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http://rosettacode.org/wiki/Perfect_shuffle
Perfect shuffle
A perfect shuffle (or faro/weave shuffle) means splitting a deck of cards into equal halves, and perfectly interleaving them - so that you end up with the first card from the left half, followed by the first card from the right half, and so on: 7♠ 8♠ 9♠ J♠ Q♠ K♠→7♠  8♠  9♠   J♠  Q♠  K♠→7♠ J♠ 8♠ Q♠ 9♠ K♠ When you repeatedly perform perfect shuffles on an even-sized deck of unique cards, it will at some point arrive back at its original order. How many shuffles this takes, depends solely on the number of cards in the deck - for example for a deck of eight cards it takes three shuffles: original: 1 2 3 4 5 6 7 8 after 1st shuffle: 1 5 2 6 3 7 4 8 after 2nd shuffle: 1 3 5 7 2 4 6 8 after 3rd shuffle: 1 2 3 4 5 6 7 8 The Task Write a function that can perform a perfect shuffle on an even-sized list of values. Call this function repeatedly to count how many shuffles are needed to get a deck back to its original order, for each of the deck sizes listed under "Test Cases" below. You can use a list of numbers (or anything else that's convenient) to represent a deck; just make sure that all "cards" are unique within each deck. Print out the resulting shuffle counts, to demonstrate that your program passes the test-cases. Test Cases input (deck size) output (number of shuffles required) 8 3 24 11 52 8 100 30 1020 1018 1024 10 10000 300
#Wren
Wren
import "/fmt" for Fmt   var areSame = Fn.new { |a, b| for (i in 0...a.count) if (a[i] != b[i]) return false return true }   var perfectShuffle = Fn.new { |a| var n = a.count var b = List.filled(n, 0) var hSize = (n/2).floor for (i in 0...hSize) b[i * 2] = a[i] var j = 1 for (i in hSize...n) { b[j] = a[i] j = j + 2 } return b }   var countShuffles = Fn.new { |a| var n = a.count if (n < 2 || n % 2 == 1) Fiber.abort("Array must be even-sized and non-empty.") var b = a var count = 0 while (true) { var c = perfectShuffle.call(b) count = count + 1 if (areSame.call(a, c)) return count b = c } }   System.print("Deck size Num shuffles") System.print("--------- ------------") var sizes = [8, 24, 52, 100, 1020, 1024, 10000] for (size in sizes) { var a = List.filled(size, 0) for (i in 1...size) a[i] = i var count = countShuffles.call(a) Fmt.print("$-9d $d", size, count) }
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
#Picat
Picat
go =>  % Create and print the deck deck(Deck), print_deck(Deck), nl,    % Shuffle the deck print_deck(shuffle(Deck)), nl,    % Deal 3 cards Deck := deal(Deck,Card1), Deck := deal(Deck,Card2), Deck := deal(Deck,Card3),   println(deal1=Card1), println(deal2=Card2), println(deal3=Card3),  % The remaining deck print_deck(Deck), nl,    % Deal 5 cards Deck := deal(Deck,Card4), Deck := deal(Deck,Card5), Deck := deal(Deck,Card6), Deck := deal(Deck,Card7), Deck := deal(Deck,Card8),   println(cards4_to_8=[Card4,Card5,Card6,Card7,Card8]), nl,    % Deal 5 cards Deck := deal_n(Deck,5,FiveCards), println(fiveCards=FiveCards), print_deck(Deck), nl,    % And deal some more cards  % This chaining works since deal/1 returns the remaining deck Deck := Deck.deal(Card9).deal(Card10).deal(Card11).deal(Card12), println("4_more_cards"=[Card9,Card10,Card11,Card12]), print_deck(Deck),   nl.   % suits(Suits) => Suits = ["♠","♥","♦","♣"]. suits(Suits) => Suits = ["C","H","S","D"]. values(Values) => Values = ["A","2","3","4","5","6","7","8","9","T","J","Q","K"].   % Create a (sorted) deck. deck(Deck) => suits(Suits), values(Values), Deck =[S++V :V in Values, S in Suits].sort().   % Shuffle a deck shuffle(Deck) = Deck2 => Deck2 = Deck, Len = Deck2.length, foreach(I in 1..Len) R2 = random(1,Len), Deck2 := swap(Deck2,I,R2) end.   % Swap position I <=> J in list L swap(L,I,J) = L2, list(L) => L2 = L, T = L2[I], L2[I] := L2[J], L2[J] := T.     % The first card is returned as the out parameter Card. % The deck is returned as the function value. deal(Deck, Card) = Deck.tail() => Card = Deck.first().   % Deal N cards deal_n(Deck, N, Cards) = [Deck[I] : I in Len+1..Deck.length] => Len = min(N,Deck.length), Cards = [Deck[I] : I in 1..Len].   % Print deck print_deck(Deck) => println("Deck:"), foreach({Card,I} in zip(Deck,1..Deck.len)) printf("%w ", Card), if I mod 10 == 0 then nl end end, nl.
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
#Swift
Swift
  // // main.swift // pi digits // // Created by max goren on 11/11/21. // Copyright © 2021 maxcodes. All rights reserved. //   import Foundation   var r = [Int]() var i = 0 var k = 2800 var b = 0 var c = 0 var d = 0   for _ in 0...2800 { r.append(2000); } while k > 0 { d = 0; i = k; while (true) { d = d + r[i] * 10000 b = 2 * i - 1 r[i] = d % b d = d / b i = i - 1 if i == 0 { break; } d = d * i; } print(c + d / 10000, "") c = d % 10000 k = k - 14 }  
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.
#Ruby
Ruby
require "prime"   class Integer   def popcount to_s(2).count("1") #Ruby 2.4: digits(2).count(1) end   def pernicious? popcount.prime? end   end   p 1.step.lazy.select(&:pernicious?).take(25).to_a p ( 888888877..888888888).select(&:pernicious?)
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#VBScript
VBScript
Function pick_random(arr) Set objRandom = CreateObject("System.Random") pick_random = arr(objRandom.Next_2(0,UBound(arr)+1)) End Function   WScript.Echo pick_random(Array("a","b","c","d","e","f"))
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#Visual_Basic_.NET
Visual Basic .NET
Module Program Sub Main() Dim list As New List(Of Integer)({0, 1, 2, 3, 4, 5, 6, 7, 8, 9}) Dim rng As New Random() Dim randomElement = list(rng.Next(list.Count)) ' Upper bound is exclusive. Console.WriteLine("I picked element {0}", randomElement) End Sub End Module
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#GAP
GAP
Filtered([1 .. 10000], n -> Sum(DivisorsInt(n)) = 2*n); # [ 6, 28, 496, 8128 ]
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#FreeBASIC
FreeBASIC
' version 07-04-2017 ' compile with: fbc -s console   ' Heap's algorithm non-recursive Sub perms(n As Long)   Dim As ULong i, j, count = 1 Dim As ULong a(0 To n -1), c(0 To n -1)   For j = 0 To n -1 a(j) = j +1 Print a(j); Next Print " ";   i = 0 While i < n If c(i) < i Then If (i And 1) = 0 Then Swap a(0), a(i) Else Swap a(c(i)), a(i) End If For j = 0 To n -1 Print a(j); Next count += 1 If count = 12 Then Print count = 0 Else Print " "; End If c(i) += 1 i = 0 Else c(i) = 0 i += 1 End If Wend   End Sub   ' ------=< MAIN >=------   perms(4)   ' empty keyboard buffer While Inkey <> "" : Wend Print : Print "hit any key to end program" Sleep End
http://rosettacode.org/wiki/Perfect_shuffle
Perfect shuffle
A perfect shuffle (or faro/weave shuffle) means splitting a deck of cards into equal halves, and perfectly interleaving them - so that you end up with the first card from the left half, followed by the first card from the right half, and so on: 7♠ 8♠ 9♠ J♠ Q♠ K♠→7♠  8♠  9♠   J♠  Q♠  K♠→7♠ J♠ 8♠ Q♠ 9♠ K♠ When you repeatedly perform perfect shuffles on an even-sized deck of unique cards, it will at some point arrive back at its original order. How many shuffles this takes, depends solely on the number of cards in the deck - for example for a deck of eight cards it takes three shuffles: original: 1 2 3 4 5 6 7 8 after 1st shuffle: 1 5 2 6 3 7 4 8 after 2nd shuffle: 1 3 5 7 2 4 6 8 after 3rd shuffle: 1 2 3 4 5 6 7 8 The Task Write a function that can perform a perfect shuffle on an even-sized list of values. Call this function repeatedly to count how many shuffles are needed to get a deck back to its original order, for each of the deck sizes listed under "Test Cases" below. You can use a list of numbers (or anything else that's convenient) to represent a deck; just make sure that all "cards" are unique within each deck. Print out the resulting shuffle counts, to demonstrate that your program passes the test-cases. Test Cases input (deck size) output (number of shuffles required) 8 3 24 11 52 8 100 30 1020 1018 1024 10 10000 300
#XPL0
XPL0
int Deck(10000), Deck0(10000); int Cases, Count, Test, Size, I;   proc Shuffle; \Do perfect shuffle of Deck0 into Deck int DeckLeft, DeckRight; int I; [DeckLeft:= Deck0; DeckRight:= Deck0 + Size*4/2; \4 bytes per integer for I:= 0 to Size-1 do Deck(I):= if I&1 then DeckRight(I/2) else DeckLeft(I/2); ];   [Cases:= [8, 24, 52, 100, 1020, 1024, 10000]; for Test:= 0 to 7-1 do [Size:= Cases(Test); for I:= 0 to Size-1 do Deck(I):= I; Count:= 0; repeat for I:= 0 to Size-1 do Deck0(I):= Deck(I); Shuffle; Count:= Count+1; for I:= 0 to Size-1 do if Deck(I) # I then I:= Size; until I = Size; \equal starting configuration IntOut(0, Size); ChOut(0, 9\tab\); IntOut(0, Count); CrLf(0); ]; ]
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
#PicoLisp
PicoLisp
(de *Suits Club Diamond Heart Spade )   (de *Pips Ace 2 3 4 5 6 7 8 9 10 Jack Queen King )   (de mkDeck () (mapcan '((Pip) (mapcar cons *Suits (circ Pip))) *Pips ) )   (de shuffle (Lst) (by '(NIL (rand)) sort Lst) )
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
#Pascal
Pascal
Program Pi_Spigot; const n = 1000; len = 10*n div 3;   var j, k, q, nines, predigit: integer; a: array[0..len] of longint;   function OneLoop(i:integer):integer; var x: integer; begin {Only calculate as far as needed } {+16 for security digits ~5 decimals} i := i*10 div 3+16; IF i > len then i := len; result := 0; repeat {Work backwards} x := 10*a[i] + result*i; result := x div (2*i - 1); a[i] := x - result*(2*i - 1);//x mod (2*i - 1) dec(i); until i<= 0 ; end;   begin   for j := 1 to len do a[j] := 2; {Start with 2s} nines := 0; predigit := 0; {First predigit is a 0}   for j := 1 to n do begin q := OneLoop(n-j); a[1] := q mod 10; q := q div 10; if q = 9 then nines := nines + 1 else if q = 10 then begin write(predigit+1); for k := 1 to nines do write(0); {zeros} predigit := 0; nines := 0 end else begin write(predigit); predigit := q; if nines <> 0 then begin for k := 1 to nines do write(9); nines := 0 end end end; writeln(predigit); end.
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.
#Rust
Rust
  extern crate aks_test_for_primes;   use std::iter::Filter; use std::ops::RangeFrom;   use aks_test_for_primes::is_prime;   fn main() { for i in pernicious().take(25) { print!("{} ", i); } println!(); for i in (888_888_877u64..888_888_888).filter(is_pernicious) { print!("{} ", i); } }   fn pernicious() -> Filter<RangeFrom<u64>, fn(&u64) -> bool> { (0u64..).filter(is_pernicious as fn(&u64) -> bool) }   fn is_pernicious(n: &u64) -> bool { is_prime(n.count_ones()) }  
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.
#S-lang
S-lang
% Simplistic prime-test from prime-by-trial-division: define is_prime(n) { if (n <= 1) return(0); if (n == 2) return(1); if ((n & 1) == 0) return(0);   variable mx = int(sqrt(n)), i;   _for i (3, mx, 1) { if ((n mod i) == 0) return(0); } return(1); }   define population(n) { variable pc = 0; do { if (n & 1) pc++; n /= 2; } while (n); return(pc); }   define is_pernicious(n) { return(is_prime(population(n))); }   variable plist = {}, n = 0; while (length(plist) < 25) { n++; if (is_pernicious(n)) list_append(plist, string(n)); } print(strjoin(list_to_array(plist), " "));   plist = {}; _for n (888888877, 888888888, 1) { if (is_pernicious(n)) list_append(plist, string(n)); } print(strjoin(list_to_array(plist), " "));  
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#Wren
Wren
import "random" for Random   var rand = Random.new() var colors = ["red", "green", "blue", "yellow", "pink"] for (i in 0..4) System.print(colors[rand.int(colors.count)])
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#XBS
XBS
set Array = ["Hello","World",1,2,3]; log(Array[rnd(0,?Array-1)]);
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Go
Go
package main   import "fmt"   func computePerfect(n int64) bool { var sum int64 for i := int64(1); i < n; i++ { if n%i == 0 { sum += i } } return sum == n }   // following function satisfies the task, returning true for all // perfect numbers representable in the argument type func isPerfect(n int64) bool { switch n { case 6, 28, 496, 8128, 33550336, 8589869056, 137438691328, 2305843008139952128: return true } return false }   // validation func main() { for n := int64(1); ; n++ { if isPerfect(n) != computePerfect(n) { panic("bug") } if n%1e3 == 0 { fmt.Println("tested", n) } } }    
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#Frink
Frink
a = [1,2,3,4] println[formatTable[a.lexicographicPermute[]]]
http://rosettacode.org/wiki/Perfect_shuffle
Perfect shuffle
A perfect shuffle (or faro/weave shuffle) means splitting a deck of cards into equal halves, and perfectly interleaving them - so that you end up with the first card from the left half, followed by the first card from the right half, and so on: 7♠ 8♠ 9♠ J♠ Q♠ K♠→7♠  8♠  9♠   J♠  Q♠  K♠→7♠ J♠ 8♠ Q♠ 9♠ K♠ When you repeatedly perform perfect shuffles on an even-sized deck of unique cards, it will at some point arrive back at its original order. How many shuffles this takes, depends solely on the number of cards in the deck - for example for a deck of eight cards it takes three shuffles: original: 1 2 3 4 5 6 7 8 after 1st shuffle: 1 5 2 6 3 7 4 8 after 2nd shuffle: 1 3 5 7 2 4 6 8 after 3rd shuffle: 1 2 3 4 5 6 7 8 The Task Write a function that can perform a perfect shuffle on an even-sized list of values. Call this function repeatedly to count how many shuffles are needed to get a deck back to its original order, for each of the deck sizes listed under "Test Cases" below. You can use a list of numbers (or anything else that's convenient) to represent a deck; just make sure that all "cards" are unique within each deck. Print out the resulting shuffle counts, to demonstrate that your program passes the test-cases. Test Cases input (deck size) output (number of shuffles required) 8 3 24 11 52 8 100 30 1020 1018 1024 10 10000 300
#zkl
zkl
fcn perfectShuffle(numCards){ deck,shuffle,n,N:=numCards.pump(List),deck,0,numCards/2; do{ shuffle=shuffle[0,N].zip(shuffle[N,*]).flatten(); n+=1 } while(deck!=shuffle); n } foreach n in (T(8,24,52,100,1020,1024,10000)){ println("%5d : %d".fmt(n,perfectShuffle(n))); }
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
#PowerShell
PowerShell
  <# .Synopsis Creates a new "Deck" which is a hashtable converted to a dictionary This is only used for creating the deck, to view/list the deck contents use Get-Deck. .DESCRIPTION Casts the string value that the user inputs to the name of the variable that holds the "deck" Creates a global variable, allowing you to use the name you choose in other functions and allows you to create multiple decks under different names. .EXAMPLE PS C:\WINDOWS\system32> New-Deck cmdlet New-Deck at command pipeline position 1 Supply values for the following parameters: YourDeckName: Deck1   PS C:\WINDOWS\system32>   .EXAMPLE PS C:\WINDOWS\system32> New-Deck -YourDeckName Deck2   PS C:\WINDOWS\system32>   .EXAMPLE PS C:\WINDOWS\system32> New-Deck -YourDeckName Deck2   PS C:\WINDOWS\system32> New-Deck -YourDeckName Deck3   PS C:\WINDOWS\system32> #> function New-Deck { [CmdletBinding()] [OutputType([int])] Param ( # Name your Deck, this will be the name of the variable that holds your deck [Parameter(Mandatory=$true, ValueFromPipelineByPropertyName=$False, Position=0)]$YourDeckName )   Begin { $Suit = @(' of Hearts', ' of Spades', ' of Diamonds', ' of Clubs') $Pip = @('Ace', 'King', 'Queen', 'Jack', '10', '9', '8', '7', '6', '5', '4', '3', '2')   #Creates the hash table that will hold the suit and pip variables $Deck = @{}   #creates counters for the loop below to make 52 total cards with 13 cards per suit [int]$SuitCounter = 0 [int]$PipCounter = 0 [int]$CardValue = 0   } Process { #Creates the initial deck do { #card2add is the rows in the hashtable $Card2Add = ($Pip[$PipCounter]+$Suit[$SuitCounter])   #Addes the row to the hashtable $Deck.Add($CardValue, $Card2Add)   #Used to create the Keys $CardValue++   #Counts the amount of cards per suit $PipCounter ++ if ($PipCounter -eq 13) { #once reached the suit is changed $SuitCounter++ #and the per-suit counter is reset $PipCounter = 0 } else { continue } } #52 cards in a deck until ($Deck.count -eq 52)   } End { #sets the name of a variable that is unknown #Then converts the hash table to a dictionary and pipes it to the Get-Random cmdlet with the arguments to randomize the contents Set-Variable -Name "$YourDeckName" -Value ($Deck.GetEnumerator() | Get-Random -Count ([int]::MaxValue)) -Scope Global } }   <# .Synopsis Lists the cards in your selected deck .DESCRIPTION Contains a Try-Catch-Finally block in case the deck requested has not been created .EXAMPLE PS C:\WINDOWS\system32> Get-Deck -YourDeckName deck1   8 of Clubs 5 of Hearts --Shortened-- King of Clubs Jack of Diamonds   PS C:\WINDOWS\system32>     .EXAMPLE PS C:\WINDOWS\system32> Get-Deck -YourDeckName deck2   deck2 does not exist... Creating Deck deck2...   Ace of Spades 10 of Hearts --Shortened-- 5 of Clubs 4 of Clubs   PS C:\WINDOWS\system32>   .EXAMPLE PS C:\WINDOWS\system32> deck deck2   Ace of Spades 10 of Hearts --Shortened-- 4 of Spades 6 of Spades Queen of Spades     PS C:\WINDOWS\system32> #> function Get-Deck { [CmdletBinding()] [Alias('Deck')] [OutputType([int])] Param ( #Brings the Vairiable in from Get-Deck [Parameter(Mandatory=$true, ValueFromPipelineByPropertyName=$true, Position=0)]$YourDeckName )   Begin {   } Process { # Will return a terminal error if the deck has not been created try { $temp = Get-Variable -name "$YourDeckName" -ValueOnly -ErrorAction stop } catch { Write-Host Write-Host "$YourDeckName does not exist..." Write-Host "Creating Deck $YourDeckName..." New-Deck -YourDeckName $YourDeckName $temp = Get-Variable -name "$YourDeckName" -ValueOnly }   finally { $temp | select Value | ft -HideTableHeaders }   } End { Write-Verbose "End of show-deck function" } }   <# .Synopsis Shuffles a deck of your selection with Get-Random .DESCRIPTION This function can be used to Shuffle any deck that has been created. This can be used on a deck that has less than 52 cards Contains a Try-Catch-Finally block in case the deck requested has not been created Does NOT output the value of the deck being shuffled (You wouldn't look at the cards you shuffled, would you?)   .EXAMPLE PS C:\WINDOWS\system32> Shuffle-Deck -YourDeckName Deck1 Your Deck was shuffled   PS C:\WINDOWS\system32>   .EXAMPLE PS C:\WINDOWS\system32> Shuffle NotMadeYet   NotMadeYet does not exist... Creating and shuffling NotMadeYet... Your Deck was shuffled   PS C:\WINDOWS\system32> #> function Shuffle-Deck { [CmdletBinding()] [Alias('Shuffle')] [OutputType([int])] Param ( #The Deck you want to shuffle [Parameter(Mandatory=$true, ValueFromPipelineByPropertyName=$true, Position=0)]$YourDeckName)   Begin { Write-Verbose 'Shuffles your deck with Get-Random' } Process { # Will return a missing variable error if the deck has net been created try { #These two commands could be on one line using the pipeline, but look cleaner on two $temp1 = Get-Variable -name "$YourDeckName" -ValueOnly -ErrorAction stop $temp1 = $temp1 | Get-Random -Count ([int]::MaxValue) } catch { Write-Host Write-Host "$YourDeckName does not exist..." Write-Host "Creating and shuffling $YourDeckName..." New-Deck -YourDeckName $YourDeckName $temp1 = Get-Variable -name "$YourDeckName" -ValueOnly $temp1 = $temp1 | Get-Random -Count ([int]::MaxValue)   }   finally { #Gets the actual value of variable $YourDeckName from the New-Deck function and uses that string value #to set the variables name Set-Variable -Name "$YourDeckName" -value ($temp1) -Scope Global } } End { Write-Host "Your Deck was shuffled" } }   <# .Synopsis Creates a new "Hand" which is a hashtable converted to a dictionary This is only used for creating the hand, to view/list the deck contents use Get-Hand. .DESCRIPTION Casts the string value that the user inputs to the name of the variable that holds the "hand" Creates a global variable, allowing you to use the name you choose in other functions and allows you to create multiple hands under different names. .EXAMPLE PS C:\WINDOWS\system32> New-Hand -YourHandName JohnDoe   PS C:\WINDOWS\system32> .EXAMPLE PS C:\WINDOWS\system32> New-Hand JaneDoe   PS C:\WINDOWS\system32> > #> function New-Hand { [CmdletBinding()] [OutputType([int])] Param ( # Name your Deck, this will be the name of the variable that holds your deck [Parameter(Mandatory=$true, ValueFromPipelineByPropertyName=$False, Position=0)]$YourHandName )   Begin { $Hand = @{} } Process { }   End { Set-Variable -Name "$YourHandName" -Value ($Hand.GetEnumerator()) -Scope Global } }   <# .Synopsis Lists the cards in the selected Hand .DESCRIPTION Contains a Try-Catch-Finally block in case the hand requested has not been created .EXAMPLE #create a new hand PS C:\WINDOWS\system32> New-Hand -YourHandName Hand1   PS C:\WINDOWS\system32> Get-Hand -YourHandName Hand1 Hand1's hand contains cards, they are...   PS C:\WINDOWS\system32> #This hand is empty .EXAMPLE PS C:\WINDOWS\system32> Get-Hand -YourHandName Hand2   Hand2 does not exist... Creating Hand Hand2... Hand2's hand contains cards, they are...   PS C:\WINDOWS\system32>   .EXAMPLE PS C:\WINDOWS\system32> hand hand3 hand3's hand contains 4 cards, they are...   5 of Spades 4 of Spades 6 of Spades Queen of Diamonds #> function Get-Hand { [CmdletBinding()] [Alias('Hand')] [OutputType([int])] Param ( #Brings the Vairiable in from Get-Deck [Parameter(Mandatory=$true, ValueFromPipelineByPropertyName=$true, Position=0)]$YourHandName ) Begin { } Process { # Will return a missing variable error if the deck has net been created try { $temp = Get-Variable -name "$YourHandName" -ValueOnly -ErrorAction stop } catch { Write-Host Write-Host "$YourHandName does not exist..." Write-Host "Creating Hand $YourHandName..." New-Hand -YourHandName $YourHandName $temp = Get-Variable -name "$YourHandName" -ValueOnly }   finally { $count = $temp.count Write-Host "$YourHandName's hand contains $count cards, they are..." $temp | select Value | ft -HideTableHeaders }   } End { Write-Verbose "End of show-deck function" } }   <# .Synopsis Draws/returns cards .DESCRIPTION Draws/returns cards from your chosen deck , to your chosen hand Can be used without creating a deck or hand first .EXAMPLE PS C:\WINDOWS\system32> DrawFrom-Deck -YourDeckName Deck1 -YourHandName test1 -HowManyCardsToDraw 10       PS C:\WINDOWS\system32> .EXAMPLE DrawFrom-Deck -YourDeckName Deck2 -YourHandName test2 -HowManyCardsToDraw 10 Deck2 does not exist... Creating Deck Deck2...   test2 does not exist... Creating Hand test2... test2's hand contains cards, they are...       .EXAMPLE PS C:\WINDOWS\system32> draw -YourDeckName deck1 -YourHandName test1 -HowManyCardsToDraw 5       #> function Draw-Deck { [CmdletBinding()] [Alias('Draw')] [OutputType([int])] Param ( # The Deck in which you want to draw cards out of [Parameter(Mandatory=$true, ValueFromPipelineByPropertyName=$true, Position=0)]$YourDeckName,   #The hand in which you want to draw cards to [Parameter(Mandatory=$true, ValueFromPipelineByPropertyName=$true, Position=0)]$YourHandName,     #Quanity of cards being drawn [Parameter(Mandatory=$true, ValueFromPipelineByPropertyName=$true, Position=0)]$HowManyCardsToDraw   ) Begin { Write-Verbose "Draws a chosen amount of cards from the chosen deck"   #try-catch-finally blocks so the user does not have to use New-Deck and New-Hand beforehand. try { $temp = Get-Variable -name "$YourDeckName" -ValueOnly -ErrorAction Stop } catch { Get-Deck -YourDeckName $YourDeckName $temp = Get-Variable -name "$YourDeckName" -ValueOnly -ErrorAction Stop } finally { Write-Host }   try { $temp2 = Get-Variable -name "$YourHandName" -ValueOnly -ErrorAction Stop } catch { Get-Hand -YourHandName $YourHandName $temp2 = Get-Variable -name "$YourHandName" -ValueOnly -ErrorAction Stop } finally { Write-Host } }   Process { Write-Host "you drew $HowManyCardsToDraw cards, they are..."   $handValues = Get-Variable -name "$YourDeckName" -ValueOnly $handValues = $handValues[0..(($HowManyCardsToDraw -1))] | select value | ft -HideTableHeaders $handValues   } End { #sets the new values for the deck and the hand selected Set-Variable -Name "$YourDeckName" -value ($temp[$HowManyCardsToDraw..($temp.count)]) -Scope Global Set-Variable -Name "$YourHandName" -value ($temp2 + $handValues) -Scope Global } }  
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
#Perl
Perl
sub pistream { my $digits = shift; my(@out, @a); my($b, $c, $d, $e, $f, $g, $i, $d4, $d3, $d2, $d1); my $outi = 0;   $digits++; $b = $d = $e = $g = $i = 0; $f = 10000; $c = 14 * (int($digits/4)+2); @a = (20000000) x $c; print "3."; while (($b = $c -= 14) > 0 && $i < $digits) { $d = $e = $d % $f; while (--$b > 0) { $d = $d * $b + $a[$b]; $g = ($b << 1) - 1; $a[$b] = ($d % $g) * $f; $d = int($d / $g); } $d4 = $e + int($d/$f); if ($d4 > 9999) { $d4 -= 10000; $out[$i-1]++; for ($b = $i-1; $out[$b] == 1; $b--) { $out[$b] = 0; $out[$b-1]++; } } $d3 = int($d4/10); $d2 = int($d3/10); $d1 = int($d2/10); $out[$i++] = $d1; $out[$i++] = $d2-$d1*10; $out[$i++] = $d3-$d2*10; $out[$i++] = $d4-$d3*10; print join "", @out[$i-15 .. $i-15+3] if $i >= 16; } # We've closed the spigot. Print the remainder without rounding. print join "", @out[$i-15+4 .. $digits-2], "\n"; }
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.
#Scala
Scala
def isPernicious( v:Long ) : Boolean = BigInt(v.toBinaryString.toList.filter( _ == '1' ).length).isProbablePrime(16)   // Generate the output { val (a,b1,b2) = (25,888888877L,888888888L) println( Stream.from(2).filter( isPernicious(_) ).take(a).toList.mkString(",") ) println( {for( i <- b1 to b2 if( isPernicious(i) ) ) yield i}.mkString(",") ) }
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#XPL0
XPL0
code Ran=1, Text=12; int List; [List:= ["hydrogen", "helium", "lithium", "beryllium", "boron"]; \(Thanks REXX) Text(0, List(Ran(5))); ]
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#Zig
Zig
const std = @import("std");   const debug = std.debug; const rand = std.rand; const time = std.time;   test "pick random element" { var pcg = rand.Pcg.init(time.milliTimestamp());   const chars = [_]u8{ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '?', '!', '<', '>', '(', ')', };   var i: usize = 0; while (i < 32) : (i += 1) { if (i % 4 == 0) { debug.warn("\n ", .{}); } debug.warn("'{c}', ", .{chars[pcg.random.int(usize) % chars.len]}); }   debug.warn("\n", .{}); }
http://rosettacode.org/wiki/Pick_random_element
Pick random element
Demonstrate how to pick a random element from a list.
#zkl
zkl
list:=T("hydrogen", "helium", "lithium", "beryllium", "boron"); list[(0).random(list.len())]
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Groovy
Groovy
def isPerfect = { n -> n > 4 && (n == (2..Math.sqrt(n)).findAll { n % it == 0 }.inject(1) { factorSum, i -> factorSum += i + n/i }) }
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#GAP
GAP
gap>List(SymmetricGroup(4), p -> Permuted([1 .. 4], p)); perms(4); [ [ 1, 2, 3, 4 ], [ 4, 2, 3, 1 ], [ 2, 4, 3, 1 ], [ 3, 2, 4, 1 ], [ 1, 4, 3, 2 ], [ 4, 1, 3, 2 ], [ 2, 1, 3, 4 ], [ 3, 1, 4, 2 ], [ 1, 3, 4, 2 ], [ 4, 3, 1, 2 ], [ 2, 3, 1, 4 ], [ 3, 4, 1, 2 ], [ 1, 2, 4, 3 ], [ 4, 2, 1, 3 ], [ 2, 4, 1, 3 ], [ 3, 2, 1, 4 ], [ 1, 4, 2, 3 ], [ 4, 1, 2, 3 ], [ 2, 1, 4, 3 ], [ 3, 1, 2, 4 ], [ 1, 3, 2, 4 ], [ 4, 3, 2, 1 ], [ 2, 3, 4, 1 ], [ 3, 4, 2, 1 ] ]
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
#Prolog
Prolog
/** <module> Cards   A card is represented by the term "card(Pip, Suit)". A deck is represented internally as a list of cards.   Usage: new_deck(D0), deck_shuffle(D0, D1), deck_deal(D1, C, D2). */ :- module(cards, [ new_deck/1, % -Deck deck_shuffle/2, % +Deck, -NewDeck deck_deal/3, % +Deck, -Card, -NewDeck print_deck/1 % +Deck ]).   %% new_deck(-Deck) new_deck(Deck) :- Suits = [clubs, hearts, spades, diamonds], Pips = [2, 3, 4, 5, 6, 7, 8, 9, 10, jack, queen, king, ace], setof(card(Pip, Suit), (member(Suit, Suits), member(Pip, Pips)), Deck).   %% deck_shuffle(+Deck, -NewDeck) deck_shuffle(Deck, NewDeck) :- length(Deck, NumCards), findall(X, (between(1, NumCards, _I), X is random(1000)), Ord), pairs_keys_values(Pairs, Ord, Deck), keysort(Pairs, OrdPairs), pairs_values(OrdPairs, NewDeck).   %% deck_deal(+Deck, -Card, -NewDeck) deck_deal([Card|Cards], Card, Cards).   %% print_deck(+Deck) print_deck(Deck) :- maplist(print_card, Deck).   % print_card(+Card) print_card(card(Pip, Suit)) :- format('~a of ~a~n', [Pip, 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
#Phix
Phix
with javascript_semantics integer a=10000,b,c=8400,d,e=0,g sequence f=repeat(floor(a/5),c+1) while c>0 do g=2*c d=0 b=c while b>0 do d+=f[b]*a g-=1 f[b]=remainder(d, g) d=floor(d/g) g-=1 b-=1 if b!=0 then d*=b end if end while printf(1,"%04d",e+floor(d/a)) c-=14 e = remainder(d,a) end while
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.
#Seed7
Seed7
$ include "seed7_05.s7i";   const set of integer: primes is {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61};   const func integer: popcount (in integer: number) is return card(bitset(number));   const proc: main is func local var integer: num is 0; var integer: count is 0; begin for num range 0 to integer.last until count >= 25 do if popcount(num) in primes then write(num <& " "); incr(count); end if; end for; writeln; for num range 888888877 to 888888888 do if popcount(num) in primes then write(num <& " "); end if; end for; writeln; end func;
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Haskell
Haskell
perfect n = n == sum [i | i <- [1..n-1], n `mod` i == 0]
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#HicEst
HicEst
DO i = 1, 1E4 IF( perfect(i) ) WRITE() i ENDDO END ! end of "main"   FUNCTION perfect(n) sum = 1 DO i = 2, n^0.5 sum = sum + (MOD(n, i) == 0) * (i + INT(n/i)) ENDDO perfect = sum == n END
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#Glee
Glee
$$ n !! k dyadic: Permutations for k out of n elements (in this case k = n) $$ #s monadic: number of elements in s $$ ,, monadic: expose with space-lf separators $$ s[n] index n of s   'Hello' 123 7.9 '•'=>s; s[s# !! (s#)],,
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
#PureBasic
PureBasic
#MaxCards = 52 ;Max Cards in a deck Structure card pip.s suit.s EndStructure   Structure _membersDeckClass *vtable.i size.i ;zero based count of cards present cards.card[#MaxCards] ;deck content EndStructure   Interface deckObject Init() shuffle() deal.s(isAbbr = #True) show(isAbbr = #True) EndInterface   Procedure.s _formatCardInfo(*card.card, isAbbr = #True) ;isAbbr determines if the card information is abbrieviated to 2 characters Static pips.s = "2 3 4 5 6 7 8 9 10 Jack Queen King Ace" Static suits.s = "Diamonds Clubs Hearts Spades" Protected c.s   If isAbbr c = *card\pip + *card\suit Else c = StringField(pips,FindString("23456789TJQKA", *card\pip, 1), " ") + " of " c + StringField(suits,FindString("DCHS", *card\suit, 1)," ") EndIf ProcedureReturn c EndProcedure   Procedure setInitialValues(*this._membersDeckClass) Protected i, c.s   Restore cardDat For i = 0 To #MaxCards - 1 Read.s c *this\cards[i]\pip = Left(c, 1) *this\cards[i]\suit = Right(c, 1) Next EndProcedure   Procedure.s dealCard(*this._membersDeckClass, isAbbr) ;isAbbr is #True if the card dealt is abbrieviated to 2 characters Protected c.card If *this\size < 0 ;deck is empty ProcedureReturn "" Else c = *this\cards[*this\size] *this\size - 1 ProcedureReturn _formatCardInfo(@c, isAbbr) EndIf EndProcedure   Procedure showDeck(*this._membersDeckClass, isAbbr) ;isAbbr determines if cards are shown with 2 character abbrieviations Protected i   For i = 0 To *this\size Print(_formatCardInfo(@*this\cards[i], isAbbr)) If i <> *this\size: Print(", "): EndIf Next PrintN("") EndProcedure   Procedure shuffle(*this._membersDeckClass) ;works with decks of any size Protected w, i Dim shuffled.card(*this\size)   For i = *this\size To 0 Step -1 w = Random(i) shuffled(i) = *this\cards[w] If w <> i *this\cards[w] = *this\cards[i] EndIf   Next   For i = 0 To *this\size *this\cards[i] = shuffled(i) Next EndProcedure   Procedure newDeck() Protected *newDeck._membersDeckClass = AllocateMemory(SizeOf(_membersDeckClass)) If *newDeck *newDeck\vtable = ?vTable_deckClass *newDeck\size = #MaxCards - 1 setInitialValues(*newDeck) EndIf ProcedureReturn *newDeck EndProcedure   DataSection vTable_deckClass: Data.i @setInitialValues() Data.i @shuffle() Data.i @dealCard() Data.i @showDeck()   cardDat: Data.s "2D", "3D", "4D", "5D", "6D", "7D", "8D", "9D", "TD", "JD", "QD", "KD", "AD" Data.s "2C", "3C", "4C", "5C", "6C", "7C", "8C", "9C", "TC", "JC", "QC", "KC", "AC" Data.s "2H", "3H", "4H", "5H", "6H", "7H", "8H", "9H", "TH", "JH", "QH", "KH", "AH" Data.s "2S", "3S", "4S", "5S", "6S", "7S", "8S", "9S", "TS", "JS", "QS", "KS", "AS" EndDataSection   If OpenConsole()   Define deck.deckObject = newDeck() Define deck2.deckObject = newDeck()   If deck = 0 Or deck2 = 0 PrintN("Unable to create decks") End EndIf   deck\shuffle() PrintN("Dealt: " + deck\deal(#False)) PrintN("Dealt: " + deck\deal(#False)) PrintN("Dealt: " + deck\deal(#False)) PrintN("Dealt: " + deck\deal(#False)) deck\show() deck2\show()   Print(#CRLF$ + #CRLF$ + "Press ENTER to exit") Input() CloseConsole() EndIf
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
#Picat
Picat
go => pi2(1,0,1,1,3,3,0), nl.   pi2(Q,R,T,K,N,L,C) => if C == 50 then nl, pi2(Q,R,T,K,N,L,0) else if (4*Q + R-T) < (N*T) then print(N), P := 10*(R-N*T), pi2(Q*10, P, T, K, ((10*(3*Q+R)) div T)-10*N, L,C+1) else P := (2*Q+R)*L, M := (Q*(7*K)+2+(R*L)) div (T*L), H := L+2, J := K+ 1, pi2(Q*K, P, T*L, J, M, H, C) end end, nl.
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.
#Sidef
Sidef
func is_pernicious(n) { n.sumdigits(2).is_prime }   say is_pernicious.first(25).join(' ') say is_pernicious.grep(888_888_877..888_888_888).join(' ')
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Icon_and_Unicon
Icon and Unicon
procedure main(arglist) limit := \arglist[1] | 100000 write("Perfect numbers from 1 to ",limit,":") every write(isperfect(1 to limit)) write("Done.") end   procedure isperfect(n) #: returns n if n is perfect local sum,i   every (sum := 0) +:= (n ~= divisors(n)) if sum = n then return n end   link factors
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#GNU_make
GNU make
  #delimiter should not occur inside elements delimiter=; #convert list to delimiter separated string implode=$(subst $() $(),$(delimiter),$(strip $1)) #convert delimiter separated string to list explode=$(strip $(subst $(delimiter), ,$1)) #enumerate all permutations and subpermutations permutations0=$(if $1,$(foreach x,$1,$x $(addprefix $x$(delimiter),$(call permutations0,$(filter-out $x,$1)))),) #remove subpermutations from permutations0 output permutations=$(strip $(foreach x,$(call permutations0,$1),$(if $(filter $(words $1),$(words $(call explode,$x))),$(call implode,$(call explode,$x)),)))   delimiter_separated_output=$(call permutations,a b c d) $(info $(delimiter_separated_output))  
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
#Python
Python
import random   class Card(object): suits = ("Clubs","Hearts","Spades","Diamonds") pips = ("2","3","4","5","6","7","8","9","10","Jack","Queen","King","Ace")   def __init__(self, pip,suit): self.pip=pip self.suit=suit   def __str__(self): return "%s %s"%(self.pip,self.suit)   class Deck(object): def __init__(self): self.deck = [Card(pip,suit) for suit in Card.suits for pip in Card.pips]   def __str__(self): return "[%s]"%", ".join( (str(card) for card in self.deck))   def shuffle(self): random.shuffle(self.deck)   def deal(self): self.shuffle() # Can't tell what is next from self.deck return self.deck.pop(0)
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
#PicoLisp
PicoLisp
#!/usr/bin/picolisp /usr/lib/picolisp/lib.l   (de piDigit () (job '((Q . 1) (R . 0) (S . 1) (K . 1) (N . 3) (L . 3)) (while (>= (- (+ R (* 4 Q)) S) (* N S)) (mapc set '(Q R S K N L) (list (* Q K) (* L (+ R (* 2 Q))) (* S L) (inc K) (/ (+ (* Q (+ 2 (* 7 K))) (* R L)) (* S L)) (+ 2 L) ) ) ) (prog1 N (let M (- (/ (* 10 (+ R (* 3 Q))) S) (* 10 N)) (setq Q (* 10 Q) R (* 10 (- R (* N S))) N M) ) ) ) )   (prin (piDigit) ".") (loop (prin (piDigit)) (flush) )
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.
#Swift
Swift
import Foundation   extension BinaryInteger { @inlinable public var isPrime: Bool { if self == 0 || self == 1 { return false } else if self == 2 { return true }   let max = Self(ceil((Double(self).squareRoot())))   for i in stride(from: 2, through: max, by: 1) where self % i == 0 { return false }   return true } }   public func populationCount(n: Int) -> Int { guard n >= 0 else { return 0 }   return String(n, radix: 2).lazy.filter({ $0 == "1" }).count }   let first25 = (1...).lazy.filter({ populationCount(n: $0).isPrime }).prefix(25) let rng = (888_888_877...888_888_888).lazy.filter({ populationCount(n: $0).isPrime })   print("First 25 Pernicious numbers: \(Array(first25))") print("Pernicious numbers between 888_888_877...888_888_888: \(Array(rng))")
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.
#Symsyn
Symsyn
    primes : 0b0010100000100000100010100010000010100000100010100010100010101100   | the first 25 pernicious numbers     $T | clear string num_pn | set to zero 2 n | start at 2 5 hi_bit if num_pn LT 25 call popcount | count ones if primes bit pop_cnt | if pop_cnt bit of bit vector primes is one + num_pn | inc number of pernicious numbers ~ n $S | convert to decimal string + ' ' $S | pad a space + $S $T | add to string $T endif + pop_cnt | next number (odd) has one more bit than previous (even) + n | next number if primes bit pop_cnt + num_pn ~ n $S + ' ' $S + $S $T endif + n goif | go back to if endif $T [] | display numbers       | pernicious numbers in range 888888877 .. 888888888   $T | clear string num_pn | set to zero 888888876 n | start at 888888876 29 hi_bit if n LE 888888888 call popcount | count ones if primes bit pop_cnt | if pop_cnt bit of bit vector primes is one + num_pn | inc number of pernicious numbers ~ n $S | convert to decimal string + ' ' $S | pad a space + $S $T | add to string $T endif + pop_cnt | next number (odd) has one more bit than previous (even) + n | next number if primes bit pop_cnt + num_pn ~ n $S + ' ' $S + $S $T endif + n goif | go back to if endif $T [] | display numbers   stop       popcount | count ones in bit field pop_cnt | pop_cnt to zero 1 bit_num | only count even numbers so skip bit 0 if bit_num LE hi_bit if n bit bit_num + pop_cnt endif + bit_num goif endif return    
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#J
J
is_perfect=: +: = >:@#.~/.~&.q:@(6>.<.)
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Java
Java
public static boolean perf(int n){ int sum= 0; for(int i= 1;i < n;i++){ if(n % i == 0){ sum+= i; } } return sum == n; }
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#Go
Go
package main   import "fmt"   func main() { demoPerm(3) }   func demoPerm(n int) { // create a set to permute. for demo, use the integers 1..n. s := make([]int, n) for i := range s { s[i] = i + 1 } // permute them, calling a function for each permutation. // for demo, function just prints the permutation. permute(s, func(p []int) { fmt.Println(p) }) }   // permute function. takes a set to permute and a function // to call for each generated permutation. func permute(s []int, emit func([]int)) { if len(s) == 0 { emit(s) return } // Steinhaus, implemented with a recursive closure. // arg is number of positions left to permute. // pass in len(s) to start generation. // on each call, weave element at pp through the elements 0..np-2, // then restore array to the way it was. var rc func(int) rc = func(np int) { if np == 1 { emit(s) return } np1 := np - 1 pp := len(s) - np1 // weave rc(np1) for i := pp; i > 0; i-- { s[i], s[i-1] = s[i-1], s[i] rc(np1) } // restore w := s[0] copy(s, s[1:pp+1]) s[pp] = w } rc(len(s)) }
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
#Quackery
Quackery
/O> newpack +jokers 3 riffles 4 players 7 deal ... say "The player's hands..." cr cr ... witheach [ echohand cr ] ... say "Cards left in the pack (the talon)..." cr cr ... echohand ... The player's hands... eight of hearts seven of clubs nine of hearts two of diamonds three of diamonds three of hearts seven of spades low joker ace of hearts ace of clubs queen of diamonds nine of clubs six of spades six of diamonds ten of diamonds five of spades jack of diamonds two of hearts two of clubs five of diamonds ten of clubs ace of diamonds ace of spades eight of clubs king of diamonds four of diamonds ten of hearts three of clubs Cards left in the pack (the talon)... eight of spades four of hearts jack of hearts four of clubs nine of spades ten of spades two of spades five of hearts seven of diamonds five of clubs jack of clubs eight of diamonds six of hearts queen of hearts three of spades nine of diamonds six of clubs queen of clubs four of spades seven of hearts jack of spades queen of spades king of hearts king of spades king of clubs high joker
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
#PL.2FI
PL/I
/* Uses the algorithm of S. Rabinowicz and S. Wagon, "A Spigot Algorithm */ /* for the Digits of Pi". */ (subrg, fofl, size): Pi_Spigot: procedure options (main); /* 21 January 2012. */ declare (n, len) fixed binary;   n = 1000; len = 10*n / 3; begin; declare ( i, j, k, q, nines, predigit ) fixed binary; declare x fixed binary (31); declare a(len) fixed binary (31);   a = 2; /* Start with 2s */ nines, predigit = 0; /* First predigit is a 0 */ do j = 1 to n; q = 0; do i = len to 1 by -1; /* Work backwards */ x = 10*a(i) + q*i; a(i) = mod (x, (2*i-1)); q = x / (2*i-1); end; a(1) = mod(q, 10); q = q / 10; if q = 9 then nines = nines + 1; else if q = 10 then do; put edit(predigit+1) (f(1)); do k = 1 to nines; put edit ('0')(a(1)); /* zeros */ end; predigit, nines = 0; end; else do; put edit(predigit) (f(1)); predigit = q; do k = 1 to nines; put edit ('9')(a(1)); end; nines = 0; end; end; put edit(predigit) (f(1)); end; /* of begin block */ end Pi_Spigot;
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.
#Tcl
Tcl
package require math::numtheory   proc pernicious {n} {  ::math::numtheory::isprime [tcl::mathop::+ {*}[split [format %b $n] ""]] }   for {set n 0;set p {}} {[llength $p] < 25} {incr n} { if {[pernicious $n]} {lappend p $n} } puts [join $p ","] for {set n 888888877; set p {}} {$n <= 888888888} {incr n} { if {[pernicious $n]} {lappend p $n} } puts [join $p ","]
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#JavaScript
JavaScript
function is_perfect(n) { var sum = 1, i, sqrt=Math.floor(Math.sqrt(n)); for (i = sqrt-1; i>1; i--) { if (n % i == 0) { sum += i + n/i; } } if(n % sqrt == 0) sum += sqrt + (sqrt*sqrt == n ? 0 : n/sqrt); return sum === n; }     var i; for (i = 1; i < 10000; i++) { if (is_perfect(i)) print(i); }
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#Groovy
Groovy
def makePermutations = { l -> l.permutations() }
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
#R
R
pips <- c("2", "3", "4", "5", "6", "7", "8", "9", "10", "Jack", "Queen", "King", "Ace") suit <- c("Clubs", "Diamonds", "Hearts", "Spades") # Create a deck deck <- data.frame(pips=rep(pips, 4), suit=rep(suit, each=13))   shuffle <- function(deck) { n <- nrow(deck) ord <- sample(seq_len(n), size=n) deck[ord,] }   deal <- function(deck, fromtop=TRUE) { index <- ifelse(fromtop, 1, nrow(deck)) print(paste("Dealt the", deck[index, "pips"], "of", deck[index, "suit"])) deck[-index,] }   # Usage deck <- shuffle(deck) deck deck <- deal(deck) # While no-one is looking, sneakily deal a card from the bottom of the pack deck <- deal(deck, FALSE)
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
#Powershell
Powershell
  Function Get-Pi ( $Digits ) { $Big = [bigint[]](0..10)   $ndigits = 0 $Output = ""   $q = $t = $k = $Big[1] $r = $Big[0] $l = $n = $Big[3] # Calculate first digit $nr = ( $Big[2] * $q + $r ) * $l $nn = ( $q * ( $Big[7] * $k + $Big[2] ) + $r * $l ) / ( $t * $l ) $q *= $k $t *= $l $l += $Big[2] $k = $k + $Big[1] $n = $nn $r = $nr   $Output += [string]$n + '.' $ndigits++   $nr = $Big[10] * ( $r - $n * $t ) $n = ( ( $Big[10] * ( 3 * $q + $r ) ) / $t ) - 10 * $n $q *= $Big[10] $r = $nr   While ( $ndigits -lt $Digits ) { While ( $ndigits % 100 -ne 0 -or -not $Output ) { If ( $Big[4] * $q + $r - $t -lt $n * $t ) { $Output += [string]$n $ndigits++ $nr = $Big[10] * ( $r - $n * $t ) $n = ( ( $Big[10] * ( 3 * $q + $r ) ) / $t ) - 10 * $n $q *= $Big[10] $r = $nr } Else { $nr = ( $Big[2] * $q + $r ) * $l $nn = ( $q * ( $Big[7] * $k + $Big[2] ) + $r * $l ) / ( $t * $l ) $q *= $k $t *= $l $l += $Big[2] $k = $k + $Big[1] $n = $nn $r = $nr } } $Output $Output = "" } }  
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.
#VBA
VBA
Private Function population_count(ByVal number As Long) As Integer Dim result As Integer Dim digit As Integer Do While number > 0 If number Mod 2 = 1 Then result = result + 1 End If number = number \ 2 Loop population_count = result End Function   Function is_prime(n As Integer) As Boolean If n < 2 Then is_prime = False Exit Function End If For i = 2 To Sqr(n) If n Mod i = 0 Then is_prime = False Exit Function End If Next i is_prime = True End Function   Function pernicious(n As Long) Dim tmp As Integer tmp = population_count(n) pernicious = is_prime(tmp) End Function   Public Sub main() Dim count As Integer Dim n As Long: n = 1 Do While count < 25 If pernicious(n) Then Debug.Print n; count = count + 1 End If n = n + 1 Loop Debug.Print For n = 888888877 To 888888888 If pernicious(n) Then Debug.Print n; End If Next n End Sub
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#jq
jq
  def is_perfect: . as $in | $in == reduce range(1;$in) as $i (0; if ($in % $i) == 0 then $i + . else . end);   # Example: range(1;10001) | select( is_perfect )
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#Haskell
Haskell
import Data.List (permutations)   main = mapM_ print (permutations [1,2,3])
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
#Racket
Racket
#lang racket   ;; suits: (define suits '(club heart diamond spade))   ;; ranks (define ranks '(1 2 3 4 5 6 7 8 9 10 jack queen king))   ;; cards (define cards (for*/list ([suit suits] [rank ranks]) (list suit rank)))   ;; a deck is a box containing a list of cards. (define (new-deck) (box cards))   ;; shuffle the cards in a deck (define (deck-shuffle deck) (set-box! deck (shuffle (unbox deck))))   ;; deal a card from tA 2 3 4 5 6 7 8 9 10 J Q K>; enum Suit he deck: (define (deck-deal deck) (begin0 (first (unbox deck)) (set-box! deck (rest (unbox deck)))))     ;; TRY IT OUT: (define my-deck (new-deck)) (deck-shuffle my-deck) (deck-deal my-deck) (deck-deal my-deck) (length (unbox my-deck))
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
#Prolog
Prolog
  pi_spigot :- pi(X), forall(member(Y, X), write(Y)).   pi(OUT) :- pi(1, 180, 60, 2, OUT).   pi(Q, R, T, I, OUT) :- freeze(OUT, ( OUT = [Digit | OUT_] -> U is 3 * (3 * I + 1) * (3 * I + 2), Y is (Q * (27 * I - 12) + 5 * R) // (5 * T), Digit is Y, Q2 is 10 * Q * I * (2 * I - 1), R2 is 10 * U * (Q * (5 * I - 2) + R - Y * T), T2 is T * U, I2 is I + 1, pi(Q2, R2, T2, I2, OUT_) ; true)).
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.
#VBScript
VBScript
'check if the number is pernicious Function IsPernicious(n) IsPernicious = False bin_num = Dec2Bin(n) sum = 0 For h = 1 To Len(bin_num) sum = sum + CInt(Mid(bin_num,h,1)) Next If IsPrime(sum) Then IsPernicious = True End If End Function   'prime number validation Function IsPrime(n) If n = 2 Then IsPrime = True ElseIf n <= 1 Or n Mod 2 = 0 Then IsPrime = False Else IsPrime = True For i = 3 To Int(Sqr(n)) Step 2 If n Mod i = 0 Then IsPrime = False Exit For End If Next End If End Function   'decimal to binary converter Function Dec2Bin(n) q = n Dec2Bin = "" Do Until q = 0 Dec2Bin = CStr(q Mod 2) & Dec2Bin q = Int(q / 2) Loop End Function   'display the first 25 pernicious numbers c = 0 WScript.StdOut.Write "First 25 Pernicious Numbers:" WScript.StdOut.WriteLine For k = 1 To 100 If IsPernicious(k) Then WScript.StdOut.Write k & ", " c = c + 1 End If If c = 25 Then Exit For End If Next WScript.StdOut.WriteBlankLines(2)   'display the pernicious numbers between 888,888,877 to 888,888,888 (inclusive) WScript.StdOut.Write "Pernicious Numbers between 888,888,877 to 888,888,888 (inclusive):" WScript.StdOut.WriteLine For l = 888888877 To 888888888 If IsPernicious(l) Then WScript.StdOut.Write l & ", " End If Next WScript.StdOut.WriteLine
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Julia
Julia
isperfect(n::Integer) = n == sum([n % i == 0 ? i : 0 for i = 1:(n - 1)]) perfects(n::Integer) = filter(isperfect, 1:n)   @show perfects(10000)
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#Icon_and_Unicon
Icon and Unicon
procedure main(A) every p := permute(A) do every writes((!p||" ")|"\n") end   procedure permute(A) if *A <= 1 then return A suspend [(A[1]<->A[i := 1 to *A])] ||| permute(A[2:0]) 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
#Raku
Raku
enum Pip <A 2 3 4 5 6 7 8 9 10 J Q K>; enum Suit <♦ ♣ ♥ ♠>;   class Card { has Pip $.pip; has Suit $.suit;   method Str { $!pip ~ $!suit } }   class Deck { has Card @.cards = pick *, map { Card.new(:$^pip, :$^suit) }, flat (Pip.pick(*) X Suit.pick(*));   method shuffle { @!cards .= pick: * }   method deal { shift @!cards }   method Str { ~@!cards } method gist { ~@!cards } }   my Deck $d = Deck.new; say "Deck: $d";   my $top = $d.deal; say "Top card: $top";   $d.shuffle; say "Deck, re-shuffled: ", $d;
http://rosettacode.org/wiki/Pi
Pi
Create a program to continually calculate and output the next decimal digit of   π {\displaystyle \pi }   (pi). The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession. The output should be a decimal sequence beginning   3.14159265 ... Note: this task is about   calculating   pi.   For information on built-in pi constants see Real constants and functions. Related Task Arithmetic-geometric mean/Calculate Pi
#PureBasic
PureBasic
#SCALE = 10000 #ARRINT= 2000   Procedure Pi(Digits) Protected First=#True, Text$ Protected Carry, i, j, sum Dim Arr(Digits) For i=0 To Digits Arr(i)=#ARRINT Next i=Digits While i>0 sum=0 j=i While j>0 sum*j+#SCALE*arr(j) Arr(j)=sum%(j*2-1) sum/(j*2-1) j-1 Wend Text$ = RSet(Str(Carry+sum/#SCALE),4,"0") If First Text$ = ReplaceString(Text$,"3","3.") First = #False EndIf Print(Text$) Carry=sum%#SCALE i-14 Wend EndProcedure   If OpenConsole() SetConsoleCtrlHandler_(?Ctrl,#True) Pi(24*1024*1024) EndIf End   Ctrl: PrintN(#CRLF$+"Ctrl-C was pressed") End
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.
#Visual_Basic_.NET
Visual Basic .NET
Module Module1   Function PopulationCount(n As Long) As Integer Dim cnt = 0 Do If (n Mod 2) <> 0 Then cnt += 1 End If n >>= 1 Loop While n > 0 Return cnt End Function   Function IsPrime(x As Integer) As Boolean If x <= 2 OrElse (x Mod 2) = 0 Then Return x = 2 End If   Dim limit = Math.Sqrt(x) For i = 3 To limit Step 2 If x Mod i = 0 Then Return False End If Next   Return True End Function   Function Pernicious(start As Integer, count As Integer, take As Integer) As IEnumerable(Of Integer) Return Enumerable.Range(start, count).Where(Function(n) IsPrime(PopulationCount(n))).Take(take) End Function   Sub Main() For Each n In Pernicious(0, Integer.MaxValue, 25) Console.Write("{0} ", n) Next Console.WriteLine()   For Each n In Pernicious(888888877, 11, 11) Console.Write("{0} ", n) Next Console.WriteLine() End Sub   End Module
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#K
K
perfect:{(x>2)&x=+/-1_{d:&~x!'!1+_sqrt x;d,_ x%|d}x} perfect 33550336 1   a@&perfect'a:!10000 6 28 496 8128   m:3 10#!30 (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29)   perfect'/: m (0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0)
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#IS-BASIC
IS-BASIC
100 PROGRAM "Permutat.bas" 110 LET N=4 ! Number of elements 120 NUMERIC T(1 TO N) 130 FOR I=1 TO N 140 LET T(I)=I 150 NEXT 160 LET S=0 170 CALL PERM(N) 180 PRINT "Number of permutations:";S 190 END 200 DEF PERM(I) 210 NUMERIC J,X 220 IF I=1 THEN 230 FOR X=1 TO N 240 PRINT T(X); 250 NEXT 260 PRINT :LET S=S+1 270 ELSE 280 CALL PERM(I-1) 290 FOR J=1 TO I-1 300 LET C=T(J):LET T(J)=T(I):LET T(I)=C 310 CALL PERM(I-1) 320 LET C=T(J):LET T(J)=T(I):LET T(I)=C 330 NEXT 340 END IF 350 END DEF
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
#Red
Red
  Red [Title: "Playing Cards"]   pip: ["a" "2" "3" "4" "5" "6" "7" "8" "9" "10" "j" "q" "k"] suit: ["♣" "♦" "♥" "♠"]   make-deck: function [] [ new-deck: make block! 52 foreach s suit [foreach p pip [append/only new-deck reduce [p s]]] return new-deck ]   shuffle: function [deck [block!]] [deck: random deck]   deal: function [other-deck [block!] deck [block!]] [unless empty? deck [append/only other-deck take deck]]   contents: function [deck [block!]] [ line: 0 repeat i length? deck [ prin [trim/all form deck/:i " "] if (to-integer i / 13) > line [line: line + 1 print ""] ]]   deck: shuffle make-deck print "40 cards from a deck:" loop 5 [ print "" loop 8 [prin [trim/all form take deck " "]]] prin "^/^/remaining: " contents deck  
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
#Python
Python
def calcPi(): q, r, t, k, n, l = 1, 0, 1, 1, 3, 3 while True: if 4*q+r-t < n*t: yield n nr = 10*(r-n*t) n = ((10*(3*q+r))//t)-10*n q *= 10 r = nr else: nr = (2*q+r)*l nn = (q*(7*k)+2+(r*l))//(t*l) q *= k t *= l l += 2 k += 1 n = nn r = nr   import sys pi_digits = calcPi() i = 0 for d in pi_digits: sys.stdout.write(str(d)) i += 1 if i == 40: print(""); i = 0
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.
#Wortel
Wortel
:ispernum ^(@isPrime \@count \=1 @arr &\`![.toString 2])
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.
#Wren
Wren
var pernicious = Fn.new { |w| var ff = 2.pow(32) - 1 var mask1 = (ff / 3).floor var mask3 = (ff / 5).floor var maskf = (ff / 17).floor var maskp = (ff / 255).floor w = w - (w >> 1 & mask1) w = (w & mask3) + (w >>2 & mask3) w = (w + (w >> 4)) & maskf return 0xa08a28ac >> (w*maskp >> 24) & 1 != 0 }   var i = 0 var n = 1 while (i < 25) { if (pernicious.call(n)) { System.write("%(n) ") i = i + 1 } n = n + 1 } System.print() for (n in 888888877..888888888) { if (pernicious.call(n)) System.write("%(n) ") } System.print()
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Kotlin
Kotlin
// version 1.0.6   fun isPerfect(n: Int): Boolean = when { n < 2 -> false n % 2 == 1 -> false // there are no known odd perfect numbers else -> { var tot = 1 var q: Int for (i in 2 .. Math.sqrt(n.toDouble()).toInt()) { if (n % i == 0) { tot += i q = n / i if (q > i) tot += q } } n == tot } }   fun main(args: Array<String>) { // expect a run time of about 6 minutes on a typical laptop println("The first five perfect numbers are:") for (i in 2 .. 33550336) if (isPerfect(i)) print("$i ") }
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#J
J
perms=: A.&i.~ !
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
#REXX
REXX
/* REXX *************************************************************** * 1) Build ordered Card deck * 2) Create shuffled stack * 3) Deal 5 cards to 4 players each * 4) show what cards have been dealt and what's left on the stack * 05.07.2012 Walter Pachl **********************************************************************/ colors='S H C D' ranks ='A 2 3 4 5 6 7 8 9 T J Q K' i=0 cards='' ss='' Do c=1 To 4 Do r=1 To 13 i=i+1 card.i=word(colors,c)word(ranks,r) cards=cards card.i End End n=52 /* number of cards on deck */ Do si=1 To 51 /* pick 51 cards */ x=random(0,n-1)+1 /* take card x (in 1...n) */ s.si=card.x /* card on shuffled stack */ ss=ss s.si /* string of shuffled stack */ card.x=card.n /* replace card taken */ n=n-1 /* decrement nr of cards */ End s.52=card.1 /* pick the last card left */ ss=ss s.52 /* add it to the string */ Say 'Ordered deck:' Say ' 'subword(cards,1,26) Say ' 'subword(cards,27,52) Say 'Shuffled stack:' Say ' 'subword(ss,1,26) Say ' 'subword(ss,27,52) si=52 deck.='' Do ci=1 To 5 /* 5 cards each */ Do pli=1 To 4 /* 4 players */ deck.pli.ci=s.si /* take top of shuffled deck */ si=si-1 /* decrement number */ deck.pli=deck.pli deck.pli.ci /* pli's cards as string */ End End Do pli=1 To 4 /* show the 4 dealt ... */ Say pli':' deck.pli End Say 'Left on shuffled stack:' Say ' 'subword(ss,1,26) /* and what's left on stack */ Say ' 'subword(ss,27,6)
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
#Quackery
Quackery
[ immovable ]this[ share ]done[ ] is value ( --> x )   [ ]'[ replace ] is to ( x --> )   [ value 1 ] is Q ( --> x ) [ value 0 ] is R ( --> x ) [ value 1 ] is T ( --> x ) [ value 1 ] is K ( --> x ) [ value 3 ] is N ( --> x ) [ value 3 ] is L ( --> x )   [ value 0 ] is chcount ( --> x )   [ echo chcount dup 79 = if cr 1+ 80 mod to chcount ] is printch   [ 4 Q * R + T - N T * < iff [ N printch R N T * - 10 * 3 Q * R + 10 * T / N 10 * - to N to R Q 10 * to Q ] else [ 2 Q * R + L * 7 K * Q * 2 + R L * + T L * / to N to R K Q * to Q T L * to T L 2 + to L K 1+ to K ] chcount again ]
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.
#zkl
zkl
primes:=T(2,3,5,7,11,13,17,19,23,29,31,37,41); N:=0; foreach n in ([2..]){ if(n.num1s : primes.holds(_)){ print(n," "); if((N+=1)==25) break; } } foreach n in ([0d888888877..888888888]){ if (n.num1s : primes.holds(_)) "%,d; ".fmt(n).print(); }
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#LabVIEW
LabVIEW
#!/usr/bin/lasso9   define isPerfect(n::integer) => { #n < 2 ? return false return #n == ( with i in generateSeries(1, math_floor(math_sqrt(#n)) + 1) where #n % #i == 0 let q = #n / #i sum (#q > #i ? (#i == 1 ? 1 | #q + #i) | 0) ) }   with x in generateSeries(1, 10000) where isPerfect(#x) select #x
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Lasso
Lasso
#!/usr/bin/lasso9   define isPerfect(n::integer) => { #n < 2 ? return false return #n == ( with i in generateSeries(1, math_floor(math_sqrt(#n)) + 1) where #n % #i == 0 let q = #n / #i sum (#q > #i ? (#i == 1 ? 1 | #q + #i) | 0) ) }   with x in generateSeries(1, 10000) where isPerfect(#x) select #x
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#Java
Java
public class PermutationGenerator { private int[] array; private int firstNum; private boolean firstReady = false;   public PermutationGenerator(int n, int firstNum_) { if (n < 1) { throw new IllegalArgumentException("The n must be min. 1"); } firstNum = firstNum_; array = new int[n]; reset(); }   public void reset() { for (int i = 0; i < array.length; i++) { array[i] = i + firstNum; } firstReady = false; }   public boolean hasMore() { boolean end = firstReady; for (int i = 1; i < array.length; i++) { end = end && array[i] < array[i-1]; } return !end; }   public int[] getNext() {   if (!firstReady) { firstReady = true; return array; }   int temp; int j = array.length - 2; int k = array.length - 1;   // Find largest index j with a[j] < a[j+1]   for (;array[j] > array[j+1]; j--);   // Find index k such that a[k] is smallest integer // greater than a[j] to the right of a[j]   for (;array[j] > array[k]; k--);   // Interchange a[j] and a[k]   temp = array[k]; array[k] = array[j]; array[j] = temp;   // Put tail end of permutation after jth position in increasing order   int r = array.length - 1; int s = j + 1;   while (r > s) { temp = array[s]; array[s++] = array[r]; array[r--] = temp; }   return array; } // getNext()   // For testing of the PermutationGenerator class public static void main(String[] args) { PermutationGenerator pg = new PermutationGenerator(3, 1);   while (pg.hasMore()) { int[] temp = pg.getNext(); for (int i = 0; i < temp.length; i++) { System.out.print(temp[i] + " "); } System.out.println(); } }   } // class
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
#Ring
Ring
  Load "guilib.ring"   nScale = 1   app1 = new qApp   mypic = new QPixmap("cards.jpg")   mypic2 = mypic.copy(0,(124*4)+1,79,124) Player1EatPic = mypic.copy(80,(124*4)+1,79,124) Player2EatPic= mypic.copy(160,(124*4)+1,79,124)   aMyCards = [] aMyValues = [] for x1 = 0 to 3 for y1 = 0 to 12 temppic = mypic.copy((79*y1)+1,(124*x1)+1,79,124) aMyCards + temppic aMyValues + (y1+1) next next   nPlayer1Score = 0 nPlayer2Score=0   do Page1 = new Game Page1.Start() again Page1.lnewgame   mypic.delete() mypic2.delete() Player1EatPic.delete() Player2EatPic.delete()   for t in aMyCards t.delete() next   func gui_setbtnpixmap pBtn,pPixmap pBtn { setIcon(new qicon(pPixmap.scaled(width(),height(),0,0))) setIconSize(new QSize(width(),height())) }   Class Game   nCardsCount = 10 win1 layout1 label1 label2 layout2 layout3 aBtns aBtns2 aCards nRole=1 aStatus = list(nCardsCount) aStatus2 = aStatus aValues aStatusValues = aStatus aStatusValues2 = aStatus Player1EatPic Player2EatPic lnewgame = false nDelayEat = 0.5 nDelayNewGame = 1   func start   win1 = new qWidget() { setwindowtitle("Five") setstylesheet("background-color: White") showfullscreen() }   layout1 = new qvboxlayout()   label1 = new qlabel(win1) { settext("Player (1) - Score : " + nPlayer1Score) setalignment(Qt_AlignHCenter | Qt_AlignVCenter) setstylesheet("color: White; background-color: Purple; font-size:20pt") setfixedheight(200) }   closebtn = new qpushbutton(win1) { settext("Close Application") setstylesheet("font-size: 18px ; color : white ; background-color: black ;") setclickevent("Page1.win1.close()") }   aCards = aMyCards aValues = aMyValues   layout2 = new qhboxlayout()   aBtns = []   for x = 1 to nCardsCount aBtns + new qpushbutton(win1) aBtns[x].setfixedwidth(79*nScale) aBtns[x].setfixedheight(124*nScale) gui_setbtnpixmap(aBtns[x],mypic2) layout2.addwidget(aBtns[x]) aBtns[x].setclickevent("Page1.Player1click("+x+")") next   layout1.addwidget(label1) layout1.addlayout(layout2)   label2 = new qlabel(win1) { settext("Player (2) - Score : " + nPlayer2Score) setalignment(Qt_AlignHCenter | Qt_AlignVCenter) setstylesheet("color: white; background-color: red; font-size:20pt") setfixedheight(200) }   layout3 = new qhboxlayout()   aBtns2 = [] for x = 1 to nCardsCount aBtns2 + new qpushbutton(win1) aBtns2[x].setfixedwidth(79*nScale) aBtns2[x].setfixedheight(124*nScale) gui_setbtnpixmap(aBtns2[x],mypic2) layout3.addwidget(aBtns2[x]) aBtns2[x].setclickevent("Page1.Player2click("+x+")") next   layout1.addwidget(label2) layout1.addlayout(layout3) layout1.addwidget(closebtn)   win1.setlayout(layout1)   app1.exec()   Func Player1Click x if nRole = 1 and aStatus[x] = 0 nPos = ((random(100)+clock())%(len(aCards)-1)) + 1 gui_setbtnpixmap(aBtns[x],aCards[nPos]) del(aCards,nPos) nRole = 2 aStatus[x] = 1 aStatusValues[x] = aValues[nPos] del(aValues,nPos) Player1Eat(x,aStatusValues[x]) checknewgame() ok   Func Player2Click x if nRole = 2 and aStatus2[x] = 0 nPos = ((random(100)+clock())%(len(aCards)-1)) + 1 gui_setbtnpixmap(aBtns2[x],aCards[nPos]) del(aCards,nPos) nRole = 1 aStatus2[x] = 1 aStatusValues2[x] = aValues[nPos] del(aValues,nPos) Player2Eat(x,aStatusValues2[x]) checknewgame() ok   Func Player1Eat nPos,nValue   app1.processEvents()   delay(nDelayEat) lEat = false for x = 1 to nCardsCount if aStatus2[x] = 1 and (aStatusValues2[x] = nValue or nValue=5) aStatus2[x] = 2 gui_setbtnpixmap(aBtns2[x],Player1EatPic) lEat = True nPlayer1Score++ ok if (x != nPos) and (aStatus[x] = 1) and (aStatusValues[x] = nValue or nValue=5) aStatus[x] = 2 gui_setbtnpixmap(aBtns[x],Player1EatPic) lEat = True nPlayer1Score++ ok next if lEat nPlayer1Score++ gui_setbtnpixmap(aBtns[nPos],Player1EatPic) aStatus[nPos] = 2 label1.settext("Player (1) - Score : " + nPlayer1Score) ok   Func Player2Eat nPos,nValue   app1.processEvents()   delay(nDelayEat) lEat = false for x = 1 to nCardsCount if aStatus[x] = 1 and (aStatusValues[x] = nValue or nValue = 5) aStatus[x] = 2 gui_setbtnpixmap(aBtns[x],Player2EatPic) lEat = True nPlayer2Score++ ok   if (x != nPos) and (aStatus2[x] = 1) and (aStatusValues2[x] = nValue or nValue=5 ) aStatus2[x] = 2 gui_setbtnpixmap(aBtns2[x],Player2EatPic) lEat = True nPlayer2Score++ ok next if lEat nPlayer2Score++ gui_setbtnpixmap(aBtns2[nPos],Player2EatPic) aStatus2[nPos] = 2 label2.settext("Player (2) - Score : " + nPlayer2Score) ok   Func checknewgame if isnewgame() lnewgame = true   if nPlayer1Score > nPlayer2Score label1.settext("Player (1) Wins!!!") ok if nPlayer2Score > nPlayer1Score label2.settext("Player (2) Wins!!!") ok   app1.processEvents() delay(nDelayNewGame)   win1.delete() app1.quit() ok   Func isnewgame for t in aStatus if t = 0 return false ok next for t in aStatus2 if t = 0 return false ok next return true   Func delay x nTime = x * 1000 oTest = new qTest oTest.qsleep(nTime)  
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
#R
R
  suppressMessages(library(gmp)) ONE <- as.bigz("1") TWO <- as.bigz("2") THREE <- as.bigz("3") FOUR <- as.bigz("4") SEVEN <- as.bigz("7") TEN <- as.bigz("10")   q <- as.bigz("1") r <- as.bigz("0") t <- as.bigz("1") k <- as.bigz("1") n <- as.bigz("3") l <- as.bigz("3")   char_printed <- 0   how_many <- 1000   first <- TRUE while (how_many > 0) { if ((FOUR * q + r - t) < (n * t)) { if (char_printed == 80) { cat("\n") char_printed <- 0 } how_many <- how_many - 1 char_printed <- char_printed + 1 cat(as.integer(n)) if (first) { cat(".") first <- FALSE char_printed <- char_printed + 1 } nr <- as.bigz(TEN * (r - n * t)) n <- as.bigz(((TEN * (THREE * q + r)) %/% t) - (TEN * n)) q <- as.bigz(q * TEN) r <- as.bigz(nr) } else { nr <- as.bigz((TWO * q + r) * l) nn <- as.bigz((q * (SEVEN * k + TWO) + r * l) %/% (t * l)) q <- as.bigz(q * k) t <- as.bigz(t * l) l <- as.bigz(l + TWO) k <- as.bigz(k + ONE) n <- as.bigz(nn) r <- as.bigz(nr) } } cat("\n")  
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Liberty_BASIC
Liberty BASIC
for n =1 to 10000 if perfect( n) =1 then print n; " is perfect." next n   end   function perfect( n) sum =0 for i =1 TO n /2 if n mod i =0 then sum =sum +i end if next i if sum =n then perfect= 1 else perfect =0 end if end function
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#JavaScript
JavaScript
<html><head><title>Permutations</title></head> <body><pre id="result"></pre> <script type="text/javascript"> var d = document.getElementById('result');   function perm(list, ret) { if (list.length == 0) { var row = document.createTextNode(ret.join(' ') + '\n'); d.appendChild(row); return; } for (var i = 0; i < list.length; i++) { var x = list.splice(i, 1); ret.push(x); perm(list, ret); ret.pop(); list.splice(i, 0, x); } }   perm([1, 2, 'A', 4], []); </script></body></html>
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
#Ruby
Ruby
class Card # class constants SUITS = %i[ Clubs Hearts Spades Diamonds ] PIPS = %i[ 2 3 4 5 6 7 8 9 10 Jack Queen King Ace ]   # class variables (private) @@suit_value = Hash[ SUITS.each_with_index.to_a ] @@pip_value = Hash[ PIPS.each_with_index.to_a ]   attr_reader :pip, :suit   def initialize(pip,suit) @pip = pip @suit = suit end   def to_s "#{@pip} #{@suit}" end   # allow sorting an array of Cards: first by suit, then by value def <=>(other) (@@suit_value[@suit] <=> @@suit_value[other.suit]).nonzero? or @@pip_value[@pip] <=> @@pip_value[other.pip] end end   class Deck def initialize @deck = Card::SUITS.product(Card::PIPS).map{|suit,pip| Card.new(pip,suit)} end   def to_s @deck.inspect end   def shuffle! @deck.shuffle! self end   def deal(*args) @deck.shift(*args) end end   deck = Deck.new.shuffle! puts card = deck.deal hand = deck.deal(5) puts hand.join(", ") puts hand.sort.join(", ")
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
#Racket
Racket
  #lang racket (require racket/generator)   (define pidig (generator () (let loop ([q 1] [r 0] [t 1] [k 1] [n 3] [l 3]) (if (< (- (+ r (* 4 q)) t) (* n t)) (begin (yield n) (loop (* q 10) (* 10 (- r (* n t))) t k (- (quotient (* 10 (+ (* 3 q) r)) t) (* 10 n)) l)) (loop (* q k) (* (+ (* 2 q) r) l) (* t l) (+ 1 k) (quotient (+ (* (+ 2 (* 7 k)) q) (* r l)) (* t l)) (+ l 2))))))   (for ([i (in-naturals)]) (display (pidig)) (when (zero? i) (display "." )) (when (zero? (modulo i 80)) (newline)))  
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Lingo
Lingo
on isPercect (n) sum = 1 cnt = n/2 repeat with i = 2 to cnt if n mod i = 0 then sum = sum + i end repeat return sum=n end
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Logo
Logo
to perfect? :n output equal? :n apply "sum filter [equal? 0 modulo :n ?] iseq 1 :n/2 end
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#jq
jq
def permutations: if length == 0 then [] else range(0;length) as $i | [.[$i]] + (del(.[$i])|permutations) end ;  
http://rosettacode.org/wiki/Playing_cards
Playing cards
Task Create a data structure and the associated methods to define and manipulate a deck of   playing cards. The deck should contain 52 unique cards. The methods must include the ability to:   make a new deck   shuffle (randomize) the deck   deal from the deck   print the current contents of a deck Each card must have a pip value and a suit value which constitute the unique value of the card. Related tasks: Card shuffles Deal cards_for_FreeCell War Card_Game Poker hand_analyser Go Fish
#Run_BASIC
Run BASIC
suite$ = "C,D,H,S" ' Club, Diamond, Heart, Spade card$ = "A,2,3,4,5,6,7,8,9,T,J,Q,K" ' Cards Ace to King   dim n(55) ' make ordered deck for i = 1 to 52 ' of 52 cards n(i) = i next i   for i = 1 to 52 * 3 ' shuffle deck 3 times i1 = int(rnd(1)*52) + 1 i2 = int(rnd(1)*52) + 1 h2 = n(i1) n(i1) = n(i2) n(i2) = h2 next i   for hand = 1 to 4 ' 4 hands for deal = 1 to 13 ' deal each 13 cards card = card + 1 ' next card in deck s = (n(card) mod 4) + 1 ' determine suite c = (n(card) mod 13) + 1 ' determine card print word$(card$,c,",");word$(suite$,s,",");" "; ' show the card next deal print next hand
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
#Raku
Raku
# based on http://www.mathpropress.com/stan/bibliography/spigot.pdf   sub stream(&next, &safe, &prod, &cons, $z is copy, @x) { gather loop { $z = safe($z, my $y = next($z)) ?? prod($z, take $y) !! cons($z, @x[$++]) } }   sub extr([$q, $r, $s, $t], $x) { ($q * $x + $r) div ($s * $x + $t) }   sub comp([$q,$r,$s,$t], [$u,$v,$w,$x]) { [$q * $u + $r * $w, $q * $v + $r * $x, $s * $u + $t * $w, $s * $v + $t * $x] }   my $pi := stream -> $z { extr($z, 3) }, -> $z, $n { $n == extr($z, 4) }, -> $z, $n { comp([10, -10*$n, 0, 1], $z) }, &comp, <1 0 0 1>, (1..*).map: { [$_, 4 * $_ + 2, 0, 2 * $_ + 1] }   for ^Inf -> $i { print $pi[$i]; once print '.' }
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Lua
Lua
function isPerfect(x) local sum = 0 for i = 1, x-1 do sum = (x % i) == 0 and sum + i or sum end return sum == x end
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#M2000_Interpreter
M2000 Interpreter
  Module PerfectNumbers { Function Is_Perfect(n as decimal) { s=1 : sN=Sqrt(n) last= n=sN*sN t=n If n mod 2=0 then s+=2+n div 2 i=3 : sN-- While i<sN { if n mod i=0 then t=n div i :i=max.data(n div t, i): s+=t+ i i++ } =n=s } Inventory Known1=2@, 3@ IsPrime=lambda Known1 (x as decimal) -> { =0=1 if exist(Known1, x) then =1=1 : exit if x<=5 OR frac(x) then {if x == 2 OR x == 3 OR x == 5 then Append Known1, x  : =1=1 Break} if frac(x/2) else exit if frac(x/3) else exit x1=sqrt(x):d = 5@ {if frac(x/d ) else exit d += 2: if d>x1 then Append Known1, x : =1=1 : exit if frac(x/d) else exit d += 4: if d<= x1 else Append Known1, x : =1=1: exit loop} } \\ Check a perfect and a non perfect number p=2 : n=3 : n1=2 Document Doc$ IsPerfect( 0, 28) IsPerfect( 0, 1544) While p<32 { ' max 32 if isprime(2^p-1@) then { perf=(2^p-1@)*2@^(p-1@) Rem Print perf \\ decompose pretty fast the Perferct Numbers \\ all have a series of 2 and last a prime equal to perf/2^(p-1) inventory queue factors For i=1 to p-1 { Append factors, 2@ } Append factors, perf/2^(p-1) \\ end decompose Rem Print factors IsPerfect(factors, Perf) } p++ }   Clipboard Doc$ \\ exit here. No need for Exit statement Sub IsPerfect(factors, n) s=false if n<10000 or type$(factors)<>"Inventory" then { s=Is_Perfect(n) } else { local mm=each(factors, 1, -2), f =true while mm {if eval(mm)<>2 then f=false } if f then if n/2@**(len(mm)-1)= factors(len(factors)-1!) then s=true } Local a$=format$("{0} is {1}perfect number", n, If$(s->"", "not ")) Doc$=a$+{ } Print a$ End Sub }   PerfectNumbers  
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#Julia
Julia
  julia> perms(l) = isempty(l) ? [l] : [[x; y] for x in l for y in perms(setdiff(l, x))]  
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
#Rust
Rust
extern crate rand;   use std::fmt; use rand::Rng; use Pip::*; use Suit::*;   #[derive(Copy, Clone, Debug)] enum Pip { Ace, Two, Three, Four, Five, Six, Seven, Eight, Nine, Ten, Jack, Queen, King }   #[derive(Copy, Clone, Debug)] enum Suit { Spades, Hearts, Diamonds, Clubs }   struct Card { pip: Pip, suit: Suit }   impl fmt::Display for Card { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "{:?} of {:?}", self.pip, self.suit) } }   struct Deck(Vec<Card>);   impl Deck { fn new() -> Deck { let mut cards:Vec<Card> = Vec::with_capacity(52); for &suit in &[Spades, Hearts, Diamonds, Clubs] { for &pip in &[Ace, Two, Three, Four, Five, Six, Seven, Eight, Nine, Ten, Jack, Queen, King] { cards.push( Card{pip: pip, suit: suit} ); } } Deck(cards) }   fn deal(&mut self) -> Option<Card> { self.0.pop() }   fn shuffle(&mut self) { rand::thread_rng().shuffle(&mut self.0) } }   impl fmt::Display for Deck { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { for card in self.0.iter() { writeln!(f, "{}", card); } write!(f, "") } }   fn main() { let mut deck = Deck::new(); deck.shuffle(); //println!("{}", deck); for _ in 0..5 { println!("{}", deck.deal().unwrap()); } }
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
#REXX
REXX
┌─ ─┐ ┌─ ─┐ π │ 1 │ │ 1 │ John ─── = 4 ∙ arctan│ ─── │ - arctan│ ───── │ Machin's 4 │ 5 │ │ 239 │ formula └─ ─┘ └─ ─┘ which expands into: ┌─ ─┐ │ 1 1 1 1 1 1 │ 4 ∙ │ ─── - ────── + ────── - ────── + ────── - ──────── + ... │ │ 1 3 5 7 9 11 │ │ 1∙5 3∙5 5∙5 7∙5 9∙5 11∙5 │ └─ ─┘ ┌─ ─┐ │ 1 1 1 1 1 1 │ - │ ─── - ────── + ────── - ────── + ────── - ──────── + ... │ │ 1 3 5 7 9 11 │ │ 1∙239 3∙239 5∙239 7∙239 9∙239 11∙239 │ └─ ─┘
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#M4
M4
define(`for', `ifelse($#,0,``$0'', `ifelse(eval($2<=$3),1, `pushdef(`$1',$2)$4`'popdef(`$1')$0(`$1',incr($2),$3,`$4')')')')dnl   define(`ispart', `ifelse(eval($2*$2<=$1),1, `ifelse(eval($1%$2==0),1, `ifelse(eval($2*$2==$1),1, `ispart($1,incr($2),eval($3+$2))', `ispart($1,incr($2),eval($3+$2+$1/$2))')', `ispart($1,incr($2),$3)')', $3)') define(`isperfect', `eval(ispart($1,2,1)==$1)')   for(`x',`2',`33550336', `ifelse(isperfect(x),1,`x ')')
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#MAD
MAD
NORMAL MODE IS INTEGER   R FUNCTION THAT CHECKS IF NUMBER IS PERFECT INTERNAL FUNCTION(N) ENTRY TO PERFCT. DSUM = 0 THROUGH SUMMAT, FOR CAND=1, 1, CAND.GE.N SUMMAT WHENEVER N/CAND*CAND.E.N, DSUM = DSUM+CAND FUNCTION RETURN DSUM.E.N END OF FUNCTION   R PRINT PERFECT NUMBERS UP TO 10,000 THROUGH SHOW, FOR I=1, 1, I.G.10000 SHOW WHENEVER PERFCT.(I), PRINT FORMAT FMT,I   VECTOR VALUES FMT = $I5*$ PRINT COMMENT $ $ END OF PROGRAM  
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#K
K
perm:{:[1<x;,/(>:'(x,x)#1,x#0)[;0,'1+_f x-1];,!x]} perm 2 (0 1 1 0)   `0:{1_,/" ",/:x}'r@perm@#r:("some";"random";"text") some random text some text random random some text random text some text some random text random some
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
#Scala
Scala
import scala.annotation.tailrec import scala.util.Random   object Pip extends Enumeration { type Pip = Value val Two, Three, Four, Five, Six, Seven, Eight, Nine, Ten, Jack, Queen, King, Ace = Value }   object Suit extends Enumeration { type Suit = Value val Diamonds, Spades, Hearts, Clubs = Value }   import Suit._ import Pip._ case class Card(suit:Suit, value:Pip){ override def toString():String=value + " of " + suit }   class Deck private(val cards:List[Card]) { def this()=this(for {s <- Suit.values.toList; v <- Pip.values} yield Card(s,v)) def shuffle:Deck=new Deck(Random.shuffle(cards))   def deal(n:Int=1):(Seq[Card], Deck)={ @tailrec def loop(count:Int, c:Seq[Card], d:Deck):(Seq[Card], Deck)={ if(count==0 || d.cards==Nil) (c,d) else { val card :: deck = d.cards loop(count-1, c :+ card, new Deck(deck)) } } loop(n, Seq(), this) } override def toString():String="Deck: " + (cards mkString ", ") }
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
#Ruby
Ruby
pi_digits = Enumerator.new do |y| q, r, t, k, n, l = 1, 0, 1, 1, 3, 3 loop do if 4*q+r-t < n*t y << n nr = 10*(r-n*t) n = ((10*(3*q+r)) / t) - 10*n q *= 10 r = nr else nr = (2*q+r) * l nn = (q*(7*k+2)+r*l) / (t*l) q *= k t *= l l += 2 k += 1 n = nn r = nr end end end   print pi_digits.next, "." loop { print pi_digits.next }
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Maple
Maple
isperfect := proc(n) return evalb(NumberTheory:-SumOfDivisors(n) = 2*n); end proc: isperfect(6); true
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Lucas-Lehmer test   is used to find primes of the form   2n-1,   all known perfect numbers can be derived from these primes using the formula   (2n - 1) × 2n - 1. It is not known if there are any odd perfect numbers (any that exist are larger than 102000). The number of   known   perfect numbers is   51   (as of December, 2018),   and the largest known perfect number contains  49,724,095  decimal digits. See also   Rational Arithmetic   Perfect numbers on OEIS   Odd Perfect showing the current status of bounds on odd perfect numbers.
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
PerfectQ[i_Integer] := Total[Divisors[i]] == 2 i
http://rosettacode.org/wiki/Permutations
Permutations
Task Write a program that generates all   permutations   of   n   different objects.   (Practically numerals!) Related tasks   Find the missing permutation   Permutations/Derangements The number of samples of size k from n objects. With   combinations and permutations   generation tasks. Order Unimportant Order Important Without replacement ( n k ) = n C k = n ( n − 1 ) … ( n − k + 1 ) k ( k − 1 ) … 1 {\displaystyle {\binom {n}{k}}=^{n}\operatorname {C} _{k}={\frac {n(n-1)\ldots (n-k+1)}{k(k-1)\dots 1}}} n P k = n ⋅ ( n − 1 ) ⋅ ( n − 2 ) ⋯ ( n − k + 1 ) {\displaystyle ^{n}\operatorname {P} _{k}=n\cdot (n-1)\cdot (n-2)\cdots (n-k+1)} Task: Combinations Task: Permutations With replacement ( n + k − 1 k ) = n + k − 1 C k = ( n + k − 1 ) ! ( n − 1 ) ! k ! {\displaystyle {\binom {n+k-1}{k}}=^{n+k-1}\operatorname {C} _{k}={(n+k-1)! \over (n-1)!k!}} n k {\displaystyle n^{k}} Task: Combinations with repetitions Task: Permutations with repetitions
#Kotlin
Kotlin
// version 1.1.2   fun <T> permute(input: List<T>): List<List<T>> { if (input.size == 1) return listOf(input) val perms = mutableListOf<List<T>>() val toInsert = input[0] for (perm in permute(input.drop(1))) { for (i in 0..perm.size) { val newPerm = perm.toMutableList() newPerm.add(i, toInsert) perms.add(newPerm) } } return perms }   fun main(args: Array<String>) { val input = listOf('a', 'b', 'c', 'd') val perms = permute(input) println("There are ${perms.size} permutations of $input, namely:\n") for (perm in perms) println(perm) }