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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 ...
#Java
Java
import java.util.*;   public class TopologicalSort {   public static void main(String[] args) { String s = "std, ieee, des_system_lib, dw01, dw02, dw03, dw04, dw05," + "dw06, dw07, dware, gtech, ramlib, std_cell_lib, synopsys";   Graph g = new Graph(s, new int[][]{ {2, 0}...
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 ...
#Phix
Phix
with javascript_semantics enum name, initState, endState, blank, rules -- Machine definitions constant incrementer = { /*name =*/ "Simple incrementer", /*initState =*/ "q0", /*endState =*/ "qf", /*blank =*/ "B", /*rules =*/ { {"q0", "1", "1", "right", "q0"}, {"q0", "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...
#PicoLisp
PicoLisp
(gc 32) (de gcd (A B) (until (=0 B) (let M (% A B) (setq A B B M) ) ) (abs A) ) (de totient (N) (let C 0 (for I N (and (=1 (gcd N I)) (inc 'C)) ) (cons C (= C (dec N))) ) ) (de p? (N) (let C 0 (for A N (and (cdr (totient A)) (inc 'C)...
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...
#HicEst
HicEst
pi = 4.0 * ATAN(1.0) dtor = pi / 180.0 rtod = 180.0 / pi radians = pi / 4.0 degrees = 45.0   WRITE(ClipBoard) SIN(radians), SIN(degrees*dtor) WRITE(ClipBoard) COS(radians), COS(degrees*dtor) WRITE(ClipBoard) TAN(radians), TAN(degrees*dtor) WRITE(ClipBoard) ASIN(SIN(radians)), ASIN(SIN(degrees*dtor))*rtod WRITE(ClipBoar...
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...
#REXX
REXX
/*REXX program implements the Trabb─Pardo-Knuth algorithm for N numbers (default is 11).*/ numeric digits 200 /*the number of digits precision to use*/ parse arg N .; if N=='' | N=="," then N=11 /*Not specified? Then use the default.*/ maxValue= 400 ...
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...
#Quackery
Quackery
1000000 eratosthenes   [ false swap number$ witheach [ char 0 = if [ conclude not ] ] ] is haszero ( n --> b )   [ 10 / ] is truncright ( n --> n )   [ number$ behead drop $->n drop ] is truncleft ( n --> n )   [ dup isprime not iff [ drop false...
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 / ...
#Elixir
Elixir
defmodule Tree_Traversal do defp tnode, do: {} defp tnode(v), do: {:node, v, {}, {}} defp tnode(v,l,r), do: {:node, v, l, r}   defp preorder(_,{}), do: :ok defp preorder(f,{:node,v,l,r}) do f.(v) preorder(f,l) preorder(f,r) end   defp inorder(_,{}), do: :ok defp inorder(f,{:node,v,l,r}) do ...
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...
#Common_Lisp
Common Lisp
(defun comma-split (string) (loop for start = 0 then (1+ finish) for finish = (position #\, string :start start) collecting (subseq string start finish) until (null finish)))   (defun write-with-periods (strings) (format t "~{~A~^.~}" strings))
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...
#Cowgol
Cowgol
include "cowgol.coh"; include "strings.coh";   # Tokenize a string. Note: the string is modified in place. sub tokenize(sep: uint8, str: [uint8], out: [[uint8]]): (length: intptr) is length := 0; loop [out] := str; out := @next out; length := length + 1; while [str] != 0 and [str...
http://rosettacode.org/wiki/Time_a_function
Time a function
Task Write a program which uses a timer (with the least granularity available on your system) to time how long a function takes to execute. Whenever possible, use methods which measure only the processing time used by the current process; instead of the difference in system time between start and finish, which could ...
#Elena
Elena
import system'calendar; import system'routines; import system'threading; import system'math; import extensions;   someProcess() { threadControl.sleep(1000);   new Range(0,10000).filterBy:(x => x.mod:2 == 0).summarize(); }   public program() { var start := now;   someProcess();   var end := now;   ...
http://rosettacode.org/wiki/Time_a_function
Time a function
Task Write a program which uses a timer (with the least granularity available on your system) to time how long a function takes to execute. Whenever possible, use methods which measure only the processing time used by the current process; instead of the difference in system time between start and finish, which could ...
#Elixir
Elixir
iex(10)> :timer.tc(fn -> Enum.each(1..100000, fn x -> x*x end) end) {236000, :ok}
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...
#Erlang
Erlang
<-module( top_rank_per_group ).   -export( [employees/0, employees_in_department/2, highest_payed/2, task/1] ).   -record( employee, {name, id, salery, department} ).   employees() -> [#employee{name="Tyler Bennett", id="E10297", salery=32000, department="D101"}, #employee{name="John Rappl", id="E21437", s...
http://rosettacode.org/wiki/Tic-tac-toe
Tic-tac-toe
Task Play a game of tic-tac-toe. Ensure that legal moves are played and that a winning position is notified. Tic-tac-toe   is also known as:   naughts and crosses   tic tac toe   tick tack toe   three in a row   tres en rayo       and   Xs  and  Os See also   MathWorld™, Tic-Tac-Toe game.   Wikipedi...
#C.2B.2B
C++
  #include <windows.h> #include <iostream> #include <string>   //-------------------------------------------------------------------------------------------------- using namespace std;   //-------------------------------------------------------------------------------------------------- enum players { Computer, Human, ...
http://rosettacode.org/wiki/Towers_of_Hanoi
Towers of Hanoi
Task Solve the   Towers of Hanoi   problem with recursion.
#Bracmat
Bracmat
( ( move = n from to via .  !arg:(?n,?from,?to,?via) & (  !n:>0 & move$(!n+-1,!from,!via,!to) & out$("Move disk from pole " !from " to pole " !to) & move$(!n+-1,!via,!to,!from) | ) ) & 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
#NewLISP
NewLISP
(define (Thue-Morse loops) (setf TM '(0)) (println TM) (for (i 1 (-- loops)) (setf tmp TM) (replace '0 tmp '_) (replace '1 tmp '0) (replace '_ tmp '1) (setf TM (append TM tmp)) (println TM) ) )   (Thue-Morse 5) (exit)  
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
#Nim
Nim
import sequtils, strutils   iterator thueMorse(maxSteps = int.high): string = var val = @[0] var count = 0 while true: yield val.join() inc count if count == maxSteps: break val &= val.mapIt(1 - it)   for bits in thueMorse(6): echo bits
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...
#OCaml
OCaml
let split_with_escaping ~esc ~sep s = let len = String.length s in let buf = Buffer.create 16 in let rec loop i = if i = len then [Buffer.contents buf] else if s.[i] = esc && i + 1 < len then begin Buffer.add_char buf s.[i + 1]; loop (i + 2) end else if s.[i] = sep then begin let s =...
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 ...
#JavaScript
JavaScript
const libs = `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 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 ...
#PHL
PHL
module turing;   extern printf;   struct @Command { field @Integer tape {get:tape,set:stape}; field @Integer move {get:move,set:smove}; field @Integer next {get:next,set:snext};   @Command init(@Integer tape, @Integer move, @Integer next) [ this.stape(tape); this.smove(move); this.snext(next); return this; ...
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...
#Python
Python
from math import gcd   def φ(n): return sum(1 for k in range(1, n + 1) if gcd(n, k) == 1)   if __name__ == '__main__': def is_prime(n): return φ(n) == n - 1   for n in range(1, 26): print(f" φ({n}) == {φ(n)}{', is prime' if is_prime(n) else ''}") count = 0 for n in range(1, 10_000 ...
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...
#IDL
IDL
deg = 35 ; arbitrary number of degrees rad = !dtor*deg ; system variables !dtor and !radeg convert between rad and deg
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...
#Ring
Ring
  # Project : Trabb Pardo–Knuth algorithm   decimals(3) x = list(11) for n=1 to 11 x[n] = n next   s = [-5, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6] for i = 1 to 11 see string(i) + " => " + s[i] + nl next see copy("-", 20) + nl i = i - 1   while i > 0 see "f(" + string(s[i]) + ") = " x = f(s[i]) ...
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...
#Ruby
Ruby
def f(x) x.abs ** 0.5 + 5 * x ** 3 end   puts "Please enter 11 numbers:" nums = 11.times.map{ gets.to_f }   nums.reverse_each do |n| print "f(#{n}) = " res = f(n) puts res > 400 ? "Overflow!" : res end
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...
#Racket
Racket
  #lang racket (require math/number-theory)   (define (truncate-right n) (quotient n 10))   (define (truncate-left n) (define s (number->string n)) (string->number (substring s 1 (string-length s))))   (define (contains-zero? n) (member #\0 (string->list (number->string n))))   (define (truncatable? truncate n)...
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 / ...
#Erlang
Erlang
-module(tree_traversal). -export([main/0]). -export([preorder/2, inorder/2, postorder/2, levelorder/2]). -export([tnode/0, tnode/1, tnode/3]).   -define(NEWLINE, io:format("~n")).   tnode() -> {}. tnode(V) -> {node, V, {}, {}}. tnode(V,L,R) -> {node, V, L, R}.   preorder(_,{}) -> ok; preorder(F,{node,V,L,R}) -> F(...
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...
#Crystal
Crystal
puts "Hello,How,Are,You,Today".split(',').join('.')
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...
#D
D
void main() { import std.stdio, std.string;   "Hello,How,Are,You,Today".split(',').join('.').writeln; }
http://rosettacode.org/wiki/Time_a_function
Time a function
Task Write a program which uses a timer (with the least granularity available on your system) to time how long a function takes to execute. Whenever possible, use methods which measure only the processing time used by the current process; instead of the difference in system time between start and finish, which could ...
#Erlang
Erlang
  5> {Time,Result} = timer:tc(fun () -> lists:foreach(fun(X) -> X*X end, lists:seq(1,100000)) end). {226391,ok} 6> Time/1000000. % Time is in microseconds. 0.226391 7> % Time is in microseconds.  
http://rosettacode.org/wiki/Time_a_function
Time a function
Task Write a program which uses a timer (with the least granularity available on your system) to time how long a function takes to execute. Whenever possible, use methods which measure only the processing time used by the current process; instead of the difference in system time between start and finish, which could ...
#Euphoria
Euphoria
atom t t = time() some_procedure() t = time() - t printf(1,"Elapsed %f seconds.\n",t)
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...
#F.23
F#
let 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,...
http://rosettacode.org/wiki/Tic-tac-toe
Tic-tac-toe
Task Play a game of tic-tac-toe. Ensure that legal moves are played and that a winning position is notified. Tic-tac-toe   is also known as:   naughts and crosses   tic tac toe   tick tack toe   three in a row   tres en rayo       and   Xs  and  Os See also   MathWorld™, Tic-Tac-Toe game.   Wikipedi...
#Common_Lisp
Common Lisp
  (defun generate-board () (loop repeat 9 collect nil))   (defparameter *straights* '((1 2 3) (4 5 6) (7 8 9) (1 4 7) (2 5 8) (3 6 9) (1 5 9) (3 5 7))) (defparameter *current-player* 'x)   (defun get-board-elt (n board) (nth (1- n) board))   (defun legal-p (n board) (null (get-board-elt n board)))   (defun set-bo...
http://rosettacode.org/wiki/Towers_of_Hanoi
Towers of Hanoi
Task Solve the   Towers of Hanoi   problem with recursion.
#Brainf.2A.2A.2A
Brainf***
[ This implementation is recursive and uses a stack, consisting of frames that are 8 bytes long. The layout is as follows:   Byte Description 0 recursion flag (the program stops if the flag is zero) 1 the step which is currently executed 4 means a call to move(a, ...
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
#OASYS_Assembler
OASYS Assembler
; Thue-Morse sequence   [*'A]  ; Ensure the vocabulary is not empty [&]  ; Declare the initialization procedure %#1>  ; Initialize length counter %@*>  ; Create first object ,#1>  ; Initialize loop counter :  ; Begin loop  %@<.#<PI ...
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
#Objeck
Objeck
class ThueMorse { function : Main(args : String[]) ~ Nil { Sequence(6); }   function : Sequence(steps : Int) ~ Nil { sb1 := "0"; sb2 := "1"; for(i := 0; i < steps; i++;) { tmp := String->New(sb1); sb1 += sb2; sb2 += tmp; }; sb1->PrintLine(); } }  
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...
#Perl
Perl
sub tokenize { my ($string, $sep, $esc) = (shift, quotemeta shift, quotemeta shift);   my @fields = split /$esc . (*SKIP)(*FAIL) | $sep/sx, $string, -1; return map { s/$esc(.)/$1/gsr } @fields; }
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 ...
#jq
jq
# independent/0 emits an array of the dependencies that have no dependencies # Input: an object representing a normalized dependency graph def independent: . as $G | reduce keys[] as $key ([]; . + ((reduce $G[$key][] as $node ([]; if ($G[$node] == null or ($G[$node]|len...
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 ...
#PicoLisp
PicoLisp
# Finite state machine (de turing (Tape Init Halt Blank Rules Verbose) (let (Head 1 State Init Rule NIL S 'start C (length Tape)) (catch NIL (loop (state 'S (start 'print (when (=0 C) (setq Ta...
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...
#Quackery
Quackery
[ [ dup while tuck mod again ] drop abs ] is gcd ( n n --> n )     [ 0 swap dup times [ i over gcd 1 = rot + swap ] drop ] is totient ( n --> n )   [ 0 temp put times [ i dup 1+ totient = temp tally ] temp take ] ...
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...
#Icon_and_Unicon
Icon and Unicon
invocable all procedure main()   d := 30 # degrees r := dtor(d) # convert to radians   every write(f := !["sin","cos","tan"],"(",r,")=",y := f(r)," ",fi := "a" || f,"(",y,")=",x := fi(y)," rad = ",rtod(x)," deg") end
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...
#Rust
Rust
  use std::io::{self, BufRead};   fn op(x: f32) -> Option<f32> { let y = x.abs().sqrt() + 5.0 * x * x * x; if y < 400.0 { Some(y) } else { None } }   fn main() { println!("Please enter 11 numbers (one number per line)"); let stdin = io::stdin();   let xs = stdin .lock...
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...
#Scala
Scala
object TPKa extends App { final val numbers = scala.collection.mutable.MutableList[Double]() final val in = new java.util.Scanner(System.in) while (numbers.length < CAPACITY) { print("enter a number: ") try { numbers += in.nextDouble() } catch { case _...
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...
#Raku
Raku
constant ltp = $[2, 3, 5, 7], -> @ltp { $[ grep { .&is-prime }, ((1..9) X~ @ltp) ] } ... *;   constant rtp = $[2, 3, 5, 7], -> @rtp { $[ grep { .&is-prime }, (@rtp X~ (1..9)) ] } ... *;   say "Highest ltp = ", ltp[5][*-1]; say "Highest rtp = ", rtp[5][*-1];
http://rosettacode.org/wiki/Tree_traversal
Tree traversal
Task Implement a binary tree where each node carries an integer,   and implement:   pre-order,   in-order,   post-order,     and   level-order   traversal. Use those traversals to output the following tree: 1 / \ / \ / \ 2 3 / \ / 4 5 6 / ...
#Euphoria
Euphoria
constant VALUE = 1, LEFT = 2, RIGHT = 3   constant tree = {1, {2, {4, {7, 0, 0}, 0}, {5, 0, 0}}, {3, {6, {8, 0, 0}, ...
http://rosettacode.org/wiki/Tokenize_a_string
Tokenize a string
Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word. Display the words to the 'user', in the simplest manner possible, separated by a period. To simplify, you may display a trailing period. Other tasks related to string operations: Me...
#Delphi
Delphi
  program Tokenize_a_string;   {$APPTYPE CONSOLE}   uses System.SysUtils;   var Words: TArray<string>;   begin Words := 'Hello,How,Are,You,Today'.Split([',']); Writeln(string.Join(#10, Words));   Readln; end.    
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...
#Dyalect
Dyalect
var str = "Hello,How,Are,You,Today" var strings = str.Split(',') print(values: strings, separator: ".")
http://rosettacode.org/wiki/Time_a_function
Time a function
Task Write a program which uses a timer (with the least granularity available on your system) to time how long a function takes to execute. Whenever possible, use methods which measure only the processing time used by the current process; instead of the difference in system time between start and finish, which could ...
#F.23
F#
  open System.Diagnostics let myfunc data = let timer = new Stopwatch() timer.Start() let result = data |> expensive_processing timer.Stop() printf "elapsed %d ms" timer.ElapsedMilliseconds result  
http://rosettacode.org/wiki/Time_a_function
Time a function
Task Write a program which uses a timer (with the least granularity available on your system) to time how long a function takes to execute. Whenever possible, use methods which measure only the processing time used by the current process; instead of the difference in system time between start and finish, which could ...
#Factor
Factor
USING: kernel sequences tools.time ;   [ 10000 <iota> sum drop ] time
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...
#Factor
Factor
USING: accessors assocs fry io kernel math.parser sequences sorting ; IN: top-rank   TUPLE: employee name id salary department ;   CONSTANT: employees { T{ employee f "Tyler Bennett" "E10297" 32000 "D101" } T{ employee f "John Rappl" "E21437" 47000 "D050" } T{ employee f "George Woltman" "E00127...
http://rosettacode.org/wiki/Tic-tac-toe
Tic-tac-toe
Task Play a game of tic-tac-toe. Ensure that legal moves are played and that a winning position is notified. Tic-tac-toe   is also known as:   naughts and crosses   tic tac toe   tick tack toe   three in a row   tres en rayo       and   Xs  and  Os See also   MathWorld™, Tic-Tac-Toe game.   Wikipedi...
#D
D
import std.stdio, std.string, std.algorithm, std.conv, std.random, std.ascii, std.array, std.range, std.math;   struct GameBoard { dchar[9] board = "123456789"; enum : dchar { human = 'X', computer = 'O' } enum Game { going, humanWins, computerWins, draw }   const pure nothrow @safe @nogc invaria...
http://rosettacode.org/wiki/Towers_of_Hanoi
Towers of Hanoi
Task Solve the   Towers of Hanoi   problem with recursion.
#C
C
#include <stdio.h>   void move(int n, int from, int via, int to) { if (n > 1) { move(n - 1, from, to, via); printf("Move disk from pole %d to pole %d\n", from, to); move(n - 1, via, from, to); } else { printf("Move disk from pole %d to pole %d\n", from, to); } } int main() { move(4, 1,2,3); re...
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
#OCaml
OCaml
(* description: Counts the number of bits set to 1 input: the number to have its bit counted output: the number of bits set to 1 *) let count_bits v = let rec aux c v = if v <= 0 then c else aux (c + (v land 1)) (v lsr 1) in aux 0 v   let () = for i = 0 to pred 256 do print_char ( ...
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
#Pascal
Pascal
Program ThueMorse;   function fThueMorse(maxLen: NativeInt):AnsiString; //double by appending the flipped original 0 -> 1;1 -> 0 //Flipping between two values:x oszillating A,B,A,B -> x_next = A+B-x //Beware A+B < High(Char), the compiler will complain ... const cVal0 = '^';cVal1 = 'v';// cVal0 = '0';cVal1 = '1';   ...
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...
#Phix
Phix
function tokenize(string s, integer sep, integer esc) sequence ret = {} string word = "" integer skip = 0 if length(s)!=0 then for i=1 to length(s) do integer si = s[i] if skip then word &= si skip = 0 elsif si=esc then sk...
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 ...
#Julia
Julia
function toposort(data::Dict{T,Set{T}}) where T data = copy(data) for (k, v) in data delete!(v, k) end extraitems = setdiff(reduce(∪, values(data)), keys(data)) for item in extraitems data[item] = Set{T}() end rst = Vector{T}() while true ordered = Set(item for (i...
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 ...
#Prolog
Prolog
turing(Config, Rules, TapeIn, TapeOut) :- call(Config, IS, _, _, _, _), perform(Config, Rules, IS, {[], TapeIn}, {Ls, Rs}), reverse(Ls, Ls1), append(Ls1, Rs, TapeOut).   perform(Config, Rules, State, TapeIn, TapeOut) :- call(Config, _, FS, RS, B, Symbols), ( memberchk(State, FS) -> TapeO...
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...
#Racket
Racket
#lang racket   (require math/number-theory)   (define (prime*? n) (= (totient n) (sub1 n)))   (for ([n (in-range 1 26)]) (printf "φ(~a) = ~a~a~a\n" n (totient n) (if (prime*? n) " is prime" "") (if (prime? n) " (confirmed)" "")))   (for/fold ([count 0] #:result (void)) ([n (in-...
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...
#J
J
(1&o. , 2&o. ,: 3&o.) (4 %~ o. 1) , 180 %~ o. 45 0.707107 0.707107 0.707107 0.707107 1 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...
#Sidef
Sidef
var nums; do { nums = Sys.readln("Please type 11 space-separated numbers: ").nums } while(nums.len != 11)   nums.reverse.each { |n| var r = (n.abs.sqrt + (5 * n**3)); say "#{n}\t#{ r > 400 ? 'Urk!' : r }"; }
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...
#Sinclair_ZX81_BASIC
Sinclair ZX81 BASIC
10 DIM A(11) 20 PRINT "ENTER ELEVEN NUMBERS:" 30 FOR I=1 TO 11 40 INPUT A(I) 50 NEXT I 60 FOR I=11 TO 1 STEP -1 70 LET Y=SQR ABS A(I)+5*A(I)**3 80 IF Y<=400 THEN GOTO 110 90 PRINT A(I),"TOO LARGE" 100 GOTO 120 110 PRINT A(I),Y 120 NEXT I
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...
#Swift
Swift
import Foundation   print("Enter 11 numbers for the Trabb─Pardo─Knuth algorithm:")   let f: (Double) -> Double = { sqrt(fabs($0)) + 5 * pow($0, 3) }   (1...11) .generate() .map { i -> Double in print("\(i): ", terminator: "") guard let s = readLine(), let n = Double(s) else { return 0 } ...
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...
#REXX
REXX
/*REXX program finds largest left─ and right─truncatable primes ≤ 1m (or argument 1).*/ parse arg hi .; if hi=='' then hi= 1000000 /*Not specified? Then use default of 1m*/ call genP /*generate some primes, about hi ÷ 2 */ ...
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 / ...
#F.23
F#
open System open System.IO   type Tree<'a> = | Tree of 'a * Tree<'a> * Tree<'a> | Empty   let rec inorder tree = seq { match tree with | Tree(x, left, right) -> yield! inorder left yield x yield! inorder right | Empty -> () }   let ...
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...
#D.C3.A9j.C3.A0_Vu
Déjà Vu
!print join "." split "Hello,How,Are,You,Today" ","
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...
#E
E
".".rjoin("Hello,How,Are,You,Today".split(","))
http://rosettacode.org/wiki/Time_a_function
Time a function
Task Write a program which uses a timer (with the least granularity available on your system) to time how long a function takes to execute. Whenever possible, use methods which measure only the processing time used by the current process; instead of the difference in system time between start and finish, which could ...
#Forth
Forth
: time: ( "word" -- ) utime 2>R ' EXECUTE utime 2R> D- <# # # # # # # [CHAR] . HOLD #S #> TYPE ." seconds" ;   1000 time: MS \ 1.000081 seconds ok
http://rosettacode.org/wiki/Time_a_function
Time a function
Task Write a program which uses a timer (with the least granularity available on your system) to time how long a function takes to execute. Whenever possible, use methods which measure only the processing time used by the current process; instead of the difference in system time between start and finish, which could ...
#Fortran
Fortran
  c The subroutine to analyze subroutine do_something() c For testing we just do nothing for 3 seconds call sleep(3) return end   c Main Program program timing integer(kind=8) start,finish,rate call system_clock(count_rate=rate) call system_clock(start) c Here co...
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...
#Forth
Forth
  \ Written in ANS-Forth; tested under VFX. \ Requires the novice package: http://www.forth.org/novice.html \ The following should already be done: \ include novice.4th \ include list.4th   marker TopRank.4th   \ This demonstrates how I typically use lists. A program such as this does not need any explicit iteration, s...
http://rosettacode.org/wiki/Tic-tac-toe
Tic-tac-toe
Task Play a game of tic-tac-toe. Ensure that legal moves are played and that a winning position is notified. Tic-tac-toe   is also known as:   naughts and crosses   tic tac toe   tick tack toe   three in a row   tres en rayo       and   Xs  and  Os See also   MathWorld™, Tic-Tac-Toe game.   Wikipedi...
#EasyLang
EasyLang
len f[] 9 state = 0 textsize 14 # func init . . linewidth 2 clear color 666 move 34 4 line 34 80 move 62 4 line 62 80 move 10 28 line 86 28 move 10 56 line 86 56 linewidth 2.5 for i range 9 f[i] = 0 . if state = 1 timer 0.2 . . func draw ind . . c = ind mod 3 r = ind div 3 ...
http://rosettacode.org/wiki/Towers_of_Hanoi
Towers of Hanoi
Task Solve the   Towers of Hanoi   problem with recursion.
#C.23
C#
public void move(int n, int from, int to, int via) { if (n == 1) { System.Console.WriteLine("Move disk from pole " + from + " to pole " + to); } else { move(n - 1, from, via, to); move(1, from, to, via); move(n - 1, via, to, from); } }
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
#Perl
Perl
sub complement { my $s = shift;   $s =~ tr/01/10/;   return $s; }   my $str = '0';   for (0..6) { say $str; $str .= complement($str); }  
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
#Phix
Phix
string tm = "0" for i=1 to 8 do printf(1,"%s\n",tm) tm &= sq_sub('0'+'1',tm) end for
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...
#PicoLisp
PicoLisp
(de tokenize (Str Sep Esc) (split (make (for (L (chop Str) L) (let C (pop 'L) (cond ((= C Esc) (link (pop 'L))) ((= C Sep) (link 0)) (T (link C)) ) ) ) ) 0 ) )
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...
#PowerShell
PowerShell
  function Split-String ([string]$String, [char]$Separator, [char]$Escape) { if ($String -notmatch "\$Separator|\$Escape") {return $String}   [bool]$escaping = $false [string]$output = ""   for ($i = 0; $i -lt $String.Length; $i++) { [char]$character = $String.Substring($i,1)   if (...
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 ...
#Kotlin
Kotlin
// version 1.1.51   val s = "std, ieee, des_system_lib, dw01, dw02, dw03, dw04, dw05, " + "dw06, dw07, dware, gtech, ramlib, std_cell_lib, synopsys"   val deps = mutableListOf( 2 to 0, 2 to 14, 2 to 13, 2 to 4, 2 to 3, 2 to 12, 2 to 1, 3 to 1, 3 to 10, 3 to 11, 4 to 1, 4 to 10, 5 to 0, 5 to ...
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 ...
#Python
Python
from __future__ import print_function   def run_utm( state = None, blank = None, rules = [], tape = [], halt = None, pos = 0): st = state if not tape: tape = [blank] if pos < 0: pos += len(tape) if pos >= len(tape) or pos < 0: raise Error( "bad init positi...
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...
#Raku
Raku
use Prime::Factor;   my \𝜑 = 0, |(1..*).hyper.map: -> \t { t * [*] t.&prime-factors.squish.map: { 1 - 1/$_ } }   printf "𝜑(%2d) = %3d %s\n", $_, 𝜑[$_], $_ - 𝜑[$_] - 1 ?? '' !! 'Prime' for 1 .. 25;   (1e2, 1e3, 1e4, 1e5).map: -> $limit { say "\nCount of primes <= $limit: " ~ +(^$limit).grep: {$_ == 𝜑[$_] + 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...
#Java
Java
public class Trig { public static void main(String[] args) { //Pi / 4 is 45 degrees. All answers should be the same. double radians = Math.PI / 4; double degrees = 45.0; //sine System.out.println(Math.sin(radians) + " " + Math.sin(M...
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...
#Symsyn
Symsyn
  |Trabb Pardo–Knuth algorithm   a : 11 0   i if i LE 10 [] $s ~ $s w w a.i + i goif endif 10 i if i GE 0 call f if x GT 400 'too large' $s else ~ x $s endif ~ i $r + ' ' $r + $r $s.1 $s [] - i goif endif stop   f a.i t * t t x * x t x ...
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm
Trabb Pardo–Knuth algorithm
The TPK algorithm is an early example of a programming chrestomathy. It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages. The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of...
#Tcl
Tcl
# Helper procedures proc f {x} {expr {abs($x)**0.5 + 5*$x**3}} proc overflow {y} {expr {$y > 400}}   # Read in 11 numbers, with nice prompting fconfigure stdout -buffering none for {set n 1} {$n <= 11} {incr n} { puts -nonewline "number ${n}: " lappend S [scan [gets stdin] "%f"] }   # Process and print results ...
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...
#Ring
Ring
  # Project : Truncatable primes   for n = 1000000 to 1 step -1 flag = 1 flag2 = 1 strn = string(n) for nr = 1 to len(strn) if strn[nr] = "0" flag2 = 0 ok next if flag2 = 1 for m = 1 to len(strn) strp = right(strn, m) if isprime(number(strp...
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...
#Ruby
Ruby
def left_truncatable?(n) truncatable?(n) {|i| i.to_s[1..-1].to_i} end     def right_truncatable?(n) truncatable?(n) {|i| i/10} end   def truncatable?(n, &trunc_func) return false if n.to_s.include? "0" loop do n = trunc_func.call(n) return true if n.zero? return false unless Prime.prime?(n) end en...
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 / ...
#Factor
Factor
USING: accessors combinators deques dlists fry io kernel math.parser ; IN: rosetta.tree-traversal   TUPLE: node data left right ;   CONSTANT: example-tree T{ node f 1 T{ node f 2 T{ node f 4 T{ node f 7 f f } f } T{ node f 5 f f } }...
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...
#Elena
Elena
import system'routines; import extensions;   public program() { var string := "Hello,How,Are,You,Today";   string.splitBy:",".forEach:(s) { console.print(s,".") } }
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...
#Elixir
Elixir
  tokens = String.split("Hello,How,Are,You,Today", ",") IO.puts Enum.join(tokens, ".")  
http://rosettacode.org/wiki/Time_a_function
Time a function
Task Write a program which uses a timer (with the least granularity available on your system) to time how long a function takes to execute. Whenever possible, use methods which measure only the processing time used by the current process; instead of the difference in system time between start and finish, which could ...
#FreeBASIC
FreeBASIC
' FB 1.05.0 Win64   Function sumToLimit(limit As UInteger) As UInteger Dim sum As UInteger = 0 For i As UInteger = 1 To limit sum += i Next Return sum End Function   Dim As Double start = timer Dim limit As UInteger = 100000000 Dim result As UInteger = sumToLimit(limit) Dim ms As UInteger = Int(1000 * (time...
http://rosettacode.org/wiki/Time_a_function
Time a function
Task Write a program which uses a timer (with the least granularity available on your system) to time how long a function takes to execute. Whenever possible, use methods which measure only the processing time used by the current process; instead of the difference in system time between start and finish, which could ...
#GAP
GAP
# Return the time passed in last function time;
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...
#Fortran
Fortran
DATA EMPLOYEE(1:3)/ 1 GRIST("Tyler Bennett","E10297",32000,"D101"), 2 GRIST("John Rappl","E21437",47000,"D050"), 3 GRIST("George Woltman","E00127",53500,"D101")/  
http://rosettacode.org/wiki/Tic-tac-toe
Tic-tac-toe
Task Play a game of tic-tac-toe. Ensure that legal moves are played and that a winning position is notified. Tic-tac-toe   is also known as:   naughts and crosses   tic tac toe   tick tack toe   three in a row   tres en rayo       and   Xs  and  Os See also   MathWorld™, Tic-Tac-Toe game.   Wikipedi...
#Erlang
Erlang
  -module(tic_tac_toe).   -export( [task/0] ).   task() -> io:fwrite( "Result: ~p.~n", [turn(player(random:uniform()), board())] ).       board() -> [{X, erlang:integer_to_list(X)} || X <- lists:seq(1, 9)].   board_tuples( Selections, Board ) -> [lists:keyfind(X, 1, Board) || X <- Selections].   computer_move( Player, ...
http://rosettacode.org/wiki/Towers_of_Hanoi
Towers of Hanoi
Task Solve the   Towers of Hanoi   problem with recursion.
#C.2B.2B
C++
void move(int n, int from, int to, int via) { if (n == 1) { std::cout << "Move disk from pole " << from << " to pole " << to << std::endl; } else { move(n - 1, from, via, to); move(1, from, to, via); move(n - 1, via, to, from); } }
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
#Phixmonti
Phixmonti
def inverte dup len for var i i get not i set endfor enddef   0 1 tolist 8 for . dup print nl nl inverte chain endfor
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
#PHP
PHP
<?php   function thueMorseSequence($length) { $sequence = ''; for ($digit = $n = 0 ; $n < $length ; $n++) { $x = $n ^ ($n - 1); if (($x ^ ($x >> 1)) & 0x55555555) { $digit = 1 - $digit; } $sequence .= $digit; } return $sequence; }   for ($n = 10 ; $n <= 100 ; ...
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...
#Python
Python
def token_with_escape(a, escape = '^', separator = '|'): ''' Issue python -m doctest thisfile.py to run the doctests.   >>> print(token_with_escape('one^|uno||three^^^^|four^^^|^cuatro|')) ['one|uno', '', 'three^^', 'four^|cuatro', ''] ''' result = [] token = '' state = 0 ...
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...
#Racket
Racket
#lang racket/base (require racket/match)   ;; Returns a tokenising function based on sep and esc (define ((tokenise-with-escape sep esc) str) (define tsil->string (compose list->string reverse)) (define (inr rem l-acc acc) (match rem ['() (if (and (null? acc) (null? l-acc)) null (reverse (cons (tsil->stri...
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 ...
#M2000_Interpreter
M2000 Interpreter
Module testthis { \\ empty stack Flush inventory LL append LL, "des_system_lib":=(List:="std", "synopsys", "std_cell_lib", "des_system_lib", "dw02", "dw01", "ramlib", "ieee") REM append LL, "dw01":=(List:="dw04","ieee", "dw01", "dware", "gtech") append LL, "dw01":=(List:="ieee", "dw01", "dware", "gtech") append ...
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 ...
#Racket
Racket
  #lang racket ;;;============================================================= ;;; Due to heavy use of pattern matching we define few macros ;;;=============================================================   (define-syntax-rule (define-m f m ...) (define f (match-lambda m ... (x x))))   (define-syntax-rule (define-m...
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...
#REXX
REXX
/*REXX program calculates the totient numbers for a range of numbers, and count primes. */ parse arg N . /*obtain optional argument from the CL.*/ if N=='' | N=="," then N= 25 /*Not specified? Then use the default.*/ tell= N>0 ...
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...
#JavaScript
JavaScript
var radians = Math.PI / 4, // Pi / 4 is 45 degrees. All answers should be the same. degrees = 45.0, sine = Math.sin(radians), cosine = Math.cos(radians), tangent = Math.tan(radians), arcsin = Math.asin(sine), arccos = Math.acos(cosine), arctan = Math.atan(tangent);   // sine window.alert(sine + " " + Math.sin(d...
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...
#VBScript
VBScript
  Function tpk(s) arr = Split(s," ") For i = UBound(arr) To 0 Step -1 n = fx(CDbl(arr(i))) If n > 400 Then WScript.StdOut.WriteLine arr(i) & " = OVERFLOW" Else WScript.StdOut.WriteLine arr(i) & " = " & n End If Next End Function   Function fx(x) fx = Sqr(Abs(x))+5*x^3 End Function   'testing the func...
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...
#Rust
Rust
fn is_prime(n: u32) -> bool { if n < 2 { return false; } if n % 2 == 0 { return n == 2; } if n % 3 == 0 { return n == 3; } let mut p = 5; while p * p <= n { if n % p == 0 { return false; } p += 2; if n % p == 0 { ...
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 / ...
#Fantom
Fantom
  class Tree { readonly Int label readonly Tree? left readonly Tree? right   new make (Int label, Tree? left := null, Tree? right := null) { this.label = label this.left = left this.right = right }   Void preorder(|Int->Void| func) { func(label) left?.preorder(func) // ?. will not ca...