> 2 (0, 2, 3, 1) -> 3 (0, 3, 1, 2) -> 4 (0, 3, 2, 1) -> 5 (1, 0, 2, 3) -> 6 (1, 0, 3, 2) -> 7 (1, 2, 0, 3) -> 8 (1, 2, 3, 0) -> 9 (1, 3, 0, 2) -> 10 (1, 3, 2, 0) -> 11 (2, 0, 1, 3) -> 12 (2, 0, 3, 1) -> 13 (2, 1, 0, 3) -> 14 (2, 1, 3, 0) -> 15 (2, 3, 0, 1) -> 16 (2, 3, 1, 0) -> 17 (3, 0, 1, 2) -> 18 (3, 0, 2, 1) -> 19 (3, 1, 0, 2) -> 20 (3, 1, 2, 0) -> 21 (3, 2, 0, 1) -> 22 (3, 2, 1, 0) -> 23 Algorithms exist that can generate a rank from a permutation for some particular ordering of permutations, and that can generate the same rank from the given individual permutation (i.e. given a rank of 17 produce (2, 3, 1, 0) in the example above). One use of such algorithms could be in generating a small, random, sample of permutations of n {\displaystyle n} items without duplicates when the total number of permutations is large. Remember that the total number of permutations of n {\displaystyle n} items is given by n ! {\displaystyle n!} which grows large very quickly: A 32 bit integer can only hold 12 ! {\displaystyle 12!} , a 64 bit integer only 20 ! {\displaystyle 20!} . It becomes difficult to take the straight-forward approach of generating all permutations then taking a random sample of them. A question on the Stack Overflow site asked how to generate one million random and indivudual permutations of 144 items. Task Create a function to generate a permutation from a rank. Create the inverse function that given the permutation generates its rank. Show that for n = 3 {\displaystyle n=3} the two functions are indeed inverses of each other. Compute and show here 4 random, individual, samples of permutations of 12 objects. Stretch goal State how reasonable it would be to use your program to address the limits of the Stack Overflow question. References Ranking and Unranking Permutations in Linear Time by Myrvold & Ruskey. (Also available via Google here). Ranks on the DevData site. Another answer on Stack Overflow to a different question that explains its algorithm in detail. Related tasks Factorial_base_numbers_indexing_permutations_of_a_collection
#Perl
Perl
use ntheory qw/:all/;   my $n = 3; print " Iterate Lexicographic rank/unrank of $n objects\n"; for my $k (0 .. factorial($n)-1) { my @perm = numtoperm($n, $k); my $rank = permtonum(\@perm); die unless $rank == $k; printf "%2d --> [@perm] --> %2d\n", $k, $rank; } print "\n";   print " Four 12-object random permutations using ranks\n"; print join(" ", numtoperm(12,urandomm(factorial(12)))), "\n" for 1..4; print "\n"; print " Four 12-object random permutations using randperm\n"; print join(" ", randperm(12)),"\n" for 1..4; print "\n"; print " Four 4-object random permutations of 100k objects using randperm\n"; print join(" ", randperm(100000,4)),"\n" for 1..4;  
http://rosettacode.org/wiki/Pierpont_primes
Pierpont primes
A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v . A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v . The term "Pierpont primes" is generally understood to mean the first definition, but will be called "Pierpont primes of the first kind" on this page to distinguish them. Task Write a routine (function, procedure, whatever) to find Pierpont primes of the first & second kinds. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the first kind. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the second kind If your language supports large integers, find and display here, on this page, the 250th Pierpont prime of the first kind and the 250th Pierpont prime of the second kind. See also Wikipedia - Pierpont primes OEIS:A005109 - Class 1 -, or Pierpont primes OEIS:A005105 - Class 1 +, or Pierpont primes of the second kind
#Lua
Lua
local function isprime(n) if n < 2 then return false end if n % 2 == 0 then return n==2 end if n % 3 == 0 then return n==3 end local f, limit = 5, math.sqrt(n) for f = 5, limit, 6 do if n % f == 0 then return false end if n % (f+2) == 0 then return false end end return true end   local function s3iter() local s, i2, i3 = {1}, 1, 1 return function() local n2, n3, val = 2*s[i2], 3*s[i3], s[#s] s[#s+1] = math.min(n2, n3) i2, i3 = i2 + (n2<=n3 and 1 or 0), i3 + (n2>=n3 and 1 or 0) return val end end   local function pierpont(n) local list1, list2, s3next = {}, {}, s3iter() while #list1 < n or #list2 < n do local s3 = s3next() if #list1 < n then if isprime(s3+1) then list1[#list1+1] = s3+1 end end if #list2 < n then if isprime(s3-1) then list2[#list2+1] = s3-1 end end end return list1, list2 end   local N = 50 local p1, p2 = pierpont(N)   print("First 50 Pierpont primes of the first kind:") for i, p in ipairs(p1) do io.write(string.format("%8d%s", p, (i%10==0 and "\n" or " "))) end   print()   print("First 50 Pierpont primes of the second kind:") for i, p in ipairs(p2) do io.write(string.format("%8d%s", p, (i%10==0 and "\n" or " "))) end
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#EasyLang
EasyLang
ar$[] = [ "spring" "summer" "autumn" "winter" ] print ar$[random len ar$[]]
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#EchoLisp
EchoLisp
  (define (pick-random list) (list-ref list (random (length list)))) (pick-random (iota 1000)) → 667 (pick-random (iota 1000)) → 179  
http://rosettacode.org/wiki/Primality_by_trial_division
Primality by trial division
Task Write a boolean function that tells whether a given integer is prime. Remember that   1   and all non-positive numbers are not prime. Use trial division. Even numbers greater than   2   may be eliminated right away. A loop from   3   to   √ n    will suffice,   but other loops are allowed. Related tasks   count in factors   prime decomposition   AKS test for primes   factors of an integer   Sieve of Eratosthenes   factors of a Mersenne number   trial factoring of a Mersenne number   partition an integer X into N primes   sequence of primes by Trial Division
#TI-83_BASIC
TI-83 BASIC
Prompt A If A=2:Then Disp "PRIME" Stop End If (fPart(A/2)=0 and A>0) or A<2:Then Disp "NOT PRIME" Stop End 1→P For(B,3,int(√(A))) If FPart(A/B)=0:Then 0→P √(A)→B End B+1→B End If P=1:Then Disp "PRIME" Else Disp "NOT PRIME" End
http://rosettacode.org/wiki/Phrase_reversals
Phrase reversals
Task Given a string of space separated words containing the following phrase: rosetta code phrase reversal Reverse the characters of the string. Reverse the characters of each individual word in the string, maintaining original word order within the string. Reverse the order of each word of the string, maintaining the order of characters in each word. Show your output here. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#D
D
void main() @safe { import std.stdio, std.range, std.algorithm;   immutable phrase = "rosetta code phrase reversal"; phrase.retro.writeln; // Reversed string. phrase.splitter.map!retro.joiner(" ").writeln; // Words reversed. phrase.split.retro.joiner(" ").writeln; // Word order reversed. }
http://rosettacode.org/wiki/Permutations/Derangements
Permutations/Derangements
A derangement is a permutation of the order of distinct items in which no item appears in its original place. For example, the only two derangements of the three items (0, 1, 2) are (1, 2, 0), and (2, 0, 1). The number of derangements of n distinct items is known as the subfactorial of n, sometimes written as !n. There are various ways to calculate !n. Task Create a named function/method/subroutine/... to generate derangements of the integers 0..n-1, (or 1..n if you prefer). Generate and show all the derangements of 4 integers using the above routine. Create a function that calculates the subfactorial of n, !n. Print and show a table of the counted number of derangements of n vs. the calculated !n for n from 0..9 inclusive. Optional stretch goal   Calculate    !20 Related tasks   Anagrams/Deranged anagrams   Best shuffle   Left_factorials Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#BBC_BASIC
BBC BASIC
PRINT"Derangements for the numbers 0,1,2,3 are:" Count% = FN_Derangement_Generate(4,TRUE)   PRINT'"Table of n, counted derangements, calculated derangements :"   FOR I% = 0 TO 9 PRINT I%, FN_Derangement_Generate(I%,FALSE), FN_SubFactorial(I%) NEXT   PRINT'"There is no long int in BBC BASIC!" PRINT"!20 = ";FN_SubFactorial(20)   END   DEF FN_Derangement_Generate(N%, fPrintOut) LOCAL A%(), O%(), C%, D%, I%, J% IF N% = 0 THEN = 1 DIM A%(N%-1), O%(N%-1) FOR I% = 0 TO N%-1 : A%(I%) = I% : NEXT O%() = A%() FOR I% = 0 TO FN_Factorial(DIM(A%(),1)+1)-1 PROC_NextPermutation(A%()) D% = TRUE FOR J%=0 TO N%-1 IF A%(J%) = O%(J%) THEN D% = FALSE NEXT IF D% THEN C% += 1 IF fPrintOut THEN FOR K% = 0 TO N%-1 PRINT ;A%(K%);" "; NEXT PRINT ENDIF ENDIF NEXT = C%   DEF PROC_NextPermutation(A%()) LOCAL first, last, elementcount, pos elementcount = DIM(A%(),1) IF elementcount < 1 THEN ENDPROC pos = elementcount-1 WHILE A%(pos) >= A%(pos+1) pos -= 1 IF pos < 0 THEN PROC_Permutation_Reverse(A%(), 0, elementcount) ENDPROC ENDIF ENDWHILE last = elementcount WHILE A%(last) <= A%(pos) last -= 1 ENDWHILE SWAP A%(pos), A%(last) PROC_Permutation_Reverse(A%(), pos+1, elementcount) ENDPROC   DEF PROC_Permutation_Reverse(A%(), firstindex, lastindex) LOCAL first, last first = firstindex last = lastindex WHILE first < last SWAP A%(first), A%(last) first += 1 last -= 1 ENDWHILE ENDPROC   DEF FN_Factorial(N) : IF (N = 1) OR (N = 0) THEN =1 ELSE = N * FN_Factorial(N-1)   DEF FN_SubFactorial(N) : IF N=0 THEN =1 ELSE =N*FN_SubFactorial(N-1)+-1^N   REM Or you could use: REM DEF FN_SubFactorial(N) : IF N<1 THEN =1 ELSE =(N-1)*(FN_SubFactorial(N-1)+FN_SubFactorial(N-2))
http://rosettacode.org/wiki/Permutations_by_swapping
Permutations by swapping
Task Generate permutations of n items in which successive permutations differ from each other by the swapping of any two items. Also generate the sign of the permutation which is +1 when the permutation is generated from an even number of swaps from the initial state, and -1 for odd. Show the permutations and signs of three items, in order of generation here. Such data are of use in generating the determinant of a square matrix and any functions created should bear this in mind. Note: The Steinhaus–Johnson–Trotter algorithm generates successive permutations where adjacent items are swapped, but from this discussion adjacency is not a requirement. References Steinhaus–Johnson–Trotter algorithm Johnson-Trotter Algorithm Listing All Permutations Heap's algorithm [1] Tintinnalogia Related tasks   Matrix arithmetic   Gray code
#C
C
  #include<stdlib.h> #include<string.h> #include<stdio.h>   int flag = 1;   void heapPermute(int n, int arr[],int arrLen){ int temp; int i;   if(n==1){ printf("\n[");   for(i=0;i<arrLen;i++) printf("%d,",arr[i]); printf("\b] Sign : %d",flag);   flag*=-1; } else{ for(i=0;i<n-1;i++){ heapPermute(n-1,arr,arrLen);   if(n%2==0){ temp = arr[i]; arr[i] = arr[n-1]; arr[n-1] = temp; } else{ temp = arr[0]; arr[0] = arr[n-1]; arr[n-1] = temp; } } heapPermute(n-1,arr,arrLen); } }   int main(int argC,char* argV[0]) { int *arr, i=0, count = 1; char* token;   if(argC==1) printf("Usage : %s <comma separated list of integers>",argV[0]); else{ while(argV[1][i]!=00){ if(argV[1][i++]==',') count++; }   arr = (int*)malloc(count*sizeof(int));   i = 0;   token = strtok(argV[1],",");   while(token!=NULL){ arr[i++] = atoi(token); token = strtok(NULL,","); }   heapPermute(i,arr,count); }   return 0; }  
http://rosettacode.org/wiki/Permutation_test
Permutation test
Permutation test You are encouraged to solve this task according to the task description, using any language you may know. A new medical treatment was tested on a population of n + m {\displaystyle n+m} volunteers, with each volunteer randomly assigned either to a group of n {\displaystyle n} treatment subjects, or to a group of m {\displaystyle m} control subjects. Members of the treatment group were given the treatment, and members of the control group were given a placebo. The effect of the treatment or placebo on each volunteer was measured and reported in this table. Table of experimental results Treatment group Control group 85 68 88 41 75 10 66 49 25 16 29 65 83 32 39 92 97 28 98 Write a program that performs a permutation test to judge whether the treatment had a significantly stronger effect than the placebo. Do this by considering every possible alternative assignment from the same pool of volunteers to a treatment group of size n {\displaystyle n} and a control group of size m {\displaystyle m} (i.e., the same group sizes used in the actual experiment but with the group members chosen differently), while assuming that each volunteer's effect remains constant regardless. Note that the number of alternatives will be the binomial coefficient ( n + m n ) {\displaystyle {\tbinom {n+m}{n}}} . Compute the mean effect for each group and the difference in means between the groups in every case by subtracting the mean of the control group from the mean of the treatment group. Report the percentage of alternative groupings for which the difference in means is less or equal to the actual experimentally observed difference in means, and the percentage for which it is greater. Note that they should sum to 100%. Extremely dissimilar values are evidence of an effect not entirely due to chance, but your program need not draw any conclusions. You may assume the experimental data are known at compile time if that's easier than loading them at run time. Test your solution on the data given above.
#Common_Lisp
Common Lisp
(defun perm-test (s1 s2) (let ((more 0) (leq 0) (all-data (append s1 s2)) (thresh (apply #'+ s1))) (labels ((recur (data sum need avail) (cond ((zerop need) (if (>= sum thresh) (incf more) (incf leq))) ((>= avail need) (recur (cdr data) sum need (1- avail)) (recur (cdr data) (+ sum (car data)) (1- need) (1- avail))))))   (recur all-data 0 (length s1) (length all-data)) (cons more leq))))   (let* ((a (perm-test '(68 41 10 49 16 65 32 92 28 98) '(85 88 75 66 25 29 83 39 97))) (x (car a)) (y (cdr a)) (s (+ x y))) (format t "<=: ~a ~6f%~% >: ~a ~6f%~%" x (* 100e0 (/ x s)) y (* 100e0 (/ y s))))
http://rosettacode.org/wiki/Perfect_totient_numbers
Perfect totient numbers
Generate and show here, the first twenty Perfect totient numbers. Related task   Totient function Also see   the OEIS entry for   perfect totient numbers.   mrob   list of the first 54
#AArch64_Assembly
AArch64 Assembly
  /* ARM assembly AARCH64 Raspberry PI 3B */ /* program totientPerfect64.s */   /************************************/ /* Constantes */ /************************************/ .include "../includeConstantesARM64.inc" .equ MAXI, 20   /*********************************/ /* Initialized data */ /*********************************/ .data szMessNumber: .asciz " @ " szCarriageReturn: .asciz "\n" /*********************************/ /* UnInitialized data */ /*********************************/ .bss sZoneConv: .skip 24 /*********************************/ /* code section */ /*********************************/ .text .global main main: mov x4,#2 // start number mov x6,#0 // line counter mov x7,#0 // result counter 1: mov x0,x4 mov x5,#0 // totient sum 2: bl totient // compute totient add x5,x5,x0 // add totient cmp x0,#1 beq 3f b 2b 3: cmp x5,x4 // compare number and totient sum bne 4f mov x0,x4 // display result if equals ldr x1,qAdrsZoneConv bl conversion10 // call décimal conversion ldr x0,qAdrszMessNumber ldr x1,qAdrsZoneConv // insert conversion in message bl strInsertAtCharInc bl affichageMess // display message add x7,x7,#1 add x6,x6,#1 // increment indice line display cmp x6,#5 // if = 5 new line bne 4f mov x6,#0 ldr x0,qAdrszCarriageReturn bl affichageMess 4: add x4,x4,#1 // increment number cmp x7,#MAXI // maxi ? blt 1b // and loop   ldr x0,qAdrszCarriageReturn bl affichageMess   100: // standard end of the program mov x0, #0 // return code mov x8,EXIT svc #0 // perform the system call qAdrszCarriageReturn: .quad szCarriageReturn qAdrsZoneConv: .quad sZoneConv qAdrszMessNumber: .quad szMessNumber /******************************************************************/ /* compute totient of number */ /******************************************************************/ /* x0 contains number */ totient: stp x1,lr,[sp,-16]! // save registers stp x2,x3,[sp,-16]! // save registers stp x4,x5,[sp,-16]! // save registers mov x4,x0 // totient mov x5,x0 // save number mov x1,#0 // for first divisor 1: // begin loop mul x3,x1,x1 // compute square cmp x3,x5 // compare number bgt 4f // end add x1,x1,#2 // next divisor udiv x2,x5,x1 msub x3,x1,x2,x5 // compute remainder cmp x3,#0 // remainder null ? bne 3f 2: // begin loop 2 udiv x2,x5,x1 msub x3,x1,x2,x5 // compute remainder cmp x3,#0 csel x5,x2,x5,eq // new value = quotient beq 2b   udiv x2,x4,x1 // divide totient sub x4,x4,x2 // compute new totient 3: cmp x1,#2 // first divisor ? mov x0,1 csel x1,x0,x1,eq // divisor = 1 b 1b // and loop 4: cmp x5,#1 // final value > 1 ble 5f mov x0,x4 // totient mov x1,x5 // divide by value udiv x2,x4,x5 // totient divide by value sub x4,x4,x2 // compute new totient 5:   mov x0,x4 100: ldp x4,x5,[sp],16 // restaur registers ldp x2,x3,[sp],16 // restaur registers ldp x1,lr,[sp],16 // restaur registers ret     /***************************************************/ /* ROUTINES INCLUDE */ /***************************************************/ .include "../includeARM64.inc"  
http://rosettacode.org/wiki/Perfect_totient_numbers
Perfect totient numbers
Generate and show here, the first twenty Perfect totient numbers. Related task   Totient function Also see   the OEIS entry for   perfect totient numbers.   mrob   list of the first 54
#ALGOL_68
ALGOL 68
BEGIN # find the first 20 perfect totient numbers # # returns the number of integers k where 1 <= k <= n that are mutually prime to n # PROC totient = ( INT n )INT: # algorithm from the second Go sample # IF n < 3 THEN 1 ELIF n = 3 THEN 2 ELSE INT result := n; INT v := n; INT i := 2; WHILE i * i <= v DO IF v MOD i = 0 THEN WHILE v MOD i = 0 DO v OVERAB i OD; result -:= result OVER i FI; IF i = 2 THEN i := 1 FI; i +:= 2 OD; IF v > 1 THEN result -:= result OVER v FI; result FI # totient # ; # find the first 20 perfect totient numbers # INT p count := 0; FOR i FROM 2 WHILE p count < 20 DO INT t := totient( i ); INT sum := t; WHILE t /= 1 DO t := totient( t ); sum +:= t OD; IF sum = i THEN # have a perfect totient # p count +:= 1; print( ( " ", whole( i, 0 ) ) ) FI OD; print( ( newline ) ) END
http://rosettacode.org/wiki/Playing_cards
Playing cards
Task Create a data structure and the associated methods to define and manipulate a deck of   playing cards. The deck should contain 52 unique cards. The methods must include the ability to:   make a new deck   shuffle (randomize) the deck   deal from the deck   print the current contents of a deck Each card must have a pip value and a suit value which constitute the unique value of the card. Related tasks: Card shuffles Deal cards_for_FreeCell War Card_Game Poker hand_analyser Go Fish
#CLU
CLU
% Represents one playing card. card = cluster is make, parse, unparse, equal, all_cards rep = struct[pip: int, suit: char] own suits: string := "CHSD"; own pips: sequence[string] := sequence[string]$ ["A","2","3","4","5","6","7","8","9","10","J","Q","K"]   find_pip = proc (pip: string) returns (int) signals (bad_format) for i: int in int$from_to(1, sequence[string]$size(pips)) do if pips[i] = pip then return(i) end end signal bad_format end find_pip   make = proc (pip: int, suit: char) returns (cvt) signals (bad_format) if string$indexc(suit, suits) = 0 cor ~(pip >= 1 cand pip <= 13) then signal bad_format end return(rep${pip: pip, suit: suit}) end make   parse = proc (s: string) returns (cvt) signals (bad_format) size: int := string$size(s) if size<2 cor size>3 then signal bad_format end pip: string := string$substr(s, 1, size-1) suit: char := string$rest(s, size-1)[1] return(down(make(find_pip(pip), suit))) resignal bad_format end parse   unparse = proc (c: cvt) returns (string) return( pips[c.pip] || string$c2s(c.suit) ) end unparse   equal = proc (a, b: cvt) returns (bool) return( a.pip = b.pip cand a.suit = b.suit ) end equal    % Yield all cards in the canonical order all_cards = iter () yields (cvt) for suit: char in string$chars(suits) do for pip: int in int$from_to(1,sequence[string]$size(pips)) do yield(down(make(pip, suit))) end end end all_cards end card   % Represents a deck deck = cluster is new, shuffle, cards, deal, unparse rep = array[card]   new = proc () returns (cvt) d: rep := rep$new() for c: card in card$all_cards() do rep$addh(d, c) end return(d) end new   shuffle = proc (d: cvt) lo: int := rep$low(d) hi: int := rep$high(d) for i: int in int$from_to_by(hi, lo+1, -1) do j: int := lo + random$next(i-lo) c: card := d[i] d[i] := d[j] d[j] := c end end shuffle   cards = iter (d: cvt) yields (card) for c: card in rep$elements(d) do yield(c) end end cards   deal = proc (d: cvt) returns (card) signals (empty) if rep$empty(d) then signal empty end return(rep$reml(d)) end deal   unparse = proc (d: cvt) returns (string) ss: stream := stream$create_output() n: int := 0 for c: card in cards(up(d)) do if n~=0 cand n//13=0 then stream$putc(ss, '\n') elseif n~=0 then stream$putc(ss, ' ') end stream$puts(ss, card$unparse(c)) n := n+1 end return(stream$get_contents(ss)) end unparse end deck   start_up = proc () po: stream := stream$primary_output()  % seed the RNG d_: date := now() random$seed(d_.second + 60*(d_.minute + 60*d_.hour))    % make a new deck d: deck := deck$new() stream$putl(po, "New deck: ") stream$putl(po, deck$unparse(d))    % shuffle the deck deck$shuffle(d) stream$putl(po, "\nShuffled deck: ") stream$putl(po, deck$unparse(d))    % deal some cards stream$puts(po, "\nDealing 10 cards:") for i: int in int$from_to(1, 10) do stream$puts(po, " " || card$unparse(deck$deal(d))) end    % show remaining deck stream$putl(po, "\n\nRemaining cards in deck:") stream$putl(po, deck$unparse(d)) end start_up
http://rosettacode.org/wiki/Pi
Pi
Create a program to continually calculate and output the next decimal digit of   π {\displaystyle \pi }   (pi). The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession. The output should be a decimal sequence beginning   3.14159265 ... Note: this task is about   calculating   pi.   For information on built-in pi constants see Real constants and functions. Related Task Arithmetic-geometric mean/Calculate Pi
#C
C
#include <stdio.h> #include <stdlib.h> #include <gmp.h>   mpz_t tmp1, tmp2, t5, t239, pows; void actan(mpz_t res, unsigned long base, mpz_t pows) { int i, neg = 1; mpz_tdiv_q_ui(res, pows, base); mpz_set(tmp1, res); for (i = 3; ; i += 2) { mpz_tdiv_q_ui(tmp1, tmp1, base * base); mpz_tdiv_q_ui(tmp2, tmp1, i); if (mpz_cmp_ui(tmp2, 0) == 0) break; if (neg) mpz_sub(res, res, tmp2); else mpz_add(res, res, tmp2); neg = !neg; } }   char * get_digits(int n, size_t* len) { mpz_ui_pow_ui(pows, 10, n + 20);   actan(t5, 5, pows); mpz_mul_ui(t5, t5, 16);   actan(t239, 239, pows); mpz_mul_ui(t239, t239, 4);   mpz_sub(t5, t5, t239); mpz_ui_pow_ui(pows, 10, 20); mpz_tdiv_q(t5, t5, pows);   *len = mpz_sizeinbase(t5, 10); return mpz_get_str(0, 0, t5); }   int main(int c, char **v) { unsigned long accu = 16384, done = 0; size_t got; char *s;   mpz_init(tmp1); mpz_init(tmp2); mpz_init(t5); mpz_init(t239); mpz_init(pows);   while (1) { s = get_digits(accu, &got);   /* write out digits up to the last one not preceding a 0 or 9*/ got -= 2; /* -2: length estimate may be longer than actual */ while (s[got] == '0' || s[got] == '9') got--;   printf("%.*s", (int)(got - done), s + done); free(s);   done = got;   /* double the desired digits; slows down at least cubically */ accu *= 2; }   return 0; }
http://rosettacode.org/wiki/Periodic_table
Periodic table
Task Display the row and column in the periodic table of the given atomic number. The periodic table Let us consider the following periodic table representation. __________________________________________________________________________ | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | | | |1 H He | | | |2 Li Be B C N O F Ne | | | |3 Na Mg Al Si P S Cl Ar | | | |4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr | | | |5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe | | | |6 Cs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn | | | |7 Fr Ra ° Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og | |__________________________________________________________________________| | | | | |8 Lantanoidi* La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu | | | |9 Aktinoidi° Ak Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr | |__________________________________________________________________________| Example test cases;   1 -> 1 1   2 -> 1 18   29 -> 4 11   42 -> 5 6   57 -> 8 4   58 -> 8 5   72 -> 6 4   89 -> 9 4 Details; The representation of the periodic table may be represented in various way. The one presented in this challenge does have the following property : Lantanides and Aktinoides are all in a dedicated row, hence there is no element that is placed at 6, 3 nor 7, 3. You may take a look at the atomic number repartitions here. The atomic number is at least 1, at most 118. See also   the periodic table   This task was an idea from CompSciFact   The periodic table in ascii that was used as template
#BASIC
BASIC
SUB MostarPos (N) DIM a(7) RESTORE a: FOR x = 0 TO 7: READ a(x): NEXT x DIM b(7) RESTORE b: FOR x = 0 TO 7: READ b(x): NEXT x   I = 7 WHILE a(I) > N I = I - 1 WEND M = N + b(I) R = (M \ 18) + 1 C = (M MOD 18) + 1 PRINT USING "Atomic number ### -> #_, ##"; N; R; C END SUB   DIM Element(0 TO 12) RESTORE elements elements: DATA 1, 2, 29, 42, 57, 58, 59, 71, 72, 89, 90, 103, 113 FOR x = 0 TO 12: READ Element(x): NEXT x   FOR I = 0 TO UBOUND(Element) MostarPos (Element(I)) NEXT I   a: DATA 1, 2, 5, 13, 57, 72, 89, 104 b: DATA -1, 15, 25, 35, 72, 21, 58, 7
http://rosettacode.org/wiki/Pig_the_dice_game
Pig the dice game
The   game of Pig   is a multiplayer game played with a single six-sided die.   The object of the game is to reach   100   points or more.   Play is taken in turns.   On each person's turn that person has the option of either: Rolling the dice:   where a roll of two to six is added to their score for that turn and the player's turn continues as the player is given the same choice again;   or a roll of   1   loses the player's total points   for that turn   and their turn finishes with play passing to the next player. Holding:   the player's score for that round is added to their total and becomes safe from the effects of throwing a   1   (one).   The player's turn finishes with play passing to the next player. Task Create a program to score for, and simulate dice throws for, a two-person game. Related task   Pig the dice game/Player
#Groovy
Groovy
  class PigDice {   final static int maxScore = 100; final static yesses = ["yes", "y", "", "Y", "YES"]   static main(args) { def playersCount = 2 Scanner sc = new Scanner(System.in) Map scores = [:] def current = 0 def player = 0 def gameOver = false def firstThrow = true Random rnd = new Random()   // Initialise the players' scores (0..(playersCount-1)).each{ it-> scores[it] = 0 }   // Game starts while (!gameOver) { def nextPlayer = false String ln   // Automatic rolls for the first dice roll if (firstThrow){ println "player ${player+1} Auto Rolling... " ln = 'y' firstThrow = false } else { println "player ${player+1} Rolling? Yes(y) or No(n) " ln = sc.nextLine() }   if (ln in yesses){ // if yes then roll the dice int rolled = rnd.nextInt(6) + 1 print "The Roll was $rolled --- "   if (rolled == 1) { println " Bust! Player ${player+1} loses $current but keep ${scores[player]}" current = 0 nextPlayer = true firstThrow = true } else { // dice rolls 2 to 6 current = current + rolled if ((current + scores[player]) > maxScore){ gameOver = true }else{ // as a session score gets larger the message returned changes switch (current){ case 6..15: print "Good. " break case 15..29: print "lucky! " break case 29..39: print "Great! " break default: print "Amazing " } println "Player ${player+1} now has $current this session (possible score of ${current + scores[player]})" } } } else{ // if no then bank the session score nextPlayer = true firstThrow = true scores[player] = scores[player] + current current = 0 println "chicken! player ${player+1} now has ${scores[player]} and $gameOver" println "Current scores :" for (i in scores){ println "player ${i.key + 1}| ${i.value} " } println "------------------------------"   } println ""   if (nextPlayer) { player = (player+1)%playersCount println "** Next player is ${player+1}" } }   // Game ends println "Player ${player+1} wins" } }  
http://rosettacode.org/wiki/Pernicious_numbers
Pernicious numbers
A   pernicious number   is a positive integer whose   population count   is a prime. The   population count   is the number of   ones   in the binary representation of a non-negative integer. Example 22   (which is   10110   in binary)   has a population count of   3,   which is prime,   and therefore 22   is a pernicious number. Task display the first   25   pernicious numbers   (in decimal). display all pernicious numbers between   888,888,877   and   888,888,888   (inclusive). display each list of integers on one line   (which may or may not include a title). See also Sequence   A052294 pernicious numbers on The On-Line Encyclopedia of Integer Sequences. Rosetta Code entry   population count, evil numbers, odious numbers.
#C.2B.2B
C++
  #include <iostream> using namespace std;   int main() { int cnt = 0, cnt2, cnt3, tmp, binary[8]; for (int i = 3; cnt < 25; i++) { tmp = i; cnt2 = 0; cnt3 = 0; for (int j = 7; j > 0; j--) { binary[j] = tmp % 2; tmp /= 2; } binary[0] = tmp; for (int j = 0; j < 8; j++) { if (binary[j] == 1) { cnt2++; } } for (int j = 2; j <= (cnt2 / 2); j++) { if (cnt2 % j == 0) { cnt3++; break; } } if (cnt3 == 0 && cnt2 != 1) { cout << i << endl; cnt++; } }   cout << endl; int binary2[31];   for (int i = 888888877; i <= 888888888; i++) { tmp = i; cnt2 = 0; cnt3 = 0; for (int j = 30; j > 0; j--) { binary2[j] = tmp % 2; tmp /= 2; } binary2[0] = tmp; for (int j = 0; j < 31; j++) { if (binary2[j] == 1) { cnt2++; } } for (int j = 2; j <= (cnt2 / 2); j++) { if (cnt2 % j == 0) { cnt3++; break; } } if (cnt3 == 0 && cnt2 != 1) { cout << i << endl; } } }  
http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation
Permutations/Rank of a permutation
A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items. For our purposes the ranking will assign integers 0.. ( n ! − 1 ) {\displaystyle 0..(n!-1)} to an ordering of all the permutations of the integers 0.. ( n − 1 ) {\displaystyle 0..(n-1)} . For example, the permutations of the digits zero to 3 arranged lexicographically have the following rank: PERMUTATION RANK (0, 1, 2, 3) -> 0 (0, 1, 3, 2) -> 1 (0, 2, 1, 3) -> 2 (0, 2, 3, 1) -> 3 (0, 3, 1, 2) -> 4 (0, 3, 2, 1) -> 5 (1, 0, 2, 3) -> 6 (1, 0, 3, 2) -> 7 (1, 2, 0, 3) -> 8 (1, 2, 3, 0) -> 9 (1, 3, 0, 2) -> 10 (1, 3, 2, 0) -> 11 (2, 0, 1, 3) -> 12 (2, 0, 3, 1) -> 13 (2, 1, 0, 3) -> 14 (2, 1, 3, 0) -> 15 (2, 3, 0, 1) -> 16 (2, 3, 1, 0) -> 17 (3, 0, 1, 2) -> 18 (3, 0, 2, 1) -> 19 (3, 1, 0, 2) -> 20 (3, 1, 2, 0) -> 21 (3, 2, 0, 1) -> 22 (3, 2, 1, 0) -> 23 Algorithms exist that can generate a rank from a permutation for some particular ordering of permutations, and that can generate the same rank from the given individual permutation (i.e. given a rank of 17 produce (2, 3, 1, 0) in the example above). One use of such algorithms could be in generating a small, random, sample of permutations of n {\displaystyle n} items without duplicates when the total number of permutations is large. Remember that the total number of permutations of n {\displaystyle n} items is given by n ! {\displaystyle n!} which grows large very quickly: A 32 bit integer can only hold 12 ! {\displaystyle 12!} , a 64 bit integer only 20 ! {\displaystyle 20!} . It becomes difficult to take the straight-forward approach of generating all permutations then taking a random sample of them. A question on the Stack Overflow site asked how to generate one million random and indivudual permutations of 144 items. Task Create a function to generate a permutation from a rank. Create the inverse function that given the permutation generates its rank. Show that for n = 3 {\displaystyle n=3} the two functions are indeed inverses of each other. Compute and show here 4 random, individual, samples of permutations of 12 objects. Stretch goal State how reasonable it would be to use your program to address the limits of the Stack Overflow question. References Ranking and Unranking Permutations in Linear Time by Myrvold & Ruskey. (Also available via Google here). Ranks on the DevData site. Another answer on Stack Overflow to a different question that explains its algorithm in detail. Related tasks Factorial_base_numbers_indexing_permutations_of_a_collection
#Phix
Phix
with javascript_semantics function get_rank(sequence l) integer r = length(l) sequence inv = repeat(0,r) for i=1 to r do inv[l[i]+1] = i-1 end for integer res = 0, mul = 1 l = deep_copy(l) for n=r to 2 by -1 do integer s = l[n] l[inv[n]+1] = s inv[s+1] = inv[n] res += s*mul mul *= n end for return res end function puts(1,"rank->permute->rank:\n") sequence l = tagset(2,0) for n=1 to factorial(length(l)) do sequence p = permute(n,l) ?{n-1,p,get_rank(p)} end for puts(1,"4 random individual samples of 12 items:\n") l = tagset(11,0) for i=1 to 4 do ?permute(rand(factorial(12)),l) end for
http://rosettacode.org/wiki/Pierpont_primes
Pierpont primes
A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v . A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v . The term "Pierpont primes" is generally understood to mean the first definition, but will be called "Pierpont primes of the first kind" on this page to distinguish them. Task Write a routine (function, procedure, whatever) to find Pierpont primes of the first & second kinds. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the first kind. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the second kind If your language supports large integers, find and display here, on this page, the 250th Pierpont prime of the first kind and the 250th Pierpont prime of the second kind. See also Wikipedia - Pierpont primes OEIS:A005109 - Class 1 -, or Pierpont primes OEIS:A005105 - Class 1 +, or Pierpont primes of the second kind
#M2000_Interpreter
M2000 Interpreter
Module Pierpoint_Primes { Form 80 Set Fast ! const NPP=50 dim pier(1 to 2, 1 to NPP), np(1 to 2) = 0 def long x = 1, j while np(1)<=NPP or np(2)<=NPP x++ j = @is_pierpont(x) if j>0 Else Continue if j mod 2 = 1 then np(1)++ :if np(1) <= NPP then pier(1, np(1)) = x if j > 1 then np(2)++ : if np(2) <= NPP then pier(2, np(2)) = x end while   print "First ";NPP;" Pierpont primes of the first kind:" for j = 1 to NPP print pier(2, j), next j if pos>0 then print print "First ";NPP;" Pierpont primes of the second kind:" for j = 1 to NPP print pier(1, j), next j if pos>0 then print Set Fast function is_prime(n as decimal) if n < 2 then = false  : exit function if n <4 then = true : exit function if n mod 2 = 0 then = false : exit function local i as long for i = 3 to int(sqrt(n))+1 step 2 if n mod i = 0 then = false  : exit function next i = true end function   function is_23(n as long) while n mod 2 = 0 n = n div 2 end while while n mod 3 = 0 n = n div 3 end while if n = 1 then = true else = false end function   function is_pierpont(n as long) if not @is_prime(n) then = 0& : exit function 'not prime Local p1 = @is_23(n+1), p2 = @is_23(n-1) if p1 and p2 then = 3  : exit function 'pierpont prime of both kinds if p1 then = 1 : exit function 'pierpont prime of the 1st kind if p2 then = 2 : exit function 'pierpont prime of the 2nd kind = 0 'prime, but not pierpont end function } Pierpoint_Primes
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#Elena
Elena
import extensions;   extension listOp { randomItem() = self[randomGenerator.eval(self.Length)]; }   public program() { var item := new int[]{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};   console.printLine("I picked element ",item.randomItem()) }
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#Elixir
Elixir
iex(1)> list = Enum.to_list(1..20) [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20] iex(2)> Enum.random(list) 19 iex(3)> Enum.take_random(list,4) [19, 20, 7, 15]
http://rosettacode.org/wiki/Primality_by_trial_division
Primality by trial division
Task Write a boolean function that tells whether a given integer is prime. Remember that   1   and all non-positive numbers are not prime. Use trial division. Even numbers greater than   2   may be eliminated right away. A loop from   3   to   √ n    will suffice,   but other loops are allowed. Related tasks   count in factors   prime decomposition   AKS test for primes   factors of an integer   Sieve of Eratosthenes   factors of a Mersenne number   trial factoring of a Mersenne number   partition an integer X into N primes   sequence of primes by Trial Division
#Tiny_BASIC
Tiny BASIC
PRINT "ENTER A NUMBER " INPUT P GOSUB 100 IF Z = 1 THEN PRINT "It is prime." IF Z = 0 THEN PRINT "It isn't prime." END   100 REM PRIMALITY OF THE NUMBER P BY TRIAL DIVISION IF P < 2 THEN RETURN LET Z = 1 IF P < 4 THEN RETURN LET I = 2 110 IF (P/I)*I = P THEN LET Z = 0 IF Z = 0 THEN RETURN LET I = I + 1 IF I*I <= P THEN GOTO 110 RETURN
http://rosettacode.org/wiki/Phrase_reversals
Phrase reversals
Task Given a string of space separated words containing the following phrase: rosetta code phrase reversal Reverse the characters of the string. Reverse the characters of each individual word in the string, maintaining original word order within the string. Reverse the order of each word of the string, maintaining the order of characters in each word. Show your output here. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#Dyalect
Dyalect
let str = "rosetta code phrase reversal"   //or you can use a built-in method String.reverse func reverse(str) { let xs = [] for i in (str.Length()-1)^-1..0 { xs.Add(str[i]) } String.Concat(values: xs) }   func reverseByWord(str) { let words = str.Split(" ") let xs = [] for w in words { xs.Add(reverse(w)) xs.Add(" ") } String.Concat(values: xs) }   func reverseWords(str) { let words = str.Split(" ") let xs = [] for i in (words.Length()-1)^-1..0 { xs.Add(words[i]) xs.Add(" ") } String.Concat(values: xs) }   print("1. \(reverse(str))") print("2. \(reverseByWord(str))") print("3. \(reverseWords(str))")
http://rosettacode.org/wiki/Phrase_reversals
Phrase reversals
Task Given a string of space separated words containing the following phrase: rosetta code phrase reversal Reverse the characters of the string. Reverse the characters of each individual word in the string, maintaining original word order within the string. Reverse the order of each word of the string, maintaining the order of characters in each word. Show your output here. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#EchoLisp
EchoLisp
  (define (string-reverse string) (list->string (reverse (string->list string))))   (define (task str) (for-each writeln (list (string-reverse str) (string-join (map string-reverse (string-split str ))) (string-join (reverse (string-split str ))))))     (task "rosetta code phrase reversal") "lasrever esarhp edoc attesor" "attesor edoc esarhp lasrever" "reversal phrase code rosetta"  
http://rosettacode.org/wiki/Permutations/Derangements
Permutations/Derangements
A derangement is a permutation of the order of distinct items in which no item appears in its original place. For example, the only two derangements of the three items (0, 1, 2) are (1, 2, 0), and (2, 0, 1). The number of derangements of n distinct items is known as the subfactorial of n, sometimes written as !n. There are various ways to calculate !n. Task Create a named function/method/subroutine/... to generate derangements of the integers 0..n-1, (or 1..n if you prefer). Generate and show all the derangements of 4 integers using the above routine. Create a function that calculates the subfactorial of n, !n. Print and show a table of the counted number of derangements of n vs. the calculated !n for n from 0..9 inclusive. Optional stretch goal   Calculate    !20 Related tasks   Anagrams/Deranged anagrams   Best shuffle   Left_factorials Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#Bracmat
Bracmat
( ( calculated-!n = memo answ . (memo==) & ( !arg:0&1 | !arg:1&0 | !(memo.):? (!arg.?answ) ?&!answ | (!arg+-1) * (calculated-!n$(!arg+-1)+calculated-!n$(!arg+-2))  : ?answ & (!arg.!answ) !(memo.):?(memo.) & !answ ) ) & ( counted-!n = p P h H A Z L .  !arg:(%?p ?P.?H.?L) &  !H  :  ?A (%@?h:~!p) (?Z&counted-!n$(!P.!A !Z.!h !L)) |  !arg:(..?L) & 1+!count:?count & (!count.!L) !D:?D & ~ ) & out$"Derangements of 1 2 3 4" & :?D & 0:?count & ( counted-!n$(4 3 2 1.4 3 2 1.) | out$!D ) & ( pad = len w . @(!arg:? [?len) & @(" ":? [!len ?w) & !w !arg ) & :?K & -1:?N & out$(str$(N pad$List pad$Calc)) & whl ' ( !N+1:<10:?N & ( 0:?count & :?D & counted-!n$(!K.!K.) | out$(str$(!N pad$!count pad$(calculated-!n$!N))) ) & !N !K:?K ) & out$("!20 =" calculated-!n$20) & lst$calculated-!n )
http://rosettacode.org/wiki/Permutations_by_swapping
Permutations by swapping
Task Generate permutations of n items in which successive permutations differ from each other by the swapping of any two items. Also generate the sign of the permutation which is +1 when the permutation is generated from an even number of swaps from the initial state, and -1 for odd. Show the permutations and signs of three items, in order of generation here. Such data are of use in generating the determinant of a square matrix and any functions created should bear this in mind. Note: The Steinhaus–Johnson–Trotter algorithm generates successive permutations where adjacent items are swapped, but from this discussion adjacency is not a requirement. References Steinhaus–Johnson–Trotter algorithm Johnson-Trotter Algorithm Listing All Permutations Heap's algorithm [1] Tintinnalogia Related tasks   Matrix arithmetic   Gray code
#C.2B.2B
C++
  #include <iostream> #include <vector>   using namespace std;   vector<int> UpTo(int n, int offset = 0) { vector<int> retval(n); for (int ii = 0; ii < n; ++ii) retval[ii] = ii + offset; return retval; }   struct JohnsonTrotterState_ { vector<int> values_; vector<int> positions_; // size is n+1, first element is not used vector<bool> directions_; int sign_;   JohnsonTrotterState_(int n) : values_(UpTo(n, 1)), positions_(UpTo(n + 1, -1)), directions_(n + 1, false), sign_(1) {}   int LargestMobile() const // returns 0 if no mobile integer exists { for (int r = values_.size(); r > 0; --r) { const int loc = positions_[r] + (directions_[r] ? 1 : -1); if (loc >= 0 && loc < values_.size() && values_[loc] < r) return r; } return 0; }   bool IsComplete() const { return LargestMobile() == 0; }   void operator++() // implement Johnson-Trotter algorithm { const int r = LargestMobile(); const int rLoc = positions_[r]; const int lLoc = rLoc + (directions_[r] ? 1 : -1); const int l = values_[lLoc]; // do the swap swap(values_[lLoc], values_[rLoc]); swap(positions_[l], positions_[r]); sign_ = -sign_; // change directions for (auto pd = directions_.begin() + r + 1; pd != directions_.end(); ++pd) *pd = !*pd; } };   int main(void) { JohnsonTrotterState_ state(4); do { for (auto v : state.values_) cout << v << " "; cout << "\n"; ++state; } while (!state.IsComplete()); }  
http://rosettacode.org/wiki/Permutation_test
Permutation test
Permutation test You are encouraged to solve this task according to the task description, using any language you may know. A new medical treatment was tested on a population of n + m {\displaystyle n+m} volunteers, with each volunteer randomly assigned either to a group of n {\displaystyle n} treatment subjects, or to a group of m {\displaystyle m} control subjects. Members of the treatment group were given the treatment, and members of the control group were given a placebo. The effect of the treatment or placebo on each volunteer was measured and reported in this table. Table of experimental results Treatment group Control group 85 68 88 41 75 10 66 49 25 16 29 65 83 32 39 92 97 28 98 Write a program that performs a permutation test to judge whether the treatment had a significantly stronger effect than the placebo. Do this by considering every possible alternative assignment from the same pool of volunteers to a treatment group of size n {\displaystyle n} and a control group of size m {\displaystyle m} (i.e., the same group sizes used in the actual experiment but with the group members chosen differently), while assuming that each volunteer's effect remains constant regardless. Note that the number of alternatives will be the binomial coefficient ( n + m n ) {\displaystyle {\tbinom {n+m}{n}}} . Compute the mean effect for each group and the difference in means between the groups in every case by subtracting the mean of the control group from the mean of the treatment group. Report the percentage of alternative groupings for which the difference in means is less or equal to the actual experimentally observed difference in means, and the percentage for which it is greater. Note that they should sum to 100%. Extremely dissimilar values are evidence of an effect not entirely due to chance, but your program need not draw any conclusions. You may assume the experimental data are known at compile time if that's easier than loading them at run time. Test your solution on the data given above.
#D
D
import std.stdio, std.algorithm, std.array, combinations3;   auto permutationTest(T)(in T[] a, in T[] b) pure nothrow @safe { immutable tObs = a.sum; auto combs = combinations!false(a ~ b, a.length); immutable under = combs.count!(perm => perm.sum <= tObs); return under * 100.0 / combs.length; }   void main() { immutable treatmentGroup = [85, 88, 75, 66, 25, 29, 83, 39, 97]; immutable controlGroup = [68, 41, 10, 49, 16, 65, 32, 92, 28, 98]; immutable under = permutationTest(treatmentGroup, controlGroup); writefln("Under =%6.2f%%\nOver =%6.2f%%", under, 100.0 - under); }
http://rosettacode.org/wiki/Perlin_noise
Perlin noise
The   Perlin noise   is a kind of   gradient noise   invented by   Ken Perlin   around the end of the twentieth century and still currently heavily used in   computer graphics,   most notably to procedurally generate textures or heightmaps. The Perlin noise is basically a   pseudo-random   mapping of   R d {\displaystyle \mathbb {R} ^{d}}   into   R {\displaystyle \mathbb {R} }   with an integer   d {\displaystyle d}   which can be arbitrarily large but which is usually   2,   3,   or   4. Either by using a dedicated library or by implementing the algorithm, show that the Perlin noise   (as defined in 2002 in the Java implementation below)   of the point in 3D-space with coordinates     3.14,   42,   7     is     0.13691995878400012. Note: this result assumes 64 bit IEEE-754 floating point calculations. If your language uses a different floating point representation, make a note of it and calculate the value accurate to 15 decimal places, or your languages accuracy threshold if it is less. Trailing zeros need not be displayed.
#11l
11l
V p = [-1] * 512 V permutation = [151,160,137,91,90,15, 131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23, 190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33, 88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166, 77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244, 102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196, 135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123, 5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42, 223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9, 129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228, 251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107, 49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254, 138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180] L(i) 256 p[256 + i] = p[i] = permutation[i]   F fade(t) R t ^ 3 * (t * (t * 6 - 15) + 10)   F linerp(t, a, b) R a + t * (b - a)   F grad(hash, x, y, z) V h = hash [&] 15 V u = I h < 8 {x} E y V v = I h < 4 {y} E (I h C (12, 14) {x} E z) R (I (h [&] 1) == 0 {u} E -u) + (I (h [&] 2) == 0 {v} E -v)   F perlin_noise(=x, =y, =z) V _x_ = Int(x) [&] 255 V Y = Int(y) [&] 255 V Z = Int(z) [&] 255 x -= Int(x) y -= Int(y) z -= Int(z) V u = fade(x) V v = fade(y) V w = fade(z) V A = :p[_x_] + Y V AA = :p[A] + Z V AB = :p[A + 1] + Z V B = :p[_x_ + 1] + Y V BA = :p[B] + Z V BB = :p[B + 1] + Z R linerp(w, linerp(v, linerp(u, grad(:p[AA], x, y, z), grad(:p[BA], x - 1, y, z)), linerp(u, grad(:p[AB], x, y - 1, z), grad(:p[BB], x - 1, y - 1, z))), linerp(v, linerp(u, grad(:p[AA + 1], x, y, z - 1), grad(:p[BA + 1], x - 1, y, z - 1)), linerp(u, grad(:p[AB + 1], x, y - 1, z - 1), grad(:p[BB + 1], x - 1, y - 1, z - 1))))   print(‘#.17’.format(perlin_noise(3.14, 42, 7)))
http://rosettacode.org/wiki/Perfect_totient_numbers
Perfect totient numbers
Generate and show here, the first twenty Perfect totient numbers. Related task   Totient function Also see   the OEIS entry for   perfect totient numbers.   mrob   list of the first 54
#APL
APL
(⊢(/⍨)((+/((1+.=⍳∨⊢)∘⊃,⊢)⍣(1=(⊃⊣)))=2∘×)¨)1↓⍳6000
http://rosettacode.org/wiki/Playing_cards
Playing cards
Task Create a data structure and the associated methods to define and manipulate a deck of   playing cards. The deck should contain 52 unique cards. The methods must include the ability to:   make a new deck   shuffle (randomize) the deck   deal from the deck   print the current contents of a deck Each card must have a pip value and a suit value which constitute the unique value of the card. Related tasks: Card shuffles Deal cards_for_FreeCell War Card_Game Poker hand_analyser Go Fish
#COBOL
COBOL
identification division. program-id. playing-cards.   environment division. configuration section. repository. function all intrinsic.   data division. working-storage section. 77 card usage index. 01 deck. 05 cards occurs 52 times ascending key slot indexed by card. 10 slot pic 99. 10 hand pic 99. 10 suit pic 9. 10 symbol pic x(4). 10 rank pic 99.   01 filler. 05 suit-name pic x(8) occurs 4 times.   *> Unicode U+1F0Ax, Bx, Cx, Dx "f09f82a0" "82b0" "8380" "8390" 01 base-s constant as 4036985504. 01 base-h constant as 4036985520. 01 base-d constant as 4036985728. 01 base-c constant as 4036985744.   01 sym pic x(4) comp-x. 01 symx redefines sym pic x(4). 77 s pic 9. 77 r pic 99. 77 c pic 99. 77 hit pic 9. 77 limiter pic 9(6).   01 spades constant as 1. 01 hearts constant as 2. 01 diamonds constant as 3. 01 clubs constant as 4.   01 players constant as 3. 01 cards-per constant as 5. 01 deal pic 99. 01 player pic 99.   01 show-tally pic zz. 01 show-rank pic z(5). 01 arg pic 9(10).   procedure division. cards-main. perform seed perform initialize-deck perform shuffle-deck perform deal-deck perform display-hands goback.   *> ******** seed. accept arg from command-line if arg not equal 0 then move random(arg) to c end-if .   initialize-deck. move "spades" to suit-name(spades) move "hearts" to suit-name(hearts) move "diamonds" to suit-name(diamonds) move "clubs" to suit-name(clubs)   perform varying s from 1 by 1 until s > 4 after r from 1 by 1 until r > 13 compute c = (s - 1) * 13 + r evaluate s when spades compute sym = base-s + r when hearts compute sym = base-h + r when diamonds compute sym = base-d + r when clubs compute sym = base-c + r end-evaluate if r > 11 then compute sym = sym + 1 end-if move s to suit(c) move r to rank(c) move symx to symbol(c) move zero to slot(c) move zero to hand(c) end-perform .   shuffle-deck. move zero to limiter perform until exit compute c = random() * 52.0 + 1.0 move zero to hit perform varying tally from 1 by 1 until tally > 52 if slot(tally) equal c then move 1 to hit exit perform end-if if slot(tally) equal 0 then if tally < 52 then move 1 to hit end-if move c to slot(tally) exit perform end-if end-perform if hit equal zero then exit perform end-if if limiter > 999999 then display "too many shuffles, deck invalid" upon syserr exit perform end-if add 1 to limiter end-perform sort cards ascending key slot .   display-card. >>IF ENGLISH IS DEFINED move rank(tally) to show-rank evaluate rank(tally) when 1 display " ace" with no advancing when 2 thru 10 display show-rank with no advancing when 11 display " jack" with no advancing when 12 display "queen" with no advancing when 13 display " king" with no advancing end-evaluate display " of " suit-name(suit(tally)) with no advancing >>ELSE display symbol(tally) with no advancing >>END-IF .   display-deck. perform varying tally from 1 by 1 until tally > 52 move tally to show-tally display "Card: " show-tally " currently in hand " hand(tally) " is " with no advancing perform display-card display space end-perform .   display-hands. perform varying player from 1 by 1 until player > players move player to tally display "Player " player ": " with no advancing perform varying deal from 1 by 1 until deal > cards-per perform display-card add players to tally end-perform display space end-perform display "Stock: " with no advancing subtract players from tally add 1 to tally perform varying tally from tally by 1 until tally > 52 perform display-card >>IF ENGLISH IS DEFINED display space >>END-IF end-perform display space .   deal-deck. display "Dealing " cards-per " cards to " players " players" move 1 to tally perform varying deal from 1 by 1 until deal > cards-per after player from 1 by 1 until player > players move player to hand(tally) add 1 to tally end-perform .   end program playing-cards.  
http://rosettacode.org/wiki/Pi
Pi
Create a program to continually calculate and output the next decimal digit of   π {\displaystyle \pi }   (pi). The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession. The output should be a decimal sequence beginning   3.14159265 ... Note: this task is about   calculating   pi.   For information on built-in pi constants see Real constants and functions. Related Task Arithmetic-geometric mean/Calculate Pi
#C.23
C#
using System; using System.Numerics;   namespace PiCalc { internal class Program { private readonly BigInteger FOUR = new BigInteger(4); private readonly BigInteger SEVEN = new BigInteger(7); private readonly BigInteger TEN = new BigInteger(10); private readonly BigInteger THREE = new BigInteger(3); private readonly BigInteger TWO = new BigInteger(2);   private BigInteger k = BigInteger.One; private BigInteger l = new BigInteger(3); private BigInteger n = new BigInteger(3); private BigInteger q = BigInteger.One; private BigInteger r = BigInteger.Zero; private BigInteger t = BigInteger.One;   public void CalcPiDigits() { BigInteger nn, nr; bool first = true; while (true) { if ((FOUR*q + r - t).CompareTo(n*t) == -1) { Console.Write(n); if (first) { Console.Write("."); first = false; } nr = TEN*(r - (n*t)); n = TEN*(THREE*q + r)/t - (TEN*n); q *= TEN; r = nr; } else { nr = (TWO*q + r)*l; nn = (q*(SEVEN*k) + TWO + r*l)/(t*l); q *= k; t *= l; l += TWO; k += BigInteger.One; n = nn; r = nr; } } }   private static void Main(string[] args) { new Program().CalcPiDigits(); } } }
http://rosettacode.org/wiki/Periodic_table
Periodic table
Task Display the row and column in the periodic table of the given atomic number. The periodic table Let us consider the following periodic table representation. __________________________________________________________________________ | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | | | |1 H He | | | |2 Li Be B C N O F Ne | | | |3 Na Mg Al Si P S Cl Ar | | | |4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr | | | |5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe | | | |6 Cs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn | | | |7 Fr Ra ° Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og | |__________________________________________________________________________| | | | | |8 Lantanoidi* La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu | | | |9 Aktinoidi° Ak Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr | |__________________________________________________________________________| Example test cases;   1 -> 1 1   2 -> 1 18   29 -> 4 11   42 -> 5 6   57 -> 8 4   58 -> 8 5   72 -> 6 4   89 -> 9 4 Details; The representation of the periodic table may be represented in various way. The one presented in this challenge does have the following property : Lantanides and Aktinoides are all in a dedicated row, hence there is no element that is placed at 6, 3 nor 7, 3. You may take a look at the atomic number repartitions here. The atomic number is at least 1, at most 118. See also   the periodic table   This task was an idea from CompSciFact   The periodic table in ascii that was used as template
#FreeBASIC
FreeBASIC
Sub MostarPos(N As Integer) Dim As Integer M, I, R, C Dim As Integer A(0 To 7) = { 1, 2, 5, 13, 57, 72, 89, 104} 'magic numbers Dim As Integer B(0 To 7) = {-1, 15, 25, 35, 72, 21, 58, 7} I = 7 While A(I) > N I -= 1 Wend M = N + B(I) R = (M \ 18) +1 C = (M Mod 18) +1 Print Using "Atomic number ### -> #_, ##"; N; R; C End Sub   Dim As Integer Element(0 To 12) = {1, 2, 29, 42, 57, 58, 59, 71, 72, 89, 90, 103, 113} For I As Integer = 0 To Ubound(Element) MostarPos(Element(I)) Next I
http://rosettacode.org/wiki/Pig_the_dice_game
Pig the dice game
The   game of Pig   is a multiplayer game played with a single six-sided die.   The object of the game is to reach   100   points or more.   Play is taken in turns.   On each person's turn that person has the option of either: Rolling the dice:   where a roll of two to six is added to their score for that turn and the player's turn continues as the player is given the same choice again;   or a roll of   1   loses the player's total points   for that turn   and their turn finishes with play passing to the next player. Holding:   the player's score for that round is added to their total and becomes safe from the effects of throwing a   1   (one).   The player's turn finishes with play passing to the next player. Task Create a program to score for, and simulate dice throws for, a two-person game. Related task   Pig the dice game/Player
#Haskell
Haskell
  import System.Random (randomRIO)   data Score = Score { stack :: Int, score :: Int }   main :: IO () main = loop (Score 0 0) (Score 0 0)   loop :: Score -> Score -> IO () loop p1 p2 = do putStrLn $ "\nPlayer 1 ~ " ++ show (score p1) p1' <- askPlayer p1 if (score p1') >= 100 then putStrLn "P1 won!" else do putStrLn $ "\nPlayer 2 ~ " ++ show (score p2) p2' <- askPlayer p2 if (score p2') >= 100 then putStrLn "P2 won!" else loop p1' p2'     askPlayer :: Score -> IO Score askPlayer (Score stack score) = do putStr "\n(h)old or (r)oll? " answer <- getChar roll <- randomRIO (1,6) case (answer, roll) of ('h', _) -> do putStrLn $ " => Score = " ++ show (stack + score) return $ Score 0 (stack + score) ('r', 1) -> do putStrLn $ " => 1 => Sorry - stack was resetted" return $ Score 0 score ('r', _) -> do putStr $ " => " ++ show roll ++ " => current stack = " ++ show (stack + roll) askPlayer $ Score (stack + roll) score _ -> do putStrLn "\nInvalid input - please try again." askPlayer $ Score stack score  
http://rosettacode.org/wiki/Pernicious_numbers
Pernicious numbers
A   pernicious number   is a positive integer whose   population count   is a prime. The   population count   is the number of   ones   in the binary representation of a non-negative integer. Example 22   (which is   10110   in binary)   has a population count of   3,   which is prime,   and therefore 22   is a pernicious number. Task display the first   25   pernicious numbers   (in decimal). display all pernicious numbers between   888,888,877   and   888,888,888   (inclusive). display each list of integers on one line   (which may or may not include a title). See also Sequence   A052294 pernicious numbers on The On-Line Encyclopedia of Integer Sequences. Rosetta Code entry   population count, evil numbers, odious numbers.
#Clojure
Clojure
(defn counting-numbers ([] (counting-numbers 1)) ([n] (lazy-seq (cons n (counting-numbers (inc n)))))) (defn divisors [n] (filter #(zero? (mod n %)) (range 1 (inc n)))) (defn prime? [n] (= (divisors n) (list 1 n))) (defn pernicious? [n] (prime? (count (filter #(= % \1) (Integer/toString n 2))))) (println (take 25 (filter pernicious? (counting-numbers)))) (println (filter pernicious? (range 888888877 888888889)))
http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation
Permutations/Rank of a permutation
A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items. For our purposes the ranking will assign integers 0.. ( n ! − 1 ) {\displaystyle 0..(n!-1)} to an ordering of all the permutations of the integers 0.. ( n − 1 ) {\displaystyle 0..(n-1)} . For example, the permutations of the digits zero to 3 arranged lexicographically have the following rank: PERMUTATION RANK (0, 1, 2, 3) -> 0 (0, 1, 3, 2) -> 1 (0, 2, 1, 3) -> 2 (0, 2, 3, 1) -> 3 (0, 3, 1, 2) -> 4 (0, 3, 2, 1) -> 5 (1, 0, 2, 3) -> 6 (1, 0, 3, 2) -> 7 (1, 2, 0, 3) -> 8 (1, 2, 3, 0) -> 9 (1, 3, 0, 2) -> 10 (1, 3, 2, 0) -> 11 (2, 0, 1, 3) -> 12 (2, 0, 3, 1) -> 13 (2, 1, 0, 3) -> 14 (2, 1, 3, 0) -> 15 (2, 3, 0, 1) -> 16 (2, 3, 1, 0) -> 17 (3, 0, 1, 2) -> 18 (3, 0, 2, 1) -> 19 (3, 1, 0, 2) -> 20 (3, 1, 2, 0) -> 21 (3, 2, 0, 1) -> 22 (3, 2, 1, 0) -> 23 Algorithms exist that can generate a rank from a permutation for some particular ordering of permutations, and that can generate the same rank from the given individual permutation (i.e. given a rank of 17 produce (2, 3, 1, 0) in the example above). One use of such algorithms could be in generating a small, random, sample of permutations of n {\displaystyle n} items without duplicates when the total number of permutations is large. Remember that the total number of permutations of n {\displaystyle n} items is given by n ! {\displaystyle n!} which grows large very quickly: A 32 bit integer can only hold 12 ! {\displaystyle 12!} , a 64 bit integer only 20 ! {\displaystyle 20!} . It becomes difficult to take the straight-forward approach of generating all permutations then taking a random sample of them. A question on the Stack Overflow site asked how to generate one million random and indivudual permutations of 144 items. Task Create a function to generate a permutation from a rank. Create the inverse function that given the permutation generates its rank. Show that for n = 3 {\displaystyle n=3} the two functions are indeed inverses of each other. Compute and show here 4 random, individual, samples of permutations of 12 objects. Stretch goal State how reasonable it would be to use your program to address the limits of the Stack Overflow question. References Ranking and Unranking Permutations in Linear Time by Myrvold & Ruskey. (Also available via Google here). Ranks on the DevData site. Another answer on Stack Overflow to a different question that explains its algorithm in detail. Related tasks Factorial_base_numbers_indexing_permutations_of_a_collection
#Python
Python
from math import factorial as fact from random import randrange from textwrap import wrap   def identity_perm(n): return list(range(n))   def unranker1(n, r, pi): while n > 0: n1, (rdivn, rmodn) = n-1, divmod(r, n) pi[n1], pi[rmodn] = pi[rmodn], pi[n1] n = n1 r = rdivn return pi   def init_pi1(n, pi): pi1 = [-1] * n for i in range(n): pi1[pi[i]] = i return pi1   def ranker1(n, pi, pi1): if n == 1: return 0 n1 = n-1 s = pi[n1] pi[n1], pi[pi1[n1]] = pi[pi1[n1]], pi[n1] pi1[s], pi1[n1] = pi1[n1], pi1[s] return s + n * ranker1(n1, pi, pi1)   def unranker2(n, r, pi): while n > 0: n1 = n-1 s, rmodf = divmod(r, fact(n1)) pi[n1], pi[s] = pi[s], pi[n1] n = n1 r = rmodf return pi   def ranker2(n, pi, pi1): if n == 1: return 0 n1 = n-1 s = pi[n1] pi[n1], pi[pi1[n1]] = pi[pi1[n1]], pi[n1] pi1[s], pi1[n1] = pi1[n1], pi1[s] return s * fact(n1) + ranker2(n1, pi, pi1)   def get_random_ranks(permsize, samplesize): perms = fact(permsize) ranks = set() while len(ranks) < samplesize: ranks |= set( randrange(perms) for r in range(samplesize - len(ranks)) ) return ranks   def test1(comment, unranker, ranker): n, samplesize, n2 = 3, 4, 12 print(comment) perms = [] for r in range(fact(n)): pi = identity_perm(n) perm = unranker(n, r, pi) perms.append((r, perm)) for r, pi in perms: pi1 = init_pi1(n, pi) print(' From rank %2i to %r back to %2i' % (r, pi, ranker(n, pi[:], pi1))) print('\n  %i random individual samples of %i items:' % (samplesize, n2)) for r in get_random_ranks(n2, samplesize): pi = identity_perm(n2) print(' ' + ' '.join('%2i' % i for i in unranker(n2, r, pi))) print('')   def test2(comment, unranker): samplesize, n2 = 4, 144 print(comment) print('  %i random individual samples of %i items:' % (samplesize, n2)) for r in get_random_ranks(n2, samplesize): pi = identity_perm(n2) print(' ' + '\n '.join(wrap(repr(unranker(n2, r, pi))))) print('')   if __name__ == '__main__': test1('First ordering:', unranker1, ranker1) test1('Second ordering:', unranker2, ranker2) test2('First ordering, large number of perms:', unranker1)
http://rosettacode.org/wiki/Pierpont_primes
Pierpont primes
A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v . A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v . The term "Pierpont primes" is generally understood to mean the first definition, but will be called "Pierpont primes of the first kind" on this page to distinguish them. Task Write a routine (function, procedure, whatever) to find Pierpont primes of the first & second kinds. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the first kind. Use the routine to find and display here, on this page, the first 50 Pierpont primes of the second kind If your language supports large integers, find and display here, on this page, the 250th Pierpont prime of the first kind and the 250th Pierpont prime of the second kind. See also Wikipedia - Pierpont primes OEIS:A005109 - Class 1 -, or Pierpont primes OEIS:A005105 - Class 1 +, or Pierpont primes of the second kind
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
ClearAll[FindUpToMax] FindUpToMax[max_Integer, b_Integer] := Module[{res, num}, res = {}; Do[ num = 2^u 3^v + b; If[PrimeQ[num], AppendTo[res, num]] , {u, 0, Ceiling@Log[2, max]} , {v, 0, Ceiling@Log[3, max]} ]; res //= Select[LessEqualThan[max]]; res //= Sort; res ] Print["Piermont primes of the first kind:"] Take[FindUpToMax[10^10, +1], UpTo[50]] Print["Piermont primes of the second kind:"] Take[FindUpToMax[10^10, -1], UpTo[50]] Print["250th Piermont prime of the first kind:"] Part[FindUpToMax[10^34, +1], 250] Print["250th Piermont prime of the second kind:"] Part[FindUpToMax[10^34, -1], 250] Print["1000th Piermont prime of the first kind:"] Part[FindUpToMax[10^130, +1], 1000] Print["1000th Piermont prime of the second kind:"] Part[FindUpToMax[10^150, -1], 1000]
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#Emacs_Lisp
Emacs Lisp
(defun random-choice (items) (nth (random (length items)) items))   (random-choice '("a" "b" "c")) ;; => "a"
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#Erlang
Erlang
% Implemented by Arjun Sunel -module(pick_random). -export([main/0]).   main() -> List =[1,2,3,4,5], Index = rand:uniform(length(List)), lists:nth(Index,List).  
http://rosettacode.org/wiki/Primality_by_trial_division
Primality by trial division
Task Write a boolean function that tells whether a given integer is prime. Remember that   1   and all non-positive numbers are not prime. Use trial division. Even numbers greater than   2   may be eliminated right away. A loop from   3   to   √ n    will suffice,   but other loops are allowed. Related tasks   count in factors   prime decomposition   AKS test for primes   factors of an integer   Sieve of Eratosthenes   factors of a Mersenne number   trial factoring of a Mersenne number   partition an integer X into N primes   sequence of primes by Trial Division
#uBasic.2F4tH
uBasic/4tH
10 LET n=0: LET p=0 20 INPUT "Enter number: ";n 30 LET p=0 : IF n>1 THEN GOSUB 1000 40 IF p=0 THEN PRINT n;" is not prime!" 50 IF p#0 THEN PRINT n;" is prime!" 60 GOTO 10 1000 REM *************** 1001 REM * PRIME CHECK * 1002 REM *************** 1010 LET p=0 1020 IF (n%2)=0 THEN RETURN 1030 LET p=1 : PUSH n,0 : GOSUB 9030 1040 FOR i=3 TO POP() STEP 2 1050 IF (n%i)=0 THEN LET p=0: PUSH n,0 : GOSUB 9030 : LET i=POP() 1060 NEXT i 1070 RETURN 9030 Push ((10^(Pop()*2))*Pop()) : @(255)=Tos() 9040 Push (@(255) + (Tos()/@(255)))/2 If Abs(@(255)-Tos())<2 Then @(255)=Pop() : If Pop() Then Push @(255) : Return @(255) = Pop() : Goto 9040 REM ** This is an integer SQR subroutine. Output is scaled by 10^(TOS()).
http://rosettacode.org/wiki/Phrase_reversals
Phrase reversals
Task Given a string of space separated words containing the following phrase: rosetta code phrase reversal Reverse the characters of the string. Reverse the characters of each individual word in the string, maintaining original word order within the string. Reverse the order of each word of the string, maintaining the order of characters in each word. Show your output here. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#Elena
Elena
import extensions; import extensions'text; import system'routines;   public program() { var reverse := (s => s.toArray().sequenceReverse().summarize(new StringWriter()));   var phrase := "rosetta code phrase reversal"; console.printLine(phrase);   //Reverse the string console.printLine(reverse(phrase)); //Reverse each individual word in the string, maintaining original string order. console.printLine(phrase.splitBy:" ".selectBy:(s => reverse(s).add(" ")).summarize(new StringWriter())); //Reverse the order of each word of the phrase, maintaining the order of characters in each word. console.printLine(reverse(phrase.splitBy:" ".selectBy:(s => s + " "))) }
http://rosettacode.org/wiki/Phrase_reversals
Phrase reversals
Task Given a string of space separated words containing the following phrase: rosetta code phrase reversal Reverse the characters of the string. Reverse the characters of each individual word in the string, maintaining original word order within the string. Reverse the order of each word of the string, maintaining the order of characters in each word. Show your output here. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#Elixir
Elixir
str = "rosetta code phrase reversal"   IO.puts String.reverse(str) IO.puts String.split(str) |> Enum.map(&String.reverse(&1)) |> Enum.join(" ") IO.puts String.split(str) |> Enum.reverse |> Enum.join(" ")
http://rosettacode.org/wiki/Permutations/Derangements
Permutations/Derangements
A derangement is a permutation of the order of distinct items in which no item appears in its original place. For example, the only two derangements of the three items (0, 1, 2) are (1, 2, 0), and (2, 0, 1). The number of derangements of n distinct items is known as the subfactorial of n, sometimes written as !n. There are various ways to calculate !n. Task Create a named function/method/subroutine/... to generate derangements of the integers 0..n-1, (or 1..n if you prefer). Generate and show all the derangements of 4 integers using the above routine. Create a function that calculates the subfactorial of n, !n. Print and show a table of the counted number of derangements of n vs. the calculated !n for n from 0..9 inclusive. Optional stretch goal   Calculate    !20 Related tasks   Anagrams/Deranged anagrams   Best shuffle   Left_factorials Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet
#C
C
#include <stdio.h> typedef unsigned long long LONG;   LONG deranged(int depth, int len, int *d, int show) { int i; char tmp; LONG count = 0;   if (depth == len) { if (show) { for (i = 0; i < len; i++) putchar(d[i] + 'a'); putchar('\n'); } return 1; } for (i = len - 1; i >= depth; i--) { if (i == d[depth]) continue;   tmp = d[i]; d[i] = d[depth]; d[depth] = tmp; count += deranged(depth + 1, len, d, show); tmp = d[i]; d[i] = d[depth]; d[depth] = tmp; } return count; }   LONG gen_n(int n, int show) { LONG i; int a[1024]; /* 1024 ought to be big enough for anybody */   for (i = 0; i < n; i++) a[i] = i; return deranged(0, n, a, show); }   LONG sub_fact(int n) { return n < 2 ? 1 - n : (sub_fact(n - 1) + sub_fact(n - 2)) * (n - 1); }   int main() { int i;   printf("Deranged Four:\n"); gen_n(4, 1);   printf("\nCompare list vs calc:\n"); for (i = 0; i < 10; i++) printf("%d:\t%llu\t%llu\n", i, gen_n(i, 0), sub_fact(i));   printf("\nfurther calc:\n"); for (i = 10; i <= 20; i++) printf("%d: %llu\n", i, sub_fact(i));   return 0; }