task_url
stringlengths
30
116
task_name
stringlengths
2
86
task_description
stringlengths
0
14.4k
language_url
stringlengths
2
53
language_name
stringlengths
1
52
code
stringlengths
0
61.9k
http://rosettacode.org/wiki/Towers_of_Hanoi
Towers of Hanoi
Task Solve the   Towers of Hanoi   problem with recursion.
#ActionScript
ActionScript
public function move(n:int, from:int, to:int, via:int):void { if (n > 0) { move(n - 1, from, via, to); trace("Move disk from pole " + from + " to pole " + to); move(n - 1, via, to, from); } }
http://rosettacode.org/wiki/Tonelli-Shanks_algorithm
Tonelli-Shanks algorithm
This page uses content from Wikipedia. The original article was at Tonelli-Shanks algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In computational number theory, the Tonelli–Shanks algor...
#11l
11l
F legendre(a, p) R pow(a, (p - 1) I/ 2, p)   F tonelli(n, p) assert(legendre(n, p) == 1, ‘not a square (mod p)’) V q = p - 1 V s = 0 L q % 2 == 0 q I/= 2 s++ I s == 1 R pow(n, (p + 1) I/ 4, p) V z = 2 L I p - 1 == legendre(z, p) L.break z++ V c = pow(z, ...
http://rosettacode.org/wiki/Tokenize_a_string_with_escaping
Tokenize a string with escaping
Task[edit] Write a function or program that can split a string at each non-escaped occurrence of a separator character. It should accept three input parameters:   The string   The separator character   The escape character It should output a list of strings. Details Rules for splitting: The fields that were s...
#Ada
Ada
with Ada.Text_Io; with Ada.Containers.Indefinite_Vectors; with Ada.Strings.Unbounded;   procedure Tokenize is   package String_Vectors is new Ada.Containers.Indefinite_Vectors (Positive, String); use String_Vectors;   function Split (Text  : String; Separator : Character := '|'; ...
http://rosettacode.org/wiki/Total_circles_area
Total circles area
Total circles area You are encouraged to solve this task according to the task description, using any language you may know. Example circles Example circles filtered Given some partially overlapping circles on the plane, compute and show the total area covered by them, with four or six (or a little more) decimal dig...
#FreeBASIC
FreeBASIC
#define dx 0.0001   'read in the data; I reordered them in descending order of radius 'This maximises our chance of being able to break early, saving run time, 'and we needn't bother finding out which circles are entirely inside others data -0.5263668798,1.7315156631,1.4428514068 data -0.1403562064,0.2437382535,1.38049...
http://rosettacode.org/wiki/Topological_sort
Topological sort
Sorting Algorithm This is a sorting algorithm.   It may be applied to a set of data in order to sort it.     For comparing various sorts, see compare sorts.   For other sorting algorithms,   see sorting algorithms,   or: O(n logn) sorts Heap sort | Merge sort | Patience sort | Quick sort O(n log2n) sorts Shell Sort ...
#Ada
Ada
with Ada.Containers.Vectors; use Ada.Containers;   package Digraphs is   type Node_Idx_With_Null is new Natural; subtype Node_Index is Node_Idx_With_Null range 1 .. Node_Idx_With_Null'Last; -- a Node_Index is a number from 1, 2, 3, ... and the representative of a node   type Graph_Type is tagged private;   ...
http://rosettacode.org/wiki/Universal_Turing_machine
Universal Turing machine
One of the foundational mathematical constructs behind computer science is the universal Turing Machine. (Alan Turing introduced the idea of such a machine in 1936–1937.) Indeed one way to definitively prove that a language is turing-complete is to implement a universal Turing machine in it. Task Simulate such ...
#EchoLisp
EchoLisp
  (require 'struct)   (struct TM (read-only: name states symbs final rules mem state-values: tape pos state))   (define-syntax-rule (rule-idx state symb numstates) (+ state (* symb numstates)))   (define-syntax-rule (make-TM name states symbs rules) (_make-TM name 'states 'symbs 'rules))   ;; a rule is (stat...
http://rosettacode.org/wiki/Totient_function
Totient function
The   totient   function is also known as:   Euler's totient function   Euler's phi totient function   phi totient function   Φ   function   (uppercase Greek phi)   φ    function   (lowercase Greek phi) Definitions   (as per number theory) The totient function:   counts the integers up to a given positiv...
#C.23
C#
using static System.Console; using static System.Linq.Enumerable;   public class Program { static void Main() { for (int i = 1; i <= 25; i++) { int t = Totient(i); WriteLine(i + "\t" + t + (t == i - 1 ? "\tprime" : "")); } WriteLine(); for (int i = 100; i ...
http://rosettacode.org/wiki/Topswops
Topswops
Topswops is a card game created by John Conway in the 1970's. Assume you have a particular permutation of a set of   n   cards numbered   1..n   on both of their faces, for example the arrangement of four cards given by   [2, 4, 1, 3]   where the leftmost card is on top. A round is composed of reversing the first  ...
#Icon_and_Unicon
Icon and Unicon
procedure main() every n := 1 to 10 do { ts := 0 every (ts := 0) <:= swop(permute([: 1 to n :])) write(right(n, 3),": ",right(ts,4)) } end   procedure swop(A) count := 0 while A[1] ~= 1 do { A := reverse(A[1+:A[1]]) ||| A[(A[1]+1):0] count +:= 1 } ...
http://rosettacode.org/wiki/Trigonometric_functions
Trigonometric functions
Task If your language has a library or built-in functions for trigonometry, show examples of:   sine   cosine   tangent   inverses   (of the above) using the same angle in radians and degrees. For the non-inverse functions,   each radian/degree pair should use arguments that evaluate to the same angle   (that i...
#bc
bc
/* t(x) = tangent of x */ define t(x) { return s(x) / c(x) }   /* y(y) = arcsine of y, domain [-1, 1], range [-pi/2, pi/2] */ define y(y) { /* Handle angles with no tangent. */ if (y == -1) return -2 * a(1) /* -pi/2 */ if (y == 1) return 2 * a(1) /* pi/2 */   /* Tangent of angle is y / x, where x^2 + y^2 = 1. ...
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm
Trabb Pardo–Knuth algorithm
The TPK algorithm is an early example of a programming chrestomathy. It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages. The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of...
#Elixir
Elixir
defmodule Trabb_Pardo_Knuth do def task do Enum.reverse( get_11_numbers ) |> Enum.each( fn x -> perform_operation( &function(&1), 400, x ) end ) end   defp alert( n ), do: IO.puts "Operation on #{n} overflowed"   defp get_11_numbers do ns = IO.gets( "Input 11 integers. Space delimited, please: " ) ...
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm
Trabb Pardo–Knuth algorithm
The TPK algorithm is an early example of a programming chrestomathy. It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages. The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of...
#Erlang
Erlang
  -module( trabb_pardo_knuth ).   -export( [task/0] ).   task() -> Sequence = get_11_numbers(), S = lists:reverse( Sequence ), [perform_operation( fun function/1, 400, X) || X <- S].     alert( N ) -> io:fwrite( "Operation on ~p overflowed~n", [N] ).   get_11_numbers() -> {ok, Ns} = io:fread( "Input 11 integers. ...
http://rosettacode.org/wiki/Twelve_statements
Twelve statements
This puzzle is borrowed from   math-frolic.blogspot. Given the following twelve statements, which of them are true? 1. This is a numbered list of twelve statements. 2. Exactly 3 of the last 6 statements are true. 3. Exactly 2 of the even-numbered statements are true. 4. If statement 5 is true, then statemen...
#Racket
Racket
  #lang racket   ;; A quick `amb' implementation (define failures null) (define (fail) (if (pair? failures) ((first failures)) (error "no more choices!"))) (define (amb/thunks choices) (let/cc k (set! failures (cons k failures))) (if (pair? choices) (let ([choice (first choices)]) (set! choices (rest choices)...
http://rosettacode.org/wiki/Twelve_statements
Twelve statements
This puzzle is borrowed from   math-frolic.blogspot. Given the following twelve statements, which of them are true? 1. This is a numbered list of twelve statements. 2. Exactly 3 of the last 6 statements are true. 3. Exactly 2 of the even-numbered statements are true. 4. If statement 5 is true, then statemen...
#Raku
Raku
sub infix:<→> ($protasis, $apodosis) { !$protasis or $apodosis }   my @tests = { .end == 12 and all(.[1..12]) === any(True, False) }, { 3 == [+] .[7..12] }, { 2 == [+] .[2,4...12] }, { .[5] → all .[6,7] }, { none .[2,3,4] }, { 4 == [+] .[1,3...11] }, { one .[2,3] }, { .[7] → all .[5,6] }...
http://rosettacode.org/wiki/Truth_table
Truth table
A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function. Task Input a Boolean function from the user as a string then calculate and print a formatted truth table for the g...
#Pascal
Pascal
  program TruthTables; const StackSize = 80;   type TVariable = record Name: Char; Value: Boolean; end;   TStackOfBool = record Top: Integer; Elements: array [0 .. StackSize - 1] of Boolean; end;   var Expression: string; Variables: array [0 .. 23] of TVariable; VariablesLength: Integer;...
http://rosettacode.org/wiki/Ulam_spiral_(for_primes)
Ulam spiral (for primes)
An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1),   constructed on a square grid, starting at the "center". An Ulam spiral is also known as a   prime spiral. The first grid (green) is shown with sequential integers,   ...
#Phix
Phix
with javascript_semantics function spiral(integer w, h, x, y) return iff(y?w+spiral(h-1,w,y-1,w-x-1):x) end function integer w = 9, h = 9 for i=h-1 to 0 by -1 do for j=w-1 to 0 by -1 do integer p = w*h-spiral(w,h,j,i) puts(1,"o "[2-is_prime(p)]) end for puts(1,'\n') end for
http://rosettacode.org/wiki/Truncatable_primes
Truncatable primes
A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number. Examples The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime. The number 7393 is a right-truncatable prime as the numbers 7393, 7...
#Go
Go
package main   import "fmt"   func main() { sieve(1e6) if !search(6, 1e6, "left", func(n, pot int) int { return n % pot }) { panic("997?") } if !search(6, 1e6, "right", func(n, _ int) int { return n / 10 }) { panic("7393?") } }   var c []bool   func sieve(ss int) { c = make([]boo...
http://rosettacode.org/wiki/Tree_traversal
Tree traversal
Task Implement a binary tree where each node carries an integer,   and implement:   pre-order,   in-order,   post-order,     and   level-order   traversal. Use those traversals to output the following tree: 1 / \ / \ / \ 2 3 / \ / 4 5 6 / ...
#APL
APL
preorder ← {l r←⍺ ⍵⍵ ⍵ ⋄ (⊃r)∇⍨⍣(×≢r)⊢(⊃l)∇⍨⍣(×≢l)⊢⍺ ⍺⍺ ⍵} inorder ← {l r←⍺ ⍵⍵ ⍵ ⋄ (⊃r)∇⍨⍣(×≢r)⊢⍵ ⍺⍺⍨(⊃l)∇⍨⍣(×≢l)⊢⍺} postorder← {l r←⍺ ⍵⍵ ⍵ ⋄ ⍵ ⍺⍺⍨(⊃r)∇⍨⍣(×≢r)⊢(⊃l)∇⍨⍣(×≢l)⊢⍺} lvlorder ← {0=⍴⍵:⍺ ⋄ (⊃⍺⍺⍨/(⌽⍵),⊂⍺)∇⊃∘(,/)⍣2⊢⍺∘⍵⍵¨⍵}
http://rosettacode.org/wiki/Topic_variable
Topic variable
Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable. A topic variable is a special variable with a very short name which can also often be omitted. Demonstrate the utilization and behaviour of the topic variable within the language and explain or demonstrate h...
#Sidef
Sidef
say [9,16,25].map {.sqrt}; # prints: [3, 4, 5]
http://rosettacode.org/wiki/Topic_variable
Topic variable
Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable. A topic variable is a special variable with a very short name which can also often be omitted. Demonstrate the utilization and behaviour of the topic variable within the language and explain or demonstrate h...
#Standard_ML
Standard ML
- 3.0; val it = 3.0 : real - it * it; val it = 9.0 : real - Math.sqrt it; val it = 3.0 : real -
http://rosettacode.org/wiki/Topic_variable
Topic variable
Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable. A topic variable is a special variable with a very short name which can also often be omitted. Demonstrate the utilization and behaviour of the topic variable within the language and explain or demonstrate h...
#Tailspin
Tailspin
  3 -> \($-1! $+1!\) -> $*$ -> [$-1..$+1] -> '$; ' -> !OUT::write  
http://rosettacode.org/wiki/Topic_variable
Topic variable
Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable. A topic variable is a special variable with a very short name which can also often be omitted. Demonstrate the utilization and behaviour of the topic variable within the language and explain or demonstrate h...
#UNIX_Shell
UNIX Shell
multiply 3 4 # We assume this user defined function has been previously defined echo $? # This will output 12, but $? will now be zero indicating a successful echo
http://rosettacode.org/wiki/Topic_variable
Topic variable
Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable. A topic variable is a special variable with a very short name which can also often be omitted. Demonstrate the utilization and behaviour of the topic variable within the language and explain or demonstrate h...
#VBA
VBA
var T // global scope   var doSomethingWithT = Fn.new { [T * T, T.sqrt] }   T = 3 System.print(doSomethingWithT.call())
http://rosettacode.org/wiki/Topic_variable
Topic variable
Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable. A topic variable is a special variable with a very short name which can also often be omitted. Demonstrate the utilization and behaviour of the topic variable within the language and explain or demonstrate h...
#Wren
Wren
var T // global scope   var doSomethingWithT = Fn.new { [T * T, T.sqrt] }   T = 3 System.print(doSomethingWithT.call())
http://rosettacode.org/wiki/Towers_of_Hanoi
Towers of Hanoi
Task Solve the   Towers of Hanoi   problem with recursion.
#Ada
Ada
with Ada.Text_Io; use Ada.Text_Io;   procedure Towers is type Pegs is (Left, Center, Right); procedure Hanoi (Ndisks : Natural; Start_Peg : Pegs := Left; End_Peg : Pegs := Right; Via_Peg : Pegs := Center) is begin if Ndisks > 0 then Hanoi(Ndisks - 1, Start_Peg, Via_Peg, End_Peg); Put_Li...
http://rosettacode.org/wiki/Tonelli-Shanks_algorithm
Tonelli-Shanks algorithm
This page uses content from Wikipedia. The original article was at Tonelli-Shanks algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In computational number theory, the Tonelli–Shanks algor...
#AArch64_Assembly
AArch64 Assembly
  /* ARM assembly AARCH64 Raspberry PI 3B or android 64 bits */ /* program tonshan64.s */   /*******************************************/ /* Constantes file */ /*******************************************/ /* for this file see task include a file in language AArch64 assembly*/ .include "../inc...
http://rosettacode.org/wiki/Tonelli-Shanks_algorithm
Tonelli-Shanks algorithm
This page uses content from Wikipedia. The original article was at Tonelli-Shanks algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In computational number theory, the Tonelli–Shanks algor...
#ARM_Assembly
ARM Assembly
  /* ARM assembly Raspberry PI or android 32 bits */ /* program tonshan.s */   /* REMARK 1 : this program use routines in a include file see task Include a file language arm assembly for the routine affichageMess conversion10 see at end of this program the instruction include */ /* for constantes see tas...
http://rosettacode.org/wiki/Tokenize_a_string_with_escaping
Tokenize a string with escaping
Task[edit] Write a function or program that can split a string at each non-escaped occurrence of a separator character. It should accept three input parameters:   The string   The separator character   The escape character It should output a list of strings. Details Rules for splitting: The fields that were s...
#ALGOL_68
ALGOL 68
BEGIN # returns s parsed according to delimiter and escape # PROC parse with escapes = ( STRING s, CHAR delimiter, escape )[]STRING: IF ( UPB s - LWB s ) + 1 < 1 THEN # empty string # [ 1 : 0 ]STRING empty a...
http://rosettacode.org/wiki/Total_circles_area
Total circles area
Total circles area You are encouraged to solve this task according to the task description, using any language you may know. Example circles Example circles filtered Given some partially overlapping circles on the plane, compute and show the total area covered by them, with four or six (or a little more) decimal dig...
#Go
Go
package main   import ( "flag" "fmt" "math" "runtime" "sort" )   // Note, the standard "image" package has Point and Rectangle but we // can't use them here since they're defined using int rather than // float64.   type Circle struct{ X, Y, R, rsq float64 }   func NewCircle(x, y,...
http://rosettacode.org/wiki/Topological_sort
Topological sort
Sorting Algorithm This is a sorting algorithm.   It may be applied to a set of data in order to sort it.     For comparing various sorts, see compare sorts.   For other sorting algorithms,   see sorting algorithms,   or: O(n logn) sorts Heap sort | Merge sort | Patience sort | Quick sort O(n log2n) sorts Shell Sort ...
#Bracmat
Bracmat
( ("des_system_lib".std synopsys "std_cell_lib" "des_system_lib" dw02 dw01 ramlib ieee) (dw01.ieee dw01 dware gtech) (dw02.ieee dw02 dware) (dw03.std synopsys dware dw03 dw02 dw01 ieee gtech) (dw04.dw04 ieee dw01 dware gtech) (dw05.dw05 ieee dware) (dw06.dw06 ieee dware) (d...
http://rosettacode.org/wiki/Universal_Turing_machine
Universal Turing machine
One of the foundational mathematical constructs behind computer science is the universal Turing Machine. (Alan Turing introduced the idea of such a machine in 1936–1937.) Indeed one way to definitively prove that a language is turing-complete is to implement a universal Turing machine in it. Task Simulate such ...
#EDSAC_order_code
EDSAC order code
  [Attempt at Turing machine for Rosetta Code.] [EDSAC program, Initial Orders 2.]   [Library subroutine M3 prints header and is then overwritten.] PFGKIFAFRDLFUFOFE@A6FG@E8FEZPF *!!NR!STEPS@&#..PZ [..PZ marks end of header]   T48K [& (delta) parameter: Turing machine tape.] ...
http://rosettacode.org/wiki/Totient_function
Totient function
The   totient   function is also known as:   Euler's totient function   Euler's phi totient function   phi totient function   Φ   function   (uppercase Greek phi)   φ    function   (lowercase Greek phi) Definitions   (as per number theory) The totient function:   counts the integers up to a given positiv...
#C.2B.2B
C++
#include <cassert> #include <iomanip> #include <iostream> #include <vector>   class totient_calculator { public: explicit totient_calculator(int max) : totient_(max + 1) { for (int i = 1; i <= max; ++i) totient_[i] = i; for (int i = 2; i <= max; ++i) { if (totient_[i] < i) ...
http://rosettacode.org/wiki/Topswops
Topswops
Topswops is a card game created by John Conway in the 1970's. Assume you have a particular permutation of a set of   n   cards numbered   1..n   on both of their faces, for example the arrangement of four cards given by   [2, 4, 1, 3]   where the leftmost card is on top. A round is composed of reversing the first  ...
#J
J
swops =: ((|.@:{. , }.)~ {.)^:a:
http://rosettacode.org/wiki/Trigonometric_functions
Trigonometric functions
Task If your language has a library or built-in functions for trigonometry, show examples of:   sine   cosine   tangent   inverses   (of the above) using the same angle in radians and degrees. For the non-inverse functions,   each radian/degree pair should use arguments that evaluate to the same angle   (that i...
#BQN
BQN
⟨sin, cos, tan⟩ ← •math Sin 0 0 Sin π÷2 1 Cos 0 1 Cos π÷2 6.123233995736766e¯17 Tan 0 0 Tan π÷2 16331239353195370 Sin⁼ 0 0 Sin⁼ 1 1.5707963267948966 Cos⁼ 1 0 Cos⁼ 0 1.5707963267948966 Tan⁼ 0 0 Tan⁼ ∞ 1.5707963267948966
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm
Trabb Pardo–Knuth algorithm
The TPK algorithm is an early example of a programming chrestomathy. It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages. The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of...
#ERRE
ERRE
  !Trabb Pardo-Knuth algorithm PROGRAM TPK !VAR I%,Y DIM A[10]   FUNCTION F(T) F=SQR(ABS(T))+5*T^3 END FUNCTION   BEGIN DATA(10,-1,1,2,3,4,4.3,4.305,4.303,4.302,4.301) FOR I%=0 TO 10 DO READ(A[I%]) END FOR FOR I%=10 TO 0 STEP -1 DO Y=F(A[I%]) PRINT("F(";A[I%];")=";) IF Y>400 THEN ...
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm
Trabb Pardo–Knuth algorithm
The TPK algorithm is an early example of a programming chrestomathy. It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages. The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of...
#F.23
F#
  module ``Trabb Pardo - Knuth`` open System let f (x: float) = sqrt(abs x) + (5.0 * (x ** 3.0))   Console.WriteLine "Enter 11 numbers:" [for _ in 1..11 -> Convert.ToDouble(Console.ReadLine())] |> List.rev |> List.map f |> List.iter (function | n when n <= 400.0 -> Console.WriteLine(n) | _ -> Console....
http://rosettacode.org/wiki/Twelve_statements
Twelve statements
This puzzle is borrowed from   math-frolic.blogspot. Given the following twelve statements, which of them are true? 1. This is a numbered list of twelve statements. 2. Exactly 3 of the last 6 statements are true. 3. Exactly 2 of the even-numbered statements are true. 4. If statement 5 is true, then statemen...
#REXX
REXX
/*REXX program solves the "Twelve Statement Puzzle". */ q=12; @stmt=right('statement',20) /*number of statements in the puzzle. */ m=0 /*[↓] statement one is TRUE by fiat.*/ do pass=1 for 2 ...
http://rosettacode.org/wiki/Truth_table
Truth table
A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function. Task Input a Boolean function from the user as a string then calculate and print a formatted truth table for the g...
#Perl
Perl
#!/usr/bin/perl   sub truth_table { my $s = shift; my (%seen, @vars); for ($s =~ /([a-zA-Z_]\w*)/g) { $seen{$_} //= do { push @vars, $_; 1 }; }   print "\n", join("\t", @vars, $s), "\n", '-' x 40, "\n"; @vars = map("\$$_", @vars);   $s =~ s/([a-zA-Z_]\w*)/\$$1/g; $s = "print(".jo...
http://rosettacode.org/wiki/Ulam_spiral_(for_primes)
Ulam spiral (for primes)
An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1),   constructed on a square grid, starting at the "center". An Ulam spiral is also known as a   prime spiral. The first grid (green) is shown with sequential integers,   ...
#PicoLisp
PicoLisp
(load "@lib/simul.l")   (de ceil (A) (/ (+ A 1) 2) )   (de prime? (N) (or (= N 2) (and (> N 1) (bit? 1 N) (let S (sqrt N) (for (D 3 T (+ D 2)) (T (> D S) T) (T (=0 (% N D)) NIL) ) ) ) ) )   (de ulam (N) (let (G (grid N N) ...
http://rosettacode.org/wiki/Truncatable_primes
Truncatable primes
A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number. Examples The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime. The number 7393 is a right-truncatable prime as the numbers 7393, 7...
#Haskell
Haskell
import Data.Numbers.Primes(primes, isPrime) import Data.List import Control.Arrow   primes1e6 = reverse. filter (notElem '0'. show) $ takeWhile(<=1000000) primes   rightT, leftT :: Int -> Bool rightT = all isPrime. takeWhile(>0). drop 1. iterate (`div`10) leftT x = all isPrime. takeWhile(<x).map (x`mod`) $ iterate (*10...
http://rosettacode.org/wiki/Tree_traversal
Tree traversal
Task Implement a binary tree where each node carries an integer,   and implement:   pre-order,   in-order,   post-order,     and   level-order   traversal. Use those traversals to output the following tree: 1 / \ / \ / \ 2 3 / \ / 4 5 6 / ...
#AppleScript
AppleScript
on run -- Sample tree of integers set tree to node(1, ¬ {node(2, ¬ {node(4, {node(7, {})}), ¬ node(5, {})}), ¬ node(3, ¬ {node(6, {node(8, {}), ¬ node(9, {})})})})     -- Output of AppleScript code at Rosetta Code task -...
http://rosettacode.org/wiki/Topic_variable
Topic variable
Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable. A topic variable is a special variable with a very short name which can also often be omitted. Demonstrate the utilization and behaviour of the topic variable within the language and explain or demonstrate h...
#zkl
zkl
a,_,c:=List(1,2,3,4,5,6) //-->a=1, c=3, here _ is used as "ignore" 3.0 : _.sqrt() : println(_) //-->"1.73205", _ (and :) is used to "explode" a computation // as syntactic sugar 1.0 + 2 : _.sqrt() : _.pow(4) // no variables used, the compiler "implodes" the computation // --> 9  
http://rosettacode.org/wiki/Top_rank_per_group
Top rank per group
Task Find the top   N   salaries in each department,   where   N   is provided as a parameter. Use this data as a formatted internal data structure (adapt it to your language-native idioms, rather than parse at runtime), or identify your external data source: Employee Name,Employee ID,Salary,Department Tyler Bennett...
#11l
11l
V data = [(‘Tyler Bennett’, ‘E10297’, 32000, ‘D101’), (‘John Rappl’, ‘E21437’, 47000, ‘D050’), (‘George Woltman’, ‘E00127’, 53500, ‘D101’), (‘Adam Smith’, ‘E63535’, 18000, ‘D202’), (‘Claire Buckman’, ‘E39876’, 27800, ‘D202’), (‘David McClellan’, ‘E04242’, 41500, ‘D101’)...
http://rosettacode.org/wiki/Towers_of_Hanoi
Towers of Hanoi
Task Solve the   Towers of Hanoi   problem with recursion.
#Agena
Agena
move := proc(n::number, src::number, dst::number, via::number) is if n > 0 then move(n - 1, src, via, dst) print(src & ' to ' & dst) move(n - 1, via, dst, src) fi end   move(4, 1, 2, 3)
http://rosettacode.org/wiki/Thue-Morse
Thue-Morse
Task Create a Thue-Morse sequence. See also   YouTube entry: The Fairest Sharing Sequence Ever   YouTube entry: Math and OCD - My story with the Thue-Morse sequence   Task: Fairshare between two and more
#11l
11l
F thue_morse_digits(digits) R (0 .< digits).map(n -> bin(n).count(‘1’) % 2)   print(thue_morse_digits(20))
http://rosettacode.org/wiki/Tonelli-Shanks_algorithm
Tonelli-Shanks algorithm
This page uses content from Wikipedia. The original article was at Tonelli-Shanks algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In computational number theory, the Tonelli–Shanks algor...
#C
C
#include <stdbool.h> #include <stdint.h> #include <stdio.h>   uint64_t modpow(uint64_t a, uint64_t b, uint64_t n) { uint64_t x = 1, y = a; while (b > 0) { if (b % 2 == 1) { x = (x * y) % n; // multiplying with base } y = (y * y) % n; // squaring the base b /= 2; }...
http://rosettacode.org/wiki/Tokenize_a_string_with_escaping
Tokenize a string with escaping
Task[edit] Write a function or program that can split a string at each non-escaped occurrence of a separator character. It should accept three input parameters:   The string   The separator character   The escape character It should output a list of strings. Details Rules for splitting: The fields that were s...
#AppleScript
AppleScript
------------------ TOKENIZE WITH ESCAPING ----------------   -- tokenize :: String -> Character -> Character -> [String] on tokenize(str, delimChar, chrEsc)   script charParse -- Record: {esc:Bool, token:String, tokens:[String]} -- charParse :: Record -> Character -> Record on |λ|(a, x) ...
http://rosettacode.org/wiki/Total_circles_area
Total circles area
Total circles area You are encouraged to solve this task according to the task description, using any language you may know. Example circles Example circles filtered Given some partially overlapping circles on the plane, compute and show the total area covered by them, with four or six (or a little more) decimal dig...
#Haskell
Haskell
data Circle = Circle { cx :: Double, cy :: Double, cr :: Double }   isInside :: Double -> Double -> Circle -> Bool isInside x y c = (x - cx c) ^ 2 + (y - cy c) ^ 2 <= (cr c ^ 2)   isInsideAny :: Double -> Double -> [Circle] -> Bool isInsideAny x y = any (isInside x y)   approximatedArea :: [Circle] -> Int -> Double app...
http://rosettacode.org/wiki/Topological_sort
Topological sort
Sorting Algorithm This is a sorting algorithm.   It may be applied to a set of data in order to sort it.     For comparing various sorts, see compare sorts.   For other sorting algorithms,   see sorting algorithms,   or: O(n logn) sorts Heap sort | Merge sort | Patience sort | Quick sort O(n log2n) sorts Shell Sort ...
#C
C
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <ctype.h>   char input[] = "des_system_lib std synopsys std_cell_lib des_system_lib dw02 dw01 ramlib ieee\n" "dw01 ieee dw01 dware gtech\n" "dw02 ieee dw02 dware\n" "dw03 std synopsys dware dw03 dw02 dw01 ieee ...
http://rosettacode.org/wiki/Universal_Turing_machine
Universal Turing machine
One of the foundational mathematical constructs behind computer science is the universal Turing Machine. (Alan Turing introduced the idea of such a machine in 1936–1937.) Indeed one way to definitively prove that a language is turing-complete is to implement a universal Turing machine in it. Task Simulate such ...
#Erlang
Erlang
#!/usr/bin/env escript   -module(turing). -mode(compile).   -export([main/1]).   % Incrementer definition: % States: a | halt % Initial state: a % Halting states: halt % Symbols: b | '1' % Blank symbol: b incrementer_config() -> {a, [halt], b}. incrementer(a, '1') -> {'1', right, a}; incrementer(a, b) -> {'1', stay, ...
http://rosettacode.org/wiki/Totient_function
Totient function
The   totient   function is also known as:   Euler's totient function   Euler's phi totient function   phi totient function   Φ   function   (uppercase Greek phi)   φ    function   (lowercase Greek phi) Definitions   (as per number theory) The totient function:   counts the integers up to a given positiv...
#D
D
import std.stdio;   int totient(int n) { int tot = n;   for (int i = 2; i * i <= n; i += 2) { if (n % i == 0) { while (n % i == 0) { n /= i; } tot -= tot / i; } if (i==2) { i = 1; } }   if (n > 1) { t...
http://rosettacode.org/wiki/Topswops
Topswops
Topswops is a card game created by John Conway in the 1970's. Assume you have a particular permutation of a set of   n   cards numbered   1..n   on both of their faces, for example the arrangement of four cards given by   [2, 4, 1, 3]   where the leftmost card is on top. A round is composed of reversing the first  ...
#Java
Java
public class Topswops { static final int maxBest = 32; static int[] best;   static private void trySwaps(int[] deck, int f, int d, int n) { if (d > best[n]) best[n] = d;   for (int i = n - 1; i >= 0; i--) { if (deck[i] == -1 || deck[i] == i) break; ...
http://rosettacode.org/wiki/Trigonometric_functions
Trigonometric functions
Task If your language has a library or built-in functions for trigonometry, show examples of:   sine   cosine   tangent   inverses   (of the above) using the same angle in radians and degrees. For the non-inverse functions,   each radian/degree pair should use arguments that evaluate to the same angle   (that i...
#C
C
#include <math.h> #include <stdio.h>   int main() { double pi = 4 * atan(1); /*Pi / 4 is 45 degrees. All answers should be the same.*/ double radians = pi / 4; double degrees = 45.0; double temp; /*sine*/ printf("%f %f\n", sin(radians), sin(degrees * pi / 180)); /*cosine*/ printf("%f %f\n", cos(radian...
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm
Trabb Pardo–Knuth algorithm
The TPK algorithm is an early example of a programming chrestomathy. It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages. The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of...
#Factor
Factor
USING: formatting io kernel math math.functions math.parser prettyprint sequences splitting ; IN: rosetta-code.trabb-pardo-knuth   CONSTANT: threshold 400 CONSTANT: prompt "Please enter 11 numbers: "   : fn ( x -- y ) [ abs 0.5 ^ ] [ 3 ^ 5 * ] bi + ;   : overflow? ( x -- ? ) threshold > ;   : get-input ( -- seq ) p...
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm
Trabb Pardo–Knuth algorithm
The TPK algorithm is an early example of a programming chrestomathy. It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages. The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of...
#Forth
Forth
: f(x) fdup fsqrt fswap 3e f** 5e f* f+ ;   4e2 fconstant f-too-big   11 Constant #Elements   : float-array ( compile: n -- / run: n -- addr ) create floats allot does> swap floats + ;   #Elements float-array vec   : get-it ( -- ) ." Enter " #Elements . ." numbers:" cr #Elements 0 DO ...
http://rosettacode.org/wiki/Twelve_statements
Twelve statements
This puzzle is borrowed from   math-frolic.blogspot. Given the following twelve statements, which of them are true? 1. This is a numbered list of twelve statements. 2. Exactly 3 of the last 6 statements are true. 3. Exactly 2 of the even-numbered statements are true. 4. If statement 5 is true, then statemen...
#Ruby
Ruby
constraints = [ ->(st) { st.size == 12 }, ->(st) { st.last(6).count(true) == 3 }, ->(st) { st.each_slice(2).map(&:last).count(true) == 2 }, ->(st) { st[4] ? (st[5] & st[6]) : true }, ->(st) { st[1..3].none? }, ->(st) { st.each_slice(2).map(&:first).count(true) == 4 }, ->(st) { st[1] ^ st[2] }, ->(st) {...
http://rosettacode.org/wiki/Truth_table
Truth table
A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function. Task Input a Boolean function from the user as a string then calculate and print a formatted truth table for the g...
#Phix
Phix
sequence opstack = {} object token object op = 0 -- 0 = none string s -- the expression being parsed integer sidx -- idx to "" integer ch -- s[sidx] procedure err(string msg) printf(1,"%s\n%s^ %s\n\nPressEnter...",{s,repeat(' ',sidx-1),msg}) {} = wait_key() abort(0) end procedure proced...
http://rosettacode.org/wiki/Ulam_spiral_(for_primes)
Ulam spiral (for primes)
An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1),   constructed on a square grid, starting at the "center". An Ulam spiral is also known as a   prime spiral. The first grid (green) is shown with sequential integers,   ...
#PowerShell
PowerShell
  function New-UlamSpiral ( [int]$N ) { # Generate list of primes $Primes = @( 2 ) For ( $X = 3; $X -le $N*$N; $X += 2 ) { If ( -not ( $Primes | Where { $X % $_ -eq 0 } | Select -First 1 ) ) { $Primes += $X } }   # Initialize variables $X = 0 $Y = -1 $i = $N * $...
http://rosettacode.org/wiki/Truncatable_primes
Truncatable primes
A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number. Examples The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime. The number 7393 is a right-truncatable prime as the numbers 7393, 7...
#Icon_and_Unicon
Icon and Unicon
procedure main(arglist) N := 0 < integer(\arglist[1]) | 1000000 # primes to generator 1 to ... (1M or 1st arglist) D := (0 < integer(\arglist[2]) | 10) / 2 # primes to display (10 or 2nd arglist) P := sieve(N) # from sieve task (modified) ...
http://rosettacode.org/wiki/Tree_traversal
Tree traversal
Task Implement a binary tree where each node carries an integer,   and implement:   pre-order,   in-order,   post-order,     and   level-order   traversal. Use those traversals to output the following tree: 1 / \ / \ / \ 2 3 / \ / 4 5 6 / ...
#ARM_Assembly
ARM Assembly
    /* ARM assembly Raspberry PI */ /* program deftree2.s */   /* Constantes */ .equ STDOUT, 1 @ Linux output console .equ EXIT, 1 @ Linux syscall .equ READ, 3 .equ WRITE, 4   .equ NBVAL, 9   /*******************************************/ /* Structures ...
http://rosettacode.org/wiki/Top_rank_per_group
Top rank per group
Task Find the top   N   salaries in each department,   where   N   is provided as a parameter. Use this data as a formatted internal data structure (adapt it to your language-native idioms, rather than parse at runtime), or identify your external data source: Employee Name,Employee ID,Salary,Department Tyler Bennett...
#Action.21
Action!
DEFINE PTR="CARD" DEFINE ENTRY_SIZE="8"   TYPE Employee=[ PTR name,id,dep ;CHAR ARRAY CARD salary]   BYTE ARRAY data(200) BYTE count=[0]   PTR FUNC GetItemAddr(INT index) PTR addr   addr=data+index*ENTRY_SIZE RETURN (addr)   PROC Append(CHAR ARRAY n,i CARD s CHAR ARRAY d) Employee POINTER dst   dst=GetItemA...
http://rosettacode.org/wiki/Towers_of_Hanoi
Towers of Hanoi
Task Solve the   Towers of Hanoi   problem with recursion.
#ALGOL_60
ALGOL 60
begin procedure movedisk(n, f, t); integer n, f, t; begin outstring (1, "Move disk from"); outinteger(1, f); outstring (1, "to"); outinteger(1, t); outstring (1, "\n"); end;   procedure dohanoi(n, f, t, u); integer n, f, t, u; begin if n < 2 then movedisk(1, f, t) else ...
http://rosettacode.org/wiki/Thue-Morse
Thue-Morse
Task Create a Thue-Morse sequence. See also   YouTube entry: The Fairest Sharing Sequence Ever   YouTube entry: Math and OCD - My story with the Thue-Morse sequence   Task: Fairshare between two and more
#8080_Assembly
8080 Assembly
org 100h ;;; Write 256 bytes of ASCII '0' starting at address 200h lxi h,200h ; The array is page-aligned so L starts at 0 mvi a,'0' ; ASCII 0 zero: mov m,a ; Write it to memory at address HL inr l ; Increment low byte of pointer, jnz zero ; until it wraps to zero. ;;; Generate the first 256 elements of the Thu...
http://rosettacode.org/wiki/Thue-Morse
Thue-Morse
Task Create a Thue-Morse sequence. See also   YouTube entry: The Fairest Sharing Sequence Ever   YouTube entry: Math and OCD - My story with the Thue-Morse sequence   Task: Fairshare between two and more
#Action.21
Action!
PROC Next(CHAR ARRAY s) BYTE i,len CHAR c   IF s(0)=0 THEN s(0)=1 s(1)='0 RETURN FI   FOR i=1 TO s(0) DO IF s(i)='0 THEN c='1 ELSE c='0 FI s(s(0)+i)=c OD s(0)==*2 RETURN   PROC Main() BYTE i CHAR ARRAY s(256)   s(0)=0 FOR i=0 TO 7 DO Next(s) PrintF("...
http://rosettacode.org/wiki/Thue-Morse
Thue-Morse
Task Create a Thue-Morse sequence. See also   YouTube entry: The Fairest Sharing Sequence Ever   YouTube entry: Math and OCD - My story with the Thue-Morse sequence   Task: Fairshare between two and more
#Ada
Ada
with Ada.Text_IO; use Ada.Text_IO;   procedure Thue_Morse is   function Replace(S: String) return String is -- replace every "0" by "01" and every "1" by "10" (if S'Length = 0 then "" else (if S(S'First) = '0' then "01" else "10") & Replace(S(S'First+1 .. S'Last)));   function Sequence (N: Na...
http://rosettacode.org/wiki/Tonelli-Shanks_algorithm
Tonelli-Shanks algorithm
This page uses content from Wikipedia. The original article was at Tonelli-Shanks algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In computational number theory, the Tonelli–Shanks algor...
#C.23
C#
using System; using System.Collections.Generic; using System.Numerics;   namespace TonelliShanks { class Solution { private readonly BigInteger root1, root2; private readonly bool exists;   public Solution(BigInteger root1, BigInteger root2, bool exists) { this.root1 = root1; ...
http://rosettacode.org/wiki/Tokenize_a_string_with_escaping
Tokenize a string with escaping
Task[edit] Write a function or program that can split a string at each non-escaped occurrence of a separator character. It should accept three input parameters:   The string   The separator character   The escape character It should output a list of strings. Details Rules for splitting: The fields that were s...
#Arturo
Arturo
tokenize: function [s sep esc][ escaping: 0   loop 0..(size s)-1 [i][ chr: get split s i   if? escaping=1 [ prints chr escaping: 0 ] else [ case [chr] when? [=sep] [print ""] when? [=esc] [escaping: 1] else [prints chr] ] ] print "" ]   str: "one^|uno||three^^^^|four^^^|^cuatro|" tok...
http://rosettacode.org/wiki/Total_circles_area
Total circles area
Total circles area You are encouraged to solve this task according to the task description, using any language you may know. Example circles Example circles filtered Given some partially overlapping circles on the plane, compute and show the total area covered by them, with four or six (or a little more) decimal dig...
#J
J
NB. check points on a regular grid within the bounding box     N=: 400 NB. grids in each dimension. Controls accuracy.     'X Y R'=: |: XYR=: (_&".;._2~ LF&=)0 :0 1.6417233788 1.6121789534 0.0848270516 -1.4944608174 1.2077959613 1.1039549836 0.6110294452 -0.6907087527 0.9089162485 0.3844862411 0.2923344616 0.23...
http://rosettacode.org/wiki/Topological_sort
Topological sort
Sorting Algorithm This is a sorting algorithm.   It may be applied to a set of data in order to sort it.     For comparing various sorts, see compare sorts.   For other sorting algorithms,   see sorting algorithms,   or: O(n logn) sorts Heap sort | Merge sort | Patience sort | Quick sort O(n log2n) sorts Shell Sort ...
#C.23
C#
  namespace Algorithms { using System; using System.Collections.Generic; using System.Linq;   public class TopologicalSorter<ValueType> { private class Relations { public int Dependencies = 0; public HashSet<ValueType> Dependents = new HashSet<ValueType>(); ...
http://rosettacode.org/wiki/Universal_Turing_machine
Universal Turing machine
One of the foundational mathematical constructs behind computer science is the universal Turing Machine. (Alan Turing introduced the idea of such a machine in 1936–1937.) Indeed one way to definitively prove that a language is turing-complete is to implement a universal Turing machine in it. Task Simulate such ...
#Fortran
Fortran
1 State 1 1,-1, 3 1,+1, 2 2 State 2 1,+1, 2 1,-1, 1
http://rosettacode.org/wiki/Totient_function
Totient function
The   totient   function is also known as:   Euler's totient function   Euler's phi totient function   phi totient function   Φ   function   (uppercase Greek phi)   φ    function   (lowercase Greek phi) Definitions   (as per number theory) The totient function:   counts the integers up to a given positiv...
#Delphi
Delphi
func totient(n) { var tot = n var i = 2 while i * i <= n { if n % i == 0 { while n % i == 0 { n /= i } tot -= tot / i } if i == 2 { i = 1 } i += 2 } if n > 1 { tot -= tot / n } ret...
http://rosettacode.org/wiki/Topswops
Topswops
Topswops is a card game created by John Conway in the 1970's. Assume you have a particular permutation of a set of   n   cards numbered   1..n   on both of their faces, for example the arrangement of four cards given by   [2, 4, 1, 3]   where the leftmost card is on top. A round is composed of reversing the first  ...
#jq
jq
# "while" as defined here is included in recent versions (>1.4) of jq: def until(cond; next): def _until: if cond then . else (next|_until) end; _until;   # Generate a stream of permutations of [1, ... n]. # This implementation uses arity-0 filters for speed. def permutations: # Given a single array, insert g...
http://rosettacode.org/wiki/Topswops
Topswops
Topswops is a card game created by John Conway in the 1970's. Assume you have a particular permutation of a set of   n   cards numbered   1..n   on both of their faces, for example the arrangement of four cards given by   [2, 4, 1, 3]   where the leftmost card is on top. A round is composed of reversing the first  ...
#Julia
Julia
function fannkuch(n) n == 1 && return 0 n == 2 && return 1 p = [1:n] q = copy(p) s = copy(p) sign = 1; maxflips = sum = 0 while true q0 = p[1] if q0 != 1 for i = 2:n q[i] = p[i] end flips = 1 while true qq = q[q0] #?? if qq == 1 sum += sign*flips flips > maxflips && (maxflip...
http://rosettacode.org/wiki/Trigonometric_functions
Trigonometric functions
Task If your language has a library or built-in functions for trigonometry, show examples of:   sine   cosine   tangent   inverses   (of the above) using the same angle in radians and degrees. For the non-inverse functions,   each radian/degree pair should use arguments that evaluate to the same angle   (that i...
#C.23
C#
using System;   namespace RosettaCode { class Program { static void Main(string[] args) { Console.WriteLine("=== radians ==="); Console.WriteLine("sin (pi/3) = {0}", Math.Sin(Math.PI / 3)); Console.WriteLine("cos (pi/3) = {0}", Math.Cos(Math.PI / 3)); Console....
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm
Trabb Pardo–Knuth algorithm
The TPK algorithm is an early example of a programming chrestomathy. It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages. The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of...
#Fortran
Fortran
program tpk implicit none   real, parameter :: overflow = 400.0 real :: a(11), res integer :: i   write(*,*) "Input eleven numbers:" read(*,*) a   a = a(11:1:-1) do i = 1, 11 res = f(a(i)) write(*, "(a, f0.3, a)", advance = "no") "f(", a(i), ") = " if(res > overflow) then write(*, "(a)...
http://rosettacode.org/wiki/Twelve_statements
Twelve statements
This puzzle is borrowed from   math-frolic.blogspot. Given the following twelve statements, which of them are true? 1. This is a numbered list of twelve statements. 2. Exactly 3 of the last 6 statements are true. 3. Exactly 2 of the even-numbered statements are true. 4. If statement 5 is true, then statemen...
#Scala
Scala
class LogicPuzzle { val s = new Array[Boolean](13) var count = 0   def check2: Boolean = { var count = 0 for (k <- 7 to 12) if (s(k)) count += 1   s(2) == (count == 3) }   def check3: Boolean = { var count = 0 for (k <- 2 to 12 by 2) if (s(k)) count += 1   s(3) == (count == 2) }   ...
http://rosettacode.org/wiki/Truth_table
Truth table
A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function. Task Input a Boolean function from the user as a string then calculate and print a formatted truth table for the g...
#PicoLisp
PicoLisp
(de truthTable (Expr) (let Vars (uniq (make (setq Expr (recur (Expr) # Convert infix to prefix notation (cond ((atom Expr) (link Expr)) ((== 'not (car Expr)) (list 'not (recurse (cadr Expr))...
http://rosettacode.org/wiki/Ulam_spiral_(for_primes)
Ulam spiral (for primes)
An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1),   constructed on a square grid, starting at the "center". An Ulam spiral is also known as a   prime spiral. The first grid (green) is shown with sequential integers,   ...
#Python
Python
# coding=UTF-8 from __future__ import print_function, division from math import sqrt   def cell(n, x, y, start=1): d, y, x = 0, y - n//2, x - (n - 1)//2 l = 2*max(abs(x), abs(y)) d = (l*3 + x + y) if y >= x else (l - x - y) return (l - 1)**2 + d + start - 1   def show_spiral(n, symbol='# ', start=1, spa...
http://rosettacode.org/wiki/Truncatable_primes
Truncatable primes
A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number. Examples The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime. The number 7393 is a right-truncatable prime as the numbers 7393, 7...
#J
J
selPrime=: #~ 1&p: seed=: selPrime digits=: 1+i.9 step=: selPrime@,@:(,&.":/&>)@{@;
http://rosettacode.org/wiki/Tree_traversal
Tree traversal
Task Implement a binary tree where each node carries an integer,   and implement:   pre-order,   in-order,   post-order,     and   level-order   traversal. Use those traversals to output the following tree: 1 / \ / \ / \ 2 3 / \ / 4 5 6 / ...
#ATS
ATS
#include "share/atspre_staload.hats" // (* ****** ****** *) // datatype tree (a:t@ype) = | tnil of () | tcons of (tree a, a, tree a) // (* ****** ****** *)   symintr ++ infixr (+) ++ overload ++ with list_append   (* ****** ****** *)   #define sing list_sing   (* ****** ****** *)   fun{ a:t@ype } preorder (t0: tr...
http://rosettacode.org/wiki/Tokenize_a_string
Tokenize a string
Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word. Display the words to the 'user', in the simplest manner possible, separated by a period. To simplify, you may display a trailing period. Other tasks related to string operations: Me...
#11l
11l
V text = ‘Hello,How,Are,You,Today’ V tokens = text.split(‘,’) print(tokens.join(‘.’))
http://rosettacode.org/wiki/Top_rank_per_group
Top rank per group
Task Find the top   N   salaries in each department,   where   N   is provided as a parameter. Use this data as a formatted internal data structure (adapt it to your language-native idioms, rather than parse at runtime), or identify your external data source: Employee Name,Employee ID,Salary,Department Tyler Bennett...
#Ada
Ada
with Ada.Containers.Vectors; with Ada.Text_IO;   procedure Top is type Departments is (D050, D101, D190, D202); type Employee_Data is record Name  : String (1 .. 15); ID  : String (1 .. 6); Salary  : Positive; Department : Departments; end record;   package Employee_Ve...
http://rosettacode.org/wiki/Towers_of_Hanoi
Towers of Hanoi
Task Solve the   Towers of Hanoi   problem with recursion.
#ALGOL_68
ALGOL 68
PROC move = (INT n, from, to, via) VOID: IF n > 0 THEN move(n - 1, from, via, to); printf(($"Move disk from pole "g" to pole "gl$, from, to)); move(n - 1, via, to, from) FI ;   main: ( move(4, 1,2,3) )
http://rosettacode.org/wiki/Thue-Morse
Thue-Morse
Task Create a Thue-Morse sequence. See also   YouTube entry: The Fairest Sharing Sequence Ever   YouTube entry: Math and OCD - My story with the Thue-Morse sequence   Task: Fairshare between two and more
#ALGOL_68
ALGOL 68
# "flips" the "bits" in a string (assumed to contain only "0" and "1" characters) # OP FLIP = ( STRING s )STRING: BEGIN STRING result := s; FOR char pos FROM LWB result TO UPB result DO result[ char pos ] := IF result[ char pos ] = "0" THEN "1" ELSE "0" FI OD; result ...
http://rosettacode.org/wiki/Thue-Morse
Thue-Morse
Task Create a Thue-Morse sequence. See also   YouTube entry: The Fairest Sharing Sequence Ever   YouTube entry: Math and OCD - My story with the Thue-Morse sequence   Task: Fairshare between two and more
#AppleScript
AppleScript
------------------------ THUE MORSE ----------------------   -- thueMorse :: Int -> String on thueMorse(nCycles) script concatBinaryInverse on |λ|(xs) script binaryInverse on |λ|(x) 1 - x end |λ| end script   xs & map(bi...
http://rosettacode.org/wiki/Tonelli-Shanks_algorithm
Tonelli-Shanks algorithm
This page uses content from Wikipedia. The original article was at Tonelli-Shanks algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In computational number theory, the Tonelli–Shanks algor...
#Clojure
Clojure
  (defn find-first " Finds first element of collection that satisifies predicate function pred " [pred coll] (first (filter pred coll)))   (defn modpow " b^e mod m (using Java which solves some cases the pure clojure method has to be modified to tackle--i.e. with large b & e and calculation simplications whe...
http://rosettacode.org/wiki/Tokenize_a_string_with_escaping
Tokenize a string with escaping
Task[edit] Write a function or program that can split a string at each non-escaped occurrence of a separator character. It should accept three input parameters:   The string   The separator character   The escape character It should output a list of strings. Details Rules for splitting: The fields that were s...
#AutoHotkey
AutoHotkey
Tokenize(s,d,e){ for i,v in x:=StrSplit(StrReplace(StrReplace(StrReplace(s,e e,Chr(0xFFFE)),e d,Chr(0xFFFF)),e),d) x[i]:=StrReplace(StrReplace(v,Chr(0xFFFE),e),Chr(0xFFFF),d) return x }
http://rosettacode.org/wiki/Tokenize_a_string_with_escaping
Tokenize a string with escaping
Task[edit] Write a function or program that can split a string at each non-escaped occurrence of a separator character. It should accept three input parameters:   The string   The separator character   The escape character It should output a list of strings. Details Rules for splitting: The fields that were s...
#BBC_BASIC
BBC BASIC
REM >tokenizer PROC_tokenize("one^|uno||three^^^^|four^^^|^cuatro|", "|", "^") END : DEF PROC_tokenize(src$, sep$, esc$) LOCAL field%, char$, escaping%, i% field% = 1 escaping% = FALSE PRINT field%; " "; FOR i% = 1 TO LEN src$ char$ = MID$(src$, i%, 1) IF escaping% THEN PRINT char$; escaping% = FALSE ELSE...
http://rosettacode.org/wiki/Total_circles_area
Total circles area
Total circles area You are encouraged to solve this task according to the task description, using any language you may know. Example circles Example circles filtered Given some partially overlapping circles on the plane, compute and show the total area covered by them, with four or six (or a little more) decimal dig...
#Java
Java
  public class CirclesTotalArea {   /* * Rectangles are given as 4-element arrays [tx, ty, w, h]. * Circles are given as 3-element arrays [cx, cy, r]. */   private static double distSq(double x1, double y1, double x2, double y2) { return (x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1); ...
http://rosettacode.org/wiki/Topological_sort
Topological sort
Sorting Algorithm This is a sorting algorithm.   It may be applied to a set of data in order to sort it.     For comparing various sorts, see compare sorts.   For other sorting algorithms,   see sorting algorithms,   or: O(n logn) sorts Heap sort | Merge sort | Patience sort | Quick sort O(n log2n) sorts Shell Sort ...
#C.2B.2B
C++
#include <map> #include <set>   template<typename Goal> class topological_sorter { protected: struct relations { std::size_t dependencies; std::set<Goal> dependents; }; std::map<Goal, relations> map; public: void add_goal(Goal const &goal) { map[goal]; } void add_dependen...
http://rosettacode.org/wiki/Universal_Turing_machine
Universal Turing machine
One of the foundational mathematical constructs behind computer science is the universal Turing Machine. (Alan Turing introduced the idea of such a machine in 1936–1937.) Indeed one way to definitively prove that a language is turing-complete is to implement a universal Turing machine in it. Task Simulate such ...
#F.C5.8Drmul.C3.A6
Fōrmulæ
package turing   type Symbol byte   type Motion byte   const ( Left Motion = 'L' Right Motion = 'R' Stay Motion = 'N' )   type Tape struct { data []Symbol pos, left int blank Symbol }   // NewTape returns a new tape filled with 'data' and position set to 'start...
http://rosettacode.org/wiki/Totient_function
Totient function
The   totient   function is also known as:   Euler's totient function   Euler's phi totient function   phi totient function   Φ   function   (uppercase Greek phi)   φ    function   (lowercase Greek phi) Definitions   (as per number theory) The totient function:   counts the integers up to a given positiv...
#Dyalect
Dyalect
func totient(n) { var tot = n var i = 2 while i * i <= n { if n % i == 0 { while n % i == 0 { n /= i } tot -= tot / i } if i == 2 { i = 1 } i += 2 } if n > 1 { tot -= tot / n } ret...
http://rosettacode.org/wiki/Topswops
Topswops
Topswops is a card game created by John Conway in the 1970's. Assume you have a particular permutation of a set of   n   cards numbered   1..n   on both of their faces, for example the arrangement of four cards given by   [2, 4, 1, 3]   where the leftmost card is on top. A round is composed of reversing the first  ...
#Kotlin
Kotlin
// version 1.1.2   val best = IntArray(32)   fun trySwaps(deck: IntArray, f: Int, d: Int, n: Int) { if (d > best[n]) best[n] = d for (i in n - 1 downTo 0) { if (deck[i] == -1 || deck[i] == i) break if (d + best[i] <= best[n]) return } val deck2 = deck.copyOf() for (i in 1 until n) { ...
http://rosettacode.org/wiki/Trigonometric_functions
Trigonometric functions
Task If your language has a library or built-in functions for trigonometry, show examples of:   sine   cosine   tangent   inverses   (of the above) using the same angle in radians and degrees. For the non-inverse functions,   each radian/degree pair should use arguments that evaluate to the same angle   (that i...
#C.2B.2B
C++
#include <iostream> #include <cmath>   #ifdef M_PI // defined by all POSIX systems and some non-POSIX ones double const pi = M_PI; #else double const pi = 4*std::atan(1); #endif   double const degree = pi/180;   int main() { std::cout << "=== radians ===\n"; std::cout << "sin(pi/3) = " << std::sin(pi/3) << "\n"; ...
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm
Trabb Pardo–Knuth algorithm
The TPK algorithm is an early example of a programming chrestomathy. It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages. The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of...
#FreeBASIC
FreeBASIC
' version 22-07-2017 ' compile with: fbc -s console   Function f(n As Double) As Double return Sqr(Abs(n)) + 5 * n ^ 3 End Function   ' ------=< MAIN >=------   Dim As Double x, s(1 To 11) Dim As Long i   For i = 1 To 11 Print Str(i); Input " => ", s(i) Next   Print Print String(20,"-")   i -= 1 Do Pri...
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm
Trabb Pardo–Knuth algorithm
The TPK algorithm is an early example of a programming chrestomathy. It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages. The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of...
#Go
Go
package main   import ( "fmt" "log" "math" )   func main() { // prompt fmt.Print("Enter 11 numbers: ") // accept sequence var s [11]float64 for i := 0; i < 11; { if n, _ := fmt.Scan(&s[i]); n > 0 { i++ } } // reverse sequence for i, item := range s...
http://rosettacode.org/wiki/Twelve_statements
Twelve statements
This puzzle is borrowed from   math-frolic.blogspot. Given the following twelve statements, which of them are true? 1. This is a numbered list of twelve statements. 2. Exactly 3 of the last 6 statements are true. 3. Exactly 2 of the even-numbered statements are true. 4. If statement 5 is true, then statemen...
#Sidef
Sidef
var conditions = [ { false }, {|a| a.len == 13 }, {|a| [a[7..12]].count(true) == 3 }, {|a| [a[2..12 `by` 2]].count(true) == 2 }, {|a| a[5] ? (a[6] && a[7]) : true }, {|a| !a[2] && !a[3] && !a[4] }, {|a| [a[1..11 `by` 2]].count(true) == 4 }, {|a| a[2] == true^a[3] }, {|a| a[7] ? (a[5]...
http://rosettacode.org/wiki/Truth_table
Truth table
A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function. Task Input a Boolean function from the user as a string then calculate and print a formatted truth table for the g...
#Prolog
Prolog
/* To evaluate the truth table a line of text is inputted and then there are three steps Let's say the expression is: 'not a and (b or c)'   Step 1: tokenize into atoms and brackets eg: Tokenized = [ not, a, and, '(', b, or, c, ')' ].   Step 2: convert to a term that can be evaluated, and get o...
http://rosettacode.org/wiki/Ulam_spiral_(for_primes)
Ulam spiral (for primes)
An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1),   constructed on a square grid, starting at the "center". An Ulam spiral is also known as a   prime spiral. The first grid (green) is shown with sequential integers,   ...
#R
R
  ## Plotting Ulam spiral (for primes) 2/12/17 aev ## plotulamspirR(n, clr, fn, ttl, psz=600), where: n - initial size; ## clr - color; fn - file name; ttl - plot title; psz - picture size. ## require(numbers); plotulamspirR <- function(n, clr, fn, ttl, psz=600) { cat(" *** START:", date(), "n=",n, "clr=",clr, "psz=...
http://rosettacode.org/wiki/Truncatable_primes
Truncatable primes
A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number. Examples The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime. The number 7393 is a right-truncatable prime as the numbers 7393, 7...
#Java
Java
import java.util.BitSet;   public class Main {   public static void main(String[] args){   final int MAX = 1000000;   //Sieve of Eratosthenes (using BitSet only for odd numbers) BitSet primeList = new BitSet(MAX>>1); primeList.set(0,primeList.size(),true);   int sqroot = (int) Math.sqrt(MAX); primeList....
http://rosettacode.org/wiki/Tree_traversal
Tree traversal
Task Implement a binary tree where each node carries an integer,   and implement:   pre-order,   in-order,   post-order,     and   level-order   traversal. Use those traversals to output the following tree: 1 / \ / \ / \ 2 3 / \ / 4 5 6 / ...
#AutoHotkey
AutoHotkey
AddNode(Tree,1,2,3,1) ; Build global Tree AddNode(Tree,2,4,5,2) AddNode(Tree,3,6,0,3) AddNode(Tree,4,7,0,4) AddNode(Tree,5,0,0,5) AddNode(Tree,6,8,9,6) AddNode(Tree,7,0,0,7) AddNode(Tree,8,0,0,8) AddNode(Tree,9,0,0,9)   MsgBox % "Preorder: " PreOrder(Tree,1) ; 1 2 4 7 5 3 6 8 9 MsgBox % "Inorder: " InOrder(Tree,1...