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 | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
value |
|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Kernighans_large_earthquake_problem | Kernighans large earthquake problem | Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example lines from the file would be lines li... | #Cixl | Cixl |
use: cx;
'data.txt' `r fopen lines {
let: (time place mag) @@s split ..;
let: (m1 m2) $mag @. split &int map ..;
$m1 6 >= $m2 0 > and {[$time @@s $place @@s $mag] say} if
} for
| Give a code snippet in #Cixl
Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example lines f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Unix/ls | Unix/ls | Task
Write a program that will list everything in the current folder, similar to:
the Unix utility “ls” [1] or
the Windows terminal command “DIR”
The output must be sorted, but printing extended details and producing multi-column output is not required.
Example output
For the list of paths:... | #Stata | Stata | . dir *.dta
6.3k 6/12/17 14:26 auto.dta
2.3k 8/10/17 7:34 titanium.dta
6.0k 8/12/17 9:28 trend.dta | Give a code snippet in #Stata
Task
Write a program that will list everything in the current folder, similar to:
the Unix utility “ls” [1] or
the Windows terminal command “DIR”
The output must be sorted, but printing extended details and producing multi-column output is not required.
Exampl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #Haxe | Haxe | static function fib(steps:Int, handler:Int->Void)
{
var current = 0;
var next = 1;
for (i in 1...steps)
{
handler(current);
var temp = current + next;
current = next;
next = temp;
}
handler(current);
} | Give a code snippet in #Haxe
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_comments_from_a_string | Strip comments from a string | Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line.
Whitespace debacle: There is s... | #Oforth | Oforth | : stripComments(s, markers)
| firstMarker |
markers map(#[ s indexOf ]) reduce(#min) ->firstMarker
s firstMarker ifNotNull: [ left(firstMarker 1 - ) ] strip ; | Give a code snippet in #Oforth
Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Natural_sorting | Natural 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
Shell Sort
... | #Racket | Racket |
#lang racket
(define (natural-sort l)
(define (list<? l1 l2)
(cond [(null? l2) #f]
[(null? l1) #t]
[(number? (car l1)) (cond [(< (car l1) (car l2)) #t]
[(< (car l2) (car l1)) #f]
[else (list<? (cdr l1) (cdr l2))])]
... | Give a code snippet in #Racket
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 s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Narcissistic_decimal_number | Narcissistic decimal number | A Narcissistic decimal number is a non-negative integer,
n
{\displaystyle n}
, that is equal to the sum of the
m
{\displaystyle m}
-th powers of each of the digits in the decimal representation of
n
{\displaystyle n}
, where
m
{\displaystyle m}
is the number of digits in... | #Rust | Rust |
fn is_narcissistic(x: u32) -> bool {
let digits: Vec<u32> = x
.to_string()
.chars()
.map(|c| c.to_digit(10).unwrap())
.collect();
digits
.iter()
.map(|d| d.pow(digits.len() as u32))
.sum::<u32>()
== x
}
fn main() {
let mut counter = 0;
... | Give a code snippet in #Rust
A Narcissistic decimal number is a non-negative integer,
n
{\displaystyle n}
, that is equal to the sum of the
m
{\displaystyle m}
-th powers of each of the digits in the decimal representation of
n
{\displaystyle n}
, where
m
{\displaystyle m}
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/FizzBuzz | FizzBuzz | Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuzz (instead of the number)
... | #F.23 | F# | let fizzbuzz n =
match n%3 = 0, n%5 = 0 with
| true, false -> "fizz"
| false, true -> "buzz"
| true, true -> "fizzbuzz"
| _ -> string n
let printFizzbuzz() =
[1..100] |> List.iter (fizzbuzz >> printfn "%s") | Give a code snippet in #F.23
Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuzz ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Colour_bars/Display | Colour bars/Display | Task
Display a series of vertical color bars across the width of the display.
The color bars should either use:
the system palette, or
the sequence of colors:
black
red
green
blue
magenta
cyan
yellow
white
| #Delphi | Delphi |
unit Colour_barsDisplay;
interface
uses
Winapi.Windows, System.SysUtils, System.Classes, Vcl.Graphics, Vcl.Forms;
type
TfmColourBar = class(TForm)
procedure FormPaint(Sender: TObject);
procedure FormResize(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }... | Give a code snippet in #Delphi
Task
Display a series of vertical color bars across the width of the display.
The color bars should either use:
the system palette, or
the sequence of colors:
black
red
green
blue
magenta
cyan
yellow
white
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Selection_sort | Sorting algorithms/Selection 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
... | #Delphi | Delphi | program TestSelectionSort;
{$APPTYPE CONSOLE}
{.$DEFINE DYNARRAY} // remove '.' to compile with dynamic array
type
TItem = Integer; // declare ordinal type for array item
{$IFDEF DYNARRAY}
TArray = array of TItem; // dynamic array
{$ELSE}
TArray = array[0..15] of TItem; // static array
{$ENDIF... | Give a code snippet in #Delphi
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 s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n)... | #Modula-2 | Modula-2 | MODULE ADP;
FROM FormatString IMPORT FormatString;
FROM Terminal IMPORT WriteString,WriteLn,ReadChar;
PROCEDURE ProperDivisorSum(n : INTEGER) : INTEGER;
VAR i,sum : INTEGER;
BEGIN
sum := 0;
IF n<2 THEN
RETURN 0
END;
FOR i:=1 TO (n DIV 2) DO
IF n MOD i = 0 THEN
INC(sum,i)
... | Give a code snippet in #Modula-2
These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as defici... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_search | Binary search | A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret number, and will only tell the p... | #Swift | Swift | func binarySearch<T: Comparable>(xs: [T], x: T) -> Int? {
var recurse: ((Int, Int) -> Int?)!
recurse = {(low, high) in switch (low + high) / 2 {
case _ where high < low: return nil
case let mid where xs[mid] > x: return recurse(low, mid - 1)
case let mid where xs[mid] < x: return recurse(mid + 1, high)
... | Give a code snippet in #Swift
A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/QR_decomposition | QR decomposition | Any rectangular
m
×
n
{\displaystyle m\times n}
matrix
A
{\displaystyle {\mathit {A}}}
can be decomposed to a product of an orthogonal matrix
Q
{\displaystyle {\mathit {Q}}}
and an upper (right) triangular matrix
R
{\displaystyle {\mathit {R}}}
, as described in QR decompositi... | #zkl | zkl | var [const] GSL=Import("zklGSL"); // libGSL (GNU Scientific Library)
A:=GSL.Matrix(3,3).set(12.0, -51.0, 4.0,
6.0, 167.0, -68.0,
4.0, 24.0, -41.0);
Q,R:=A.QRDecomp();
println("Q:\n",Q.format());
println("R:\n",R.format());
println("Q*R:\n",(Q*R).format()); | Give a code snippet in #zkl
Any rectangular
m
×
n
{\displaystyle m\times n}
matrix
A
{\displaystyle {\mathit {A}}}
can be decomposed to a product of an orthogonal matrix
Q
{\displaystyle {\mathit {Q}}}
and an upper (right) triangular matrix
R
{\displaystyle {\mathit {R}}}
, a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number | Guess the number | Task
Write a program where the program chooses a number between 1 and 10.
A player is then prompted to enter a guess. If the player guesses wrong, then the prompt appears again until the guess is correct.
When the player has made a successful guess the computer will issue a "Well guessed!" message, a... | #Crystal | Crystal | n = rand(1..10)
puts "Guess the number: 1..10"
until gets.to_s.to_i == n; puts "Wrong! Guess again: " end
puts "Well guessed!" | Give a code snippet in #Crystal
Task
Write a program where the program chooses a number between 1 and 10.
A player is then prompted to enter a guess. If the player guesses wrong, then the prompt appears again until the guess is correct.
When the player has made a successful guess the computer will issue a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third... | #Clarion | Clarion |
program
map
end
MAX_DOOR_NUMBER equate(100)
CRLF equate('<13,10>')
Doors byte,dim(MAX_DOOR_NUMBER)
Pass byte
DoorNumber byte
DisplayString cstring(2000)
ResultWindow window('Result'),at(,,133,291),cen... | Give a code snippet in #Clarion
There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generate_lower_case_ASCII_alphabet | Generate lower case ASCII alphabet | Task
Generate an array, list, lazy sequence, or even an indexable string of all the lower case ASCII characters, from a to z. If the standard library contains such a sequence, show how to access it, but don't fail to show how to generate a similar sequence.
For this basic task use a reliable style of coding, a sty... | #Ada | Ada | type Lower_Case is new Character range 'a' .. 'z'; | Give a code snippet in #Ada
Task
Generate an array, list, lazy sequence, or even an indexable string of all the lower case ASCII characters, from a to z. If the standard library contains such a sequence, show how to access it, but don't fail to show how to generate a similar sequence.
For this basic task use a re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Eertree | Eertree | An eertree is a data structure designed for efficient processing of certain palindrome tasks, for instance counting the number of sub-palindromes in an input string.
The data structure has commonalities to both tries and suffix trees.
See links below.
Task
Construct an eertree for the string "eertree", then outp... | #Ring | Ring |
# Project : Eertree
str = "eertree"
pal = []
for n=1 to len(str)
for m=1 to len(str)
strrev = ""
strpal = substr(str, n, m)
if strpal != ""
for p=len(strpal) to 1 step -1
strrev = strrev + strpal[p]
next
if strpal = strrev
ad... | Give a code snippet in #Ring
An eertree is a data structure designed for efficient processing of certain palindrome tasks, for instance counting the number of sub-palindromes in an input string.
The data structure has commonalities to both tries and suffix trees.
See links below.
Task
Construct an eertree for t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Memory_allocation | Memory allocation | Task
Show how to explicitly allocate and deallocate blocks of memory in your language.
Show access to different types of memory (i.e., heap, stack, shared, foreign) if applicable.
| #Oforth | Oforth |
'ALLOCATING MEMORY FROM DIFFERENT MEMORY SOURCES
sys p
static byte b[0x1000] 'global memory
p=@b
function f()
local byte b[0x1000] 'stack memory in a procedure
p=@b
end function
p=getmemory 0x1000 'heap memory
...
freememory p 'to disallocate
sub rsp,0x1000 'stack memory direct
p=rsp
...
rsp=p ... | Give a code snippet in #Oforth
Task
Show how to explicitly allocate and deallocate blocks of memory in your language.
Show access to different types of memory (i.e., heap, stack, shared, foreign) if applicable.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Tokenize_a_string_with_escaping | Tokenize a string with escaping | Task[edit]
Write a function or program that can split a string at each non-escaped occurrence of a separator character.
It should accept three input parameters:
The string
The separator character
The escape character
It should output a list of strings.
Details
Rules for splitting:
The fields that were s... | #ALGOL_68 | ALGOL 68 | BEGIN
# returns s parsed according to delimiter and escape #
PROC parse with escapes = ( STRING s, CHAR delimiter, escape )[]STRING:
IF ( UPB s - LWB s ) + 1 < 1 THEN
# empty string #
[ 1 : 0 ]STRING empty a... | Give a code snippet in #ALGOL_68
Task[edit]
Write a function or program that can split a string at each non-escaped occurrence of a separator character.
It should accept three input parameters:
The string
The separator character
The escape character
It should output a list of strings.
Details
Rules for s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ordered_words | Ordered words | An ordered word is a word in which the letters appear in alphabetic order.
Examples include abbey and dirt.
Task[edit]
Find and display all the ordered words in the dictionary unixdict.txt that have the longest word length.
(Examples that access the dictionary file locally assume that you have download... | #D | D | void main() {
import std.stdio, std.algorithm, std.range, std.string;
string[] result;
size_t maxLen;
foreach (string word; "unixdict.txt".File.lines) {
word = word.chomp;
immutable len = word.walkLength;
if (len < maxLen || !word.isSorted)
continue;
if (l... | Give a code snippet in #D
An ordered word is a word in which the letters appear in alphabetic order.
Examples include abbey and dirt.
Task[edit]
Find and display all the ordered words in the dictionary unixdict.txt that have the longest word length.
(Examples that access the dictionary file locally as... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calendar_-_for_%22REAL%22_programmers | Calendar - for "REAL" programmers | Task
Provide an algorithm as per the Calendar task, except the entire code for the algorithm must be presented entirely without lowercase.
Also - as per many 1969 era line printers - format the calendar to nicely fill a page that is 132 characters wide.
(Hint: manually convert the code from the Calendar task to al... | #PicoLisp | PicoLisp | (DE CAL (YEAR)
(PRINL "====== " YEAR " ======")
(FOR DAT (RANGE (DATE YEAR 1 1) (DATE YEAR 12 31))
(LET D (DATE DAT)
(TAB (3 3 4 8)
(WHEN (= 1 (CADDR D))
(GET `(INTERN (PACK (MAPCAR CHAR (42 77 111 110)))) (CADR D)) )
(CADDR D)
(DAY DAT `(INTERN (P... | Give a code snippet in #PicoLisp
Task
Provide an algorithm as per the Calendar task, except the entire code for the algorithm must be presented entirely without lowercase.
Also - as per many 1969 era line printers - format the calendar to nicely fill a page that is 132 characters wide.
(Hint: manually convert the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #Maxima | Maxima | s: ""$
/* check using string contents */
sequal(s, "");
not sequal(s, "");
/* check using string length */
slength(s) = "";
slength(s) # ""; | Give a code snippet in #Maxima
Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Ot... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number/With_feedback_(player) | Guess the number/With feedback (player) | Task
Write a player for the game that follows the following rules:
The scorer will choose a number between set limits. The computer player will print a guess of the target number. The computer asks for a score of whether its guess is higher than, lower than, or equal to the target. The computer guesses, and the score... | #Delphi | Delphi |
program Guess_the_number;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
system.console;
type
TCharSet = set of char;
var
PlayerNumber, CPUNumber: word;
CPULow: word = 0;
CPUHi: word = 1000;
PlayerLow: word = 0;
PlayerHi: word = 1000;
CPUWin, PlayerWin: boolean;
CPUGuessList: string = 'Previus g... | Give a code snippet in #Delphi
Task
Write a player for the game that follows the following rules:
The scorer will choose a number between set limits. The computer player will print a guess of the target number. The computer asks for a score of whether its guess is higher than, lower than, or equal to the target. The... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Archimedean_spiral | Archimedean spiral |
The Archimedean spiral is a spiral named after the Greek mathematician Archimedes.
An Archimedean spiral can be described by the equation:
r
=
a
+
b
θ
{\displaystyle \,r=a+b\theta }
with real numbers a and b.
Task
Draw an Archimedean spiral.
| #C.2B.2B | C++ |
#include <windows.h>
#include <string>
#include <iostream>
const int BMP_SIZE = 600;
class myBitmap {
public:
myBitmap() : pen( NULL ), brush( NULL ), clr( 0 ), wid( 1 ) {}
~myBitmap() {
DeleteObject( pen ); DeleteObject( brush );
DeleteDC( hdc ); DeleteObject( bmp );
}
bool create... | Give a code snippet in #C.2B.2B
The Archimedean spiral is a spiral named after the Greek mathematician Archimedes.
An Archimedean spiral can be described by the equation:
r
=
a
+
b
θ
{\displaystyle \,r=a+b\theta }
with real numbers a and b.
Task
Draw an Archimedean spiral.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Call_a_foreign-language_function | Call a foreign-language function | Task
Show how a foreign language function can be called from the language.
As an example, consider calling functions defined in the C language. Create a string containing "Hello World!" of the string type typical to the language. Pass the string content to C's strdup. The content can be copied if necessary. Get the... | #Crystal | Crystal | @[Link("c")] # name of library that is passed to linker. Not needed as libc is linked by stdlib.
lib LibC
fun free(ptr : Void*) : Void
fun strdup(ptr : Char*) : Char*
end
s1 = "Hello World!"
p = LibC.strdup(s1) # returns Char* allocated by LibC
s2 = String.new(p)
LibC.free p # pointer can be freed as String.new(... | Give a code snippet in #Crystal
Task
Show how a foreign language function can be called from the language.
As an example, consider calling functions defined in the C language. Create a string containing "Hello World!" of the string type typical to the language. Pass the string content to C's strdup. The content ca... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Unicode_strings | Unicode strings | As the world gets smaller each day, internationalization becomes more and more important. For handling multiple languages, Unicode is your best friend.
It is a very capable tool, but also quite complex compared to older single- and double-byte character encodings.
How well prepared is your programming language for ... | #Java | Java | --raw-input | -R :: each line of input is converted to a JSON string;
--ascii-output | -a :: every non-ASCII character that would otherwise
be sent to output is translated to an equivalent
ASCII escape sequence;
--raw-output | -r :: output strings as raw strings, ... | Give a code snippet in #Java
As the world gets smaller each day, internationalization becomes more and more important. For handling multiple languages, Unicode is your best friend.
It is a very capable tool, but also quite complex compared to older single- and double-byte character encodings.
How well prepared is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brace_expansion | Brace expansion | Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified.
Task[edit]
W... | #PowerShell | PowerShell |
function Expand-Braces ( [string]$String )
{
$Escaped = $False
$Stack = New-Object System.Collections.Stack
$ClosedBraces = $BracesToParse = $Null
ForEach ( $i in 0..($String.Length-1) )
{
Switch ( $String[$i] )
{
'\' {
$Escaped = -not $Esc... | Give a code snippet in #PowerShell
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Towers_of_Hanoi | Towers of Hanoi | Task
Solve the Towers of Hanoi problem with recursion.
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | Hanoi[0, from_, to_, via_] := Null
Hanoi[n_Integer, from_, to_, via_] := (Hanoi[n-1, from, via, to];Print["Move disk from pole ", from, " to ", to, "."];Hanoi[n-1, via, to, from]) | Give a code snippet in #Mathematica.2FWolfram_Language
Task
Solve the Towers of Hanoi problem with recursion.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Largest_proper_divisor_of_n | Largest proper divisor of n | Task
a(1) = 1; for n > 1, a(n) = largest proper divisor of n, where n < 101 .
| #Forth | Forth | : largest-proper-divisor { n -- n }
n 1 and 0= if n 2/ exit then
3
begin
dup dup * n <=
while
dup n swap /mod swap
0= if nip exit else drop then
2 +
repeat drop 1 ;
: main
101 1 do
i largest-proper-divisor 2 .r
i 10 mod 0= if cr else space then
loop ;
main
bye | Give a code snippet in #Forth
Task
a(1) = 1; for n > 1, a(n) = largest proper divisor of n, where n < 101 .
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Tau_number | Tau number | A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau function
| #F.23 | F# |
// Tau number. Nigel Galloway: March 9th., 2021
Seq.initInfinite((+)1)|>Seq.filter(fun n->n%(tau n)=0)|>Seq.take 100|>Seq.iter(printf "%d "); printfn ""
| Give a code snippet in #F.23
A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau function
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/MD5 | MD5 | Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the Wikipedia article.
Warning:... | #RPG | RPG | **FREE
Ctl-opt MAIN(Main);
Ctl-opt DFTACTGRP(*NO) ACTGRP(*NEW);
dcl-pr QDCXLATE EXTPGM('QDCXLATE');
dataLen packed(5 : 0) CONST;
data char(32767) options(*VARSIZE);
conversionTable char(10) CONST;
end-pr;
dcl-pr Qc3CalculateHash EXTPROC('Qc3CalculateHash');
inputData pointer v... | Give a code snippet in #RPG
Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the Wi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence_of_non-squares | Sequence of non-squares | Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 in the OEIS database.
| #Fortran | Fortran | PROGRAM NONSQUARES
IMPLICIT NONE
INTEGER :: m, n, nonsqr
DO n = 1, 22
nonsqr = n + FLOOR(0.5 + SQRT(REAL(n))) ! or could use NINT(SQRT(REAL(n)))
WRITE(*,*) nonsqr
END DO
DO n = 1, 1000000
nonsqr = n + FLOOR(0.5 + SQRT(REAL(n)))
m = INT(SQRT(REAL(nonsqr)))
IF (m*m == nonsqr) THEN... | Give a code snippet in #Fortran
Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's stat... | #Slate | Slate | Method traits define: #Y &builder:
[[| :f | [| :x | f applyWith: (x applyWith: x)]
applyWith: [| :x | f applyWith: (x applyWith: x)]]]. | Give a code snippet in #Slate
In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a va... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #Run_BASIC | Run BASIC | a$ = timeInfo$()
print " UTC:";word$(a$,1,"|")
print "Date:";word$(a$,2,"|")
print "Time:";word$(a$,3,"|")
wait
function timeInfo$()
utc$ = word$(word$(httpget$("http://tycho.usno.navy.mil/cgi-bin/timer.pl"),1,"UTC"),2,"<BR>") ' Universal time
d$ = date$()
t$ = time$()
timeInfo$ = utc$;"|";d$;"|";t$
end function | Give a code snippet in #Run_BASIC
Task
Show how to return more than one value from a function.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Additive_primes | Additive primes | Definitions
In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes.
Task
Write a program to determine (and show here) all additive primes less than 500.
Optionally, show the number of additive primes.
Also see
the OEIS entry: A046704 additive primes.
... | #FreeBASIC | FreeBASIC | #include "isprime.bas"
function digsum( n as uinteger ) as uinteger
dim as uinteger s
while n
s+=n mod 10
n\=10
wend
return s
end function
dim as uinteger s
print "Prime","Digit Sum"
for i as uinteger = 2 to 499
if isprime(i) then
s = digsum(i)
if isprime(s) the... | Give a code snippet in #FreeBASIC
Definitions
In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes.
Task
Write a program to determine (and show here) all additive primes less than 500.
Optionally, show the number of additive primes.
Also see
the OEIS en... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Leap_year | Leap year | Task
Determine whether a given year is a leap year in the Gregorian calendar.
See also
Leap year (wiki)
| #Bash | Bash |
#!/bin/bash
is_leap_year () # Define function named is_leap_year
{
declare -i year=$1 # declare integer variable "year" and set it to function parm 1
echo -n "$year ($2)-> " # print the year passed in, but do not go to the next line
if (( $year % 4 == 0 )) # if year not dividable by 4, then not a leap y... | Give a code snippet in #Bash
Task
Determine whether a given year is a leap year in the Gregorian calendar.
See also
Leap year (wiki)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/CSV_to_HTML_translation | CSV to HTML translation | Consider a simplified CSV format where all rows are separated by a newline
and all columns are separated by commas.
No commas are allowed as field data, but the data may contain
other characters and character sequences that would
normally be escaped when converted to HTML
Task
Create a function that takes a st... | #Prolog | Prolog | csv_html :-
L = "Character,Speech
The multitude,The messiah! Show us the messiah!
Brians mother,<angry>Now you listen here! He's not the messiah; he's a very naughty boy! Now go away!</angry>
The multitude,Who are you?
Brians mother,I'm his mother; that's who!
The multitude,Behold his mother! Behold his mother!",
c... | Give a code snippet in #Prolog
Consider a simplified CSV format where all rows are separated by a newline
and all columns are separated by commas.
No commas are allowed as field data, but the data may contain
other characters and character sequences that would
normally be escaped when converted to HTML
Task
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/State_name_puzzle | State name puzzle | Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearrange the letters to form the... | #Wren | Wren | import "/str" for Str
import "/sort" for Sort
import "/fmt" for Fmt
var solve = Fn.new { |states|
var dict = {}
for (state in states) {
var key = Str.lower(state).replace(" ", "")
if (!dict[key]) dict[key] = state
}
var keys = dict.keys.toList
Sort.quick(keys)
var solutions = [... | Give a code snippet in #Wren
Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rea... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_a_system_command | Execute a system command | Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| #Make | Make | contents=$(shell cat foo)
curdir=`pwd` | Give a code snippet in #Make
Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Palindrome_detection | Palindrome detection | A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly as a wrapper to the first) which ... | #PHP | PHP | <?php
function is_palindrome($string) {
return $string == strrev($string);
}
?> | Give a code snippet in #PHP
A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly as a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Magnanimous_numbers | Magnanimous numbers | A magnanimous number is an integer where there is no place in the number where a + (plus sign) could be added between any two digits to give a non-prime sum.
E.G.
6425 is a magnanimous number. 6 + 425 == 431 which is prime; 64 + 25 == 89 which is prime; 642 + 5 == 647 which is prime.
3538 is not a magnanimous numb... | #ALGOL_68 | ALGOL 68 | BEGIN # find some magnanimous numbers - numbers where inserting a + between any #
# digits ab=nd evaluatinf the sum results in a prime in all cases #
# returns the first n magnanimous numbers #
# uses global sieve prime which must include 0 and be large en... | Give a code snippet in #ALGOL_68
A magnanimous number is an integer where there is no place in the number where a + (plus sign) could be added between any two digits to give a non-prime sum.
E.G.
6425 is a magnanimous number. 6 + 425 == 431 which is prime; 64 + 25 == 89 which is prime; 642 + 5 == 647 which is prim... | 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... | #Lasso | Lasso | loop(-from=10, -to=0, -by=-1) => {^ loop_count + ' ' ^} | Give a code snippet in #Lasso
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/Increm... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitwise_operations | Bitwise operations |
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 |... | #Erlang | Erlang |
-module(bitwise_operations).
-export([test/0]).
test() ->
A = 255,
B = 170,
io:format("~p band ~p = ~p\n",[A,B,A band B]),
io:format("~p bor ~p = ~p\n",[A,B,A bor B]),
io:format("~p bxor ~p = ~p\n",[A,B,A bxor B]),
io:format("not ~p = ~p\n",[A,bnot A]),
io:format("~p bsl ~p = ~p\n",[A,B,A bsl... | Give a code snippet in #Erlang
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perlin_noise | Perlin noise | The Perlin noise is a kind of gradient noise invented by Ken Perlin around the end of the twentieth century and still currently heavily used in computer graphics, most notably to procedurally generate textures or heightmaps.
The Perlin noise is basically a pseudo-random mapping of
R
d
... | #Kotlin | Kotlin | // version 1.1.3
object Perlin {
private val permutation = intArrayOf(
151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7, 225,
140, 36, 103, 30, 69, 142, 8, 99, 37, 240, 21, 10, 23, 190, 6, 148,
247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 20... | Give a code snippet in #Kotlin
The Perlin noise is a kind of gradient noise invented by Ken Perlin around the end of the twentieth century and still currently heavily used in computer graphics, most notably to procedurally generate textures or heightmaps.
The Perlin noise is basically a pseudo-rando... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sleep | Sleep | Task
Write a program that does the following in this order:
Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
Print "Sleeping..."
Sleep the main thread for the given amount of time.
... | #ERRE | ERRE |
..............
INPUT("Enter the time to sleep in seconds: ";sleep)
PRINT("Sleeping...")
PAUSE(sleep)
PRINT("Awake!")
..............
| Give a code snippet in #ERRE
Task
Write a program that does the following in this order:
Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
Print "Sleeping..."
Sleep the main thread ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations_with_repetitions | Combinations with repetitions | The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of those sets is chosen from
S... | #JavaScript | JavaScript | <html><head><title>Donuts</title></head>
<body><pre id='x'></pre><script type="application/javascript">
function disp(x) {
var e = document.createTextNode(x + '\n');
document.getElementById('x').appendChild(e);
}
function pick(n, got, pos, from, show) {
var cnt = 0;
if (got.length == n) {
if (show) disp(got.joi... | Give a code snippet in #JavaScript
The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each membe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Achilles_numbers | Achilles numbers |
This page uses content from Wikipedia. The original article was at Achilles number. 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)
An Achilles number is a number that is powerful but imperfect. Na... | #Raku | Raku | use Prime::Factor;
use Math::Root;
sub is-square-free (Int \n) {
constant @p = ^100 .map: { next unless .is-prime; .² };
for @p -> \p { return False if n %% p }
True
}
sub powerful (\n, \k = 2) {
my @p;
p(1, 2*k - 1);
sub p (\m, \r) {
@p.push(m) and return if r < k;
for 1 .. ... | Give a code snippet in #Raku
This page uses content from Wikipedia. The original article was at Achilles number. 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)
An Achilles number is a number that... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Named_parameters | Named parameters | Create a function which takes in a number of arguments which are specified by name rather than (necessarily) position, and show how to call the function. If the language supports reordering the arguments or optionally omitting some of them, note this.
Note:
Named parameters relies on being able to use the names give... | #VBA | VBA |
Public Function timedelta(Optional weeks As Integer = 0, Optional days As Integer = 0, _
Optional hours As Integer = 0, Optional minutes As Integer = 0, Optional seconds As Integer = 0, _
Optional milliseconds As Integer = 0, Optional microseconds As Integer = 0) As Variant
End Function
Public Sub main()
... | Give a code snippet in #VBA
Create a function which takes in a number of arguments which are specified by name rather than (necessarily) position, and show how to call the function. If the language supports reordering the arguments or optionally omitting some of them, note this.
Note:
Named parameters relies on bei... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_search | Binary search | A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret number, and will only tell the p... | #ACL2 | ACL2 | (defun defarray (name size initial-element)
(cons name
(compress1 name
(cons (list :HEADER
:DIMENSIONS (list size)
:MAXIMUM-LENGTH (1+ size)
:DEFAULT initial-element
... | Give a code snippet in #ACL2
A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret nu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
Th... | #Crystal | Crystal | require "uri"
puts URI.decode "http%3A%2F%2Ffoo%20bar%2F"
puts URI.decode "google.com/search?q=%60Abdu%27l-Bah%C3%A1" | Give a code snippet in #Crystal
This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencode... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Damm_algorithm | Damm algorithm | The Damm algorithm is a checksum algorithm which detects all single digit errors and adjacent transposition errors.
The algorithm is named after H. Michael Damm.
Task
Verify the checksum, stored as last digit of an input.
| #Ruby | Ruby | TABLE = [
[0,3,1,7,5,9,8,6,4,2], [7,0,9,2,1,5,4,8,6,3],
[4,2,0,6,8,7,1,3,5,9], [1,7,5,0,9,8,3,4,2,6],
[6,1,2,3,0,4,5,9,7,8], [3,6,7,4,2,0,9,5,8,1],
[5,8,6,9,7,2,0,1,3,4], [8,9,4,5,3,6,2,0,1,7],
[9,4,3,8,6,1,7,2,0,5], [2,5,8,1,4,3,6,7,9,0]
]
def damm_valid?(n) = n.digits.reverse.inject(0){|idx, a| ... | Give a code snippet in #Ruby
The Damm algorithm is a checksum algorithm which detects all single digit errors and adjacent transposition errors.
The algorithm is named after H. Michael Damm.
Task
Verify the checksum, stored as last digit of an input.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime | Add a variable to a class instance at runtime | Demonstrate how to dynamically add variables to an object (a class instance) at runtime.
This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re... | #LOLCODE | LOLCODE | HAI 1.3
I HAS A object ITZ A BUKKIT
I HAS A name, I HAS A value
IM IN YR interface
VISIBLE "R U WANTIN 2 (A)DD A VAR OR (P)RINT 1? "!
I HAS A option, GIMMEH option
option, WTF?
OMG "A"
VISIBLE "NAME: "!, GIMMEH name
VISIBLE "VALUE: "!, GIMMEH value
object HAS A SRS name ITZ... | Give a code snippet in #LOLCODE
Demonstrate how to dynamically add variables to an object (a class instance) at runtime.
This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Meta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abbreviations,_easy | Abbreviations, easy | This task is an easier (to code) variant of the Rosetta Code task: Abbreviations, simple.
For this task, the following command table will be used:
Add ALTer BAckup Bottom CAppend Change SCHANGE CInsert CLAst COMPress COpy
COUnt COVerlay CURsor DELete CDelete Down DUPlicate Xedit EXPand EXTract Find
... | #Lua | Lua | #!/usr/bin/lua
local list1 = [[
Add ALTer BAckup Bottom CAppend Change SCHANGE CInsert CLAst
COMPress COpy COUnt COVerlay CURsor DELete CDelete Down DUPlicate
Xedit EXPand EXTract Find NFind NFINDUp NFUp CFind FINdup FUp
FOrward GET Help HEXType Input POWerinput Join SPlit SPLTJOIN
LOAD Locate CLocate LOW... | Give a code snippet in #Lua
This task is an easier (to code) variant of the Rosetta Code task: Abbreviations, simple.
For this task, the following command table will be used:
Add ALTer BAckup Bottom CAppend Change SCHANGE CInsert CLAst COMPress COpy
COUnt COVerlay CURsor DELete CDelete Down DUPlica... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parsing/Shunting-yard_algorithm | Parsing/Shunting-yard algorithm | Task
Given the operator characteristics and input from the Shunting-yard algorithm page and tables, use the algorithm to show the changes in the operator stack and RPN output
as each individual token is processed.
Assume an input of a correct, space separated, string of tokens representing an infix expression
Gener... | #Raku | Raku | my %prec =
'^' => 4,
'*' => 3,
'/' => 3,
'+' => 2,
'-' => 2,
'(' => 1;
my %assoc =
'^' => 'right',
'*' => 'left',
'/' => 'left',
'+' => 'left',
'-' => 'left';
sub shunting-yard ($prog) {
my @inp = $prog.words;
my @ops;
my @res;
sub report($op) { printf "... | Give a code snippet in #Raku
Task
Given the operator characteristics and input from the Shunting-yard algorithm page and tables, use the algorithm to show the changes in the operator stack and RPN output
as each individual token is processed.
Assume an input of a correct, space separated, string of tokens represent... | 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 |... | #Julia | Julia | using Primes
function factors(n)
f = [one(n)]
for (p,e) in factor(n)
f = reduce(vcat, [f*p^j for j in 1:e], init=f)
end
return length(f) == 1 ? [one(n), n] : sort!(f)
end
const examples = [28, 45, 53, 64, 6435789435768]
for n in examples
@time println("The factors of $n are: $(factors(... | Give a code snippet in #Julia
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
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations | Permutations | Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations generation tasks.
Order Uni... | #ALGOL_68 | ALGOL 68 | # -*- coding: utf-8 -*- #
COMMENT REQUIRED BY "prelude_permutations.a68"
MODE PERMDATA = ~;
PROVIDES:
# PERMDATA*=~* #
# perm*=~ list* #
END COMMENT
MODE PERMDATALIST = REF[]PERMDATA;
MODE PERMDATALISTYIELD = PROC(PERMDATALIST)VOID;
# Generate permutations of the input data list of data list #
PROC perm gen per... | Give a code snippet in #ALGOL_68
Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations g... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat... | #Octave | Octave | # not a function file:
1;
function fun = foo(init)
currentSum = init;
fun = @(add) currentSum = currentSum + add; currentSum;
endfunction
x = foo(1);
x(5);
foo(3);
disp(x(2.3)); | Give a code snippet in #Octave
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values pa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Population_count | Population count | Population count
You are encouraged to solve this task according to the task description, using any language you may know.
The population count is the number of 1s (ones) in the binary representation of a non-negative integer.
Population count is also known as:
pop count
popcount
sideways sum
... | #JavaScript | JavaScript | (() => {
'use strict';
// populationCount :: Int -> Int
const populationCount = n =>
// The number of non-zero bits in the binary
// representation of the integer n.
sum(unfoldr(
x => 0 < x ? (
Just(Tuple(x % 2)(Math.floor(x / 2)))
) : Nothin... | Give a code snippet in #JavaScript
Population count
You are encouraged to solve this task according to the task description, using any language you may know.
The population count is the number of 1s (ones) in the binary representation of a non-negative integer.
Population count is also known as:
pop ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Simple_database | Simple database | Task
Write a simple tool to track a small set of data.
The tool should have a command-line interface to enter at least two different values.
The entered data should be stored in a structured format and saved to disk.
It does not matter what kind of data is being tracked. It could be a collection (CDs, coins, base... | #Erlang | Erlang |
#! /usr/bin/env escript
-compile({no_auto_import,[date/0]}).
main( ["add", Tag | Descriptions] ) -> add( date(), Tag, Descriptions );
main( ["add_date", Date, Tag | Descriptions] ) -> add( date_internal(string:tokens(Date, "-")), Tag, Descriptions );
main( ["print_latest"] ) -> print_latest( contents() );
main( [... | Give a code snippet in #Erlang
Task
Write a simple tool to track a small set of data.
The tool should have a command-line interface to enter at least two different values.
The entered data should be stored in a structured format and saved to disk.
It does not matter what kind of data is being tracked. It could b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations | Permutations | Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations generation tasks.
Order Uni... | #Maple | Maple | combinat:-permute(3);
[[1, 2, 3], [1, 3, 2], [2, 1, 3], [2, 3, 1], [3, 1, 2], [3, 2, 1]]
combinat:-permute([a,b,c]);
[[a, b, c], [a, c, b], [b, a, c], [b, c, a], [c, a, b], [c, b, a]] | Give a code snippet in #Maple
Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations gene... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Array_length | Array length | Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I befo... | #Dart | Dart |
arrLength(arr) {
return arr.length;
}
main() {
var fruits = ['apple', 'orange'];
print(arrLength(fruits));
}
| Give a code snippet in #Dart
Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter freque... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_Brain**** | Execute Brain**** | Execute Brain**** is an implementation of Brainf***.
Other implementations of Brainf***.
RCBF is a set of Brainf*** compilers and interpreters written for Rosetta Code in a variety of languages.
Below are links to each of the versions of RCBF.
An implementation need only properly implement the following instructions:... | #Elena | Elena | USE: brainf***
"++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++." run-brainf*** | Give a code snippet in #Elena
Execute Brain**** is an implementation of Brainf***.
Other implementations of Brainf***.
RCBF is a set of Brainf*** compilers and interpreters written for Rosetta Code in a variety of languages.
Below are links to each of the versions of RCBF.
An implementation need only properly implem... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_numbers | Perfect numbers | Write a function which says whether a number is perfect.
A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself.
Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself).
Note: The faster Luca... | #Elixir | Elixir | defmodule RC do
def is_perfect(1), do: false
def is_perfect(n) when n > 1 do
Enum.sum(factor(n, 2, [1])) == n
end
defp factor(n, i, factors) when n < i*i , do: factors
defp factor(n, i, factors) when n == i*i , do: [i | factors]
defp factor(n, i, factors) when rem(n,i)==0, do: factor(n, i+1, [i, ... | Give a code snippet in #Elixir
Write a function which says whether a number is perfect.
A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself.
Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itsel... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Palindrome_detection | Palindrome detection | A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly as a wrapper to the first) which ... | #Delphi | Delphi | uses
SysUtils, StrUtils;
function IsPalindrome(const aSrcString: string): Boolean;
begin
Result := SameText(aSrcString, ReverseString(aSrcString));
end; | Give a code snippet in #Delphi
A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_an_array_of_composite_structures | Sort an array of composite structures |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Kotlin | Kotlin | // version 1.1
data class Employee(val name: String, var category: String) : Comparable<Employee> {
override fun compareTo(other: Employee) = this.name.compareTo(other.name)
}
fun main(args: Array<String>) {
val employees = arrayOf(
Employee("David", "Manager"),
Employee("Alice", "Sales"),
... | Give a code snippet in #Kotlin
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 s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pascal%27s_triangle | Pascal's triangle | Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either 1 or the sum of the two elemen... | #Excel | Excel | PASCAL
=LAMBDA(n,
BINCOEFF(n - 1)(
SEQUENCE(1, n, 0, 1)
)
)
BINCOEFF
=LAMBDA(n,
LAMBDA(k,
QUOTIENT(FACT(n), FACT(k) * FACT(n - k))
)
) | Give a code snippet in #Excel
Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_to_Windows_event_log | Write to Windows event log | Task
Write script status to the Windows Event Log
| #PowerShell | PowerShell | # Create Event Log object
$EventLog=new-object System.Diagnostics.EventLog("Application")
#Declare Event Source; must be 'registered' with Windows
$EventLog.Source="Application" # It is possible to register a new source (see Note2)
# Setup the Event Types; you don't have to use them all, but I'm including all the possi... | Give a code snippet in #PowerShell
Task
Write script status to the Windows Event Log
| christopher/rosetta-code | |
http://rosettacode.org/wiki/ABC_problem | ABC problem | ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet is guaranteed amongst all sid... | #CLU | CLU | ucase = proc (s: string) returns (string)
rslt: array[char] := array[char]$predict(1,string$size(s))
for c: char in string$chars(s) do
if c>='a' & c<='z' then
c := char$i2c(char$c2i(c) - 32)
end
array[char]$addh(rslt,c)
end
return(string$ac2s(rslt))
end ucase
abc... | Give a code snippet in #CLU
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/GUI_component_interaction | GUI component interaction |
Almost every application needs to communicate with the user in some way.
Therefore, a substantial part of the code deals with the interaction
of program logic with GUI components.
Typically, the following is needed:
put values into input fields under program control
read and check input from the user
pop up dial... | #Common_Lisp | Common Lisp |
;; Using the LTK library...
(defun gui-test ()
"the main window for the input test"
(ltk:with-ltk ()
(ltk:wm-title ltk:*tk* "GUI Test")
(ltk:bind ltk:*tk* "<Alt-q>" (lambda (evt)
(declare (ignore evt))
(setf ltk:*exit-mainloop* t)))
(let* (;; Initializing random generator
(*random-... | Give a code snippet in #Common_Lisp
Almost every application needs to communicate with the user in some way.
Therefore, a substantial part of the code deals with the interaction
of program logic with GUI components.
Typically, the following is needed:
put values into input fields under program control
read and c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Harshad_or_Niven_series | Harshad or Niven series | The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task is to create a function/method/... | #BQN | BQN | SumDgt ← +´•Fmt-'0'˙
Niven ← 0=SumDgt|⊢
nivens ← Niven¨⊸/↕1100
⟨20↑nivens, ⊑(⊢>1000˙)⊸/nivens⟩ | Give a code snippet in #BQN
The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task is... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Monads/Writer_monad | Monads/Writer monad | The Writer monad is a programming design pattern which makes it possible to compose functions which return their result values paired with a log string. The final result of a composed function yields both a value, and a concatenation of the logs from each component function application.
Demonstrate in your programming... | #C.2B.2B | C++ | #include <cmath>
#include <iostream>
#include <string>
using namespace std;
// Use a struct as the monad
struct LoggingMonad
{
double Value;
string Log;
};
// Use the >> operator as the bind function
auto operator>>(const LoggingMonad& monad, auto f)
{
auto result = f(monad.Value);
return LoggingM... | Give a code snippet in #C.2B.2B
The Writer monad is a programming design pattern which makes it possible to compose functions which return their result values paired with a log string. The final result of a composed function yields both a value, and a concatenation of the logs from each component function application.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jensen%27s_Device | Jensen's Device | Jensen's Device
You are encouraged to solve this task according to the task description, using any language you may know.
This task is an exercise in call by name.
Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the ALGOL 60 Report.
The following pr... | #Seed7 | Seed7 |
$ include "seed7_05.s7i";
include "float.s7i";
var integer: i is 0;
const func float: sum (inout integer: i, in integer: lo, in integer: hi,
ref func float: term) is func
result
var float: sum is 0.0
begin
for i range lo to hi do
sum +:= term;
end for;
end func;
const proc: main is... | Give a code snippet in #Seed7
Jensen's Device
You are encouraged to solve this task according to the task description, using any language you may know.
This task is an exercise in call by name.
Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the ALG... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conway%27s_Game_of_Life | Conway's Game of Life | The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, in an m-by-m (or m×m) sq... | #ZPL | ZPL | program Life;
config var
n : integer = 100;
region
BigR = [0 .. n+1, 0 .. n+1];
R = [1 .. n, 1 .. n ];
direction
nw = [-1, -1]; north = [-1, 0]; ne = [-1, 1];
west = [ 0, -1]; east = [ 0, 1];
sw = [ 1, -1]; south = [ 1, 0]; se = [ 1, 1];
var
TW... | Give a code snippet in #ZPL
The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation | Horner's rule for polynomial evaluation | A fast scheme for evaluating a polynomial such as:
−
19
+
7
x
−
4
x
2
+
6
x
3
{\displaystyle -19+7x-4x^{2}+6x^{3}\,}
when
x
=
3
{\displaystyle x=3\;}
.
is to arrange the computation as follows:
(
(
(
(
0
)
x
+
6
)
x
+
(
−
4
)
)
x
+
7
)
x
+
(
−
19
)
{\displaystyle ((((0)x+6)x+(-4))x... | #APL | APL | h←⊥∘⌽ | Give a code snippet in #APL
A fast scheme for evaluating a polynomial such as:
−
19
+
7
x
−
4
x
2
+
6
x
3
{\displaystyle -19+7x-4x^{2}+6x^{3}\,}
when
x
=
3
{\displaystyle x=3\;}
.
is to arrange the computation as follows:
(
(
(
(
0
)
x
+
6
)
x
+
(
−
4
)
)
x
+
7
)
x
+
(
−
19
)
{\di... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Character_codes | Character codes |
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out... | #ALGOL_W | ALGOL W | begin
% display the character code of "a" (97 in ASCII) %
write( decode( "a" ) );
% display the character corresponding to 97 ("a" in ASCII) %
write( code( 97 ) );
end. | Give a code snippet in #ALGOL_W
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ray-casting_algorithm | Ray-casting algorithm |
This page uses content from Wikipedia. The original article was at Point_in_polygon. 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)
Given a point and a polygon, check if the point is inside or out... | #C.2B.2B | C++ | #include <algorithm>
#include <cstdlib>
#include <iomanip>
#include <iostream>
#include <limits>
using namespace std;
const double epsilon = numeric_limits<float>().epsilon();
const numeric_limits<double> DOUBLE;
const double MIN = DOUBLE.min();
const double MAX = DOUBLE.max();
struct Point { const double x, y; }... | Give a code snippet in #C.2B.2B
This page uses content from Wikipedia. The original article was at Point_in_polygon. 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)
Given a point and a polygon, ch... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Runge-Kutta_method | Runge-Kutta method | Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This equation has an exact solution:
... | #BASIC | BASIC | y = 1
for i = 0 to 100
t = i / 10
if t = int(t) then
actual = ((t ^ 2 + 4) ^ 2) / 16
print "y("; int(t); ") = "; left(string(y), 13), "Error = "; left(string(actual - y), 13)
end if
k1 = t * sqr(y)
k2 = (t + 0.05) * sqr(y + 0.05 * k1)
k3 = (t + 0.05) * sqr(y + 0.05 * k2)
k4 = (t + 0.10... | Give a code snippet in #BASIC
Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This eq... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #Python | Python | import os;
if os.listdir(raw_input("directory")):
print "not empty"
else:
print "empty"
| Give a code snippet in #Python
Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_occurrences_of_a_substring | Count occurrences of a substring | Task
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
the first argument being the string to search, and
the second a substring to be searched for.
It should return an integer cou... | #Java | Java | public class CountSubstring {
public static int countSubstring(String subStr, String str){
return (str.length() - str.replace(subStr, "").length()) / subStr.length();
}
public static void main(String[] args){
System.out.println(countSubstring("th", "the three truths"));
System.out.println(countSubstring("aba... | Give a code snippet in #Java
Task
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
the first argument being the string to search, and
the second a substring to be searched for.
I... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Window_creation | Window creation | Display a GUI window. The window need not have any contents, but should respond to requests to be closed.
| #Toka | Toka | needs sdl
800 600 sdl_setup
| Give a code snippet in #Toka
Display a GUI window. The window need not have any contents, but should respond to requests to be closed.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Magic_squares_of_odd_order | Magic squares of odd order | A magic square is an NxN square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column, and both long (main) diagonals are equal to the same sum (which is called the magic number or magic constant).
The numbers are usually (but not always) t... | #Icon_and_Unicon | Icon and Unicon | procedure main(A)
n := integer(!A) | 3
write("Magic number: ",n*(n*n+1)/2)
sq := buildSquare(n)
showSquare(sq)
end
procedure buildSquare(n)
sq := [: |list(n)\n :]
r := 0
c := n/2
every i := !(n*n) do {
/sq[r+1,c+1] := i
nr := (n+r-1)%n
nc := (c+1)%n
if /... | Give a code snippet in #Icon_and_Unicon
A magic square is an NxN square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column, and both long (main) diagonals are equal to the same sum (which is called the magic number or magic constant).
T... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Nonogram_solver | Nonogram solver | A nonogram is a puzzle that provides
numeric clues used to fill in a grid of cells,
establishing for each cell whether it is filled or not.
The puzzle solution is typically a picture of some kind.
Each row and column of a rectangular grid is annotated with the lengths
of its distinct runs of occupied cells.
Using only... | #D | D | import std.stdio, std.range, std.file, std.algorithm, std.string;
/// Create all patterns of a row or col that match given runs.
auto genRow(in int w, in int[] s) pure nothrow @safe {
static int[][] genSeg(in int[][] o, in int sp) pure nothrow @safe {
if (o.empty)
return [[2].replicate(sp)];
... | Give a code snippet in #D
A nonogram is a puzzle that provides
numeric clues used to fill in a grid of cells,
establishing for each cell whether it is filled or not.
The puzzle solution is typically a picture of some kind.
Each row and column of a rectangular grid is annotated with the lengths
of its distinct runs of... | 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... | #Nim | Nim | proc print(xs: varargs[string, `$`]) =
for x in xs:
echo x | Give a code snippet in #Nim
Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Rel... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Last_Friday_of_each_month | Last Friday of each month | Task
Write a program or a script that returns the date of the last Fridays of each month of a given year.
The year may be given through any simple input method in your language (command line, std in, etc).
Example of an expected output:
./last_fridays 2012
2012-01-27
2012-02-24
2012-03-30
2012-04-27
2012-05-25
20... | #Elixir | Elixir | defmodule RC do
def lastFriday(year) do
Enum.map(1..12, fn month ->
lastday = :calendar.last_day_of_the_month(year, month)
daynum = :calendar.day_of_the_week(year, month, lastday)
friday = lastday - rem(daynum + 2, 7)
{year, month, friday}
end)
end
end
y = String.to_integer(hd(Syst... | Give a code snippet in #Elixir
Task
Write a program or a script that returns the date of the last Fridays of each month of a given year.
The year may be given through any simple input method in your language (command line, std in, etc).
Example of an expected output:
./last_fridays 2012
2012-01-27
2012-02-24
201... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Here_document | Here document | A here document (or "heredoc") is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text.
Depending on the language being used, a here document is constructed using a command followed by "<<" (or some other symbol) followed by a token string.
The text ... | #Run_BASIC | Run BASIC | text$ ="
<<'FOO'
Now
is
the
time
for
all
good mem
to come to the aid of their country."
print text$ | Give a code snippet in #Run_BASIC
A here document (or "heredoc") is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text.
Depending on the language being used, a here document is constructed using a command followed by "<<" (or some other symbol) fol... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mandelbrot_set | Mandelbrot set | Mandelbrot set
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw the Mandelbrot set.
Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
| #Scala | Scala | import org.rosettacode.ArithmeticComplex._
import java.awt.Color
object Mandelbrot
{
def generate(width:Int =600, height:Int =400)={
val bm=new RgbBitmap(width, height)
val maxIter=1000
val xMin = -2.0
val xMax = 1.0
val yMin = -1.0
val yMax = 1.0
val cx=(xMax-xMin)/... | Give a code snippet in #Scala
Mandelbrot set
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw the Mandelbrot set.
Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Pythagorean_means | Averages/Pythagorean means | Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldots ,x_{n})}
for this set of p... | #Pascal | Pascal | sub A
{
my $a = 0;
$a += $_ for @_;
return $a / @_;
}
sub G
{
my $p = 1;
$p *= $_ for @_;
return $p**(1/@_); # power of 1/n == root of n
}
sub H
{
my $h = 0;
$h += 1/$_ for @_;
return @_/$h;
}
my @ints = (1..10);
my $a = A(@ints);
my $g = G(@int... | Give a code snippet in #Pascal
Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ld... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Move-to-front_algorithm | Move-to-front algorithm | Given a symbol table of a zero-indexed array of all possible input symbols
this algorithm reversibly transforms a sequence
of input symbols into an array of output numbers (indices).
The transform in many cases acts to give frequently repeated input symbols
lower indices which is useful in some compression algorithms... | #VBScript | VBScript | Function mtf_encode(s)
'create the array list and populate it with the initial symbol position
Set symbol_table = CreateObject("System.Collections.ArrayList")
For j = 97 To 122 'a to z in decimal.
symbol_table.Add Chr(j)
Next
output = ""
For i = 1 To Len(s)
char = Mid(s,i,1)
If i = Len(s) Then
output = o... | Give a code snippet in #VBScript
Given a symbol table of a zero-indexed array of all possible input symbols
this algorithm reversibly transforms a sequence
of input symbols into an array of output numbers (indices).
The transform in many cases acts to give frequently repeated input symbols
lower indices which is use... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Type IntFunc As Function(As Integer, As Integer) As Integer
Function reduce(a() As Integer, f As IntFunc) As Integer
'' if array is empty or function pointer is null, return 0 say
If UBound(a) = -1 OrElse f = 0 Then Return 0
Dim result As Integer = a(LBound(a))
For i As Integer = LB... | Give a code snippet in #FreeBASIC
Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Standard_error | Hello world/Standard error | Hello world/Standard error is part of Short Circuit's Console Program Basics selection.
A common practice in computing is to send error messages
to a different output stream than normal text console messages.
The normal messages print to what is called "standard output" or "standard out".
The error messages print to ... | #ooRexx | ooRexx | .error~lineout("Goodbye, World!") | Give a code snippet in #ooRexx
Hello world/Standard error is part of Short Circuit's Console Program Basics selection.
A common practice in computing is to send error messages
to a different output stream than normal text console messages.
The normal messages print to what is called "standard output" or "standard out... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number | Guess the number | Task
Write a program where the program chooses a number between 1 and 10.
A player is then prompted to enter a guess. If the player guesses wrong, then the prompt appears again until the guess is correct.
When the player has made a successful guess the computer will issue a "Well guessed!" message, a... | #Kotlin | Kotlin | // version 1.0.5-2
fun main(args: Array<String>) {
val n = (1 + java.util.Random().nextInt(10)).toString()
println("Guess which number I've chosen in the range 1 to 10\n")
do { print(" Your guess : ") } while (n != readLine())
println("\nWell guessed!")
} | Give a code snippet in #Kotlin
Task
Write a program where the program chooses a number between 1 and 10.
A player is then prompted to enter a guess. If the player guesses wrong, then the prompt appears again until the guess is correct.
When the player has made a successful guess the computer will issue a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Leonardo_numbers | Leonardo numbers |
Leonardo numbers are also known as the Leonardo series.
The Leonardo numbers are a sequence of numbers defined by:
L(0) = 1 [1st equation]
L(1) = 1 [2nd equation]
L(n) = L(n-1) + L(n-2) + 1 ... | #Lua | Lua | function leoNums (n, L0, L1, add)
local L0, L1, add = L0 or 1, L1 or 1, add or 1
local lNums, nextNum = {L0, L1}
while #lNums < n do
nextNum = lNums[#lNums] + lNums[#lNums - 1] + add
table.insert(lNums, nextNum)
end
return lNums
end
function show (msg, t)
print(msg .. ":")
for i, x in ipairs(t) ... | Give a code snippet in #Lua
Leonardo numbers are also known as the Leonardo series.
The Leonardo numbers are a sequence of numbers defined by:
L(0) = 1 [1st equation]
L(1) = 1 [2nd equation]
L(n) = L... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Angle_difference_between_two_bearings | Angle difference between two bearings | Finding the angle between two bearings is often confusing.[1]
Task
Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings.
Input bearings are expressed in the range -180 to +180 degrees.
The result is also expressed in the range -180 to +180 degrees.
... | #FreeBASIC | FreeBASIC | ' version 28-01-2019
' compile with: fbc -s console
#Include "string.bi"
Function frmt(num As Double) As String
Dim As String temp = Format(num, "#######.#############")
Dim As Integer i = Len(temp) -1
If temp[i] = Asc(".") Then temp[i] = 32
If InStr(temp, ".") = 0 Then
Return Right(Spac... | Give a code snippet in #FreeBASIC
Finding the angle between two bearings is often confusing.[1]
Task
Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings.
Input bearings are expressed in the range -180 to +180 degrees.
The result is also expressed in the rang... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Break_OO_privacy | Break OO privacy | Show how to access private or protected members of a class in an object-oriented language from outside an instance of the class, without calling non-private or non-protected members of the class as a proxy.
The intent is to show how a debugger, serializer, or other meta-programming tool might access information that is... | #Factor | Factor | ( scratchpad ) USING: sets sets.private ;
( scratchpad ) { 1 2 3 } { 1 2 4 } sequence/tester count .
2 | Give a code snippet in #Factor
Show how to access private or protected members of a class in an object-oriented language from outside an instance of the class, without calling non-private or non-protected members of the class as a proxy.
The intent is to show how a debugger, serializer, or other meta-programming tool ... | 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.
| #OCaml | OCaml | Sys.remove "input.txt";;
Sys.remove "/input.txt";; | Give a code snippet in #OCaml
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/Arithmetic/Complex | Arithmetic/Complex | A complex number is a number which can be written as:
a
+
b
×
i
{\displaystyle a+b\times i}
(sometimes shown as:
b
+
a
×
i
{\displaystyle b+a\times i}
where
a
{\displaystyle a}
and
b
{\displaystyle b}
are real numbers, and
i
{\displaystyle i}
is √ -1
Typica... | #ERRE | ERRE |
PROGRAM COMPLEX_ARITH
TYPE COMPLEX=(REAL#,IMAG#)
DIM X:COMPLEX,Y:COMPLEX,Z:COMPLEX
!
! complex arithmetic routines
!
DIM A:COMPLEX,B:COMPLEX,C:COMPLEX
PROCEDURE ADD(A.,B.->C.)
C.REAL#=A.REAL#+B.REAL#
C.IMAG#=A.IMAG#+B.IMAG#
END PROCEDURE
PROCEDURE INV(A.->B.)
LOCAL DENOM#
DENOM#=A.REAL#^2+A.IM... | Give a code snippet in #ERRE
A complex number is a number which can be written as:
a
+
b
×
i
{\displaystyle a+b\times i}
(sometimes shown as:
b
+
a
×
i
{\displaystyle b+a\times i}
where
a
{\displaystyle a}
and
b
{\displaystyle b}
are real numbers, and
i
{\displaysty... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_that_file_exists | Check that file exists | Task
Verify that a file called input.txt and a directory called docs exist.
This should be done twice:
once for the current working directory, and
once for a file and a directory in the filesystem root.
Optional criteria (May 2015): verify it works with:
zero-length files
an ... | #Phix | Phix | without js -- (file i/o)
procedure check(string name)
bool bExists = file_exists(name),
bDir = get_file_type(name)=FILETYPE_DIRECTORY
string exists = iff(bExists?"exists":"does not exist"),
dfs = iff(bExists?iff(bDir?"directory ":"file "):"")
printf(1,"%s%s %s.\n",{dfs,name,exists})
end ... | Give a code snippet in #Phix
Task
Verify that a file called input.txt and a directory called docs exist.
This should be done twice:
once for the current working directory, and
once for a file and a directory in the filesystem root.
Optional criteria (May 2015): verify it works with... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Numeric_error_propagation | Numeric error propagation | If f, a, and b are values with uncertainties σf, σa, and σb, and c is a constant;
then if f is derived from a, b, and c in the following ways,
then σf can be calculated as follows:
Addition/Subtraction
If f = a ± c, or f = c ± a then σf = σa
If f = a ± b then... | #Perl | Perl | use utf8;
package ErrVar;
use strict;
# helper function, apply f to pairs (a, b) from listX and listY
sub zip(&$$) {
my ($f, $x, $y) = @_;
my $l = $#$x;
if ($l < $#$y) { $l = $#$y };
my @out;
for (0 .. $l) {
local $a = $x->[$_];
local $b = $y->[$_];
push @out, $f->();
}
\@out
}
use overload
'""' => ... | Give a code snippet in #Perl
If f, a, and b are values with uncertainties σf, σa, and σb, and c is a constant;
then if f is derived from a, b, and c in the following ways,
then σf can be calculated as follows:
Addition/Subtraction
If f = a ± c, or f = c ± a then ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously | Loop over multiple arrays simultaneously | Task
Loop over multiple arrays (or lists or tuples or whatever they're called in
your language) and display the i th element of each.
Use your language's "for each" loop if it has one, otherwise iterate
through the collection in order with some other loop.
For this example, loop over the arrays:
... | #Lambdatalk | Lambdatalk |
1) loop over 3 sentences of equal length and returning 3 sentences
{def A a b c} -> A
{def B A B C} -> B
{def C 1 2 3} -> C
{S.map {lambda {:i} {br}{S.get :i {A}}
{S.get :i {B}}
{S.get :i {C}} }
{S.serie 0 {- {S.length {A}} 1}}}
->
a A 1
b B 2
c C 3
2) ... | Give a code snippet in #Lambdatalk
Task
Loop over multiple arrays (or lists or tuples or whatever they're called in
your language) and display the i th element of each.
Use your language's "for each" loop if it has one, otherwise iterate
through the collection in order with some other loop.
For this... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hunt_the_Wumpus | Hunt the Wumpus | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Create a simple implementation of the classic textual game Hunt The Wumpus.
The rules are:
The game is set in a cave that consists ... | #Shale | Shale |
#!/usr/local/bin/shale
// This is an implementation of the old game called Hunt the Wumpus.
//
// You can read about it here: https://en.wikipedia.org/wiki/Hunt_the_Wumpus
//
// Here's a quick summary:
//
// You are in a maze of 20 rooms, numbered 1 through 20. Each room is connected to
// 3 other rooms. There is n... | Give a code snippet in #Shale
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Create a simple implementation of the classic textual game Hunt The Wumpus.
The rules are:
The game ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_comments_from_a_string | Strip comments from a string | Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line.
Whitespace debacle: There is s... | #Red | Red |
>> parse s: "apples, pears ; and bananas" [to [any space ";"] remove thru end]
== true
>> s
== "apples, pears"
| Give a code snippet in #Red
Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line.
Whi... | christopher/rosetta-code |
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