mlfoundations-dev/load_in_code_rosetta · Data Studio

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	instruction_seed stringlengths 27 14.4k	_source stringclasses 1 value
http://rosettacode.org/wiki/Brownian_tree	Brownian tree	Brownian tree You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw a Brownian Tree. A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes. The initial "seed" is placed somewhere wi...	#Action.21	Action!	BYTE FUNC CheckNeighbors(CARD x BYTE y) IF Locate(x-1,y-1)=1 THEN RETURN (1) FI IF Locate(x,y-1)=1 THEN RETURN (1) FI IF Locate(x+1,y-1)=1 THEN RETURN (1) FI IF Locate(x-1,y)=1 THEN RETURN (1) FI IF Locate(x+1,y)=1 THEN RETURN (1) FI IF Locate(x-1,y+1)=1 THEN RETURN (1) FI IF Locate(x,y+1)=1 THEN RETURN (...	Give a code snippet in #Action.21 Brownian tree You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw a Brownian Tree. A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes. The in...	christopher/rosetta-code
http://rosettacode.org/wiki/Fraction_reduction	Fraction reduction	There is a fine line between numerator and denominator. ─── anonymous A method to "reduce" some reducible fractions is to cross out a digit from the numerator and the denominator. An example is: 16 16 ──── and then (simp...	#Raku	Raku	my %reduced; my $digits = 2..4; for $digits.map: * - 1 -> $exp { my $start = sum (0..$exp).map( { 10 ** $_ * ($exp - $_ + 1) }); my $end = 10($exp+1) - sum (^$exp).map( { 10 $_ * ($exp - $_) } ) - 1; ($start ..^ $end).race(:8degree, :3batch).map: -> $den { next if $den.contains: '0'; ...	Give a code snippet in #Raku There is a fine line between numerator and denominator. ─── anonymous A method to "reduce" some reducible fractions is to cross out a digit from the numerator and the denominator. An example is: 16 16...	christopher/rosetta-code
http://rosettacode.org/wiki/JSON	JSON	Load a JSON string into a data structure. Also, create a new data structure and serialize it into JSON. Use objects and arrays (as appropriate for your language) and make sure your JSON is valid (https://jsonformatter.org).	#Crystal	Crystal	require "json_mapping" class Foo JSON.mapping( num: Int64, array: Array(String), ) end def json foo = Foo.from_json(%({"num": 1, "array": ["a", "b"]})) puts("#{foo.num} #{foo.array}") puts(foo.to_json) end	Give a code snippet in #Crystal Load a JSON string into a data structure. Also, create a new data structure and serialize it into JSON. Use objects and arrays (as appropriate for your language) and make sure your JSON is valid (https://jsonformatter.org).	christopher/rosetta-code
http://rosettacode.org/wiki/Last_Friday_of_each_month	Last Friday of each month	Task Write a program or a script that returns the date of the last Fridays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc). Example of an expected output: ./last_fridays 2012 2012-01-27 2012-02-24 2012-03-30 2012-04-27 2012-05-25 20...	#Delphi	Delphi	program LastFridayOfMonth; {$APPTYPE CONSOLE} uses System.SysUtils, System.DateUtils; var Year: Word; Month: Word; D1: TDateTime; D2: Word; begin Write('Enter year: '); ReadLn(Year); for Month := MonthJanuary to MonthDecember do begin D1 := EndOfAMonth(Year, Month); D2 := DayOfTheWeek(...	Give a code snippet in #Delphi Task Write a program or a script that returns the date of the last Fridays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc). Example of an expected output: ./last_fridays 2012 2012-01-27 2012-02-24 201...	christopher/rosetta-code
http://rosettacode.org/wiki/Find_largest_left_truncatable_prime_in_a_given_base	Find largest left truncatable prime in a given base	A truncatable prime is one where all non-empty substrings that finish at the end of the number (right-substrings) are also primes when understood as numbers in a particular base. The largest such prime in a given (integer) base is therefore computable, provided the base is larger than 2. Let's consider what happens in...	#Scala	Scala	import scala.collection.parallel.immutable.ParSeq object LeftTruncatablePrime extends App { private def leftTruncatablePrime(maxRadix: Int, millerRabinCertainty: Int) { def getLargestLeftTruncatablePrime(radix: Int, millerRabinCertainty: Int): BigInt = { def getNextLeftTruncatablePrimes(n: BigInt, radix: ...	Give a code snippet in #Scala A truncatable prime is one where all non-empty substrings that finish at the end of the number (right-substrings) are also primes when understood as numbers in a particular base. The largest such prime in a given (integer) base is therefore computable, provided the base is larger than 2. ...	christopher/rosetta-code
http://rosettacode.org/wiki/Find_palindromic_numbers_in_both_binary_and_ternary_bases	Find palindromic numbers in both binary and ternary bases	Find palindromic numbers in both binary and ternary bases You are encouraged to solve this task according to the task description, using any language you may know. Task Find and show (in decimal) the first six numbers (non-negative integers) that are palindromes in both: base 2 base 3 Display 0 ...	#Ada	Ada	with Ada.Text_IO, Base_Conversion; procedure Brute is type Long is range 0 .. 2**63-1; package BC is new Base_Conversion(Long); function Palindrome (S : String) return Boolean is (if S'Length < 2 then True elsif S(S'First) /= S(S'Last) then False else Palindrome(S(S'First+1 .. S'Last-1)...	Give a code snippet in #Ada Find palindromic numbers in both binary and ternary bases You are encouraged to solve this task according to the task description, using any language you may know. Task Find and show (in decimal) the first six numbers (non-negative integers) that are palindromes in both: base ...	christopher/rosetta-code
http://rosettacode.org/wiki/9_billion_names_of_God_the_integer	9 billion names of God the integer	This task is a variation of the short story by Arthur C. Clarke. (Solvers should be aware of the consequences of completing this task.) In detail, to specify what is meant by a “name”: The integer 1 has 1 name “1”. The integer 2 has 2 names “1+1”, and “2”. The integer 3 has 3 names “1+1+1”, “2+1”, ...	#AutoHotkey	AutoHotkey	SetBatchLines -1 InputBox, Enter_value, Enter the no. of lines sought array := [] Loop, % 2*Enter_value - 1 Loop, % x := A_Index y := A_Index, Array[x, y] := 1 x := 3 Loop { base_r := x - 1 , x++ , y := 2 , index := x , new := 1 Loop, % base_r - 1 { array[x, new+1] := array[x-1, new] + array[base_r,...	Give a code snippet in #AutoHotkey This task is a variation of the short story by Arthur C. Clarke. (Solvers should be aware of the consequences of completing this task.) In detail, to specify what is meant by a “name”: The integer 1 has 1 name “1”. The integer 2 has 2 names “1+1”, and “2”. The integer ...	christopher/rosetta-code
http://rosettacode.org/wiki/Grayscale_image	Grayscale image	Many image processing algorithms are defined for grayscale (or else monochromatic) images. Task Extend the data storage type defined on this page to support grayscale images. Define two operations, one to convert a color image to a grayscale image and one for the backward conversion. To get luminance of a color u...	#Visual_Basic_.NET	Visual Basic .NET	Imports System.Drawing.Imaging Public Function Grayscale(ByVal Map As Bitmap) As Bitmap Dim oData() As Integer = GetData(Map) Dim oReturn As New Bitmap(Map.Width, Map.Height, Map.PixelFormat) Dim a As Integer = 0 Dim r As Integer = 0 Dim g As Integer = 0 Dim b As Integer = 0 Dim l As...	Give a code snippet in #Visual_Basic_.NET Many image processing algorithms are defined for grayscale (or else monochromatic) images. Task Extend the data storage type defined on this page to support grayscale images. Define two operations, one to convert a color image to a grayscale image and one for the backward...	christopher/rosetta-code
http://rosettacode.org/wiki/Identity_matrix	Identity matrix	Task Build an identity matrix of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 0 1 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ...	#Eiffel	Eiffel	class APPLICATION inherit ARGUMENTS create make feature {NONE} -- Initialization make -- Run application. local dim : INTEGER -- Dimension of the identity matrix do from dim := 1 until dim > 10 loop print_matrix( identity_matrix(dim) ) dim := dim + 1 io.new_line end ...	Give a code snippet in #Eiffel Task Build an identity matrix of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 ...	christopher/rosetta-code
http://rosettacode.org/wiki/Simple_turtle_graphics	Simple turtle graphics	The first turtle graphic discussed in Mindstorms: Children, Computers, and Powerful Ideas by Seymour Papert is a simple drawing of a house. It is a square with a triangle on top for the roof. For a slightly more advanced audience, a more practical introduction to turtle graphics might be to draw a bar chart. See imag...	#Yabasic	Yabasic	// Rosetta Code problem: http://rosettacode.org/wiki/Simple_turtle_graphics // Adapted from Python to Yabasic by Galileo, 01/2022 import turtle sub rectang(width, height) local i for i = 1 to 2 move(height) turn(-90) move(width) turn(-90) next end sub sub square(size)...	Give a code snippet in #Yabasic The first turtle graphic discussed in Mindstorms: Children, Computers, and Powerful Ideas by Seymour Papert is a simple drawing of a house. It is a square with a triangle on top for the roof. For a slightly more advanced audience, a more practical introduction to turtle graphics might ...	christopher/rosetta-code
http://rosettacode.org/wiki/Power_set	Power set	A set is a collection (container) of certain values, without any particular order, and no repeated values. It corresponds with a finite set in mathematics. A set can be implemented as an associative array (partial mapping) in which the value of each key-value pair is ignored. Given a set S, the power set (or pow...	#Scheme	Scheme	(define (power-set set) (if (null? set) '(()) (let ((rest (power-set (cdr set)))) (append (map (lambda (element) (cons (car set) element)) rest) rest)))) (display (power-set (list 1 2 3))) (newline) (display (power-set (list "A" "C" "E"))) (newline)	Give a code snippet in #Scheme A set is a collection (container) of certain values, without any particular order, and no repeated values. It corresponds with a finite set in mathematics. A set can be implemented as an associative array (partial mapping) in which the value of each key-value pair is ignored. Give...	christopher/rosetta-code
http://rosettacode.org/wiki/Identity_matrix	Identity matrix	Task Build an identity matrix of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 0 1 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ...	#PL.2FI	PL/I	identity: procedure (A, n); declare A(n,n) fixed controlled; declare (i,n) fixed binary; allocate A; A = 0; do i = 1 to n; A(i,i) = 1; end; end identity;	Give a code snippet in #PL.2FI Task Build an identity matrix of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 ...	christopher/rosetta-code
http://rosettacode.org/wiki/Averages/Arithmetic_mean	Averages/Arithmetic mean	Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin...	#Mathprog	Mathprog	/Arithmetic Mean of a large number of Integers - or - solve a very large constraint matrix over 1 million rows and columns Nigel_Galloway March 18th., 2008. / param e := 20; set Sample := {1..2*e-1}; var Mean; var E{z in Sample}; / sum of variances is zero */ zumVariance: sum{z in Sample} E[z...	Give a code snippet in #Mathprog Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an e...	christopher/rosetta-code
http://rosettacode.org/wiki/Sum_of_squares	Sum of squares	Task Write a program to find the sum of squares of a numeric vector. The program should work on a zero-length vector (with an answer of 0). Related task Mean	#Tailspin	Tailspin	templates ssq when <[](0)> do 0 ! otherwise $... -> $*$ -> ..=Sum&{of: :()} ! end ssq [] -> ssq -> !OUT::write // outputs 0 [1..5] -> ssq -> !OUT::write // outputs 55	Give a code snippet in #Tailspin Task Write a program to find the sum of squares of a numeric vector. The program should work on a zero-length vector (with an answer of 0). Related task Mean	christopher/rosetta-code
http://rosettacode.org/wiki/Collections	Collections	This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Collections are abstractions to represent sets of values. In statically-typed languages, the values are typically of a common data type. Task Create a collection, and add a fe...	#REXX	REXX	pr. = /define a default for all elements for the array/ pr.1 = 2 /note that this array starts at 1 (one). / pr.2 = 3 pr.3 = 5 pr.4 = 7 pr.5 = 11 pr.6 = 13 pr.7 = 17 pr.8 = 19 pr.9 = 23 pr.10 = 29 pr.11 = 31 pr.12 = 37 pr.13 = 41 pr.14 = 43 pr.15 ...	Give a code snippet in #REXX This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Collections are abstractions to represent sets of values. In statically-typed languages, the values are typically of a common data type. Task Cre...	christopher/rosetta-code
http://rosettacode.org/wiki/Map_range	Map range	Given two ranges: [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]} and [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ; then a value s {\displaystyle s} in range [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]} is linearly mapped to a value t {\di...	#GDScript	GDScript	func mapRange(s:float, a1:float, a2:float, b1:float, b2:float) -> float : return b1 + ((b2-b1)/(a2-a1))*(s-a1) for i in 11 : print( "%2d %+.1f" % [i,mapRange(i,0.0,10.0,-1.0,0.0)] )	Give a code snippet in #GDScript Given two ranges: [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]} and [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ; then a value s {\displaystyle s} in range [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]} is linearl...	christopher/rosetta-code
http://rosettacode.org/wiki/Anonymous_recursion	Anonymous recursion	While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion. This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the f...	#LOLCODE	LOLCODE	HAI 1.3 HOW IZ I fib YR x DIFFRINT x AN BIGGR OF x AN 0, O RLY? YA RLY, FOUND YR "ERROR" OIC HOW IZ I fib_i YR n DIFFRINT n AN BIGGR OF n AN 2, O RLY? YA RLY, FOUND YR n OIC FOUND YR SUM OF... I IZ fib_i YR DIFF OF n AN 2 MKAY AN... I IZ fib_...	Give a code snippet in #LOLCODE While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion. This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwa...	christopher/rosetta-code
http://rosettacode.org/wiki/Create_an_HTML_table	Create an HTML table	Create an HTML table. The table body should have at least three rows of three columns. Each of these three columns should be labelled "X", "Y", and "Z". An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled with sequential row numbers. The...	#Julia	Julia	function tag(x::Pair, attr::Pair...) t, b = x attrstr = join(" $n=\"$p\"" for (n, p) in attr) return "<$t$attrstr>$b</$t>" end colnames = split(",X,Y,Z", ',') header = join(tag(:th => txt) for txt in colnames) * "\n" rows = collect(tag(:tr => join(tag(:td => i, :style => "font-weight: bold;") * join(t...	Give a code snippet in #Julia Create an HTML table. The table body should have at least three rows of three columns. Each of these three columns should be labelled "X", "Y", and "Z". An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled wit...	christopher/rosetta-code
http://rosettacode.org/wiki/File_input/output	File input/output	File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable. In other words, your program will demonstrate: how to read from a file into a variable how to write ...	#mIRC_Scripting_Language	mIRC Scripting Language	alias Write2FileAndReadIt { .write myfilename.txt Goodbye Mike! .echo -a Myfilename.txt contains: $read(myfilename.txt,1) }	Give a code snippet in #mIRC_Scripting_Language File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable. In other words, your program will demonstrate: how to ...	christopher/rosetta-code
http://rosettacode.org/wiki/Primes_-_allocate_descendants_to_their_ancestors	Primes - allocate descendants to their ancestors	The concept, is to add the decomposition into prime factors of a number to get its 'ancestors'. The objective is to demonstrate that the choice of the algorithm can be crucial in term of performance. This solution could be compared to the solution that would use the decomposition into primes for all the numbers betw...	#C.2B.2B	C++	#include <algorithm> #include <iostream> #include <vector> typedef unsigned long long integer; // returns all ancestors of n. n is not its own ancestor. std::vector<integer> get_ancestors(const std::vector<integer>& ancestor, integer n) { std::vector<integer> result; for (integer a = ancestor[n]; a != 0 && ...	Give a code snippet in #C.2B.2B The concept, is to add the decomposition into prime factors of a number to get its 'ancestors'. The objective is to demonstrate that the choice of the algorithm can be crucial in term of performance. This solution could be compared to the solution that would use the decomposition int...	christopher/rosetta-code
http://rosettacode.org/wiki/Knuth_shuffle	Knuth shuffle	The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array. Task Implement the Knuth shuffle for an integer array (or, if possible, an array of any type). Specification Given an array items with indices ranging from 0 to last, the algorithm can be d...	#Nemerle	Nemerle	Shuffle[T] (arr : array[T]) : array[T] { def rnd = Random(); foreach (i in [0 .. (arr.Length - 2)]) arr[i] <-> arr[(rnd.Next(i, arr.Length))]; arr }	Give a code snippet in #Nemerle The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array. Task Implement the Knuth shuffle for an integer array (or, if possible, an array of any type). Specification Given an array items with indices ranging from ...	christopher/rosetta-code
http://rosettacode.org/wiki/Isqrt_(integer_square_root)_of_X	Isqrt (integer square root) of X	Sometimes a function is needed to find the integer square root of X, where X can be a real non─negative number. Often X is actually a non─negative integer. For the purposes of this task, X can be an integer or a real number, but if it simplifies things in your computer programming language, assume...	#Phix	Phix	with javascript_semantics include mpfr.e function isqrt(mpz x) if mpz_cmp_si(x,0)<0 then crash("Argument cannot be negative.") end if mpz q = mpz_init(1), r = mpz_init(0), t = mpz_init(), z = mpz_init_set(x) while mpz_cmp(q,x)<= 0 do mpz_mul_si(q,q,4) end wh...	Give a code snippet in #Phix Sometimes a function is needed to find the integer square root of X, where X can be a real non─negative number. Often X is actually a non─negative integer. For the purposes of this task, X can be an integer or a real number, but if it simplifies things in your computer ...	christopher/rosetta-code
http://rosettacode.org/wiki/Least_common_multiple	Least common multiple	Least common multiple You are encouraged to solve this task according to the task description, using any language you may know. Task Compute the least common multiple (LCM) of two integers. Given m and n, the least common multiple is the smallest positive integer that has both m and n as factor...	#Ring	Ring	see lcm(24,36) func lcm m,n lcm = m*n / gcd(m,n) return lcm func gcd gcd, b while b c = gcd gcd = b b = c % b end return gcd	Give a code snippet in #Ring Least common multiple You are encouraged to solve this task according to the task description, using any language you may know. Task Compute the least common multiple (LCM) of two integers. Given m and n, the least common multiple is the smallest positive integer that has ...	christopher/rosetta-code
http://rosettacode.org/wiki/Old_lady_swallowed_a_fly	Old lady swallowed a fly	Task Present a program which emits the lyrics to the song I Knew an Old Lady Who Swallowed a Fly, taking advantage of the repetitive structure of the song's lyrics. This song has multiple versions with slightly different lyrics, so all these programs might not emit identical output. Other tasks related to st...	#PL.2FM	PL/M	100H: /* CP/M CALL / BDOS: PROCEDURE(FUNC, ARGS); DECLARE FUNC BYTE, ARGS ADDRESS; GO TO 5; END BDOS; / PRINT STRING */ PRINT: PROCEDURE(STRING); DECLARE STRING ADDRESS; CALL BDOS(9, STRING); END PRINT; DECLARE COMMA$CRLF DATA (',',13,10,'$'); DECLARE CRLF DATA (13,10,'$'); DECLARE ANIMALS (8)...	Give a code snippet in #PL.2FM Task Present a program which emits the lyrics to the song I Knew an Old Lady Who Swallowed a Fly, taking advantage of the repetitive structure of the song's lyrics. This song has multiple versions with slightly different lyrics, so all these programs might not emit identical outpu...	christopher/rosetta-code
http://rosettacode.org/wiki/Pernicious_numbers	Pernicious numbers	A pernicious number is a positive integer whose population count is a prime. The population count is the number of ones in the binary representation of a non-negative integer. Example 22 (which is 10110 in binary) has a population count of 3, which is prime, and therefore 22 is a pe...	#AWK	AWK	# syntax: GAWK -f PERNICIOUS_NUMBERS.AWK BEGIN { pernicious(25) pernicious(888888877,888888888) exit(0) } function pernicious(x,y, count,n) { if (y == "") { # print first X pernicious numbers while (count < x) { if (is_prime(pop_count(++n)) == 1) { printf("%d ",n) co...	Give a code snippet in #AWK A pernicious number is a positive integer whose population count is a prime. The population count is the number of ones in the binary representation of a non-negative integer. Example 22 (which is 10110 in binary) has a population count of 3, which is prime, ...	christopher/rosetta-code
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters	Determine if a string has all the same characters	Task Given a character string (which may be empty, or have a length of zero characters): create a function/procedure/routine to: determine if all the characters in the string are the same indicate if or which character is different from the previous character display each string and its length (as the...	#Clojure	Clojure	(defn check-all-chars-same [s] (println (format "String (%s) of len: %d" s (count s))) (let [num-same (-> (take-while #(= (first s) %) s) count)] (if (= num-same (count s)) (println "...all characters the same") (println (format "...character %d differs - it is 0x%x" ...	Give a code snippet in #Clojure Task Given a character string (which may be empty, or have a length of zero characters): create a function/procedure/routine to: determine if all the characters in the string are the same indicate if or which character is different from the previous character display eac...	christopher/rosetta-code
http://rosettacode.org/wiki/Faulhaber%27s_formula	Faulhaber's formula	In mathematics, Faulhaber's formula, named after Johann Faulhaber, expresses the sum of the p-th powers of the first n positive integers as a (p + 1)th-degree polynomial function of n, the coefficients involving Bernoulli numbers. Task Generate the first 10 closed-form expressions, starting with p = 0. R...	#F.C5.8Drmul.C3.A6	Fōrmulæ	n := X(Rationals, "n"); sum1 := p -> Sum([0 .. p], k -> Stirling2(p, k) * Product([0 .. k], j -> n + 1 - j) / (k + 1)) + 2 * Bernoulli(2 * p + 1); sum2 := p -> Sum([0 .. p], j -> (-1)^j * Binomial(p + 1, j) * Bernoulli(j) * n^(p + 1 - j)) / (p + 1); ForAll([0 .. 20], k -> sum1(k) = sum2(k)); for p in [0 .. 9] do ...	Give a code snippet in #F.C5.8Drmul.C3.A6 In mathematics, Faulhaber's formula, named after Johann Faulhaber, expresses the sum of the p-th powers of the first n positive integers as a (p + 1)th-degree polynomial function of n, the coefficients involving Bernoulli numbers. Task Generate the first 10 closed-...	christopher/rosetta-code
http://rosettacode.org/wiki/Pangram_checker	Pangram checker	Pangram checker You are encouraged to solve this task according to the task description, using any language you may know. A pangram is a sentence that contains all the letters of the English alphabet at least once. For example: The quick brown fox jumps over the lazy dog. Task Write a function or method to chec...	#Erlang	Erlang	-module(pangram). -export([is_pangram/1]). is_pangram(String) -> ordsets:is_subset(lists:seq($a, $z), ordsets:from_list(string:to_lower(String))).	Give a code snippet in #Erlang Pangram checker You are encouraged to solve this task according to the task description, using any language you may know. A pangram is a sentence that contains all the letters of the English alphabet at least once. For example: The quick brown fox jumps over the lazy dog. Task Wr...	christopher/rosetta-code
http://rosettacode.org/wiki/Sierpinski_triangle	Sierpinski triangle	Task Produce an ASCII representation of a Sierpinski triangle of order N. Example The Sierpinski triangle of order 4 should look like this: * * * * * * * * * * * * * * * ...	#Delphi	Delphi	program SierpinskiTriangle; {$APPTYPE CONSOLE} procedure PrintSierpinski(order: Integer); var x, y, size: Integer; begin size := (1 shl order) - 1; for y := size downto 0 do begin Write(StringOfChar(' ', y)); for x := 0 to size - y do begin if (x and y) = 0 then Write('* ') e...	Give a code snippet in #Delphi Task Produce an ASCII representation of a Sierpinski triangle of order N. Example The Sierpinski triangle of order 4 should look like this: * * * * * * * * * * * ...	christopher/rosetta-code
http://rosettacode.org/wiki/A%2BB	A+B	A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used. Task Given two integers, A and B. Their sum needs to be calculated. Input data Two integers are written in the input stream, separated by space(s): ( − 1000 ≤...	#Gosu	Gosu	uses java.io.InputStreamReader uses java.util.Scanner uses java.lang.System var scanner = new Scanner( new InputStreamReader( System.in ) ) var a = scanner.nextInt() var b = scanner.nextInt() print( a + b )	Give a code snippet in #Gosu A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used. Task Given two integers, A and B. Their sum needs to be calculated. Input data Two integers are written in the input stream, separated...	christopher/rosetta-code
http://rosettacode.org/wiki/Recaman%27s_sequence	Recaman's sequence	The Recamán's sequence generates Natural numbers. Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated. If the conditions don't hold then a(n) = a(n-1) + n. Task Generate and show here the...	#Forth	Forth	: array ( n -- ) ( i -- addr) create cells allot does> swap cells + ; 100 array sequence : sequence. ( n -- ) cr 0 ?do i sequence @ . loop ; : ?unused ( n -- t \| n ) 100 0 ?do dup i sequence @ = if unloop exit then loop drop true ; : sequence-next ( n -- a[n] ) dup 0= if 0 0 sequence ! exit then ...	Give a code snippet in #Forth The Recamán's sequence generates Natural numbers. Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated. If the conditions don't hold then a(n) = a(n-1) + n. Ta...	christopher/rosetta-code
http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation	Permutations/Rank of a permutation	A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items. For our purposes the ranking will assign integers 0.. ( n ! − 1 ) {\displaystyle 0..(n!-1)} to an ordering of all the permutations of the integers 0.. ( n − 1 ) {\disp...	#D	D	import std.stdio, std.algorithm, std.range; alias TRank = ulong; TRank factorial(in uint n) pure nothrow { TRank result = 1; foreach (immutable i; 2 .. n + 1) result *= i; return result; } /// Fill the integer array <vec> with the permutation at rank <rank>. void computePermutation(size_t N)(r...	Give a code snippet in #D A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items. For our purposes the ranking will assign integers 0.. ( n ! − 1 ) {\displaystyle 0..(n!-1)} to an ordering of all the permutations of the integers...	christopher/rosetta-code
http://rosettacode.org/wiki/Averages/Arithmetic_mean	Averages/Arithmetic mean	Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin...	#C.23	C#	using System; using System.Linq; class Program { static void Main() { Console.WriteLine(new[] { 1, 2, 3 }.Average()); } }	Give a code snippet in #C.23 Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an estab...	christopher/rosetta-code
http://rosettacode.org/wiki/Longest_string_challenge	Longest string challenge	Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through th...	#Phix	Phix	with javascript_semantics --integer fn = open(command_line()[2],"r") -- (reading the source file) sequence fn = unix_dict()[1..40]&-1 function allx(string line) line[1..-1] = 'x' return line end function function longest(string mask) -- object line = gets(fn) object line = fn[1]; fn = fn[2..$]; if ...	Give a code snippet in #Phix Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challeng...	christopher/rosetta-code
http://rosettacode.org/wiki/Sum_of_a_series	Sum of a series	Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence. Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task. For this task, use: S n = ∑ k = 1 n 1 k 2 {\displa...	#WDTE	WDTE	let s => import 'stream'; s.range 1 1001 -> s.map (@ inner k => / 1 (* k k)) -> s.reduce 0 + -- io.writeln io.stdout ;	Give a code snippet in #WDTE Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence. Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task. For this task, use: S n = ∑ k = 1 ...	christopher/rosetta-code
http://rosettacode.org/wiki/Optional_parameters	Optional parameters	Task Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters: ordering A function specifying the ordering of strings; lexicographic by default. column ...	#Mathematica.2FWolfram_Language	Mathematica/Wolfram Language	Options[OptionalSort]={ordering->lexicographic,column->1,reverse-> False}; OptionalSort[x_List,OptionsPattern[]]:=If[OptionValue[reverse]==True, SortBy[x ,#[[OptionValue[column]]]&]//Reverse, SortBy[x,#[[OptionValue[column]]]&] ] OptionalSort[{{"a" ,"b", "c"}, {"", "q", "z"},{"zap" ,"zip", "Zot"}} ] ->{{,q,z},{a,b,c}...	Give a code snippet in #Mathematica.2FWolfram_Language Task Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters: ordering A function specifying the...	christopher/rosetta-code
http://rosettacode.org/wiki/Comments	Comments	Task Show all ways to include text in a language source file that's completely ignored by the compiler or interpreter. Related tasks Documentation Here_document See also Wikipedia xkcd (Humor: hand gesture denoting // for "commenting out" people.)	#PHP	PHP	# this is commented // this is commented	Give a code snippet in #PHP Task Show all ways to include text in a language source file that's completely ignored by the compiler or interpreter. Related tasks Documentation Here_document See also Wikipedia xkcd (Humor: hand gesture denoting // for "commenting out" people.)	christopher/rosetta-code
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas	The Twelve Days of Christmas	Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) Other tasks related to string operations: Metrics Array length Stri...	#Run_BASIC	Run BASIC	gifts$ = " A partridge in a pear tree., Two turtle doves, Three french hens, Four calling birds, Five golden rings, Six geese a-laying, Seven swans a-swimming, Eight maids a-milking, Nine ladies dancing, Ten lords a-leaping, Eleven pipers piping, Twelve drummers drumming" days$ = "first second third fourth fifth sixt...	Give a code snippet in #Run_BASIC Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) Other tasks related to string opera...	christopher/rosetta-code
http://rosettacode.org/wiki/Amb	Amb	Define and give an example of the Amb operator. The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"). The Amb operator takes a v...	#Perl	Perl	use strict; use warnings; use constant EXIT_FAILURE => 1; use constant EXIT_SUCCESS => 0; sub amb { exit(EXIT_FAILURE) if !@_; for my $word (@_) { my $pid = fork; die $! unless defined $pid; return $word if !$pid; my $wpid = waitpid $pid, 0; die $! unless $wpid == $pid; exi...	Give a code snippet in #Perl Define and give an example of the Amb operator. The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"...	christopher/rosetta-code
http://rosettacode.org/wiki/ABC_problem	ABC problem	ABC problem You are encouraged to solve this task according to the task description, using any language you may know. You are given a collection of ABC blocks (maybe like the ones you had when you were a kid). There are twenty blocks with two letters on each block. A complete alphabet is guaranteed amongst all sid...	#360_Assembly	360 Assembly	* ABC Problem 21/07/2016 ABC CSECT USING ABC,R13 base register B 72(R15) skip savearea DC 17F'0' savearea STM R14,R12,12(R13) prolog ST R13,4(R15) " <- ST R15,8(R13) ...	Give a code snippet in #360_Assembly ABC problem You are encouraged to solve this task according to the task description, using any language you may know. You are given a collection of ABC blocks (maybe like the ones you had when you were a kid). There are twenty blocks with two letters on each block. A complete ...	christopher/rosetta-code
http://rosettacode.org/wiki/Nth_root	Nth root	Task Implement the algorithm to compute the principal nth root A n {\displaystyle {\sqrt[{n}]{A}}} of a positive real number A, as explained at the Wikipedia page.	#Swift	Swift	extension FloatingPoint where Self: ExpressibleByFloatLiteral { @inlinable public func power(_ e: Int) -> Self { var res = Self(1) for _ in 0..<e { res *= self } return res } @inlinable public func root(n: Int, epsilon: Self = 2.220446049250313e-16) -> Self { var d = Self(0) ...	Give a code snippet in #Swift Task Implement the algorithm to compute the principal nth root A n {\displaystyle {\sqrt[{n}]{A}}} of a positive real number A, as explained at the Wikipedia page.	christopher/rosetta-code
http://rosettacode.org/wiki/Find_the_intersection_of_two_lines	Find the intersection of two lines	[1] Task Find the point of intersection of two lines in 2D. The 1st line passes though (4,0) and (6,10) . The 2nd line passes though (0,3) and (10,7) .	#XPL0	XPL0	func real Det; real A0, B0, A1, B1; return A0B1 - A1B0; func Cramer; real A0, B0, C0, A1, B1, C1; real Denom; [Denom:= Det(A0, B0, A1, B1); RlOut(0, Det(C0, B0, C1, B1) / Denom); RlOut(0, Det(A0, C0, A1, C1) / Denom); ]; real L0, L1, M0, M1; [L0:= [[ 4., 0.], [ 6., 10.]]; L1:= [[ 0., 3.], [10., 7.]]; M0:= (L0...	Give a code snippet in #XPL0 [1] Task Find the point of intersection of two lines in 2D. The 1st line passes though (4,0) and (6,10) . The 2nd line passes though (0,3) and (10,7) .	christopher/rosetta-code
http://rosettacode.org/wiki/Digital_root	Digital root	The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X} , repeating until X {\displ...	#PARI.2FGP	PARI/GP	dsum(n)=my(s); while(n, s+=n%10; n\=10); s additivePersistence(n)=my(s); while(n>9, s++; n=dsum(n)); s digitalRoot(n)=if(n, (n-1)%9+1, 0)	Give a code snippet in #PARI.2FGP The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X}...	christopher/rosetta-code
http://rosettacode.org/wiki/Abundant_odd_numbers	Abundant odd numbers	An Abundant number is a number n for which the sum of divisors σ(n) > 2n, or, equivalently, the sum of proper divisors (or aliquot sum) s(n) > n. E.G. 12 is abundant, it has the proper divisors 1,2,3,4 & 6 which sum to 16 ( > 12 or n); or alternately, has the sigma sum of ...	#q	q	s:{c where 0=x mod c:1+til x div 2} / proper divisors sd:sum s@ / sum of proper divisors abundant:{x<sd x} Filter:{y where x each y}	Give a code snippet in #q An Abundant number is a number n for which the sum of divisors σ(n) > 2n, or, equivalently, the sum of proper divisors (or aliquot sum) s(n) > n. E.G. 12 is abundant, it has the proper divisors 1,2,3,4 & 6 which sum to 16 ( > 12 or n); or alternate...	christopher/rosetta-code
http://rosettacode.org/wiki/Loops/Break	Loops/Break	Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never gener...	#dc	dc	1 ss [s = seed of the random number generator]sz 0k [scale = 0]sz [Function r: Push a random number from 0 to 20.]sz [ [2Q]SA [ [Formula (from POSIX) for random numbers of low quality.]sz ls 1103515245 * 12345 + 4294967296 % d ss [Compute next s]sz 65536 / [it = s / 65536]sz d 16 !>A [Break loop...	Give a code snippet in #dc Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If ...	christopher/rosetta-code
http://rosettacode.org/wiki/Averages/Arithmetic_mean	Averages/Arithmetic mean	Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin...	#NewLISP	NewLISP	(define (Mean Lst) (if (empty? Lst) 0 (/ (apply + Lst) (length Lst)))) (Mean (sequence 1 1000))-> 500 (Mean '()) -> 0	Give a code snippet in #NewLISP Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an es...	christopher/rosetta-code
http://rosettacode.org/wiki/Haversine_formula	Haversine formula	This page uses content from Wikipedia. The original article was at Haversine formula. 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) The haversine formula is an equation important in navigation, g...	#TechBASIC	TechBASIC	{{trans\|BASIC}} FUNCTION HAVERSINE !--------------------------------------------------------------- !* Haversine Formula - Calculate distances by LAT/LONG ! !* LAT/LON of the two locations and Unit of measure are GLOBAL !* as they are defined in the main logic of the program, so they !* available for use in...	Give a code snippet in #TechBASIC This page uses content from Wikipedia. The original article was at Haversine formula. 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) The haversine formula is an ...	christopher/rosetta-code
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers	Case-sensitivity of identifiers	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output: The three dogs are named Benjamin, Samba and Bernie. For a language...	#dc	dc	[Benjamin]sd [Samba]sD [The two dogs are named ]P ldP [ and ]P lDP [. ]P	Give a code snippet in #dc Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output: The three dogs are named Benjamin, Samba...	christopher/rosetta-code
http://rosettacode.org/wiki/Non-decimal_radices/Convert	Non-decimal radices/Convert	Number base conversion is when you express a stored integer in an integer base, such as in octal (base 8) or binary (base 2). It also is involved when you take a string representing a number in a given base and convert it to the stored integer form. Normally, a stored integer is in binary, but that's typically invisibl...	#OCaml	OCaml	let int_of_basen n str = match n with \| 16 -> int_of_string("0x" ^ str) \| 2 -> int_of_string("0b" ^ str) \| 8 -> int_of_string("0o" ^ str) \| _ -> failwith "unhandled" let basen_of_int n d = match n with \| 16 -> Printf.sprintf "%x" d \| 8 -> Printf.sprintf "%o" d \| _ -> failwith "unhandled"	Give a code snippet in #OCaml Number base conversion is when you express a stored integer in an integer base, such as in octal (base 8) or binary (base 2). It also is involved when you take a string representing a number in a given base and convert it to the stored integer form. Normally, a stored integer is in binary...	christopher/rosetta-code
http://rosettacode.org/wiki/15_puzzle_game	15 puzzle game	Task Implement the Fifteen Puzzle Game. The 15-puzzle is also known as: Fifteen Puzzle Gem Puzzle Boss Puzzle Game of Fifteen Mystic Square 14-15 Puzzle and some others. Related Tasks 15 Puzzle Solver 16 Puzzle Game	#Visual_Prolog	Visual Prolog	/* ------------------------------------------------------------------------------------------------------ Copyright (c) 2004 - Gal Zsolt (CalmoSoft) ------------------------------------------------------------------------------------------------------ */ impleme...	Give a code snippet in #Visual_Prolog Task Implement the Fifteen Puzzle Game. The 15-puzzle is also known as: Fifteen Puzzle Gem Puzzle Boss Puzzle Game of Fifteen Mystic Square 14-15 Puzzle and some others. Related Tasks 15 Puzzle Solver 16 Puzzle Game	christopher/rosetta-code
http://rosettacode.org/wiki/Zig-zag_matrix	Zig-zag matrix	Task Produce a zig-zag array. A zig-zag array is a square arrangement of the first N2 natural numbers, where the numbers increase sequentially as you zig-zag along the array's anti-diagonals. For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images). For example, gi...	#Icon_and_Unicon	Icon and Unicon	procedure main(args) n := integer(!args) \| 5 every !(A := list(n)) := list(n) A := zigzag(A) show(A) end procedure show(A) every writes(right(!A,5) \| "\n") end procedure zigzag(A) x := [0,0] every i := 0 to (A^2 -1) do { x := nextIndices(A, x) A[x[1]][x[2]] := i } ...	Give a code snippet in #Icon_and_Unicon Task Produce a zig-zag array. A zig-zag array is a square arrangement of the first N2 natural numbers, where the numbers increase sequentially as you zig-zag along the array's anti-diagonals. For a graphical representation, see JPG zigzag (JPG uses such arr...	christopher/rosetta-code
http://rosettacode.org/wiki/Fibonacci_word	Fibonacci word	The Fibonacci Word may be created in a manner analogous to the Fibonacci Sequence as described here: Define F_Word1 as 1 Define F_Word2 as 0 Form F_Word3 as F_Word2 concatenated with F_Word1 i.e.: 01 Form F_Wordn as F_Wordn-1 concatenated with F_wordn-...	#Common_Lisp	Common Lisp	(defun make-fibwords (array) (loop for i from 0 below 37 for j = "0" then (concatenate 'string j k) and k = "1" then j do (setf (aref array i) k)) array) (defvar fib (make-fibwords (make-array 37))) (defun entropy (string) (let ((table (make-hash-table :test 'eql)) (entropy 0d0)...	Give a code snippet in #Common_Lisp The Fibonacci Word may be created in a manner analogous to the Fibonacci Sequence as described here: Define F_Word1 as 1 Define F_Word2 as 0 Form F_Word3 as F_Word2 concatenated with F_Word1 i.e.: 01 Form F_Wordn as F_W...	christopher/rosetta-code
http://rosettacode.org/wiki/Arrays	Arrays	This task is about arrays. For hashes or associative arrays, please see Creating an Associative Array. For a definition and in-depth discussion of what an array is, see Array. Task Show basic array syntax in your language. Basically, create an array, assign a value to it, and retrieve an element (if available,...	#Unicon_2	Unicon	L := list(100); L[12] := 7; a := array(100, 0.0); a[3] +:= a[1]+a[2]	Give a code snippet in #Unicon_2 This task is about arrays. For hashes or associative arrays, please see Creating an Associative Array. For a definition and in-depth discussion of what an array is, see Array. Task Show basic array syntax in your language. Basically, create an array, assign a value to it, and re...	christopher/rosetta-code
http://rosettacode.org/wiki/Roots_of_a_quadratic_function	Roots of a quadratic function	This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Write a program to find the roots of a quadratic equation, i.e., solve the equation a x 2 + b x + c = 0 {\displaystyle ax^{2}+bx+c=0} . Your program must correctly handle n...	#PicoLisp	PicoLisp	(scl 40) (de solveQuad (A B C) (let SD (sqrt (- (* B B) (* 4 A C))) (if (lt0 B) (list (/ (- SD B) A 2.0) (/ C 2.0 (/ A A (- SD B) `( 1.0 1.0))) ) (list (/ C 2.0 (/ A A (- 0 B SD) `(* 1.0 1.0))) (*/ (- 0 B SD) A 2.0) ) ) ) ) (mapcar rou...	Give a code snippet in #PicoLisp This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Write a program to find the roots of a quadratic equation, i.e., solve the equation a x 2 + b x + c = 0 {\displaystyle ax^{2}+bx+c=0} . Yo...	christopher/rosetta-code
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers	Luhn test of credit card numbers	The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Tak...	#TI-83_BASIC	TI-83 BASIC	PROGRAM:LUHN :Disp "ENTER NUMBER" :Input Str1 :0→S :0→E :For(I,length(Str1),1,-1) :inString("0123456789",sub(Str1,I,1))–1→X :If X<0 :Goto BA :If E≠0 :Then :2X→X :If X>9 :X–9→X :End :X+S→S :not(E)→E :End :If fPart(S/10)=0 :Then :Disp "GOOD CARD" :Else :Lbl BA :Disp "BAD CARD" :End	Give a code snippet in #TI-83_BASIC The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the or...	christopher/rosetta-code
http://rosettacode.org/wiki/Sorting_algorithms/Merge_sort	Sorting algorithms/Merge 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 ...	#PARI.2FGP	PARI/GP	mergeSort(v)={ if(#v<2, return(v)); my(m=#v\2,left=vector(m,i,v[i]),right=vector(#v-m,i,v[m+i])); left=mergeSort(left); right=mergeSort(right); merge(left, right) }; merge(u,v)={ my(ret=vector(#u+#v),i=1,j=1); for(k=1,#ret, if(i<=#u & (j>#v \| u[i]<v[j]), ret[k]=u[i]; i++ , ret[k]=v[j]; j++ ...	Give a code snippet in #PARI.2FGP 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 \| Quic...	christopher/rosetta-code
http://rosettacode.org/wiki/Maze_generation	Maze generation	This page uses content from Wikipedia. The original article was at Maze generation 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) Task Generate and show a maze, using the simple Depth...	#Swift	Swift	import Foundation extension Array { mutating func shuffle() { guard count > 1 else { return } for i in 0..<self.count - 1 { let j = Int(arc4random_uniform(UInt32(count - i))) + i guard i != j else { continue } swap(&self[i], &self[j]) } } } enum ...	Give a code snippet in #Swift This page uses content from Wikipedia. The original article was at Maze generation 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) Task Generate and show...	christopher/rosetta-code
http://rosettacode.org/wiki/Boolean_values	Boolean values	Task Show how to represent the boolean states "true" and "false" in a language. If other objects represent "true" or "false" in conditionals, note it. Related tasks Logical operations	#8051_Assembly	8051 Assembly	clr bit ; clears setb bit ; sets	Give a code snippet in #8051_Assembly Task Show how to represent the boolean states "true" and "false" in a language. If other objects represent "true" or "false" in conditionals, note it. Related tasks Logical operations	christopher/rosetta-code
http://rosettacode.org/wiki/Loops/Downward_for	Loops/Downward for	Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body...	#HicEst	HicEst	DO i = 10, 0, -1 WRITE() i ENDDO	Give a code snippet in #HicEst Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Incre...	christopher/rosetta-code
http://rosettacode.org/wiki/Polynomial_long_division	Polynomial long division	This page uses content from Wikipedia. The original article was at Polynomial long division. 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 algebra, polynomial long division is an algorithm for d...	#Maple	Maple	> p := randpoly( x ); # pick a random polynomial in x 5 4 3 2 p := -56 - 7 x + 22 x - 55 x - 94 x + 87 x > rem( p, x^2 + 2, x, 'q' ); # remainder 220 + 169 x > q; # quotient 3 2 ...	Give a code snippet in #Maple This page uses content from Wikipedia. The original article was at Polynomial long division. 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 algebra, polynomial long...	christopher/rosetta-code
http://rosettacode.org/wiki/Optional_parameters	Optional parameters	Task Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters: ordering A function specifying the ordering of strings; lexicographic by default. column ...	#Common_Lisp	Common Lisp	(defun sort-table (table &key (ordering #'string<) (column 0) reverse) (sort table (if reverse (complement ordering) ordering) :key (lambda (row) (elt row column))))	Give a code snippet in #Common_Lisp Task Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters: ordering A function specifying the ordering of string...	christopher/rosetta-code
http://rosettacode.org/wiki/Order_two_numerical_lists	Order two numerical lists	sorting 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 She...	#AppleScript	AppleScript	-- <= for lists -- compare :: [a] -> [a] -> Bool on compare(xs, ys) if length of xs = 0 then true else if length of ys = 0 then false else set {hx, txs} to uncons(xs) set {hy, tys} to uncons(ys) if hx = hy then compare(txs...	Give a code snippet in #AppleScript sorting 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 s...	christopher/rosetta-code
http://rosettacode.org/wiki/Exceptions	Exceptions	Control Structures These are examples of control structures. You may also be interested in: Conditional structures Exceptions Flow-control structures Loops This task is to give an example of an exception handling routine and to "throw" a new exception. Related task Exceptions Through Nested Calls	#Forth	Forth	: f ( -- ) 1 throw ." f " ; \ will throw a "1" : g ( -- ) 0 throw ." g " ; \ does not throw	Give a code snippet in #Forth Control Structures These are examples of control structures. You may also be interested in: Conditional structures Exceptions Flow-control structures Loops This task is to give an example of an exception handling routine and to "throw" a new exception. Related task Exceptions...	christopher/rosetta-code
http://rosettacode.org/wiki/Egyptian_fractions	Egyptian fractions	An Egyptian fraction is the sum of distinct unit fractions such as: 1 2 + 1 3 + 1 16 ( = 43 48 ) {\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})} Each fraction in the expression has a numerator equal to 1 (unity) and a denominator that...	#Common_Lisp	Common Lisp	(defun egyption-fractions (x y &optional acc) (let* ((a (/ x y))) (cond ((> (numerator a) (denominator a)) (multiple-value-bind (q r) (floor x y) (if (zerop r) (cons q acc) (egyption-fractions r y (cons q acc))))) ((= (numerator a) 1) (reverse (cons a acc))) (t (let ((b (ceiling y ...	Give a code snippet in #Common_Lisp An Egyptian fraction is the sum of distinct unit fractions such as: 1 2 + 1 3 + 1 16 ( = 43 48 ) {\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})} Each fraction in the expression has a numerator equal to ...	christopher/rosetta-code
http://rosettacode.org/wiki/Singly-linked_list/Element_definition	Singly-linked list/Element definition	singly-linked list See also Array Associative array: Creation, Iteration Collections Compound data type Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal Linked list Queue: Definition, Usage Set Singly-linked list: Element definition, Element insertion, Lis...	#Ada	Ada	type Link; type Link_Access is access Link; type Link is record Next : Link_Access := null; Data : Integer; end record;	Give a code snippet in #Ada singly-linked list See also Array Associative array: Creation, Iteration Collections Compound data type Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal Linked list Queue: Definition, Usage Set Singly-linked list: Element defin...	christopher/rosetta-code
http://rosettacode.org/wiki/Sum_and_product_of_an_array	Sum and product of an array	Task Compute the sum and product of an array of integers.	#C	C	/* using pointer arithmetic (because we can, I guess) / int arg[] = { 1,2,3,4,5 }; int arg_length = sizeof(arg)/sizeof(arg[0]); int end = arg+arg_length; int sum = 0, prod = 1; int p; for (p = arg; p!=end; ++p) { sum += p; prod = p; }	Give a code snippet in #C Task Compute the sum and product of an array of integers.	christopher/rosetta-code
http://rosettacode.org/wiki/Linear_congruential_generator	Linear congruential generator	The linear congruential generator is a very simple example of a random number generator. All linear congruential generators use this formula: r n + 1 = a × r n + c ( mod m ) {\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}} Where: r 0 {\displaystyle r_{0}} is a seed. r 1 ...	#D	D	struct LinearCongruentialGenerator { enum uint RAND_MAX = (1U << 31) - 1; uint seed = 0; uint randBSD() pure nothrow @nogc { seed = (seed * 1_103_515_245 + 12_345) & RAND_MAX; return seed; } uint randMS() pure nothrow @nogc { seed = (seed * 214_013 + 2_531_011) & RAND_MAX...	Give a code snippet in #D The linear congruential generator is a very simple example of a random number generator. All linear congruential generators use this formula: r n + 1 = a × r n + c ( mod m ) {\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}} Where: r 0 {\displaystyle r_{0}...	christopher/rosetta-code
http://rosettacode.org/wiki/Display_a_linear_combination	Display a linear combination	Task Display a finite linear combination in an infinite vector basis ( e 1 , e 2 , … ) {\displaystyle (e_{1},e_{2},\ldots )} . Write a function that, when given a finite list of scalars ( α 1 , α 2 , … ) {\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )} , creates a string representing t...	#Go	Go	package main import ( "fmt" "strings" ) func linearCombo(c []int) string { var sb strings.Builder for i, n := range c { if n == 0 { continue } var op string switch { case n < 0 && sb.Len() == 0: op = "-" case n < 0: ...	Give a code snippet in #Go Task Display a finite linear combination in an infinite vector basis ( e 1 , e 2 , … ) {\displaystyle (e_{1},e_{2},\ldots )} . Write a function that, when given a finite list of scalars ( α 1 , α 2 , … ) {\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )} , cre...	christopher/rosetta-code
http://rosettacode.org/wiki/Towers_of_Hanoi	Towers of Hanoi	Task Solve the Towers of Hanoi problem with recursion.	#Dart	Dart	main() { moveit(from,to) { print("move ${from} ---> ${to}"); } hanoi(height,toPole,fromPole,usePole) { if (height>0) { hanoi(height-1,usePole,fromPole,toPole); moveit(fromPole,toPole); hanoi(height-1,toPole,usePole,fromPole); } } hanoi(3,3,1,2); }	Give a code snippet in #Dart Task Solve the Towers of Hanoi problem with recursion.	christopher/rosetta-code
http://rosettacode.org/wiki/ABC_problem	ABC problem	ABC problem You are encouraged to solve this task according to the task description, using any language you may know. You are given a collection of ABC blocks (maybe like the ones you had when you were a kid). There are twenty blocks with two letters on each block. A complete alphabet is guaranteed amongst all sid...	#Quackery	Quackery	[ $ "BOXKDQCPNAGTRETGQDFS" $ "JWHUVIANOBERFSLYPCZM" join ] constant is blocks ( --> $ ) [ -2 & tuck pluck drop swap pluck drop ] is remove2 ( $ n --> $ ) [ iff [ say "True" ] else [ say "False" ] ] is echotruth ( b --> ) [ true blocks rot witheach [ upper...	Give a code snippet in #Quackery ABC problem You are encouraged to solve this task according to the task description, using any language you may know. You are given a collection of ABC blocks (maybe like the ones you had when you were a kid). There are twenty blocks with two letters on each block. A complete alph...	christopher/rosetta-code
http://rosettacode.org/wiki/Go_Fish	Go Fish	Write a program to let the user play Go Fish against a computer opponent. Use the following rules: Each player is dealt nine cards to start with. On their turn, a player asks their opponent for a given rank (such as threes or kings). A player must already have at least one card of a given rank to ask for more. If t...	#PicoLisp	PicoLisp	Red [ Title: "Go Fish" Author: "gltewalt" ] chand: [] ;-- c and p = computer and player cguesses: [] phand: [] cbooks: 0 pbooks: 0 gf: { *************** * GO FISH * *************** } pip: ["a" "2" "3" "4" "5" "6" "7" "8" "9" "10" "j" "q" "k"] ;-- suits are not relevant pile: [] ;-- whe...	Give a code snippet in #PicoLisp Write a program to let the user play Go Fish against a computer opponent. Use the following rules: Each player is dealt nine cards to start with. On their turn, a player asks their opponent for a given rank (such as threes or kings). A player must already have at least one card of a...	christopher/rosetta-code
http://rosettacode.org/wiki/Chowla_numbers	Chowla numbers	Chowla numbers are also known as: Chowla's function chowla numbers the chowla function the chowla number the chowla sequence The chowla number of n is (as defined by Chowla's function): the sum of the divisors of n excluding unity and n where n is a positive integer The s...	#Pascal	Pascal	program Chowla_numbers; {$IFDEF FPC} {$MODE Delphi} {$ELSE} {$APPTYPE CONSOLE} {$ENDIF} uses SysUtils {$IFDEF FPC} ,StrUtils{for Numb2USA} {$ENDIF} ; {$IFNDEF FPC} function Numb2USA(const S: string): string; var I, NA: Integer; begin I := Length(S); Result := S; NA := 0; while (I > 0) do...	Give a code snippet in #Pascal Chowla numbers are also known as: Chowla's function chowla numbers the chowla function the chowla number the chowla sequence The chowla number of n is (as defined by Chowla's function): the sum of the divisors of n excluding unity and n where n...	christopher/rosetta-code
http://rosettacode.org/wiki/Stem-and-leaf_plot	Stem-and-leaf plot	Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits: 12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 11...	#Python	Python	from collections import namedtuple from pprint import pprint as pp from math import floor Stem = namedtuple('Stem', 'data, leafdigits') data0 = Stem((12, 127, 28, 42, 39, 113, 42, 18, 44, 118, 44, 37, 113, 124, 37, 48, 127, 36, 29, 31, 125, 139, 131, 115, 105, 132, 104, 123, 35, 113, 122...	Give a code snippet in #Python Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits: 12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37...	christopher/rosetta-code
http://rosettacode.org/wiki/Continued_fraction	Continued fraction	continued fraction Mathworld a 0 + b 1 a 1 + b 2 a 2 + b 3 a 3 + ⋱ {\displaystyle a_{0}+{\cfrac {b_{1}}{a_{1}+{\cfrac {b_{2}}{a_{2}+{\cfrac {b_{3}}{a_{3}+\ddots }}}}}}} The task is to write a program which generates su...	#Groovy	Groovy	import java.util.function.Function import static java.lang.Math.pow class Test { static double calc(Function<Integer, Integer[]> f, int n) { double temp = 0 for (int ni = n; ni >= 1; ni--) { Integer[] p = f.apply(ni) temp = p[1] / (double) (p[0] + temp) } ...	Give a code snippet in #Groovy continued fraction Mathworld a 0 + b 1 a 1 + b 2 a 2 + b 3 a 3 + ⋱ {\displaystyle a_{0}+{\cfrac {b_{1}}{a_{1}+{\cfrac {b_{2}}{a_{2}+{\cfrac {b_{3}}{a_{3}+\ddots }}}}}}} The task is to wr...	christopher/rosetta-code
http://rosettacode.org/wiki/Elementary_cellular_automaton/Infinite_length	Elementary cellular automaton/Infinite length	The purpose of this task is to create a version of an Elementary cellular automaton whose number of cells is only limited by the memory size of the computer. To be precise, consider the state of the automaton to be made of an infinite number of cells, but with a bounded support. In other words, to describe the state o...	#J	J	ext9=: (9#1-{.!.1),],9#1-{:!.1 trim=: \|.@(}.~ ] i. 1-{.)^:2 next=: trim@(((8$2) #: [) {~ 2 #. 1 - [: \|: \|.~"1 0&_1 0 1@]) ext9	Give a code snippet in #J The purpose of this task is to create a version of an Elementary cellular automaton whose number of cells is only limited by the memory size of the computer. To be precise, consider the state of the automaton to be made of an infinite number of cells, but with a bounded support. In other wor...	christopher/rosetta-code
http://rosettacode.org/wiki/Loops/Do-while	Loops/Do-while	Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loo...	#Ring	Ring	n = 0 While True n++ See n + nl if n % 6 = 0 exit ok end	Give a code snippet in #Ring Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Do...	christopher/rosetta-code
http://rosettacode.org/wiki/Find_the_missing_permutation	Find the missing permutation	ABCD CABD ACDB DACB BCDA ACBD ADCB CDAB DABC BCAD CADB CDBA ...	#Ada	Ada	with Ada.Text_IO; procedure Missing_Permutations is subtype Permutation_Character is Character range 'A' .. 'D'; Character_Count : constant := 1 + Permutation_Character'Pos (Permutation_Character'Last) - Permutation_Character'Pos (Permutation_Character'First); type Permutation_String is ...	Give a code snippet in #Ada ABCD CABD ACDB DACB BCDA ACBD ADCB CDAB DABC BCAD CADB ...	christopher/rosetta-code
http://rosettacode.org/wiki/Percolation/Site_percolation	Percolation/Site percolation	Percolation Simulation This is a simulation of aspects of mathematical percolation theory. For other percolation simulations, see Category:Percolation Simulations, or: 1D finite grid simulation Mean run density 2D finite grid simulations Site percolation \| Bond percolation \| Mean cluster density Given an M × N...	#Python	Python	from random import random import string from pprint import pprint as pp M, N, t = 15, 15, 100 cell2char = ' #' + string.ascii_letters NOT_VISITED = 1 # filled cell not walked class PercolatedException(Exception): pass def newgrid(p): return [[int(random() < p) for m in range(M)] for n in range(N)] # cel...	Give a code snippet in #Python Percolation Simulation This is a simulation of aspects of mathematical percolation theory. For other percolation simulations, see Category:Percolation Simulations, or: 1D finite grid simulation Mean run density 2D finite grid simulations Site percolation \| Bond percolation \| Mean clu...	christopher/rosetta-code
http://rosettacode.org/wiki/Closures/Value_capture	Closures/Value capture	Task Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, i 2. Display the result of runnin...	#Objective-C	Objective-C	NSMutableArray funcs = [[NSMutableArray alloc] init]; for (int i = 0; i < 10; i++) { [funcs addObject:[^ { return i i; } copy]]; } int (^foo)(void) = funcs[3]; NSLog(@"%d", foo()); // logs "9"	Give a code snippet in #Objective-C Task Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, ...	christopher/rosetta-code
http://rosettacode.org/wiki/Write_language_name_in_3D_ASCII	Write language name in 3D ASCII	Task Write/display a language's name in 3D ASCII. (We can leave the definition of "3D ASCII" fuzzy, so long as the result is interesting or amusing, not a cheap hack to satisfy the task.) Related tasks draw a sphere draw a cuboid draw a rotating cube draw a Deathstar	#Clojure	Clojure	(use 'clj-figlet.core) (println (render-to-string (load-flf "ftp://ftp.figlet.org/pub/figlet/fonts/contributed/larry3d.flf") "Clojure"))	Give a code snippet in #Clojure Task Write/display a language's name in 3D ASCII. (We can leave the definition of "3D ASCII" fuzzy, so long as the result is interesting or amusing, not a cheap hack to satisfy the task.) Related tasks draw a sphere draw a cuboid draw a rotating cube draw a Deathstar	christopher/rosetta-code
http://rosettacode.org/wiki/Esthetic_numbers	Esthetic numbers	An esthetic number is a positive integer where every adjacent digit differs from its neighbour by 1. E.G. 12 is an esthetic number. One and two differ by 1. 5654 is an esthetic number. Each digit is exactly 1 away from its neighbour. 890 is not an esthetic number. Nine and zero differ by 9. These examples are n...	#Sidef	Sidef	func generate_esthetic(root, upto, callback, b=10) { var v = root.digits2num(b) return nil if (v > upto) callback(v) var t = root.head __FUNC__([t+1, root...], upto, callback, b) if (t+1 < b) __FUNC__([t-1, root...], upto, callback, b) if (t-1 >= 0) } func between_esthetic(from, upto,...	Give a code snippet in #Sidef An esthetic number is a positive integer where every adjacent digit differs from its neighbour by 1. E.G. 12 is an esthetic number. One and two differ by 1. 5654 is an esthetic number. Each digit is exactly 1 away from its neighbour. 890 is not an esthetic number. Nine and zero diff...	christopher/rosetta-code
http://rosettacode.org/wiki/Monty_Hall_problem	Monty Hall problem	Suppose you're on a game show and you're given the choice of three doors. Behind one door is a car; behind the others, goats. The car and the goats were placed randomly behind the doors before the show. Rules of the game After you have chosen a door, the door remains closed for the time being. The game show hos...	#Prolog	Prolog	:- initialization(main). % Simulate a play. play(Switch, Won) :- % Random prize door random(1, 4, P), % Random contestant door random(1, 4, C), % Random reveal door, not prize or contestant door repeat, random(1, 4, R), R \= P, R \= C, !, % Final door ( ...	Give a code snippet in #Prolog Suppose you're on a game show and you're given the choice of three doors. Behind one door is a car; behind the others, goats. The car and the goats were placed randomly behind the doors before the show. Rules of the game After you have chosen a door, the door remains closed for th...	christopher/rosetta-code
http://rosettacode.org/wiki/Factors_of_an_integer	Factors of an integer	Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic \| Comparison Boolean Operations Bitwise \| Logical String Operations Concatenation \| Interpolation \|...	#Tailspin	Tailspin	[1..351 -> \(when <?(351 mod $ <=0>)> do $! \)] -> !OUT::write	Give a code snippet in #Tailspin Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic \| Comparison Boolean Operations Bitwise \| Logical String Operatio...	christopher/rosetta-code
http://rosettacode.org/wiki/Comma_quibbling	Comma quibbling	Comma quibbling is a task originally set by Eric Lippert in his blog. Task Write a function to generate a string output which is the concatenation of input words from a list/sequence where: An input of no words produces the output string of just the two brace characters "{}". An input of just one word, e.g. ["AB...	#Swift	Swift	let inputs = [[], ["ABC"], ["ABC", "DEF"], ["ABC", "DEF", "G", "H"]] func quibbling(var words:[String]) { if words.count == 0 { println("{}") } else if words.count == 1 { println("{\(words[0])}") } else if words.count == 2 { println("{\(words[0]) and \(words[1])}") } else { ...	Give a code snippet in #Swift Comma quibbling is a task originally set by Eric Lippert in his blog. Task Write a function to generate a string output which is the concatenation of input words from a list/sequence where: An input of no words produces the output string of just the two brace characters "{}". An in...	christopher/rosetta-code
http://rosettacode.org/wiki/Read_a_configuration_file	Read a configuration file	The task is to read a configuration file in standard configuration file format, and set variables accordingly. For this task, we have a configuration file as follows: # This is a configuration file in standard configuration file format # # Lines beginning with a hash or a semicolon are ignored by the application # pr...	#Go	Go	package config import ( "errors" "io" "fmt" "bytes" "strings" "io/ioutil" ) var ( ENONE = errors.New("Requested value does not exist") EBADTYPE = errors.New("Requested type and actual type do not match") EBADVAL = errors.New("Value and type do not match") ) type varError struct { err error n stri...	Give a code snippet in #Go The task is to read a configuration file in standard configuration file format, and set variables accordingly. For this task, we have a configuration file as follows: # This is a configuration file in standard configuration file format # # Lines beginning with a hash or a semicolon are ign...	christopher/rosetta-code
http://rosettacode.org/wiki/Make_directory_path	Make directory path	Task Create a directory and any missing parents. This task is named after the posix mkdir -p command, and several libraries which implement the same behavior. Please implement a function of a single path string (for example ./path/to/dir) which has the above side-effect. If the directory already exists, return succe...	#JavaScript	JavaScript	var path = require('path'); var fs = require('fs'); function mkdirp (p, cb) { cb = cb \|\| function () {}; p = path.resolve(p); fs.mkdir(p, function (er) { if (!er) { return cb(null); } switch (er.code) { case 'ENOENT': // The directory doesn...	Give a code snippet in #JavaScript Task Create a directory and any missing parents. This task is named after the posix mkdir -p command, and several libraries which implement the same behavior. Please implement a function of a single path string (for example ./path/to/dir) which has the above side-effect. If the di...	christopher/rosetta-code
http://rosettacode.org/wiki/Partition_an_integer_x_into_n_primes	Partition an integer x into n primes	Task Partition a positive integer X into N distinct primes. Or, to put it in another way: Find N unique primes such that they add up to X. Show in the output section the sum X and the N primes in ascending order separated by plus (+) signs: • partition 99809 with 1 prime. ...	#C	C	#include <assert.h> #include <stdbool.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> typedef struct bit_array_tag { uint32_t size; uint32_t* array; } bit_array; bool bit_array_create(bit_array* b, uint32_t size) { uint32_t* array = calloc((size + 31)/32, sizeof(uint32_t)); if (array =...	Give a code snippet in #C Task Partition a positive integer X into N distinct primes. Or, to put it in another way: Find N unique primes such that they add up to X. Show in the output section the sum X and the N primes in ascending order separated by plus (+) signs: • partition ...	christopher/rosetta-code
http://rosettacode.org/wiki/Modular_inverse	Modular inverse	From Wikipedia: In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that a x ≡ 1 ( mod m ) . {\displaystyle a\,x\equiv 1{\pmod {m}}.} Or in other words, such that: ∃ k ∈ Z , a x = 1 + k m {\displaystyle \exists k\in \math...	#BCPL	BCPL	get "libhdr" let mulinv(a, b) = b<0 -> mulinv(a, -b), a<0 -> mulinv(b - (-a rem b), b), valof $( let t, nt, r, nr = 0, 1, b, a rem b until nr = 0 $( let tmp, q = ?, r / nr tmp := nt ; nt := t - qnt ; t := tmp tmp := nr ; nr := r - qnr ; r := tmp $) ...	Give a code snippet in #BCPL From Wikipedia: In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that a x ≡ 1 ( mod m ) . {\displaystyle a\,x\equiv 1{\pmod {m}}.} Or in other words, such that: ∃ k ∈ Z , a x = 1 + k m {\d...	christopher/rosetta-code
http://rosettacode.org/wiki/Send_email	Send email	Task Write a function to send an email. The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details. If appropriate, explain what notifications of problems/success are given. Solutions using libraries or f...	#Lua	Lua	-- load the smtp support local smtp = require("socket.smtp") -- Connects to server "localhost" and sends a message to users -- "fulano@example.com", "beltrano@example.com", -- and "sicrano@example.com". -- Note that "fulano" is the primary recipient, "beltrano" receives a -- carbon copy and neither of them knows th...	Give a code snippet in #Lua Task Write a function to send an email. The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details. If appropriate, explain what notifications of problems/success are given. S...	christopher/rosetta-code
http://rosettacode.org/wiki/Word_frequency	Word frequency	Task Given a text file and an integer n, print/display the n most common words in the file (and the number of their occurrences) in decreasing frequency. For the purposes of this task: A word is a sequence of one or more contiguous letters. You are free to define what a letter is. Undersc...	#AppleScript	AppleScript	(* For simplicity here, words are considered to be uninterrupted sequences of letters and/or digits. The set text is too messy to warrant faffing around with anything more sophisticated. The first letter in each word is upper-cased and the rest lower-cased for case equivalence and presentation. Where mo...	Give a code snippet in #AppleScript Task Given a text file and an integer n, print/display the n most common words in the file (and the number of their occurrences) in decreasing frequency. For the purposes of this task: A word is a sequence of one or more contiguous letters. You are free to def...	christopher/rosetta-code
http://rosettacode.org/wiki/Variadic_function	Variadic function	Task Create a function which takes in a variable number of arguments and prints each one on its own line. Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime. Functions of this type are also known as Variadic Functions. Related task Call a function...	#Visual_Basic	Visual Basic	Option Explicit '-------------------------------------------------- Sub varargs(ParamArray a()) Dim n As Long, m As Long Debug.Assert VarType(a) = (vbVariant Or vbArray) For n = LBound(a) To UBound(a) If IsArray(a(n)) Then For m = LBound(a(n)) To UBound(a(n)) Debug.Print a(n)...	Give a code snippet in #Visual_Basic Task Create a function which takes in a variable number of arguments and prints each one on its own line. Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime. Functions of this type are also known as Variadic Function...	christopher/rosetta-code
http://rosettacode.org/wiki/Delete_a_file	Delete a file	Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.	#Forth	Forth	s" input.txt" delete-file throw s" /input.txt" delete-file throw	Give a code snippet in #Forth Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.	christopher/rosetta-code
http://rosettacode.org/wiki/Combinations	Combinations	Task Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted). Example 3 comb 5 is: 0 1 2 0 1 3 0 1 4 0 2 3 0 2 4 0 3 4 1 2 3 1 2 4 1 3 4 2 3 4 ...	#PowerShell	PowerShell	$source = @' using System; using System.Collections.Generic; namespace Powershell { public class CSharp { public static IEnumerable<int[]> Combinations(int m, int n) { int[] result = new int[m]; Stack<int> stack = new Stack<int>...	Give a code snippet in #PowerShell Task Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted). Example 3 comb 5 is: 0 1 2 0 1 3 0 1 4 0 2 3 ...	christopher/rosetta-code
http://rosettacode.org/wiki/FASTA_format	FASTA format	In bioinformatics, long character strings are often encoded in a format called FASTA. A FASTA file can contain several strings, each identified by a name marked by a > (greater than) character at the beginning of the line. Task Write a program that reads a FASTA file such as: >Rosetta_Example_1 THERECANBENOSPACE ...	#Wren	Wren	import "io" for File var checkNoSpaces = Fn.new { \|s\| !s.contains(" ") && !s.contains("\t") } var first = true var process = Fn.new { \|line\| if (line[0] == ">") { if (!first) System.print() System.write("%(line[1..-1]): ") if (first) first = false } else if (first) { Fiber....	Give a code snippet in #Wren In bioinformatics, long character strings are often encoded in a format called FASTA. A FASTA file can contain several strings, each identified by a name marked by a > (greater than) character at the beginning of the line. Task Write a program that reads a FASTA file such as: >Rosett...	christopher/rosetta-code
http://rosettacode.org/wiki/Shell_one-liner	Shell one-liner	Task Show how to specify and execute a short program in the language from a command shell, where the input to the command shell is only one line in length. Avoid depending on the particular shell or operating system used as much as is reasonable; if the language has notable implementations which have different comman...	#R	R	$ echo 'cat("Hello\n")' \| R --slave Hello	Give a code snippet in #R Task Show how to specify and execute a short program in the language from a command shell, where the input to the command shell is only one line in length. Avoid depending on the particular shell or operating system used as much as is reasonable; if the language has notable implementations ...	christopher/rosetta-code
http://rosettacode.org/wiki/Rep-string	Rep-string	Given a series of ones and zeroes in a string, define a repeated string or rep-string as a string which is created by repeating a substring of the first N characters of the string truncated on the right to the length of the input string, and in which the substring appears repeated at least twice in the original. For e...	#ALGOL_68	ALGOL 68	# procedure to find the longest rep-string in a given string # # the input string is not validated to contain only "0" and "1" characters # PROC longest rep string = ( STRING input )STRING: BEGIN STRING result := ""; # ensure the string we are working on has a lower-bound of 1 ...	Give a code snippet in #ALGOL_68 Given a series of ones and zeroes in a string, define a repeated string or rep-string as a string which is created by repeating a substring of the first N characters of the string truncated on the right to the length of the input string, and in which the substring appears repeated at l...	christopher/rosetta-code
http://rosettacode.org/wiki/Babbage_problem	Babbage problem	Charles Babbage, looking ahead to the sorts of problems his Analytical Engine would be able to solve, gave this example: What is the smallest positive integer whose square ends in the digits 269,696? — Babbage, letter to Lord Bowden, 1837; see Hollingdale and Tootill, Electronic Computers, second edition, 1970, p....	#F.C5.8Drmul.C3.A6	Fōrmulæ	Public Sub Main() Dim iNum As Long For iNum = 1 To 100000 If Str(iNum * iNum) Ends "269696" Then Break Next Print "The lowest number squared that ends in '269696' is " & Str(iNum) End	Give a code snippet in #F.C5.8Drmul.C3.A6 Charles Babbage, looking ahead to the sorts of problems his Analytical Engine would be able to solve, gave this example: What is the smallest positive integer whose square ends in the digits 269,696? — Babbage, letter to Lord Bowden, 1837; see Hollingdale and Tootill, Ele...	christopher/rosetta-code
http://rosettacode.org/wiki/XML/XPath	XML/XPath	Perform the following three XPath queries on the XML Document below: //item[1]: Retrieve the first "item" element //price/text(): Perform an action on each "price" element (print it out) //name: Get an array of all the "name" elements XML Document: <inventory title="OmniCorp Store #45x10^3"> <section name="heal...	#C.2B.2B	C++	#include <cassert> #include <cstdlib> #include <iostream> #include <stdexcept> #include <utility> #include <vector> #include <libxml/parser.h> #include <libxml/tree.h> #include <libxml/xmlerror.h> #include <libxml/xmlstring.h> #include <libxml/xmlversion.h> #include <libxml/xpath.h> #ifndef LIBXML_XPATH_ENABLED # ...	Give a code snippet in #C.2B.2B Perform the following three XPath queries on the XML Document below: //item[1]: Retrieve the first "item" element //price/text(): Perform an action on each "price" element (print it out) //name: Get an array of all the "name" elements XML Document: <inventory title="OmniCorp Store...	christopher/rosetta-code
http://rosettacode.org/wiki/Increment_a_numerical_string	Increment a numerical string	Task Increment a numerical string.	#F.23	F#	let next = string( int( "1234" ) + 1 )	Give a code snippet in #F.23 Task Increment a numerical string.	christopher/rosetta-code
http://rosettacode.org/wiki/Web_scraping	Web scraping	Task Create a program that downloads the time from this URL: http://tycho.usno.navy.mil/cgi-bin/timer.pl and then prints the current UTC time by extracting just the UTC time from the web page's HTML. Alternatively, if the above url is not working, grab the first date/time off this page's talk page. If possible,...	#Common_Lisp	Common Lisp	BOA> (let* ((url "http://tycho.usno.navy.mil/cgi-bin/timer.pl") (regexp (load-time-value (cl-ppcre:create-scanner "(?m)^.{4}(.+? UTC)"))) (data (drakma:http-request url))) (multiple-value-bind (start end start-regs end-regs) (cl-ppcre:scan regexp data) ...	Give a code snippet in #Common_Lisp Task Create a program that downloads the time from this URL: http://tycho.usno.navy.mil/cgi-bin/timer.pl and then prints the current UTC time by extracting just the UTC time from the web page's HTML. Alternatively, if the above url is not working, grab the first date/time off t...	christopher/rosetta-code

http://rosettacode.org/wiki/Brownian_tree

Brownian tree

Brownian tree You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw a Brownian Tree. A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes. The initial "seed" is placed somewhere wi...

#Action.21

Action!

BYTE FUNC CheckNeighbors(CARD x BYTE y) IF Locate(x-1,y-1)=1 THEN RETURN (1) FI IF Locate(x,y-1)=1 THEN RETURN (1) FI IF Locate(x+1,y-1)=1 THEN RETURN (1) FI IF Locate(x-1,y)=1 THEN RETURN (1) FI IF Locate(x+1,y)=1 THEN RETURN (1) FI IF Locate(x-1,y+1)=1 THEN RETURN (1) FI IF Locate(x,y+1)=1 THEN RETURN (...

Give a code snippet in #Action.21 Brownian tree You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw a Brownian Tree. A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes. The in...

christopher/rosetta-code

http://rosettacode.org/wiki/Fraction_reduction

Fraction reduction

There is a fine line between numerator and denominator. ─── anonymous A method to "reduce" some reducible fractions is to cross out a digit from the numerator and the denominator. An example is: 16 16 ──── and then (simp...

#Raku

Raku

my %reduced; my $digits = 2..4; for $digits.map: * - 1 -> $exp { my $start = sum (0..$exp).map( { 10 ** $_ * ($exp - $_ + 1) }); my $end = 10**($exp+1) - sum (^$exp).map( { 10 ** $_ * ($exp - $_) } ) - 1; ($start ..^ $end).race(:8degree, :3batch).map: -> $den { next if $den.contains: '0'; ...

Give a code snippet in #Raku There is a fine line between numerator and denominator. ─── anonymous A method to "reduce" some reducible fractions is to cross out a digit from the numerator and the denominator. An example is: 16 16...

christopher/rosetta-code

http://rosettacode.org/wiki/JSON

JSON

Load a JSON string into a data structure. Also, create a new data structure and serialize it into JSON. Use objects and arrays (as appropriate for your language) and make sure your JSON is valid (https://jsonformatter.org).

#Crystal

Crystal

require "json_mapping" class Foo JSON.mapping( num: Int64, array: Array(String), ) end def json foo = Foo.from_json(%({"num": 1, "array": ["a", "b"]})) puts("#{foo.num} #{foo.array}") puts(foo.to_json) end

Give a code snippet in #Crystal Load a JSON string into a data structure. Also, create a new data structure and serialize it into JSON. Use objects and arrays (as appropriate for your language) and make sure your JSON is valid (https://jsonformatter.org).

christopher/rosetta-code

http://rosettacode.org/wiki/Last_Friday_of_each_month

Last Friday of each month

Task Write a program or a script that returns the date of the last Fridays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc). Example of an expected output: ./last_fridays 2012 2012-01-27 2012-02-24 2012-03-30 2012-04-27 2012-05-25 20...

#Delphi

Delphi

program LastFridayOfMonth; {$APPTYPE CONSOLE} uses System.SysUtils, System.DateUtils; var Year: Word; Month: Word; D1: TDateTime; D2: Word; begin Write('Enter year: '); ReadLn(Year); for Month := MonthJanuary to MonthDecember do begin D1 := EndOfAMonth(Year, Month); D2 := DayOfTheWeek(...

Give a code snippet in #Delphi Task Write a program or a script that returns the date of the last Fridays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc). Example of an expected output: ./last_fridays 2012 2012-01-27 2012-02-24 201...

christopher/rosetta-code

http://rosettacode.org/wiki/Find_largest_left_truncatable_prime_in_a_given_base

Find largest left truncatable prime in a given base

A truncatable prime is one where all non-empty substrings that finish at the end of the number (right-substrings) are also primes when understood as numbers in a particular base. The largest such prime in a given (integer) base is therefore computable, provided the base is larger than 2. Let's consider what happens in...

#Scala

Scala

import scala.collection.parallel.immutable.ParSeq object LeftTruncatablePrime extends App { private def leftTruncatablePrime(maxRadix: Int, millerRabinCertainty: Int) { def getLargestLeftTruncatablePrime(radix: Int, millerRabinCertainty: Int): BigInt = { def getNextLeftTruncatablePrimes(n: BigInt, radix: ...

Give a code snippet in #Scala A truncatable prime is one where all non-empty substrings that finish at the end of the number (right-substrings) are also primes when understood as numbers in a particular base. The largest such prime in a given (integer) base is therefore computable, provided the base is larger than 2. ...

christopher/rosetta-code

http://rosettacode.org/wiki/Find_palindromic_numbers_in_both_binary_and_ternary_bases

Find palindromic numbers in both binary and ternary bases

Find palindromic numbers in both binary and ternary bases You are encouraged to solve this task according to the task description, using any language you may know. Task Find and show (in decimal) the first six numbers (non-negative integers) that are palindromes in both: base 2 base 3 Display 0 ...

#Ada

Ada

with Ada.Text_IO, Base_Conversion; procedure Brute is type Long is range 0 .. 2**63-1; package BC is new Base_Conversion(Long); function Palindrome (S : String) return Boolean is (if S'Length < 2 then True elsif S(S'First) /= S(S'Last) then False else Palindrome(S(S'First+1 .. S'Last-1)...

Give a code snippet in #Ada Find palindromic numbers in both binary and ternary bases You are encouraged to solve this task according to the task description, using any language you may know. Task Find and show (in decimal) the first six numbers (non-negative integers) that are palindromes in both: base ...

christopher/rosetta-code

http://rosettacode.org/wiki/9_billion_names_of_God_the_integer

9 billion names of God the integer

This task is a variation of the short story by Arthur C. Clarke. (Solvers should be aware of the consequences of completing this task.) In detail, to specify what is meant by a “name”: The integer 1 has 1 name “1”. The integer 2 has 2 names “1+1”, and “2”. The integer 3 has 3 names “1+1+1”, “2+1”, ...

#AutoHotkey

AutoHotkey

SetBatchLines -1 InputBox, Enter_value, Enter the no. of lines sought array := [] Loop, % 2*Enter_value - 1 Loop, % x := A_Index y := A_Index, Array[x, y] := 1 x := 3 Loop { base_r := x - 1 , x++ , y := 2 , index := x , new := 1 Loop, % base_r - 1 { array[x, new+1] := array[x-1, new] + array[base_r,...

Give a code snippet in #AutoHotkey This task is a variation of the short story by Arthur C. Clarke. (Solvers should be aware of the consequences of completing this task.) In detail, to specify what is meant by a “name”: The integer 1 has 1 name “1”. The integer 2 has 2 names “1+1”, and “2”. The integer ...

christopher/rosetta-code

http://rosettacode.org/wiki/Grayscale_image

Grayscale image

Many image processing algorithms are defined for grayscale (or else monochromatic) images. Task Extend the data storage type defined on this page to support grayscale images. Define two operations, one to convert a color image to a grayscale image and one for the backward conversion. To get luminance of a color u...

#Visual_Basic_.NET

Visual Basic .NET

Imports System.Drawing.Imaging Public Function Grayscale(ByVal Map As Bitmap) As Bitmap Dim oData() As Integer = GetData(Map) Dim oReturn As New Bitmap(Map.Width, Map.Height, Map.PixelFormat) Dim a As Integer = 0 Dim r As Integer = 0 Dim g As Integer = 0 Dim b As Integer = 0 Dim l As...

Give a code snippet in #Visual_Basic_.NET Many image processing algorithms are defined for grayscale (or else monochromatic) images. Task Extend the data storage type defined on this page to support grayscale images. Define two operations, one to convert a color image to a grayscale image and one for the backward...

christopher/rosetta-code

http://rosettacode.org/wiki/Identity_matrix

Identity matrix

Task Build an identity matrix of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 0 1 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ...

#Eiffel

Eiffel

class APPLICATION inherit ARGUMENTS create make feature {NONE} -- Initialization make -- Run application. local dim : INTEGER -- Dimension of the identity matrix do from dim := 1 until dim > 10 loop print_matrix( identity_matrix(dim) ) dim := dim + 1 io.new_line end ...

Give a code snippet in #Eiffel Task Build an identity matrix of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 ...

christopher/rosetta-code

http://rosettacode.org/wiki/Simple_turtle_graphics

Simple turtle graphics

The first turtle graphic discussed in Mindstorms: Children, Computers, and Powerful Ideas by Seymour Papert is a simple drawing of a house. It is a square with a triangle on top for the roof. For a slightly more advanced audience, a more practical introduction to turtle graphics might be to draw a bar chart. See imag...

#Yabasic

Yabasic

// Rosetta Code problem: http://rosettacode.org/wiki/Simple_turtle_graphics // Adapted from Python to Yabasic by Galileo, 01/2022 import turtle sub rectang(width, height) local i for i = 1 to 2 move(height) turn(-90) move(width) turn(-90) next end sub sub square(size)...

Give a code snippet in #Yabasic The first turtle graphic discussed in Mindstorms: Children, Computers, and Powerful Ideas by Seymour Papert is a simple drawing of a house. It is a square with a triangle on top for the roof. For a slightly more advanced audience, a more practical introduction to turtle graphics might ...

christopher/rosetta-code

http://rosettacode.org/wiki/Power_set

Power set

A set is a collection (container) of certain values, without any particular order, and no repeated values. It corresponds with a finite set in mathematics. A set can be implemented as an associative array (partial mapping) in which the value of each key-value pair is ignored. Given a set S, the power set (or pow...

#Scheme

Scheme

(define (power-set set) (if (null? set) '(()) (let ((rest (power-set (cdr set)))) (append (map (lambda (element) (cons (car set) element)) rest) rest)))) (display (power-set (list 1 2 3))) (newline) (display (power-set (list "A" "C" "E"))) (newline)

Give a code snippet in #Scheme A set is a collection (container) of certain values, without any particular order, and no repeated values. It corresponds with a finite set in mathematics. A set can be implemented as an associative array (partial mapping) in which the value of each key-value pair is ignored. Give...

christopher/rosetta-code

http://rosettacode.org/wiki/Identity_matrix

Identity matrix

Task Build an identity matrix of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 0 1 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ...

#PL.2FI

PL/I

identity: procedure (A, n); declare A(n,n) fixed controlled; declare (i,n) fixed binary; allocate A; A = 0; do i = 1 to n; A(i,i) = 1; end; end identity;

Give a code snippet in #PL.2FI Task Build an identity matrix of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 ...

christopher/rosetta-code

http://rosettacode.org/wiki/Averages/Arithmetic_mean

Averages/Arithmetic mean

Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin...

#Mathprog

Mathprog

/*Arithmetic Mean of a large number of Integers - or - solve a very large constraint matrix over 1 million rows and columns Nigel_Galloway March 18th., 2008. */ param e := 20; set Sample := {1..2**e-1}; var Mean; var E{z in Sample}; /* sum of variances is zero */ zumVariance: sum{z in Sample} E[z...

Give a code snippet in #Mathprog Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an e...

christopher/rosetta-code

http://rosettacode.org/wiki/Sum_of_squares

Sum of squares

Task Write a program to find the sum of squares of a numeric vector. The program should work on a zero-length vector (with an answer of 0). Related task Mean

#Tailspin

Tailspin

templates ssq when <[](0)> do 0 ! otherwise $... -> $*$ -> ..=Sum&{of: :()} ! end ssq [] -> ssq -> !OUT::write // outputs 0 [1..5] -> ssq -> !OUT::write // outputs 55

Give a code snippet in #Tailspin Task Write a program to find the sum of squares of a numeric vector. The program should work on a zero-length vector (with an answer of 0). Related task Mean

christopher/rosetta-code

http://rosettacode.org/wiki/Collections

Collections

This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Collections are abstractions to represent sets of values. In statically-typed languages, the values are typically of a common data type. Task Create a collection, and add a fe...

#REXX

REXX

pr. = /*define a default for all elements for the array*/ pr.1 = 2 /*note that this array starts at 1 (one). */ pr.2 = 3 pr.3 = 5 pr.4 = 7 pr.5 = 11 pr.6 = 13 pr.7 = 17 pr.8 = 19 pr.9 = 23 pr.10 = 29 pr.11 = 31 pr.12 = 37 pr.13 = 41 pr.14 = 43 pr.15 ...

Give a code snippet in #REXX This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Collections are abstractions to represent sets of values. In statically-typed languages, the values are typically of a common data type. Task Cre...

christopher/rosetta-code

http://rosettacode.org/wiki/Map_range

Map range

Given two ranges: [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]} and [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ; then a value s {\displaystyle s} in range [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]} is linearly mapped to a value t {\di...

#GDScript

GDScript

func mapRange(s:float, a1:float, a2:float, b1:float, b2:float) -> float : return b1 + ((b2-b1)/(a2-a1))*(s-a1) for i in 11 : print( "%2d %+.1f" % [i,mapRange(i,0.0,10.0,-1.0,0.0)] )

Give a code snippet in #GDScript Given two ranges: [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]} and [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ; then a value s {\displaystyle s} in range [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]} is linearl...

christopher/rosetta-code

http://rosettacode.org/wiki/Anonymous_recursion

Anonymous recursion

While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion. This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the f...

#LOLCODE

LOLCODE

HAI 1.3 HOW IZ I fib YR x DIFFRINT x AN BIGGR OF x AN 0, O RLY? YA RLY, FOUND YR "ERROR" OIC HOW IZ I fib_i YR n DIFFRINT n AN BIGGR OF n AN 2, O RLY? YA RLY, FOUND YR n OIC FOUND YR SUM OF... I IZ fib_i YR DIFF OF n AN 2 MKAY AN... I IZ fib_...

Give a code snippet in #LOLCODE While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion. This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwa...

christopher/rosetta-code

http://rosettacode.org/wiki/Create_an_HTML_table

Create an HTML table

Create an HTML table. The table body should have at least three rows of three columns. Each of these three columns should be labelled "X", "Y", and "Z". An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled with sequential row numbers. The...

#Julia

Julia

function tag(x::Pair, attr::Pair...) t, b = x attrstr = join(" $n=\"$p\"" for (n, p) in attr) return "<$t$attrstr>$b</$t>" end colnames = split(",X,Y,Z", ',') header = join(tag(:th => txt) for txt in colnames) * "\n" rows = collect(tag(:tr => join(tag(:td => i, :style => "font-weight: bold;") * join(t...

Give a code snippet in #Julia Create an HTML table. The table body should have at least three rows of three columns. Each of these three columns should be labelled "X", "Y", and "Z". An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled wit...

christopher/rosetta-code

http://rosettacode.org/wiki/File_input/output

File input/output

File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable. In other words, your program will demonstrate: how to read from a file into a variable how to write ...

#mIRC_Scripting_Language

mIRC Scripting Language

alias Write2FileAndReadIt { .write myfilename.txt Goodbye Mike! .echo -a Myfilename.txt contains: $read(myfilename.txt,1) }

Give a code snippet in #mIRC_Scripting_Language File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable. In other words, your program will demonstrate: how to ...

christopher/rosetta-code

http://rosettacode.org/wiki/Primes_-_allocate_descendants_to_their_ancestors

Primes - allocate descendants to their ancestors

The concept, is to add the decomposition into prime factors of a number to get its 'ancestors'. The objective is to demonstrate that the choice of the algorithm can be crucial in term of performance. This solution could be compared to the solution that would use the decomposition into primes for all the numbers betw...

#C.2B.2B

C++

#include <algorithm> #include <iostream> #include <vector> typedef unsigned long long integer; // returns all ancestors of n. n is not its own ancestor. std::vector<integer> get_ancestors(const std::vector<integer>& ancestor, integer n) { std::vector<integer> result; for (integer a = ancestor[n]; a != 0 && ...

Give a code snippet in #C.2B.2B The concept, is to add the decomposition into prime factors of a number to get its 'ancestors'. The objective is to demonstrate that the choice of the algorithm can be crucial in term of performance. This solution could be compared to the solution that would use the decomposition int...

christopher/rosetta-code

http://rosettacode.org/wiki/Knuth_shuffle

Knuth shuffle

The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array. Task Implement the Knuth shuffle for an integer array (or, if possible, an array of any type). Specification Given an array items with indices ranging from 0 to last, the algorithm can be d...

#Nemerle

Nemerle

Shuffle[T] (arr : array[T]) : array[T] { def rnd = Random(); foreach (i in [0 .. (arr.Length - 2)]) arr[i] <-> arr[(rnd.Next(i, arr.Length))]; arr }

Give a code snippet in #Nemerle The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array. Task Implement the Knuth shuffle for an integer array (or, if possible, an array of any type). Specification Given an array items with indices ranging from ...

christopher/rosetta-code

http://rosettacode.org/wiki/Isqrt_(integer_square_root)_of_X

Isqrt (integer square root) of X

Sometimes a function is needed to find the integer square root of X, where X can be a real non─negative number. Often X is actually a non─negative integer. For the purposes of this task, X can be an integer or a real number, but if it simplifies things in your computer programming language, assume...

#Phix

Phix

with javascript_semantics include mpfr.e function isqrt(mpz x) if mpz_cmp_si(x,0)<0 then crash("Argument cannot be negative.") end if mpz q = mpz_init(1), r = mpz_init(0), t = mpz_init(), z = mpz_init_set(x) while mpz_cmp(q,x)<= 0 do mpz_mul_si(q,q,4) end wh...

Give a code snippet in #Phix Sometimes a function is needed to find the integer square root of X, where X can be a real non─negative number. Often X is actually a non─negative integer. For the purposes of this task, X can be an integer or a real number, but if it simplifies things in your computer ...

christopher/rosetta-code

http://rosettacode.org/wiki/Least_common_multiple

Least common multiple

Least common multiple You are encouraged to solve this task according to the task description, using any language you may know. Task Compute the least common multiple (LCM) of two integers. Given m and n, the least common multiple is the smallest positive integer that has both m and n as factor...

#Ring

Ring

see lcm(24,36) func lcm m,n lcm = m*n / gcd(m,n) return lcm func gcd gcd, b while b c = gcd gcd = b b = c % b end return gcd

Give a code snippet in #Ring Least common multiple You are encouraged to solve this task according to the task description, using any language you may know. Task Compute the least common multiple (LCM) of two integers. Given m and n, the least common multiple is the smallest positive integer that has ...

christopher/rosetta-code

http://rosettacode.org/wiki/Old_lady_swallowed_a_fly

Old lady swallowed a fly

Task Present a program which emits the lyrics to the song I Knew an Old Lady Who Swallowed a Fly, taking advantage of the repetitive structure of the song's lyrics. This song has multiple versions with slightly different lyrics, so all these programs might not emit identical output. Other tasks related to st...

#PL.2FM

PL/M

100H: /* CP/M CALL */ BDOS: PROCEDURE(FUNC, ARGS); DECLARE FUNC BYTE, ARGS ADDRESS; GO TO 5; END BDOS; /* PRINT STRING */ PRINT: PROCEDURE(STRING); DECLARE STRING ADDRESS; CALL BDOS(9, STRING); END PRINT; DECLARE COMMA$CRLF DATA (',',13,10,'$'); DECLARE CRLF DATA (13,10,'$'); DECLARE ANIMALS (8)...

Give a code snippet in #PL.2FM Task Present a program which emits the lyrics to the song I Knew an Old Lady Who Swallowed a Fly, taking advantage of the repetitive structure of the song's lyrics. This song has multiple versions with slightly different lyrics, so all these programs might not emit identical outpu...

christopher/rosetta-code

http://rosettacode.org/wiki/Pernicious_numbers

Pernicious numbers

A pernicious number is a positive integer whose population count is a prime. The population count is the number of ones in the binary representation of a non-negative integer. Example 22 (which is 10110 in binary) has a population count of 3, which is prime, and therefore 22 is a pe...

#AWK

AWK

# syntax: GAWK -f PERNICIOUS_NUMBERS.AWK BEGIN { pernicious(25) pernicious(888888877,888888888) exit(0) } function pernicious(x,y, count,n) { if (y == "") { # print first X pernicious numbers while (count < x) { if (is_prime(pop_count(++n)) == 1) { printf("%d ",n) co...

Give a code snippet in #AWK A pernicious number is a positive integer whose population count is a prime. The population count is the number of ones in the binary representation of a non-negative integer. Example 22 (which is 10110 in binary) has a population count of 3, which is prime, ...

christopher/rosetta-code

http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters

Determine if a string has all the same characters

Task Given a character string (which may be empty, or have a length of zero characters): create a function/procedure/routine to: determine if all the characters in the string are the same indicate if or which character is different from the previous character display each string and its length (as the...

#Clojure

Clojure

(defn check-all-chars-same [s] (println (format "String (%s) of len: %d" s (count s))) (let [num-same (-> (take-while #(= (first s) %) s) count)] (if (= num-same (count s)) (println "...all characters the same") (println (format "...character %d differs - it is 0x%x" ...

Give a code snippet in #Clojure Task Given a character string (which may be empty, or have a length of zero characters): create a function/procedure/routine to: determine if all the characters in the string are the same indicate if or which character is different from the previous character display eac...

christopher/rosetta-code

http://rosettacode.org/wiki/Faulhaber%27s_formula

Faulhaber's formula

In mathematics, Faulhaber's formula, named after Johann Faulhaber, expresses the sum of the p-th powers of the first n positive integers as a (p + 1)th-degree polynomial function of n, the coefficients involving Bernoulli numbers. Task Generate the first 10 closed-form expressions, starting with p = 0. R...

#F.C5.8Drmul.C3.A6

Fōrmulæ

n := X(Rationals, "n"); sum1 := p -> Sum([0 .. p], k -> Stirling2(p, k) * Product([0 .. k], j -> n + 1 - j) / (k + 1)) + 2 * Bernoulli(2 * p + 1); sum2 := p -> Sum([0 .. p], j -> (-1)^j * Binomial(p + 1, j) * Bernoulli(j) * n^(p + 1 - j)) / (p + 1); ForAll([0 .. 20], k -> sum1(k) = sum2(k)); for p in [0 .. 9] do ...

Give a code snippet in #F.C5.8Drmul.C3.A6 In mathematics, Faulhaber's formula, named after Johann Faulhaber, expresses the sum of the p-th powers of the first n positive integers as a (p + 1)th-degree polynomial function of n, the coefficients involving Bernoulli numbers. Task Generate the first 10 closed-...

christopher/rosetta-code

http://rosettacode.org/wiki/Pangram_checker

Pangram checker

Pangram checker You are encouraged to solve this task according to the task description, using any language you may know. A pangram is a sentence that contains all the letters of the English alphabet at least once. For example: The quick brown fox jumps over the lazy dog. Task Write a function or method to chec...

#Erlang

Erlang

-module(pangram). -export([is_pangram/1]). is_pangram(String) -> ordsets:is_subset(lists:seq($a, $z), ordsets:from_list(string:to_lower(String))).

Give a code snippet in #Erlang Pangram checker You are encouraged to solve this task according to the task description, using any language you may know. A pangram is a sentence that contains all the letters of the English alphabet at least once. For example: The quick brown fox jumps over the lazy dog. Task Wr...

christopher/rosetta-code

http://rosettacode.org/wiki/Sierpinski_triangle

Sierpinski triangle

Task Produce an ASCII representation of a Sierpinski triangle of order N. Example The Sierpinski triangle of order 4 should look like this: * * * * * * * * * * * * * * * ...

#Delphi

Delphi

program SierpinskiTriangle; {$APPTYPE CONSOLE} procedure PrintSierpinski(order: Integer); var x, y, size: Integer; begin size := (1 shl order) - 1; for y := size downto 0 do begin Write(StringOfChar(' ', y)); for x := 0 to size - y do begin if (x and y) = 0 then Write('* ') e...

Give a code snippet in #Delphi Task Produce an ASCII representation of a Sierpinski triangle of order N. Example The Sierpinski triangle of order 4 should look like this: * * * * * * * * * * * ...

christopher/rosetta-code

http://rosettacode.org/wiki/A%2BB

A+B

A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used. Task Given two integers, A and B. Their sum needs to be calculated. Input data Two integers are written in the input stream, separated by space(s): ( − 1000 ≤...

#Gosu

Gosu

uses java.io.InputStreamReader uses java.util.Scanner uses java.lang.System var scanner = new Scanner( new InputStreamReader( System.in ) ) var a = scanner.nextInt() var b = scanner.nextInt() print( a + b )

Give a code snippet in #Gosu A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used. Task Given two integers, A and B. Their sum needs to be calculated. Input data Two integers are written in the input stream, separated...

christopher/rosetta-code

http://rosettacode.org/wiki/Recaman%27s_sequence

Recaman's sequence

The Recamán's sequence generates Natural numbers. Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated. If the conditions don't hold then a(n) = a(n-1) + n. Task Generate and show here the...

#Forth

Forth

: array ( n -- ) ( i -- addr) create cells allot does> swap cells + ; 100 array sequence : sequence. ( n -- ) cr 0 ?do i sequence @ . loop ; : ?unused ( n -- t | n ) 100 0 ?do dup i sequence @ = if unloop exit then loop drop true ; : sequence-next ( n -- a[n] ) dup 0= if 0 0 sequence ! exit then ...

Give a code snippet in #Forth The Recamán's sequence generates Natural numbers. Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated. If the conditions don't hold then a(n) = a(n-1) + n. Ta...

christopher/rosetta-code

http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation

Permutations/Rank of a permutation

A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items. For our purposes the ranking will assign integers 0.. ( n ! − 1 ) {\displaystyle 0..(n!-1)} to an ordering of all the permutations of the integers 0.. ( n − 1 ) {\disp...

#D

D

import std.stdio, std.algorithm, std.range; alias TRank = ulong; TRank factorial(in uint n) pure nothrow { TRank result = 1; foreach (immutable i; 2 .. n + 1) result *= i; return result; } /// Fill the integer array <vec> with the permutation at rank <rank>. void computePermutation(size_t N)(r...

Give a code snippet in #D A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items. For our purposes the ranking will assign integers 0.. ( n ! − 1 ) {\displaystyle 0..(n!-1)} to an ordering of all the permutations of the integers...

christopher/rosetta-code

http://rosettacode.org/wiki/Averages/Arithmetic_mean

Averages/Arithmetic mean

Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin...

#C.23

C#

using System; using System.Linq; class Program { static void Main() { Console.WriteLine(new[] { 1, 2, 3 }.Average()); } }

Give a code snippet in #C.23 Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an estab...

christopher/rosetta-code

http://rosettacode.org/wiki/Longest_string_challenge

Longest string challenge

Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through th...

#Phix

Phix

with javascript_semantics --integer fn = open(command_line()[2],"r") -- (reading the source file) sequence fn = unix_dict()[1..40]&-1 function allx(string line) line[1..-1] = 'x' return line end function function longest(string mask) -- object line = gets(fn) object line = fn[1]; fn = fn[2..$]; if ...

Give a code snippet in #Phix Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challeng...

christopher/rosetta-code

http://rosettacode.org/wiki/Sum_of_a_series

Sum of a series

Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence. Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task. For this task, use: S n = ∑ k = 1 n 1 k 2 {\displa...

#WDTE

WDTE

let s => import 'stream'; s.range 1 1001 -> s.map (@ inner k => / 1 (* k k)) -> s.reduce 0 + -- io.writeln io.stdout ;

Give a code snippet in #WDTE Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence. Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task. For this task, use: S n = ∑ k = 1 ...

christopher/rosetta-code

http://rosettacode.org/wiki/Optional_parameters

Optional parameters

Task Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters: ordering A function specifying the ordering of strings; lexicographic by default. column ...

#Mathematica.2FWolfram_Language

Mathematica/Wolfram Language

Options[OptionalSort]={ordering->lexicographic,column->1,reverse-> False}; OptionalSort[x_List,OptionsPattern[]]:=If[OptionValue[reverse]==True, SortBy[x ,#[[OptionValue[column]]]&]//Reverse, SortBy[x,#[[OptionValue[column]]]&] ] OptionalSort[{{"a" ,"b", "c"}, {"", "q", "z"},{"zap" ,"zip", "Zot"}} ] ->{{,q,z},{a,b,c}...

Give a code snippet in #Mathematica.2FWolfram_Language Task Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters: ordering A function specifying the...

christopher/rosetta-code

http://rosettacode.org/wiki/Comments

Comments

Task Show all ways to include text in a language source file that's completely ignored by the compiler or interpreter. Related tasks Documentation Here_document See also Wikipedia xkcd (Humor: hand gesture denoting // for "commenting out" people.)

#PHP

PHP

# this is commented // this is commented

Give a code snippet in #PHP Task Show all ways to include text in a language source file that's completely ignored by the compiler or interpreter. Related tasks Documentation Here_document See also Wikipedia xkcd (Humor: hand gesture denoting // for "commenting out" people.)

christopher/rosetta-code

http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas

The Twelve Days of Christmas

Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) Other tasks related to string operations: Metrics Array length Stri...

#Run_BASIC

Run BASIC

gifts$ = " A partridge in a pear tree., Two turtle doves, Three french hens, Four calling birds, Five golden rings, Six geese a-laying, Seven swans a-swimming, Eight maids a-milking, Nine ladies dancing, Ten lords a-leaping, Eleven pipers piping, Twelve drummers drumming" days$ = "first second third fourth fifth sixt...

Give a code snippet in #Run_BASIC Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) Other tasks related to string opera...

christopher/rosetta-code

http://rosettacode.org/wiki/Amb

Amb

Define and give an example of the Amb operator. The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"). The Amb operator takes a v...

#Perl

Perl

use strict; use warnings; use constant EXIT_FAILURE => 1; use constant EXIT_SUCCESS => 0; sub amb { exit(EXIT_FAILURE) if !@_; for my $word (@_) { my $pid = fork; die $! unless defined $pid; return $word if !$pid; my $wpid = waitpid $pid, 0; die $! unless $wpid == $pid; exi...

Give a code snippet in #Perl Define and give an example of the Amb operator. The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"...

christopher/rosetta-code

http://rosettacode.org/wiki/ABC_problem

ABC problem

ABC problem You are encouraged to solve this task according to the task description, using any language you may know. You are given a collection of ABC blocks (maybe like the ones you had when you were a kid). There are twenty blocks with two letters on each block. A complete alphabet is guaranteed amongst all sid...

#360_Assembly

360 Assembly

* ABC Problem 21/07/2016 ABC CSECT USING ABC,R13 base register B 72(R15) skip savearea DC 17F'0' savearea STM R14,R12,12(R13) prolog ST R13,4(R15) " <- ST R15,8(R13) ...

Give a code snippet in #360_Assembly ABC problem You are encouraged to solve this task according to the task description, using any language you may know. You are given a collection of ABC blocks (maybe like the ones you had when you were a kid). There are twenty blocks with two letters on each block. A complete ...

christopher/rosetta-code

http://rosettacode.org/wiki/Nth_root

Nth root

Task Implement the algorithm to compute the principal nth root A n {\displaystyle {\sqrt[{n}]{A}}} of a positive real number A, as explained at the Wikipedia page.

#Swift

Swift

extension FloatingPoint where Self: ExpressibleByFloatLiteral { @inlinable public func power(_ e: Int) -> Self { var res = Self(1) for _ in 0..<e { res *= self } return res } @inlinable public func root(n: Int, epsilon: Self = 2.220446049250313e-16) -> Self { var d = Self(0) ...

Give a code snippet in #Swift Task Implement the algorithm to compute the principal nth root A n {\displaystyle {\sqrt[{n}]{A}}} of a positive real number A, as explained at the Wikipedia page.

christopher/rosetta-code

http://rosettacode.org/wiki/Find_the_intersection_of_two_lines

Find the intersection of two lines

[1] Task Find the point of intersection of two lines in 2D. The 1st line passes though (4,0) and (6,10) . The 2nd line passes though (0,3) and (10,7) .

#XPL0

XPL0

func real Det; real A0, B0, A1, B1; return A0*B1 - A1*B0; func Cramer; real A0, B0, C0, A1, B1, C1; real Denom; [Denom:= Det(A0, B0, A1, B1); RlOut(0, Det(C0, B0, C1, B1) / Denom); RlOut(0, Det(A0, C0, A1, C1) / Denom); ]; real L0, L1, M0, M1; [L0:= [[ 4., 0.], [ 6., 10.]]; L1:= [[ 0., 3.], [10., 7.]]; M0:= (L0...

Give a code snippet in #XPL0 [1] Task Find the point of intersection of two lines in 2D. The 1st line passes though (4,0) and (6,10) . The 2nd line passes though (0,3) and (10,7) .

christopher/rosetta-code

http://rosettacode.org/wiki/Digital_root

Digital root

The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X} , repeating until X {\displ...

#PARI.2FGP

PARI/GP

dsum(n)=my(s); while(n, s+=n%10; n\=10); s additivePersistence(n)=my(s); while(n>9, s++; n=dsum(n)); s digitalRoot(n)=if(n, (n-1)%9+1, 0)

Give a code snippet in #PARI.2FGP The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X}...

christopher/rosetta-code

http://rosettacode.org/wiki/Abundant_odd_numbers

Abundant odd numbers

An Abundant number is a number n for which the sum of divisors σ(n) > 2n, or, equivalently, the sum of proper divisors (or aliquot sum) s(n) > n. E.G. 12 is abundant, it has the proper divisors 1,2,3,4 & 6 which sum to 16 ( > 12 or n); or alternately, has the sigma sum of ...

#q

q

s:{c where 0=x mod c:1+til x div 2} / proper divisors sd:sum s@ / sum of proper divisors abundant:{x<sd x} Filter:{y where x each y}

Give a code snippet in #q An Abundant number is a number n for which the sum of divisors σ(n) > 2n, or, equivalently, the sum of proper divisors (or aliquot sum) s(n) > n. E.G. 12 is abundant, it has the proper divisors 1,2,3,4 & 6 which sum to 16 ( > 12 or n); or alternate...

christopher/rosetta-code

http://rosettacode.org/wiki/Loops/Break

Loops/Break

Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never gener...

#dc

dc

1 ss [s = seed of the random number generator]sz 0k [scale = 0]sz [Function r: Push a random number from 0 to 20.]sz [ [2Q]SA [ [Formula (from POSIX) for random numbers of low quality.]sz ls 1103515245 * 12345 + 4294967296 % d ss [Compute next s]sz 65536 / [it = s / 65536]sz d 16 !>A [Break loop...

Give a code snippet in #dc Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If ...

christopher/rosetta-code

http://rosettacode.org/wiki/Averages/Arithmetic_mean

Averages/Arithmetic mean

Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin...

#NewLISP

NewLISP

(define (Mean Lst) (if (empty? Lst) 0 (/ (apply + Lst) (length Lst)))) (Mean (sequence 1 1000))-> 500 (Mean '()) -> 0

Give a code snippet in #NewLISP Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an es...

christopher/rosetta-code

http://rosettacode.org/wiki/Haversine_formula

Haversine formula

This page uses content from Wikipedia. The original article was at Haversine formula. 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) The haversine formula is an equation important in navigation, g...

#TechBASIC

TechBASIC

{{trans|BASIC}} FUNCTION HAVERSINE !--------------------------------------------------------------- !*** Haversine Formula - Calculate distances by LAT/LONG ! !*** LAT/LON of the two locations and Unit of measure are GLOBAL !*** as they are defined in the main logic of the program, so they !*** available for use in...

Give a code snippet in #TechBASIC This page uses content from Wikipedia. The original article was at Haversine formula. 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) The haversine formula is an ...

christopher/rosetta-code

http://rosettacode.org/wiki/Case-sensitivity_of_identifiers

Case-sensitivity of identifiers

Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output: The three dogs are named Benjamin, Samba and Bernie. For a language...

#dc

dc

[Benjamin]sd [Samba]sD [The two dogs are named ]P ldP [ and ]P lDP [. ]P

Give a code snippet in #dc Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output: The three dogs are named Benjamin, Samba...

christopher/rosetta-code

http://rosettacode.org/wiki/Non-decimal_radices/Convert

Non-decimal radices/Convert

Number base conversion is when you express a stored integer in an integer base, such as in octal (base 8) or binary (base 2). It also is involved when you take a string representing a number in a given base and convert it to the stored integer form. Normally, a stored integer is in binary, but that's typically invisibl...

#OCaml

OCaml

Give a code snippet in #OCaml Number base conversion is when you express a stored integer in an integer base, such as in octal (base 8) or binary (base 2). It also is involved when you take a string representing a number in a given base and convert it to the stored integer form. Normally, a stored integer is in binary...

christopher/rosetta-code

http://rosettacode.org/wiki/15_puzzle_game

15 puzzle game

Task Implement the Fifteen Puzzle Game. The 15-puzzle is also known as: Fifteen Puzzle Gem Puzzle Boss Puzzle Game of Fifteen Mystic Square 14-15 Puzzle and some others. Related Tasks 15 Puzzle Solver 16 Puzzle Game

#Visual_Prolog

Visual Prolog

/* ------------------------------------------------------------------------------------------------------ Copyright (c) 2004 - Gal Zsolt (CalmoSoft) ------------------------------------------------------------------------------------------------------ */ impleme...

Give a code snippet in #Visual_Prolog Task Implement the Fifteen Puzzle Game. The 15-puzzle is also known as: Fifteen Puzzle Gem Puzzle Boss Puzzle Game of Fifteen Mystic Square 14-15 Puzzle and some others. Related Tasks 15 Puzzle Solver 16 Puzzle Game

christopher/rosetta-code

http://rosettacode.org/wiki/Zig-zag_matrix

Zig-zag matrix

Task Produce a zig-zag array. A zig-zag array is a square arrangement of the first N2 natural numbers, where the numbers increase sequentially as you zig-zag along the array's anti-diagonals. For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images). For example, gi...

#Icon_and_Unicon

Icon and Unicon

procedure main(args) n := integer(!args) | 5 every !(A := list(n)) := list(n) A := zigzag(A) show(A) end procedure show(A) every writes(right(!A,5) | "\n") end procedure zigzag(A) x := [0,0] every i := 0 to (*A^2 -1) do { x := nextIndices(*A, x) A[x[1]][x[2]] := i } ...

Give a code snippet in #Icon_and_Unicon Task Produce a zig-zag array. A zig-zag array is a square arrangement of the first N2 natural numbers, where the numbers increase sequentially as you zig-zag along the array's anti-diagonals. For a graphical representation, see JPG zigzag (JPG uses such arr...

christopher/rosetta-code

http://rosettacode.org/wiki/Fibonacci_word

Fibonacci word

The Fibonacci Word may be created in a manner analogous to the Fibonacci Sequence as described here: Define F_Word1 as 1 Define F_Word2 as 0 Form F_Word3 as F_Word2 concatenated with F_Word1 i.e.: 01 Form F_Wordn as F_Wordn-1 concatenated with F_wordn-...

#Common_Lisp

Common Lisp

(defun make-fibwords (array) (loop for i from 0 below 37 for j = "0" then (concatenate 'string j k) and k = "1" then j do (setf (aref array i) k)) array) (defvar *fib* (make-fibwords (make-array 37))) (defun entropy (string) (let ((table (make-hash-table :test 'eql)) (entropy 0d0)...

Give a code snippet in #Common_Lisp The Fibonacci Word may be created in a manner analogous to the Fibonacci Sequence as described here: Define F_Word1 as 1 Define F_Word2 as 0 Form F_Word3 as F_Word2 concatenated with F_Word1 i.e.: 01 Form F_Wordn as F_W...

christopher/rosetta-code

http://rosettacode.org/wiki/Arrays

Arrays

This task is about arrays. For hashes or associative arrays, please see Creating an Associative Array. For a definition and in-depth discussion of what an array is, see Array. Task Show basic array syntax in your language. Basically, create an array, assign a value to it, and retrieve an element (if available,...

#Unicon_2

Unicon

L := list(100); L[12] := 7; a := array(100, 0.0); a[3] +:= a[1]+a[2]

Give a code snippet in #Unicon_2 This task is about arrays. For hashes or associative arrays, please see Creating an Associative Array. For a definition and in-depth discussion of what an array is, see Array. Task Show basic array syntax in your language. Basically, create an array, assign a value to it, and re...

christopher/rosetta-code

http://rosettacode.org/wiki/Roots_of_a_quadratic_function

Roots of a quadratic function

This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Write a program to find the roots of a quadratic equation, i.e., solve the equation a x 2 + b x + c = 0 {\displaystyle ax^{2}+bx+c=0} . Your program must correctly handle n...

#PicoLisp

PicoLisp

(scl 40) (de solveQuad (A B C) (let SD (sqrt (- (* B B) (* 4 A C))) (if (lt0 B) (list (*/ (- SD B) A 2.0) (*/ C 2.0 (*/ A A (- SD B) `(* 1.0 1.0))) ) (list (*/ C 2.0 (*/ A A (- 0 B SD) `(* 1.0 1.0))) (*/ (- 0 B SD) A 2.0) ) ) ) ) (mapcar rou...

Give a code snippet in #PicoLisp This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Write a program to find the roots of a quadratic equation, i.e., solve the equation a x 2 + b x + c = 0 {\displaystyle ax^{2}+bx+c=0} . Yo...

christopher/rosetta-code

http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers

Luhn test of credit card numbers

The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Tak...

#TI-83_BASIC

TI-83 BASIC

PROGRAM:LUHN :Disp "ENTER NUMBER" :Input Str1 :0→S :0→E :For(I,length(Str1),1,-1) :inString("0123456789",sub(Str1,I,1))–1→X :If X<0 :Goto BA :If E≠0 :Then :2X→X :If X>9 :X–9→X :End :X+S→S :not(E)→E :End :If fPart(S/10)=0 :Then :Disp "GOOD CARD" :Else :Lbl BA :Disp "BAD CARD" :End

Give a code snippet in #TI-83_BASIC The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the or...

christopher/rosetta-code

http://rosettacode.org/wiki/Sorting_algorithms/Merge_sort

Sorting algorithms/Merge 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 ...

#PARI.2FGP

PARI/GP

mergeSort(v)={ if(#v<2, return(v)); my(m=#v\2,left=vector(m,i,v[i]),right=vector(#v-m,i,v[m+i])); left=mergeSort(left); right=mergeSort(right); merge(left, right) }; merge(u,v)={ my(ret=vector(#u+#v),i=1,j=1); for(k=1,#ret, if(i<=#u & (j>#v | u[i]<v[j]), ret[k]=u[i]; i++ , ret[k]=v[j]; j++ ...

Give a code snippet in #PARI.2FGP 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 | Quic...

christopher/rosetta-code

http://rosettacode.org/wiki/Maze_generation

Maze generation

This page uses content from Wikipedia. The original article was at Maze generation 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) Task Generate and show a maze, using the simple Depth...

#Swift

Swift

import Foundation extension Array { mutating func shuffle() { guard count > 1 else { return } for i in 0..<self.count - 1 { let j = Int(arc4random_uniform(UInt32(count - i))) + i guard i != j else { continue } swap(&self[i], &self[j]) } } } enum ...

Give a code snippet in #Swift This page uses content from Wikipedia. The original article was at Maze generation 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) Task Generate and show...

christopher/rosetta-code

http://rosettacode.org/wiki/Boolean_values

Boolean values

Task Show how to represent the boolean states "true" and "false" in a language. If other objects represent "true" or "false" in conditionals, note it. Related tasks Logical operations

#8051_Assembly

8051 Assembly

clr bit ; clears setb bit ; sets

Give a code snippet in #8051_Assembly Task Show how to represent the boolean states "true" and "false" in a language. If other objects represent "true" or "false" in conditionals, note it. Related tasks Logical operations

christopher/rosetta-code

http://rosettacode.org/wiki/Loops/Downward_for

Loops/Downward for

Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body...

#HicEst

HicEst

DO i = 10, 0, -1 WRITE() i ENDDO

Give a code snippet in #HicEst Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Incre...

christopher/rosetta-code

http://rosettacode.org/wiki/Polynomial_long_division

Polynomial long division

This page uses content from Wikipedia. The original article was at Polynomial long division. 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 algebra, polynomial long division is an algorithm for d...

#Maple

Maple

> p := randpoly( x ); # pick a random polynomial in x 5 4 3 2 p := -56 - 7 x + 22 x - 55 x - 94 x + 87 x > rem( p, x^2 + 2, x, 'q' ); # remainder 220 + 169 x > q; # quotient 3 2 ...

Give a code snippet in #Maple This page uses content from Wikipedia. The original article was at Polynomial long division. 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 algebra, polynomial long...

christopher/rosetta-code

http://rosettacode.org/wiki/Optional_parameters

Optional parameters

Task Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters: ordering A function specifying the ordering of strings; lexicographic by default. column ...

#Common_Lisp

Common Lisp

(defun sort-table (table &key (ordering #'string<) (column 0) reverse) (sort table (if reverse (complement ordering) ordering) :key (lambda (row) (elt row column))))

Give a code snippet in #Common_Lisp Task Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters: ordering A function specifying the ordering of string...

christopher/rosetta-code

http://rosettacode.org/wiki/Order_two_numerical_lists

Order two numerical lists

sorting 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 She...

#AppleScript

AppleScript

-- <= for lists -- compare :: [a] -> [a] -> Bool on compare(xs, ys) if length of xs = 0 then true else if length of ys = 0 then false else set {hx, txs} to uncons(xs) set {hy, tys} to uncons(ys) if hx = hy then compare(txs...

Give a code snippet in #AppleScript sorting 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 s...

christopher/rosetta-code

http://rosettacode.org/wiki/Exceptions

Exceptions

Control Structures These are examples of control structures. You may also be interested in: Conditional structures Exceptions Flow-control structures Loops This task is to give an example of an exception handling routine and to "throw" a new exception. Related task Exceptions Through Nested Calls

#Forth

Forth

: f ( -- ) 1 throw ." f " ; \ will throw a "1" : g ( -- ) 0 throw ." g " ; \ does not throw

Give a code snippet in #Forth Control Structures These are examples of control structures. You may also be interested in: Conditional structures Exceptions Flow-control structures Loops This task is to give an example of an exception handling routine and to "throw" a new exception. Related task Exceptions...

christopher/rosetta-code

http://rosettacode.org/wiki/Egyptian_fractions

Egyptian fractions

An Egyptian fraction is the sum of distinct unit fractions such as: 1 2 + 1 3 + 1 16 ( = 43 48 ) {\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})} Each fraction in the expression has a numerator equal to 1 (unity) and a denominator that...

#Common_Lisp

Common Lisp

(defun egyption-fractions (x y &optional acc) (let* ((a (/ x y))) (cond ((> (numerator a) (denominator a)) (multiple-value-bind (q r) (floor x y) (if (zerop r) (cons q acc) (egyption-fractions r y (cons q acc))))) ((= (numerator a) 1) (reverse (cons a acc))) (t (let ((b (ceiling y ...

Give a code snippet in #Common_Lisp An Egyptian fraction is the sum of distinct unit fractions such as: 1 2 + 1 3 + 1 16 ( = 43 48 ) {\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})} Each fraction in the expression has a numerator equal to ...

christopher/rosetta-code

http://rosettacode.org/wiki/Singly-linked_list/Element_definition

Singly-linked list/Element definition

singly-linked list See also Array Associative array: Creation, Iteration Collections Compound data type Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal Linked list Queue: Definition, Usage Set Singly-linked list: Element definition, Element insertion, Lis...

#Ada

Ada

type Link; type Link_Access is access Link; type Link is record Next : Link_Access := null; Data : Integer; end record;

Give a code snippet in #Ada singly-linked list See also Array Associative array: Creation, Iteration Collections Compound data type Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal Linked list Queue: Definition, Usage Set Singly-linked list: Element defin...

christopher/rosetta-code

http://rosettacode.org/wiki/Sum_and_product_of_an_array

Sum and product of an array

Task Compute the sum and product of an array of integers.

#C

C

/* using pointer arithmetic (because we can, I guess) */ int arg[] = { 1,2,3,4,5 }; int arg_length = sizeof(arg)/sizeof(arg[0]); int *end = arg+arg_length; int sum = 0, prod = 1; int *p; for (p = arg; p!=end; ++p) { sum += *p; prod *= *p; }

Give a code snippet in #C Task Compute the sum and product of an array of integers.

christopher/rosetta-code

http://rosettacode.org/wiki/Linear_congruential_generator

Linear congruential generator

The linear congruential generator is a very simple example of a random number generator. All linear congruential generators use this formula: r n + 1 = a × r n + c ( mod m ) {\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}} Where: r 0 {\displaystyle r_{0}} is a seed. r 1 ...

#D

D

struct LinearCongruentialGenerator { enum uint RAND_MAX = (1U << 31) - 1; uint seed = 0; uint randBSD() pure nothrow @nogc { seed = (seed * 1_103_515_245 + 12_345) & RAND_MAX; return seed; } uint randMS() pure nothrow @nogc { seed = (seed * 214_013 + 2_531_011) & RAND_MAX...

Give a code snippet in #D The linear congruential generator is a very simple example of a random number generator. All linear congruential generators use this formula: r n + 1 = a × r n + c ( mod m ) {\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}} Where: r 0 {\displaystyle r_{0}...

christopher/rosetta-code

http://rosettacode.org/wiki/Display_a_linear_combination

Display a linear combination

Task Display a finite linear combination in an infinite vector basis ( e 1 , e 2 , … ) {\displaystyle (e_{1},e_{2},\ldots )} . Write a function that, when given a finite list of scalars ( α 1 , α 2 , … ) {\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )} , creates a string representing t...

#Go

Go

package main import ( "fmt" "strings" ) func linearCombo(c []int) string { var sb strings.Builder for i, n := range c { if n == 0 { continue } var op string switch { case n < 0 && sb.Len() == 0: op = "-" case n < 0: ...

Give a code snippet in #Go Task Display a finite linear combination in an infinite vector basis ( e 1 , e 2 , … ) {\displaystyle (e_{1},e_{2},\ldots )} . Write a function that, when given a finite list of scalars ( α 1 , α 2 , … ) {\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )} , cre...

christopher/rosetta-code

http://rosettacode.org/wiki/Towers_of_Hanoi

Towers of Hanoi

Task Solve the Towers of Hanoi problem with recursion.

#Dart

Dart

main() { moveit(from,to) { print("move ${from} ---> ${to}"); } hanoi(height,toPole,fromPole,usePole) { if (height>0) { hanoi(height-1,usePole,fromPole,toPole); moveit(fromPole,toPole); hanoi(height-1,toPole,usePole,fromPole); } } hanoi(3,3,1,2); }

Give a code snippet in #Dart Task Solve the Towers of Hanoi problem with recursion.

christopher/rosetta-code

http://rosettacode.org/wiki/ABC_problem

ABC problem

ABC problem You are encouraged to solve this task according to the task description, using any language you may know. You are given a collection of ABC blocks (maybe like the ones you had when you were a kid). There are twenty blocks with two letters on each block. A complete alphabet is guaranteed amongst all sid...

#Quackery

Quackery

[ $ "BOXKDQCPNAGTRETGQDFS" $ "JWHUVIANOBERFSLYPCZM" join ] constant is blocks ( --> $ ) [ -2 & tuck pluck drop swap pluck drop ] is remove2 ( $ n --> $ ) [ iff [ say "True" ] else [ say "False" ] ] is echotruth ( b --> ) [ true blocks rot witheach [ upper...

Give a code snippet in #Quackery ABC problem You are encouraged to solve this task according to the task description, using any language you may know. You are given a collection of ABC blocks (maybe like the ones you had when you were a kid). There are twenty blocks with two letters on each block. A complete alph...

christopher/rosetta-code

http://rosettacode.org/wiki/Go_Fish

Go Fish

Write a program to let the user play Go Fish against a computer opponent. Use the following rules: Each player is dealt nine cards to start with. On their turn, a player asks their opponent for a given rank (such as threes or kings). A player must already have at least one card of a given rank to ask for more. If t...

#PicoLisp

PicoLisp

Red [ Title: "Go Fish" Author: "gltewalt" ] chand: [] ;-- c and p = computer and player cguesses: [] phand: [] cbooks: 0 pbooks: 0 gf: { *************** * GO FISH * *************** } pip: ["a" "2" "3" "4" "5" "6" "7" "8" "9" "10" "j" "q" "k"] ;-- suits are not relevant pile: [] ;-- whe...

Give a code snippet in #PicoLisp Write a program to let the user play Go Fish against a computer opponent. Use the following rules: Each player is dealt nine cards to start with. On their turn, a player asks their opponent for a given rank (such as threes or kings). A player must already have at least one card of a...

christopher/rosetta-code

http://rosettacode.org/wiki/Chowla_numbers

Chowla numbers

Chowla numbers are also known as: Chowla's function chowla numbers the chowla function the chowla number the chowla sequence The chowla number of n is (as defined by Chowla's function): the sum of the divisors of n excluding unity and n where n is a positive integer The s...

#Pascal

Pascal

program Chowla_numbers; {$IFDEF FPC} {$MODE Delphi} {$ELSE} {$APPTYPE CONSOLE} {$ENDIF} uses SysUtils {$IFDEF FPC} ,StrUtils{for Numb2USA} {$ENDIF} ; {$IFNDEF FPC} function Numb2USA(const S: string): string; var I, NA: Integer; begin I := Length(S); Result := S; NA := 0; while (I > 0) do...

Give a code snippet in #Pascal Chowla numbers are also known as: Chowla's function chowla numbers the chowla function the chowla number the chowla sequence The chowla number of n is (as defined by Chowla's function): the sum of the divisors of n excluding unity and n where n...

christopher/rosetta-code

http://rosettacode.org/wiki/Stem-and-leaf_plot

Stem-and-leaf plot

Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits: 12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 11...

#Python

Python

from collections import namedtuple from pprint import pprint as pp from math import floor Stem = namedtuple('Stem', 'data, leafdigits') data0 = Stem((12, 127, 28, 42, 39, 113, 42, 18, 44, 118, 44, 37, 113, 124, 37, 48, 127, 36, 29, 31, 125, 139, 131, 115, 105, 132, 104, 123, 35, 113, 122...

Give a code snippet in #Python Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits: 12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37...

christopher/rosetta-code

http://rosettacode.org/wiki/Continued_fraction

Continued fraction

continued fraction Mathworld a 0 + b 1 a 1 + b 2 a 2 + b 3 a 3 + ⋱ {\displaystyle a_{0}+{\cfrac {b_{1}}{a_{1}+{\cfrac {b_{2}}{a_{2}+{\cfrac {b_{3}}{a_{3}+\ddots }}}}}}} The task is to write a program which generates su...

#Groovy

Groovy

import java.util.function.Function import static java.lang.Math.pow class Test { static double calc(Function<Integer, Integer[]> f, int n) { double temp = 0 for (int ni = n; ni >= 1; ni--) { Integer[] p = f.apply(ni) temp = p[1] / (double) (p[0] + temp) } ...

Give a code snippet in #Groovy continued fraction Mathworld a 0 + b 1 a 1 + b 2 a 2 + b 3 a 3 + ⋱ {\displaystyle a_{0}+{\cfrac {b_{1}}{a_{1}+{\cfrac {b_{2}}{a_{2}+{\cfrac {b_{3}}{a_{3}+\ddots }}}}}}} The task is to wr...

christopher/rosetta-code

http://rosettacode.org/wiki/Elementary_cellular_automaton/Infinite_length

Elementary cellular automaton/Infinite length

The purpose of this task is to create a version of an Elementary cellular automaton whose number of cells is only limited by the memory size of the computer. To be precise, consider the state of the automaton to be made of an infinite number of cells, but with a bounded support. In other words, to describe the state o...

#J

J

ext9=: (9#1-{.!.1),],9#1-{:!.1 trim=: |.@(}.~ ] i. 1-{.)^:2 next=: trim@(((8$2) #: [) {~ 2 #. 1 - [: |: |.~"1 0&_1 0 1@]) ext9

Give a code snippet in #J The purpose of this task is to create a version of an Elementary cellular automaton whose number of cells is only limited by the memory size of the computer. To be precise, consider the state of the automaton to be made of an infinite number of cells, but with a bounded support. In other wor...

christopher/rosetta-code

http://rosettacode.org/wiki/Loops/Do-while

Loops/Do-while

Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loo...

#Ring

Ring

n = 0 While True n++ See n + nl if n % 6 = 0 exit ok end

Give a code snippet in #Ring Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Do...

christopher/rosetta-code

http://rosettacode.org/wiki/Find_the_missing_permutation

Find the missing permutation

ABCD CABD ACDB DACB BCDA ACBD ADCB CDAB DABC BCAD CADB CDBA ...

#Ada

Ada

with Ada.Text_IO; procedure Missing_Permutations is subtype Permutation_Character is Character range 'A' .. 'D'; Character_Count : constant := 1 + Permutation_Character'Pos (Permutation_Character'Last) - Permutation_Character'Pos (Permutation_Character'First); type Permutation_String is ...

Give a code snippet in #Ada ABCD CABD ACDB DACB BCDA ACBD ADCB CDAB DABC BCAD CADB ...

christopher/rosetta-code

http://rosettacode.org/wiki/Percolation/Site_percolation

Percolation/Site percolation

Percolation Simulation This is a simulation of aspects of mathematical percolation theory. For other percolation simulations, see Category:Percolation Simulations, or: 1D finite grid simulation Mean run density 2D finite grid simulations Site percolation | Bond percolation | Mean cluster density Given an M × N...

#Python

Python

from random import random import string from pprint import pprint as pp M, N, t = 15, 15, 100 cell2char = ' #' + string.ascii_letters NOT_VISITED = 1 # filled cell not walked class PercolatedException(Exception): pass def newgrid(p): return [[int(random() < p) for m in range(M)] for n in range(N)] # cel...

Give a code snippet in #Python Percolation Simulation This is a simulation of aspects of mathematical percolation theory. For other percolation simulations, see Category:Percolation Simulations, or: 1D finite grid simulation Mean run density 2D finite grid simulations Site percolation | Bond percolation | Mean clu...

christopher/rosetta-code

http://rosettacode.org/wiki/Closures/Value_capture

Closures/Value capture

Task Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, i 2. Display the result of runnin...

#Objective-C

Objective-C

NSMutableArray *funcs = [[NSMutableArray alloc] init]; for (int i = 0; i < 10; i++) { [funcs addObject:[^ { return i * i; } copy]]; } int (^foo)(void) = funcs[3]; NSLog(@"%d", foo()); // logs "9"

Give a code snippet in #Objective-C Task Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, ...

christopher/rosetta-code

http://rosettacode.org/wiki/Write_language_name_in_3D_ASCII

Write language name in 3D ASCII

Task Write/display a language's name in 3D ASCII. (We can leave the definition of "3D ASCII" fuzzy, so long as the result is interesting or amusing, not a cheap hack to satisfy the task.) Related tasks draw a sphere draw a cuboid draw a rotating cube draw a Deathstar

#Clojure

Clojure

(use 'clj-figlet.core) (println (render-to-string (load-flf "ftp://ftp.figlet.org/pub/figlet/fonts/contributed/larry3d.flf") "Clojure"))

Give a code snippet in #Clojure Task Write/display a language's name in 3D ASCII. (We can leave the definition of "3D ASCII" fuzzy, so long as the result is interesting or amusing, not a cheap hack to satisfy the task.) Related tasks draw a sphere draw a cuboid draw a rotating cube draw a Deathstar

christopher/rosetta-code

http://rosettacode.org/wiki/Esthetic_numbers

Esthetic numbers

An esthetic number is a positive integer where every adjacent digit differs from its neighbour by 1. E.G. 12 is an esthetic number. One and two differ by 1. 5654 is an esthetic number. Each digit is exactly 1 away from its neighbour. 890 is not an esthetic number. Nine and zero differ by 9. These examples are n...

#Sidef

Sidef

func generate_esthetic(root, upto, callback, b=10) { var v = root.digits2num(b) return nil if (v > upto) callback(v) var t = root.head __FUNC__([t+1, root...], upto, callback, b) if (t+1 < b) __FUNC__([t-1, root...], upto, callback, b) if (t-1 >= 0) } func between_esthetic(from, upto,...

Give a code snippet in #Sidef An esthetic number is a positive integer where every adjacent digit differs from its neighbour by 1. E.G. 12 is an esthetic number. One and two differ by 1. 5654 is an esthetic number. Each digit is exactly 1 away from its neighbour. 890 is not an esthetic number. Nine and zero diff...

christopher/rosetta-code

http://rosettacode.org/wiki/Monty_Hall_problem

Monty Hall problem

Suppose you're on a game show and you're given the choice of three doors. Behind one door is a car; behind the others, goats. The car and the goats were placed randomly behind the doors before the show. Rules of the game After you have chosen a door, the door remains closed for the time being. The game show hos...

#Prolog

Prolog

:- initialization(main). % Simulate a play. play(Switch, Won) :- % Random prize door random(1, 4, P), % Random contestant door random(1, 4, C), % Random reveal door, not prize or contestant door repeat, random(1, 4, R), R \= P, R \= C, !, % Final door ( ...

Give a code snippet in #Prolog Suppose you're on a game show and you're given the choice of three doors. Behind one door is a car; behind the others, goats. The car and the goats were placed randomly behind the doors before the show. Rules of the game After you have chosen a door, the door remains closed for th...

christopher/rosetta-code

http://rosettacode.org/wiki/Factors_of_an_integer

Factors of an integer

Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...

#Tailspin

Tailspin

[1..351 -> $when <?(351 mod $ <=0>)> do $! $] -> !OUT::write

Give a code snippet in #Tailspin Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operatio...

christopher/rosetta-code

http://rosettacode.org/wiki/Comma_quibbling

Comma quibbling

Comma quibbling is a task originally set by Eric Lippert in his blog. Task Write a function to generate a string output which is the concatenation of input words from a list/sequence where: An input of no words produces the output string of just the two brace characters "{}". An input of just one word, e.g. ["AB...

#Swift

Swift

let inputs = [[], ["ABC"], ["ABC", "DEF"], ["ABC", "DEF", "G", "H"]] func quibbling(var words:[String]) { if words.count == 0 { println("{}") } else if words.count == 1 { println("{\(words[0])}") } else if words.count == 2 { println("{\(words[0]) and \(words[1])}") } else { ...

Give a code snippet in #Swift Comma quibbling is a task originally set by Eric Lippert in his blog. Task Write a function to generate a string output which is the concatenation of input words from a list/sequence where: An input of no words produces the output string of just the two brace characters "{}". An in...

christopher/rosetta-code

http://rosettacode.org/wiki/Read_a_configuration_file

Read a configuration file

The task is to read a configuration file in standard configuration file format, and set variables accordingly. For this task, we have a configuration file as follows: # This is a configuration file in standard configuration file format # # Lines beginning with a hash or a semicolon are ignored by the application # pr...

#Go

Go

package config import ( "errors" "io" "fmt" "bytes" "strings" "io/ioutil" ) var ( ENONE = errors.New("Requested value does not exist") EBADTYPE = errors.New("Requested type and actual type do not match") EBADVAL = errors.New("Value and type do not match") ) type varError struct { err error n stri...

Give a code snippet in #Go The task is to read a configuration file in standard configuration file format, and set variables accordingly. For this task, we have a configuration file as follows: # This is a configuration file in standard configuration file format # # Lines beginning with a hash or a semicolon are ign...

christopher/rosetta-code

http://rosettacode.org/wiki/Make_directory_path

Make directory path

Task Create a directory and any missing parents. This task is named after the posix mkdir -p command, and several libraries which implement the same behavior. Please implement a function of a single path string (for example ./path/to/dir) which has the above side-effect. If the directory already exists, return succe...

#JavaScript

JavaScript

var path = require('path'); var fs = require('fs'); function mkdirp (p, cb) { cb = cb || function () {}; p = path.resolve(p); fs.mkdir(p, function (er) { if (!er) { return cb(null); } switch (er.code) { case 'ENOENT': // The directory doesn...

Give a code snippet in #JavaScript Task Create a directory and any missing parents. This task is named after the posix mkdir -p command, and several libraries which implement the same behavior. Please implement a function of a single path string (for example ./path/to/dir) which has the above side-effect. If the di...

christopher/rosetta-code

http://rosettacode.org/wiki/Partition_an_integer_x_into_n_primes

Partition an integer x into n primes

Task Partition a positive integer X into N distinct primes. Or, to put it in another way: Find N unique primes such that they add up to X. Show in the output section the sum X and the N primes in ascending order separated by plus (+) signs: • partition 99809 with 1 prime. ...

#C

C

#include <assert.h> #include <stdbool.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> typedef struct bit_array_tag { uint32_t size; uint32_t* array; } bit_array; bool bit_array_create(bit_array* b, uint32_t size) { uint32_t* array = calloc((size + 31)/32, sizeof(uint32_t)); if (array =...

Give a code snippet in #C Task Partition a positive integer X into N distinct primes. Or, to put it in another way: Find N unique primes such that they add up to X. Show in the output section the sum X and the N primes in ascending order separated by plus (+) signs: • partition ...

christopher/rosetta-code

http://rosettacode.org/wiki/Modular_inverse

Modular inverse

From Wikipedia: In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that a x ≡ 1 ( mod m ) . {\displaystyle a\,x\equiv 1{\pmod {m}}.} Or in other words, such that: ∃ k ∈ Z , a x = 1 + k m {\displaystyle \exists k\in \math...

#BCPL

BCPL

get "libhdr" let mulinv(a, b) = b<0 -> mulinv(a, -b), a<0 -> mulinv(b - (-a rem b), b), valof $( let t, nt, r, nr = 0, 1, b, a rem b until nr = 0 $( let tmp, q = ?, r / nr tmp := nt ; nt := t - q*nt ; t := tmp tmp := nr ; nr := r - q*nr ; r := tmp $) ...

Give a code snippet in #BCPL From Wikipedia: In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that a x ≡ 1 ( mod m ) . {\displaystyle a\,x\equiv 1{\pmod {m}}.} Or in other words, such that: ∃ k ∈ Z , a x = 1 + k m {\d...

christopher/rosetta-code

http://rosettacode.org/wiki/Send_email

Send email

Task Write a function to send an email. The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details. If appropriate, explain what notifications of problems/success are given. Solutions using libraries or f...

#Lua

Lua

-- load the smtp support local smtp = require("socket.smtp") -- Connects to server "localhost" and sends a message to users -- "fulano@example.com", "beltrano@example.com", -- and "sicrano@example.com". -- Note that "fulano" is the primary recipient, "beltrano" receives a -- carbon copy and neither of them knows th...

Give a code snippet in #Lua Task Write a function to send an email. The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details. If appropriate, explain what notifications of problems/success are given. S...

christopher/rosetta-code

http://rosettacode.org/wiki/Word_frequency

Word frequency

Task Given a text file and an integer n, print/display the n most common words in the file (and the number of their occurrences) in decreasing frequency. For the purposes of this task: A word is a sequence of one or more contiguous letters. You are free to define what a letter is. Undersc...

#AppleScript

AppleScript

(* For simplicity here, words are considered to be uninterrupted sequences of letters and/or digits. The set text is too messy to warrant faffing around with anything more sophisticated. The first letter in each word is upper-cased and the rest lower-cased for case equivalence and presentation. Where mo...

Give a code snippet in #AppleScript Task Given a text file and an integer n, print/display the n most common words in the file (and the number of their occurrences) in decreasing frequency. For the purposes of this task: A word is a sequence of one or more contiguous letters. You are free to def...

christopher/rosetta-code

http://rosettacode.org/wiki/Variadic_function

Variadic function

Task Create a function which takes in a variable number of arguments and prints each one on its own line. Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime. Functions of this type are also known as Variadic Functions. Related task Call a function...

#Visual_Basic

Visual Basic

Option Explicit '-------------------------------------------------- Sub varargs(ParamArray a()) Dim n As Long, m As Long Debug.Assert VarType(a) = (vbVariant Or vbArray) For n = LBound(a) To UBound(a) If IsArray(a(n)) Then For m = LBound(a(n)) To UBound(a(n)) Debug.Print a(n)...

Give a code snippet in #Visual_Basic Task Create a function which takes in a variable number of arguments and prints each one on its own line. Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime. Functions of this type are also known as Variadic Function...

christopher/rosetta-code

http://rosettacode.org/wiki/Delete_a_file

Delete a file

Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.

#Forth

Forth

s" input.txt" delete-file throw s" /input.txt" delete-file throw

Give a code snippet in #Forth Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.

christopher/rosetta-code

http://rosettacode.org/wiki/Combinations

Combinations

Task Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted). Example 3 comb 5 is: 0 1 2 0 1 3 0 1 4 0 2 3 0 2 4 0 3 4 1 2 3 1 2 4 1 3 4 2 3 4 ...

#PowerShell

PowerShell

$source = @' using System; using System.Collections.Generic; namespace Powershell { public class CSharp { public static IEnumerable<int[]> Combinations(int m, int n) { int[] result = new int[m]; Stack<int> stack = new Stack<int>...

Give a code snippet in #PowerShell Task Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted). Example 3 comb 5 is: 0 1 2 0 1 3 0 1 4 0 2 3 ...

christopher/rosetta-code

http://rosettacode.org/wiki/FASTA_format

FASTA format

In bioinformatics, long character strings are often encoded in a format called FASTA. A FASTA file can contain several strings, each identified by a name marked by a > (greater than) character at the beginning of the line. Task Write a program that reads a FASTA file such as: >Rosetta_Example_1 THERECANBENOSPACE ...

#Wren

Wren

import "io" for File var checkNoSpaces = Fn.new { |s| !s.contains(" ") && !s.contains("\t") } var first = true var process = Fn.new { |line| if (line[0] == ">") { if (!first) System.print() System.write("%(line[1..-1]): ") if (first) first = false } else if (first) { Fiber....

Give a code snippet in #Wren In bioinformatics, long character strings are often encoded in a format called FASTA. A FASTA file can contain several strings, each identified by a name marked by a > (greater than) character at the beginning of the line. Task Write a program that reads a FASTA file such as: >Rosett...

christopher/rosetta-code

http://rosettacode.org/wiki/Shell_one-liner

Shell one-liner

Task Show how to specify and execute a short program in the language from a command shell, where the input to the command shell is only one line in length. Avoid depending on the particular shell or operating system used as much as is reasonable; if the language has notable implementations which have different comman...

#R

R

$ echo 'cat("Hello\n")' | R --slave Hello

Give a code snippet in #R Task Show how to specify and execute a short program in the language from a command shell, where the input to the command shell is only one line in length. Avoid depending on the particular shell or operating system used as much as is reasonable; if the language has notable implementations ...

christopher/rosetta-code

http://rosettacode.org/wiki/Rep-string

Rep-string

Given a series of ones and zeroes in a string, define a repeated string or rep-string as a string which is created by repeating a substring of the first N characters of the string truncated on the right to the length of the input string, and in which the substring appears repeated at least twice in the original. For e...

#ALGOL_68

ALGOL 68

# procedure to find the longest rep-string in a given string # # the input string is not validated to contain only "0" and "1" characters # PROC longest rep string = ( STRING input )STRING: BEGIN STRING result := ""; # ensure the string we are working on has a lower-bound of 1 ...

Give a code snippet in #ALGOL_68 Given a series of ones and zeroes in a string, define a repeated string or rep-string as a string which is created by repeating a substring of the first N characters of the string truncated on the right to the length of the input string, and in which the substring appears repeated at l...

christopher/rosetta-code

http://rosettacode.org/wiki/Babbage_problem

Babbage problem

Charles Babbage, looking ahead to the sorts of problems his Analytical Engine would be able to solve, gave this example: What is the smallest positive integer whose square ends in the digits 269,696? — Babbage, letter to Lord Bowden, 1837; see Hollingdale and Tootill, Electronic Computers, second edition, 1970, p....

#F.C5.8Drmul.C3.A6

Fōrmulæ

Public Sub Main() Dim iNum As Long For iNum = 1 To 100000 If Str(iNum * iNum) Ends "269696" Then Break Next Print "The lowest number squared that ends in '269696' is " & Str(iNum) End

Give a code snippet in #F.C5.8Drmul.C3.A6 Charles Babbage, looking ahead to the sorts of problems his Analytical Engine would be able to solve, gave this example: What is the smallest positive integer whose square ends in the digits 269,696? — Babbage, letter to Lord Bowden, 1837; see Hollingdale and Tootill, Ele...

christopher/rosetta-code

http://rosettacode.org/wiki/XML/XPath

XML/XPath

Perform the following three XPath queries on the XML Document below: //item[1]: Retrieve the first "item" element //price/text(): Perform an action on each "price" element (print it out) //name: Get an array of all the "name" elements XML Document: <inventory title="OmniCorp Store #45x10^3"> <section name="heal...

#C.2B.2B

C++

#include <cassert> #include <cstdlib> #include <iostream> #include <stdexcept> #include <utility> #include <vector> #include <libxml/parser.h> #include <libxml/tree.h> #include <libxml/xmlerror.h> #include <libxml/xmlstring.h> #include <libxml/xmlversion.h> #include <libxml/xpath.h> #ifndef LIBXML_XPATH_ENABLED # ...

Give a code snippet in #C.2B.2B Perform the following three XPath queries on the XML Document below: //item[1]: Retrieve the first "item" element //price/text(): Perform an action on each "price" element (print it out) //name: Get an array of all the "name" elements XML Document: <inventory title="OmniCorp Store...

christopher/rosetta-code

http://rosettacode.org/wiki/Increment_a_numerical_string

Increment a numerical string

Task Increment a numerical string.

#F.23

F#

let next = string( int( "1234" ) + 1 )

Give a code snippet in #F.23 Task Increment a numerical string.

christopher/rosetta-code

http://rosettacode.org/wiki/Web_scraping

Web scraping

Task Create a program that downloads the time from this URL: http://tycho.usno.navy.mil/cgi-bin/timer.pl and then prints the current UTC time by extracting just the UTC time from the web page's HTML. Alternatively, if the above url is not working, grab the first date/time off this page's talk page. If possible,...

#Common_Lisp

Common Lisp

BOA> (let* ((url "http://tycho.usno.navy.mil/cgi-bin/timer.pl") (regexp (load-time-value (cl-ppcre:create-scanner "(?m)^.{4}(.+? UTC)"))) (data (drakma:http-request url))) (multiple-value-bind (start end start-regs end-regs) (cl-ppcre:scan regexp data) ...

Give a code snippet in #Common_Lisp Task Create a program that downloads the time from this URL: http://tycho.usno.navy.mil/cgi-bin/timer.pl and then prints the current UTC time by extracting just the UTC time from the web page's HTML. Alternatively, if the above url is not working, grab the first date/time off t...

christopher/rosetta-code