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/Bitmap | Bitmap | Show a basic storage type to handle a simple RGB raster graphics image,
and some primitive associated functions.
If possible provide a function to allocate an uninitialised image,
given its width and height, and provide 3 additional functions:
one to fill an image with a plain RGB color,
one to set a given pixe... | #C | C | #ifndef _IMGLIB_0
#define _IMGLIB_0
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <string.h>
#include <math.h>
#include <sys/queue.h>
typedef unsigned char color_component;
typedef color_component pixel[3];
typedef struct {
unsigned int width;
unsigned int height;
pixel * buf;
}... | Give a code snippet in #C
Show a basic storage type to handle a simple RGB raster graphics image,
and some primitive associated functions.
If possible provide a function to allocate an uninitialised image,
given its width and height, and provide 3 additional functions:
one to fill an image with a plain RGB color,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reverse_words_in_a_string | Reverse words in a string | Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spaces (formally, white-space); t... | #Emacs_Lisp | Emacs Lisp | (defun reverse-words (line)
(insert
(format "%s\n"
(mapconcat 'identity (reverse (split-string line)) " "))))
(defun reverse-lines (lines)
(mapcar 'reverse-words lines))
(reverse-lines
'("---------- Ice and Fire ------------"
""
"fire, in end will world the say Some"
"ice. in say Some"
... | Give a code snippet in #Emacs_Lisp
Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Feigenbaum_constant_calculation | Feigenbaum constant calculation | Task
Calculate the Feigenbaum constant.
See
Details in the Wikipedia article: Feigenbaum constant.
| #FreeBASIC | FreeBASIC | ' version 25-0-2019
' compile with: fbc -s console
Dim As UInteger i, j, k, maxit = 13, maxitj = 13
Dim As Double x, y, a, a1 = 1, a2, d, d1 = 3.2
Print "Feigenbaum constant calculation:"
Print
Print " i d"
Print "==================="
For i = 2 To maxIt
a = a1 + (a1 - a2) / d1
For j = 1 To maxItJ
... | Give a code snippet in #FreeBASIC
Task
Calculate the Feigenbaum constant.
See
Details in the Wikipedia article: Feigenbaum constant.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Thiele%27s_interpolation_formula | Thiele's interpolation formula |
This page uses content from Wikipedia. The original article was at Thiele's interpolation formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Thiele's interpolation formula is an interpolation ... | #Haskell | Haskell | thiele :: [Double] -> [Double] -> Double -> Double
thiele xs ys = f rho1 (tail xs)
where
f _ [] _ = 1
f r@(r0:r1:r2:rs) (x:xs) v = r2 - r0 + (v - x) / f (tail r) xs v
rho1 = (!! 1) . (++ [0]) <$> rho
rho = repeat 0 : repeat 0 : ys : rnext (tail rho) xs (tail xs)
where
rnext _ _ [] = []
... | Give a code snippet in #Haskell
This page uses content from Wikipedia. The original article was at Thiele's interpolation formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Thiele's interpola... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_language_name_in_3D_ASCII | Write language name in 3D ASCII | Task
Write/display a language's name in 3D ASCII.
(We can leave the definition of "3D ASCII" fuzzy,
so long as the result is interesting or amusing,
not a cheap hack to satisfy the task.)
Related tasks
draw a sphere
draw a cuboid
draw a rotating cube
draw a Deathstar
| #BASIC | BASIC | 10 S$ = "BASIC" : REM OUR LANGUAGE NAME
20 DIM B(5,5) : REM OUR BIGMAP CHARACTERS
30 FOR L = 1 TO 5 : REM 5 CHARACTERS
40 FOR M = 1 TO 5 : REM 5 ROWS
50 READ B(L,M)
60 NEXT M, L
100 GR : REM BLACK BACKGROUND
110 COLOR = 1 : REM OUR SHADOW WILL BE RED
120 HOME : REM CLS
130 R = 9 : REM SHADOW WILL START ON... | Give a code snippet in #BASIC
Task
Write/display a language's name in 3D ASCII.
(We can leave the definition of "3D ASCII" fuzzy,
so long as the result is interesting or amusing,
not a cheap hack to satisfy the task.)
Related tasks
draw a sphere
draw a cuboid
draw a rotating cube
draw a Deathstar
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_totient_numbers | Perfect totient numbers | Generate and show here, the first twenty Perfect totient numbers.
Related task
Totient function
Also see
the OEIS entry for perfect totient numbers.
mrob list of the first 54
| #Arturo | Arturo | totient: function [n][
tt: new n
nn: new n
i: new 2
while [nn >= i ^ 2][
if zero? nn % i [
while [zero? nn % i]->
'nn / i
'tt - tt/i
]
if i = 2 ->
i: new 1
'i + 2
]
if nn > 1 ->
'tt - tt/nn
ret... | Give a code snippet in #Arturo
Generate and show here, the first twenty Perfect totient numbers.
Related task
Totient function
Also see
the OEIS entry for perfect totient numbers.
mrob list of the first 54
| christopher/rosetta-code | |
http://rosettacode.org/wiki/M%C3%B6bius_function | Möbius function | The classical Möbius function: μ(n) is an important multiplicative function in number theory and combinatorics.
There are several ways to implement a Möbius function.
A fairly straightforward method is to find the prime factors of a positive integer n, then define μ(n) based on the sum of the primitive factors. It ha... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | Grid[Partition[MoebiusMu[Range[99]], UpTo[10]]] | Give a code snippet in #Mathematica.2FWolfram_Language
The classical Möbius function: μ(n) is an important multiplicative function in number theory and combinatorics.
There are several ways to implement a Möbius function.
A fairly straightforward method is to find the prime factors of a positive integer n, then defi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bulls_and_cows | Bulls and cows | Bulls and Cows
Task
Create a four digit random number from the digits 1 to 9, without duplication.
The program should:
ask for guesses to this number
reject guesses that are malformed
print the score for the guess
The score is computed as:
The player wins if the guess is the same as the random... | #Nanoquery | Nanoquery | import Nanoquery.Util; random = new(Random)
// a function to verify the user's input
def verify_digits(input)
global size
seen = ""
if len(input) != size
return false
else
for char in input
if not char in "0123456789"
return false
else if char in seen
return false
end
seen += char
en... | Give a code snippet in #Nanoquery
Bulls and Cows
Task
Create a four digit random number from the digits 1 to 9, without duplication.
The program should:
ask for guesses to this number
reject guesses that are malformed
print the score for the guess
The score is computed as:
The player wins if ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/0-1 | Knapsack problem/0-1 | A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature, so he needs to pack well for the trip.
He has a good knapsack for carrying things, but knows that he can carry a maximum of only 4kg in it, and it will have to last the whole day.
He cre... | #Crystal | Crystal | require "bit_array"
struct BitArray
def clone
BitArray.new(size).tap { |new| new.to_slice.copy_from (to_slice) }
end
end
record Item, name : String, weight : Int32, value : Int32
record Selection, mask : BitArray, cur_index : Int32, total_value : Int32
class Knapsack
@threshold_value = 0
@threshold_... | Give a code snippet in #Crystal
A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature, so he needs to pack well for the trip.
He has a good knapsack for carrying things, but knows that he can carry a maximum of only 4kg in it, and it will ha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Kaprekar_numbers | Kaprekar numbers | A positive integer is a Kaprekar number if:
It is 1 (unity)
The decimal representation of its square may be split once into two parts consisting of positive integers which sum to the original number.
Note that a split resulting in a part consisting purely of 0s is not valid,
as 0 is not considered positive.
... | #Maple | Maple |
isKaprekar := proc(n::posint)
local holder, square, num_of_digits, k, left, right;
holder := true;
if n = 1 then
holder := true;
else
holder := false;
square := n^2;
num_of_digits := length(n^2);
for k to num_of_digits do left := floor(square/10^k);
right := irem(square, 10^k);
if left + right... | Give a code snippet in #Maple
A positive integer is a Kaprekar number if:
It is 1 (unity)
The decimal representation of its square may be split once into two parts consisting of positive integers which sum to the original number.
Note that a split resulting in a part consisting purely of 0s is not valid,
as... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring | Substring |
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 |... | #Arturo | Arturo | str: "abcdefgh"
n: 2
m: 3
; starting from n=2 characters in and m=3 in length
print slice str n-1 n+m-2
; starting from n characters in, up to the end of the string
print slice str n-1 (size str)-1
; whole string minus last character
print slice str 0 (size str)-2
; starting from a known character char="d"
; w... | Give a code snippet in #Arturo
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/Sorting_algorithms/Counting_sort | Sorting algorithms/Counting 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
... | #VBScript | VBScript | function findMax( a )
dim num
dim max
max = 0
for each num in a
if num > max then max = num
next
findMax = max
end function
function findMin( a )
dim num
dim min
min = 0
for each num in a
if num < min then min = num
next
findMin = min
end function
'the function returns the sorted array, but the fact... | Give a code snippet in #VBScript
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_concatenation | String concatenation | String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another string literal.
To illustrate the operat... | #Vlang | Vlang | s := 'hello'
println(s)
println(s+' literal')
s2:= s+ ' literal'
println(s2) | Give a code snippet in #Vlang
String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another string lit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Assertions | Assertions | Assertions are a way of breaking out of code when there is an error or an unexpected input.
Some languages throw exceptions and some treat it as a break point.
Task
Show an assertion in your language by asserting that an integer variable is equal to 42.
| #GAP | GAP | # See section 7.5 of reference manual
# GAP has assertions levels. An assertion is tested if its level
# is less then the global level.
# Set global level
SetAssertionLevel(10);
a := 1;
Assert(20, a > 1, "a should be greater than one");
# nothing happens
a := 1;
Assert(4, a > 1, "a should be greater than one");... | Give a code snippet in #GAP
Assertions are a way of breaking out of code when there is an error or an unexpected input.
Some languages throw exceptions and some treat it as a break point.
Task
Show an assertion in your language by asserting that an integer variable is equal to 42.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Do-while | Loops/Do-while | Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loo... | #Fortran | Fortran | INTEGER :: i = 0
DO
i = i + 1
WRITE(*, *) i
IF (MOD(i, 6) == 0) EXIT
END DO | Give a code snippet in #Fortran
Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generator/Exponential | Generator/Exponential | A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that the internal state of the objec... | #Raku | Raku | sub powers($m) { $m XR** 0..* }
my @squares = powers(2);
my @cubes = powers(3);
sub infix:<with-out> (@orig,@veto) {
gather for @veto -> $veto {
take @orig.shift while @orig[0] before $veto;
@orig.shift if @orig[0] eqv $veto;
}
}
say (@squares with-out @cubes)[20 ..^ 20+10].join(', '); | Give a code snippet in #Raku
A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pell%27s_equation | Pell's equation | Pell's equation (also called the Pell–Fermat equation) is a Diophantine equation of the form:
x2 - ny2 = 1
with integer solutions for x and y, where n is a given non-square positive integer.
Task requirements
find the smallest solution in positive integers to Pell's equation for... | #langur | langur | val .fun = f [.b, .b x .c + .a]
val .solvePell = f(.n) {
val .x = truncate .n ^/ 2
var .y, .z, .r = .x, 1, .x x 2
var .e1, .e2, .f1, .f2 = 1, 0, 0, 1
for {
.y = .r x .z - .y
.z = (.n - .y x .y) \ .z
.r = (.x + .y) \ .z
.e1, .e2 = .fun(.e1, .e2, .r)
.f1, .f2 = ... | Give a code snippet in #langur
Pell's equation (also called the Pell–Fermat equation) is a Diophantine equation of the form:
x2 - ny2 = 1
with integer solutions for x and y, where n is a given non-square positive integer.
Task requirements
find the smallest solution in positive... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tau_function | Tau function | Given a positive integer, count the number of its positive divisors.
Task
Show the result for the first 100 positive integers.
Related task
Tau number
| #APL | APL | tau ← 0+.=⍳|⊢
tau¨ 5 20⍴⍳100 | Give a code snippet in #APL
Given a positive integer, count the number of its positive divisors.
Task
Show the result for the first 100 positive integers.
Related task
Tau number
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Dining_philosophers | Dining philosophers | The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra.
Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a rou... | #C | C | #include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdarg.h>
#define N 5
const char *names[N] = { "Aristotle", "Kant", "Spinoza", "Marx", "Russell" };
pthread_mutex_t forks[N];
#define M 5 /* think bubbles */
const char *topic[M] = { "Spaghetti!", "Life", "Universe", "Everythi... | Give a code snippet in #C
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra.
Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Singly-linked_list/Traversal | Singly-linked list/Traversal | Traverse from the beginning of a singly-linked list to the end.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Definition, Usage
Set
Singly-linked ... | #Computer.2Fzero_Assembly | Computer/zero Assembly | start: LDA load
ADD car ; head of list
STA ldcar
ADD one
STA ldcdr
ldcar: NOP
STA value
ldcdr: NOP
BRZ done ; 0 == NIL
STA car
JMP start
done: LDA value
STP
load: LDA 0
value: 0
car: 28 ; head of li... | Give a code snippet in #Computer.2Fzero_Assembly
Traverse from the beginning of a singly-linked list to the end.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked l... | christopher/rosetta-code | |
http://rosettacode.org/wiki/99_bottles_of_beer | 99 bottles of beer | Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one dow... | #FutureBasic | FutureBasic |
include "NSLog.incl"
NSUInteger i
CFStringRef a, b, c
a = @" bottles of beer on the wall,\n"
b = @" bottles of beer.\n"
c = @"Take one down, pass it around,\n"
for i = 99 to 1 step -1
NSLog( @"%ld%@%ld%@%@%ld%@\n", i, a, i, b, c, i -1, a )
next
HandleEvents
| Give a code snippet in #FutureBasic
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wal... | christopher/rosetta-code | |
http://rosettacode.org/wiki/99_bottles_of_beer | 99 bottles of beer | Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one dow... | #Ada | Ada | with Ada.Text_Io; use Ada.Text_Io;
procedure Bottles is
begin
for X in reverse 1..99 loop
Put_Line(Integer'Image(X) & " bottles of beer on the wall");
Put_Line(Integer'Image(X) & " bottles of beer");
Put_Line("Take one down, pass it around");
Put_Line(Integer'Image(X - 1) & " bottles... | Give a code snippet in #Ada
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #REXX | REXX | aa = 10 /*assigns chars 10 ───► AA */
bb = '' /*assigns a null value ───► BB */
cc = 2*10 /*assigns chars 20 ───► CC */
dd = 'Adam' /*assigns chars Adam ───► DD */
ee = "Adam" ... | Give a code snippet in #REXX
Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Stream_merge | Stream merge | 2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from which the written item was.
N-strea... | #360_Assembly | 360 Assembly | * Stream Merge 07/02/2017
STRMERGE CSECT
USING STRMERGE,R13 base register
B 72(R15) skip savearea
DC 17F'0' savearea
STM R14,R12,12(R13) prolog
ST R13,4(R15) " <-
ST R15,8(R13) ... | Give a code snippet in #360_Assembly
2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream fro... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #FunL | FunL | native java.security.MessageDigest
def sha256Java( message ) = map( a -> format('%02x', a), list(MessageDigest.getInstance('SHA-256').digest(message.getBytes('UTF-8'))) ).mkString() | Give a code snippet in #FunL
SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785... | christopher/rosetta-code | |
http://rosettacode.org/wiki/LZW_compression | LZW compression | The Lempel-Ziv-Welch (LZW) algorithm provides loss-less data compression.
You can read a complete description of it in the Wikipedia article on the subject. It was patented, but it entered the public domain in 2004.
| #C.2B.2B | C++ | #include <string>
#include <map>
// Compress a string to a list of output symbols.
// The result will be written to the output iterator
// starting at "result"; the final iterator is returned.
template <typename Iterator>
Iterator compress(const std::string &uncompressed, Iterator result) {
// Build the dictionary.... | Give a code snippet in #C.2B.2B
The Lempel-Ziv-Welch (LZW) algorithm provides loss-less data compression.
You can read a complete description of it in the Wikipedia article on the subject. It was patented, but it entered the public domain in 2004.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Bioinformatics/Sequence_mutation | Bioinformatics/Sequence mutation | Task
Given a string of characters A, C, G, and T representing a DNA sequence write a routine to mutate the sequence, (string) by:
Choosing a random base position in the sequence.
Mutate the sequence by doing one of either:
Swap the base at that position by changing it to one of A, C, G, or T. (which has a chance o... | #Vlang | Vlang | import rand
import rand.seed
const bases = "ACGT"
// 'w' contains the weights out of 300 for each
// of swap, delete or insert in that order.
fn mutate(dna string, w [3]int) string {
le := dna.len
// get a random position in the dna to mutate
p := rand.intn(le) or {0}
// get a random number between ... | Give a code snippet in #Vlang
Task
Given a string of characters A, C, G, and T representing a DNA sequence write a routine to mutate the sequence, (string) by:
Choosing a random base position in the sequence.
Mutate the sequence by doing one of either:
Swap the base at that position by changing it to one of A, C,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/24_game | 24 game | The 24 Game tests one's mental arithmetic.
Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those four digits, used exactly once each. T... | #Racket | Racket |
#lang racket
(define (interprete expr numbers)
;; the cashe for used numbers
(define cashe numbers)
;; updating the cashe and handling invalid cases
(define (update-cashe! x)
(unless (member x numbers) (error "Number is not in the given set:" x))
(unless (member x cashe) (error "Number is used m... | Give a code snippet in #Racket
The 24 Game tests one's mental arithmetic.
Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those four d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Include_a_file | Include a file | Task
Demonstrate the language's ability to include source code from other files.
See Also
Compiler/Simple file inclusion pre processor
| #Kotlin | Kotlin | fun f() = println("f called") | Give a code snippet in #Kotlin
Task
Demonstrate the language's ability to include source code from other files.
See Also
Compiler/Simple file inclusion pre processor
| 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... | #D | D | import std.array;
bool isEmptyNotNull(in string s) pure nothrow @safe {
return s is "";
}
void main(){
string s1 = null;
string s2 = "";
// the content is the same
assert(!s1.length);
assert(!s2.length);
assert(s1 == "" && s1 == null);
assert(s2 == "" && s2 == null);
assert(s... | Give a code snippet in #D
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 t... | 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... | #Mercury | Mercury | :- module doors.
:- interface.
:- import_module io.
:- pred main(io::di, io::uo) is det.
:- implementation.
:- import_module bitmap, bool, list, string, int.
:- func doors = bitmap.
doors = bitmap.init(100, no).
:- pred walk(int, bitmap, bitmap).
:- mode walk(in, bitmap_di, bitmap_uo) is det.
walk(Pass, !Doors) :-
... | Give a code snippet in #Mercury
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/Reduced_row_echelon_form | Reduced row echelon form | Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenient
(for most languages, this wil... | #R | R | rref <- function(m) {
pivot <- 1
norow <- nrow(m)
nocolumn <- ncol(m)
for(r in 1:norow) {
if ( nocolumn <= pivot ) break;
i <- r
while( m[i,pivot] == 0 ) {
i <- i + 1
if ( norow == i ) {
i <- r
pivot <- pivot + 1
if ( nocolumn == pivot ) return(m)
}
}
... | Give a code snippet in #R
Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenient
(f... | 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.
| #Axe | Axe | DelVar "appvINPUT" | Give a code snippet in #Axe
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/Ruth-Aaron_numbers | Ruth-Aaron numbers | A Ruth–Aaron pair consists of two consecutive integers (e.g., 714 and 715) for which the sums of the prime divisors of each integer are equal. So called because 714 is Babe Ruth's lifetime home run record; Hank Aaron's 715th home run broke this record and 714 and 715 have the same prime divisor sum.
A Ruth–Aaron tri... | #Perl | Perl | #!/usr/bin/perl
use strict;
use warnings;
use ntheory qw( factor vecsum );
use List::AllUtils qw( uniq );
#use Data::Dump 'dd'; dd factor(6); exit;
my $n = 1;
my @answers;
while( @answers < 30 )
{
vecsum(factor($n)) == vecsum(factor($n+1)) and push @answers, $n;
$n++;
}
print "factors:\n\n@answers\n\n" =~... | Give a code snippet in #Perl
A Ruth–Aaron pair consists of two consecutive integers (e.g., 714 and 715) for which the sums of the prime divisors of each integer are equal. So called because 714 is Babe Ruth's lifetime home run record; Hank Aaron's 715th home run broke this record and 714 and 715 have the same prime di... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_largest_left_truncatable_prime_in_a_given_base | Find largest left truncatable prime in a given base | A truncatable prime is one where all non-empty substrings that finish at the end of the number (right-substrings) are also primes when understood as numbers in a particular base. The largest such prime in a given (integer) base is therefore computable, provided the base is larger than 2.
Let's consider what happens in... | #Phix | Phix | with javascript_semantics
include mpfr.e
sequence tens = mpz_inits(1,1),
vals = mpz_inits(1),
digits = {0}
mpz answer = mpz_init(0)
integer base, seen_depth
procedure add_digit(integer i)
atom t1 = time()+1
if i>length(vals) then
vals &= mpz_init_set(vals[i-1])
tens &= mpz_in... | Give a code snippet in #Phix
A truncatable prime is one where all non-empty substrings that finish at the end of the number (right-substrings) are also primes when understood as numbers in a particular base. The largest such prime in a given (integer) base is therefore computable, provided the base is larger than 2.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sieve_of_Eratosthenes | Sieve of Eratosthenes | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algorithm, with the only allowed... | #Scilab | Scilab | function a = sieve(n)
a = ~zeros(n, 1)
a(1) = %f
for i = 1:n
if a(i)
j = i*i
if j > n
return
end
a(j:i:n) = %f
end
end
endfunction
find(sieve(100))
// [2 3 5 ... 97]
sum(sieve(1000))
// 168, the number of primes below 10... | Give a code snippet in #Scilab
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Word_frequency | Word frequency | Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define what a letter is.
Undersc... | #R | R |
wordcount<-function(file,n){
punctuation=c("`","~","!","@","#","$","%","^","&","*","(",")","_","+","=","{","[","}","]","|","\\",":",";","\"","<",",",">",".","?","/","'s")
wordlist=scan(file,what=character())
wordlist=tolower(wordlist)
for(i in 1:length(punctuation)){
wordlist=gsub(punctuation[i],"",wordli... | Give a code snippet in #R
Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define what a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Call_a_function | Call a function | Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function with a variable number of arguments
C... | #Forth | Forth | a-function \ requiring no arguments
a-function \ with a fixed number of arguents
a-function \ having optional arguments
a-function \ having a variable number of arguments
a-function \ having such named arguments as we have in Forth
' a-function var ! \ using a function in a first... | Give a code snippet in #Forth
Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function with a va... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Base64_decode_data | Base64 decode data | See Base64 encode data.
Now write a program that takes the output of the Base64 encode data task as input and regenerate the original file.
When working on the VBA implementation I found several 'solutions' on the net, including one from the software maker himself, that showed output with incorrect padding. Obviously... | #OCaml | OCaml | # let plain = Base64.decode_exn enc;;
val plain : string =
"\000\000\001\000\002\000\016\016\000\000\000\000\000\000h\005\000\000&\000"... (* string length 3638; truncated *)
| Give a code snippet in #OCaml
See Base64 encode data.
Now write a program that takes the output of the Base64 encode data task as input and regenerate the original file.
When working on the VBA implementation I found several 'solutions' on the net, including one from the software maker himself, that showed output wi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/With_multiple_ranges | Loops/With multiple ranges | Loops/With multiple ranges
You are encouraged to solve this task according to the task description, using any language you may know.
Some languages allow multiple loop ranges, such as the PL/I example (snippet) below.
/* all variables are DECLARED as integers. */
prod=... | #PureBasic | PureBasic | #X = 5 : #Y = -5 : #Z = -2
#ONE = 1 : #THREE = 3 : #SEVEN = 7
Define j.i
Global prod.i = 1, sum.i = 0
Macro ipow(n, e)
Int(Pow(n, e))
EndMacro
Macro ifn(x)
FormatNumber(x,0,".",",")
EndMacro
Macro loop_for(start, stop, step_for=1)
For j = start To stop Step step_for
proc(j)
Next
EndMacro
Procedure... | Give a code snippet in #PureBasic
Loops/With multiple ranges
You are encouraged to solve this task according to the task description, using any language you may know.
Some languages allow multiple loop ranges, such as the PL/I example (snippet) below.
/* all variables are DECLA... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #Icon_and_Unicon | Icon and Unicon | link math
procedure main(A)
limit := (integer(A[1])|15)+1
every write(right(binocoef(i := 2*seq(0)\limit,i/2)-binocoef(i,i/2+1),30))
end | Give a code snippet in #Icon_and_Unicon
Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #Perl | Perl | sub dofruit {
$fruit='apple';
}
dofruit;
print "The fruit is $fruit"; | Give a code snippet in #Perl
Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Polynomial_regression | Polynomial regression | Find an approximating polynomial of known degree for a given data.
Example:
For input data:
x = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
y = {1, 6, 17, 34, 57, 86, 121, 162, 209, 262, 321};
The approximating polynomial is:
3 x2 + 2 x + 1
Here, the polynomial's coefficients are (3, 2, 1).
This task is i... | #Python | Python | >>> x = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> y = [1, 6, 17, 34, 57, 86, 121, 162, 209, 262, 321]
>>> coeffs = numpy.polyfit(x,y,deg=2)
>>> coeffs
array([ 3., 2., 1.]) | Give a code snippet in #Python
Find an approximating polynomial of known degree for a given data.
Example:
For input data:
x = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
y = {1, 6, 17, 34, 57, 86, 121, 162, 209, 262, 321};
The approximating polynomial is:
3 x2 + 2 x + 1
Here, the polynomial's coefficient... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Text_processing/1 | Text processing/1 | 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.
Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another pr... | #Ursala | Ursala | #import std
#import nat
#import flo
parsed_data = ^|A(~&,* ^|/%ep@iNC ~&h==`1)*htK27K28pPCS (sep 9%cOi&)*FyS readings_dot_txt
daily_stats =
* ^|A(~&,@rFlS ^/length ^/plus:-0. ||0.! ~&i&& mean); mat` + <.
~&n,
'accept: '--+ @ml printf/'%7.0f'+ float,
'total: '--+ @mrl printf/'%10.1f',
'average: '--+ @... | Give a code snippet in #Ursala
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.
Often data is produced by one program, in the wrong format for later use by another program or person... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Element_definition | Doubly-linked list/Element definition | Task
Define the data structure for a doubly-linked list element.
The element should include a data member to hold its value and pointers to both the next element in the list and the previous element in the list.
The pointers should be mutable.
See also
Array
Associative array: Creation, Iteration
Collections
... | #REXX | REXX | ╔═════════════════════════════════════════════════════════════════════════╗
║ ☼☼☼☼☼☼☼☼☼☼☼ Functions of the List Manager ☼☼☼☼☼☼☼☼☼☼☼ ║
║ @init ─── initializes the List. ║
║ ... | Give a code snippet in #REXX
Task
Define the data structure for a doubly-linked list element.
The element should include a data member to hold its value and pointers to both the next element in the list and the previous element in the list.
The pointers should be mutable.
See also
Array
Associative array: Cre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ternary_logic | Ternary logic |
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In logic, a three-valued logic (also trivalent, ternary, or trinary... | #Alternative_version | Alternative version | # built-in: true, false and missing
using Printf
const tril = (true, missing, false)
@printf("\n%8s | %8s\n", "A", "¬A")
for A in tril
@printf("%8s | %8s\n", A, !A)
end
@printf("\n%8s | %8s | %8s\n", "A", "B", "A ∧ B")
for (A, B) in Iterators.product(tril, tril)
@printf("%8s | %8s | %8s\n", A, B, A & B)... | Give a code snippet in #Alternative_version
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In logic, a three-valu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Forward_difference | Forward difference | Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer elem... | #ALGOL_W | ALGOL W | begin
% calculate forward differences %
% sets elements of B to the first order forward differences of A %
% A should have bounds 1 :: n, B should have bounds 1 :: n - 1 %
procedure FirstOrderFDifference ( integer array A( * )
; in... | Give a code snippet in #ALGOL_W
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List... | christopher/rosetta-code | |
http://rosettacode.org/wiki/User_input/Graphical | User input/Graphical |
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | str = InputString["Input a string"]; nb =
InputString["Input a number"]; Print[str, " " , ToString@nb] | Give a code snippet in #Mathematica.2FWolfram_Language
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_an_integer_array | Sort an integer array |
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
... | #Huginn | Huginn | main() {
nums = [2, 4, 3, 1, 2];
nums.sort();
} | Give a code snippet in #Huginn
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/Angles_(geometric),_normalization_and_conversion | Angles (geometric), normalization and conversion | This task is about the normalization and/or conversion of (geometric) angles using
some common scales.
The angular scales that will be used in this task are:
degree
gradian
mil
radian
Definitions
The angular scales used or referenced here:
turn is a full turn or 360 degrees, also shown as 360º
... | #JavaScript | JavaScript |
/*****************************************************************\
| Expects an angle, an origin unit and a unit to convert to, |
| where in/out units are: |
| --------------------------------------------------------------- |
| 'D'/'d' ..... degrees 'M'/'d' ..... | Give a code snippet in #JavaScript
This task is about the normalization and/or conversion of (geometric) angles using
some common scales.
The angular scales that will be used in this task are:
degree
gradian
mil
radian
Definitions
The angular scales used or referenced here:
turn is a full turn... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tic-tac-toe | Tic-tac-toe |
Task
Play a game of tic-tac-toe.
Ensure that legal moves are played and that a winning position is notified.
Tic-tac-toe is also known as:
naughts and crosses
tic tac toe
tick tack toe
three in a row
tres en rayo and
Xs and Os
See also
MathWorld™, Tic-Tac-Toe game.
Wikipedi... | #Lua | Lua | #!/usr/bin/env luajit
ffi=require"ffi"
local function printf(fmt,...) io.write(string.format(fmt, ...)) end
local board="123456789" -- board
local pval={1, -1} -- player 1=1 2=-1 for negamax
local pnum={} for k,v in ipairs(pval) do pnum[v]=k end
local symbol={'X','O'} -- default symbols X and O
local isymbol={} f... | Give a code snippet in #Lua
Task
Play a game of tic-tac-toe.
Ensure that legal moves are played and that a winning position is notified.
Tic-tac-toe is also known as:
naughts and crosses
tic tac toe
tick tack toe
three in a row
tres en rayo and
Xs and Os
See also
MathWorld™, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multiplication_tables | Multiplication tables | Task
Produce a formatted 12×12 multiplication table of the kind memorized by rote when in primary (or elementary) school.
Only print the top half triangle of products.
| #Wren | Wren | import "/fmt" for Fmt
var nums = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
Fmt.print(" x | $4d", nums)
System.print("----+%("-" * 60)")
for (i in 1..12) {
var nums2 = nums.map { |n| (n >= i) ? (n * i).toString : " " }.toList
Fmt.print("$3d | $4s", i, nums2)
} | Give a code snippet in #Wren
Task
Produce a formatted 12×12 multiplication table of the kind memorized by rote when in primary (or elementary) school.
Only print the top half triangle of products.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Cramer%27s_rule | Cramer's rule | linear algebra
Cramer's rule
system of linear equations
Given
{
a
1
x
+
b
1
y
+
c
1
z
=
d
1
a
2
x
+
b
2
y
+
c
2
z
=
d
2
a
3
x
+
b
3
y
+
c
3
z
=
d
3
{\displaystyle \left\{{\begin{matrix}a_{1}x+b_{1}y+c_{1}z&={\color {red}d_{1... | #Common_Lisp | Common Lisp | (defun minor (m col)
(loop with dim = (1- (array-dimension m 0))
with result = (make-array (list dim dim))
for i from 1 to dim
for r = (1- i)
do (loop with c = 0
for j to dim
when (/= j col)
do (setf (aref result r c) (aref m i j))
... | Give a code snippet in #Common_Lisp
linear algebra
Cramer's rule
system of linear equations
Given
{
a
1
x
+
b
1
y
+
c
1
z
=
d
1
a
2
x
+
b
2
y
+
c
2
z
=
d
2
a
3
x
+
b
3
y
+
c
3
z
=
d
3
{\displaystyle \left\{{\begin{matrix}a_... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Histogram | Bitmap/Histogram | Extend the basic bitmap storage defined on this page to support dealing with image histograms. The image histogram contains for each luminance the count of image pixels having this luminance. Choosing a histogram representation take care about the data type used for the counts. It must have range of at least 0..NxM, wh... | #Raku | Raku | class Pixel { has UInt ($.R, $.G, $.B) }
class Bitmap {
has UInt ($.width, $.height);
has Pixel @.data;
}
role PBM {
has @.BM;
method P4 returns Blob {
"P4\n{self.width} {self.height}\n".encode('ascii')
~ Blob.new: self.BM
}
}
sub getline ( $fh ) {
my $line = '#'; # skip comments when read... | Give a code snippet in #Raku
Extend the basic bitmap storage defined on this page to support dealing with image histograms. The image histogram contains for each luminance the count of image pixels having this luminance. Choosing a histogram representation take care about the data type used for the counts. It must hav... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm | Trabb Pardo–Knuth algorithm | The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of... | #AutoIt | AutoIt | ; Trabb Pardo–Knuth algorithm
; by James1337 (autoit.de)
; AutoIt Version: 3.3.8.1
Local $S, $i, $y
Do
$S = InputBox("Trabb Pardo–Knuth algorithm", "Please enter 11 numbers:", "1 2 3 4 5 6 7 8 9 10 11")
If @error Then Exit
$S = StringSplit($S, " ")
Until ($S[0] = 11)
For $i = 11 To 1 Step -1
$y = f($S[$i])
I... | Give a code snippet in #AutoIt
The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm | Trabb Pardo–Knuth algorithm | The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of... | #Haskell | Haskell | import Control.Monad (replicateM, mapM_)
f :: Floating a => a -> a
f x = sqrt (abs x) + 5 * x ** 3
main :: IO ()
main = do
putStrLn "Enter 11 numbers for evaluation"
x <- replicateM 11 readLn
mapM_
((\x ->
if x > 400
then putStrLn "OVERFLOW"
else print x) .
f) $
rev... | Give a code snippet in #Haskell
The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Number_reversal_game | Number reversal game | Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
The score is the count of the reversa... | #VBA | VBA | Private Function shuffle(ByVal a As Variant) As Variant
Dim t As Variant, i As Integer
For i = UBound(a) To LBound(a) + 1 Step -1
j = Int((UBound(a) - LBound(a) + 1) * Rnd + LBound(a))
t = a(i)
a(i) = a(j)
a(j) = t
Next i
shuffle = a
End Function
Private Sub reverse(ByRef... | Give a code snippet in #VBA
Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
The scor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Vigen%C3%A8re_cipher | Vigenère cipher | Task
Implement a Vigenère cypher, both encryption and decryption.
The program should handle keys and text of unequal length,
and should capitalize everything and discard non-alphabetic characters.
(If your program handles non-alphabetic characters in another way,
make a note of it.)
Related tasks
Caesar ... | #Action.21 | Action! | PROC Fix(CHAR ARRAY in,fixed)
INT i
CHAR c
fixed(0)=0
FOR i=1 TO in(0)
DO
c=in(i)
IF c>='a AND c<='z THEN
c==-('a-'A)
FI
IF c>='A AND c<='Z THEN
fixed(0)==+1
fixed(fixed(0))=c
FI
OD
RETURN
PROC Process(CHAR ARRAY in,key,out INT dir)
CHAR ARRAY inFixed(256),keyFixe... | Give a code snippet in #Action.21
Task
Implement a Vigenère cypher, both encryption and decryption.
The program should handle keys and text of unequal length,
and should capitalize everything and discard non-alphabetic characters.
(If your program handles non-alphabetic characters in another way,
make a note o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Scope_modifiers | Scope modifiers | Most programming languages offer support for subroutines.
When execution changes between subroutines, different sets of variables and functions ("scopes") are available to the program.
Frequently these sets are defined by the placement of the variable and function declarations ("static scoping" or "lexical scoping").
T... | #Phix | Phix | forward function localf() -- not normally necesssary, but will not harm
forward global function globalf() -- ""
function localf()
return 1
end function
global function globalf()
return 2
end function
| Give a code snippet in #Phix
Most programming languages offer support for subroutines.
When execution changes between subroutines, different sets of variables and functions ("scopes") are available to the program.
Frequently these sets are defined by the placement of the variable and function declarations ("static sco... | 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... | #Prolog | Prolog | assign_empty_string(Variable) :- Variable = "".
is_empty_string(String) :- String == "".
not_empty_string(String) :- String \== "".
| Give a code snippet in #Prolog
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/Multiplication_tables | Multiplication tables | Task
Produce a formatted 12×12 multiplication table of the kind memorized by rote when in primary (or elementary) school.
Only print the top half triangle of products.
| #COBOL | COBOL | identification division.
program-id. multiplication-table.
environment division.
configuration section.
repository.
function all intrinsic.
data division.
working-storage section.
01 multiplication.
05 rows occurs 12 times.
10... | Give a code snippet in #COBOL
Task
Produce a formatted 12×12 multiplication table of the kind memorized by rote when in primary (or elementary) school.
Only print the top half triangle of products.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Partition_an_integer_x_into_n_primes | Partition an integer x into n primes | Task
Partition a positive integer X into N distinct primes.
Or, to put it in another way:
Find N unique primes such that they add up to X.
Show in the output section the sum X and the N primes in ascending order separated by plus (+) signs:
• partition 99809 with 1 prime.
... | #Nim | Nim | import math, sugar
const N = 100_000
# Fill a sieve of Erathostenes.
var isPrime {.noInit.}: array[2..N, bool]
for item in isPrime.mitems: item = true
for n in 2..int(sqrt(N.toFloat)):
if isPrime[n]:
for k in countup(n * n, N, n):
isPrime[k] = false
# Build list of primes.
let primes = collect(newSeq)... | Give a code snippet in #Nim
Task
Partition a positive integer X into N distinct primes.
Or, to put it in another way:
Find N unique primes such that they add up to X.
Show in the output section the sum X and the N primes in ascending order separated by plus (+) signs:
• partition... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Convert_seconds_to_compound_duration | Convert seconds to compound duration | Task
Write a function or program which:
takes a positive integer representing a duration in seconds as input (e.g., 100), and
returns a string which shows the same duration decomposed into:
weeks,
days,
hours,
minutes, and
seconds.
This is detailed below (e.g., "2 hr, 59 sec").
Demonstrat... | #Phix | Phix | with javascript_semantics
?elapsed(7259)
?elapsed(86400)
?elapsed(6000000)
| Give a code snippet in #Phix
Task
Write a function or program which:
takes a positive integer representing a duration in seconds as input (e.g., 100), and
returns a string which shows the same duration decomposed into:
weeks,
days,
hours,
minutes, and
seconds.
This is detailed below (e.g., ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Singly-linked_list/Element_insertion | Singly-linked list/Element insertion | Singly-Linked List (element)
singly-linked list
Using this method, insert an element C into a list comprised of elements A->B, following element A.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Trav... | #ooRexx | ooRexx |
list = .linkedlist~new
index = list~insert("abc") -- insert a first item, keeping the index
list~insert("def") -- adds to the end
list~insert("123", .nil) -- adds to the begining
list~insert("456", index) -- inserts between "abc" and "def"
list~remove(index) -- removes "abc"
| Give a code snippet in #ooRexx
Singly-Linked List (element)
singly-linked list
Using this method, insert an element C into a list comprised of elements A->B, following element A.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definiti... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root | Digital root/Multiplicative digital root | The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
{\displaystyle i}
to
0
... | #ALGOL_W | ALGOL W | begin
% calculate the Multiplicative Digital Root (mdr) and Multiplicative Persistence (mp) of n %
procedure getMDR ( integer value n
; integer result mdr, mp
) ;
begin
mp := 0;
mdr := abs n;
while mdr > 9 do begin
integer v;
... | Give a code snippet in #ALGOL_W
The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
... | 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... | #PicoLisp | PicoLisp | # To assign a variable an empty string:
(off String)
(setq String "")
(setq String NIL)
# To check for an empty string:
(or String ..)
(ifn String ..)
(unless String ..)
# or a non-empty string:
(and String ..)
(if String ..)
(when String ..) | Give a code snippet in #PicoLisp
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.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Null_object | Null object |
Null (or nil) is the computer science concept of an undefined or unbound object.
Some languages have an explicit way to access the null object, and some don't.
Some languages distinguish the null object from undefined values, and some don't.
Task
Show how to access null in your language by checking to see if an ob... | #JavaScript | JavaScript | if (object === null) {
alert("object is null");
// The object is nothing
}
typeof null === "object"; // This stands since the beginning of JavaScript | Give a code snippet in #JavaScript
Null (or nil) is the computer science concept of an undefined or unbound object.
Some languages have an explicit way to access the null object, and some don't.
Some languages distinguish the null object from undefined values, and some don't.
Task
Show how to access null in your ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations_by_swapping | Permutations by swapping | Task
Generate permutations of n items in which successive permutations differ from each other by the swapping of any two items.
Also generate the sign of the permutation which is +1 when the permutation is generated from an even number of swaps from the initial state, and -1 for odd.
Show the permutations and signs ... | #Ruby | Ruby | def perms(n)
p = Array.new(n+1){|i| -i}
s = 1
loop do
yield p[1..-1].map(&:abs), s
k = 0
for i in 2..n
k = i if p[i] < 0 and p[i].abs > p[i-1].abs and p[i].abs > p[k].abs
end
for i in 1...n
k = i if p[i] > 0 and p[i].abs > p[i+1].abs and p[i].abs > p[k].abs
end
break if k.... | Give a code snippet in #Ruby
Task
Generate permutations of n items in which successive permutations differ from each other by the swapping of any two items.
Also generate the sign of the permutation which is +1 when the permutation is generated from an even number of swaps from the initial state, and -1 for odd.
Sh... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multisplit | Multisplit | It is often necessary to split a string into pieces
based on several different (potentially multi-character) separator strings,
while still retaining the information about which separators were present in the input.
This is particularly useful when doing small parsing tasks.
The task is to write code to demonstrate ... | #SenseTalk | SenseTalk | set source to "a!===b=!=c"
set separators to ["==", "!=", "="]
put each line delimited by separators of source | Give a code snippet in #SenseTalk
It is often necessary to split a string into pieces
based on several different (potentially multi-character) separator strings,
while still retaining the information about which separators were present in the input.
This is particularly useful when doing small parsing tasks.
The ta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_multiplication | Matrix multiplication | Task
Multiply two matrices together.
They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
| #Fantom | Fantom |
class Main
{
// multiply two matrices (with no error checking)
public static Int[][] multiply (Int[][] m1, Int[][] m2)
{
Int[][] result := [,]
m1.each |Int[] row1|
{
Int[] row := [,]
m2[0].size.times |Int colNumber|
{
Int value := 0
m2.each |Int[] row2, Int index|
... | Give a code snippet in #Fantom
Task
Multiply two matrices together.
They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Extend_your_language | Extend your language | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Some programming languages allow you to extend the language. While this can be done to a certain degree in most languages (e.g. by using macros), other langua... | #Clojure | Clojure |
(defmacro if2 [[cond1 cond2] bothTrue firstTrue secondTrue else]
`(let [cond1# ~cond1
cond2# ~cond2]
(if cond1# (if cond2# ~bothTrue ~firstTrue)
(if cond2# ~secondTrue ~else))))
| Give a code snippet in #Clojure
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Some programming languages allow you to extend the language. While this can be done to a certain degree in most languages (e.... | 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... | #Batch_File | Batch File |
@echo off
setlocal enabledelayedexpansion
set arr=ABCD
set /a n=4
:: echo !arr!
call :permu %n% arr
goto:eof
:permu num &arr
setlocal
if %1 equ 1 call echo(!%2! & exit /b
set /a "num=%1-1,n2=num-1"
set arr=!%2!
for /L %%c in (0,1,!n2!) do (
call:permu !num! arr
set /a n1="num&1"
if !n1! equ 0 (call:s... | Give a code snippet in #Batch_File
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Introspection | Introspection | Task
verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old.
check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compute abs(bloop).
Extra credit
Repor... | #PARI.2FGP | PARI/GP | if(lex(version(), [2,4,3]) < 0, quit()); \\ Compare the version to 2.4.3 lexicographically
if(bloop!='bloop && type(abs) == "t_CLOSURE", abs(bloop)) | Give a code snippet in #PARI.2FGP
Task
verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old.
check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compute... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Koch_curve | Koch curve | Draw a Koch curve. See details: Koch curve
| #BASIC256 | BASIC256 | global RtoD, DtoR
RtoD = 180 / Pi
DtoR = Pi / 180
global posX, posY, angulo
posX = 170 : posY = 100 : angulo = 0
global ancho, alto
ancho = 650 : alto = 650
graphsize ancho, alto
subroutine kochLado(longitud, fondo)
if fondo = 0 then
dx = cos(angulo*DtoR) * longitud
dy = sin(angulo*DtoR) * longitud
color r... | Give a code snippet in #BASIC256
Draw a Koch curve. See details: Koch curve
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_join | Hash join | An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash join" algorithm, and demonstrate tha... | #D | D | import std.stdio, std.typecons;
auto hashJoin(size_t index1, size_t index2, T1, T2)
(in T1[] table1, in T2[] table2) pure /*nothrow*/ @safe
if (is(typeof(T1.init[index1]) == typeof(T2.init[index2]))) {
// Hash phase.
T1[][typeof(T1.init[index1])] h;
foreach (const s; table1)
h[s[index... | Give a code snippet in #D
An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash join" alg... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Almost_prime | Almost prime | A k-Almost-prime is a natural number
n
{\displaystyle n}
that is the product of
k
{\displaystyle k}
(possibly identical) primes.
Example
1-almost-primes, where
k
=
1
{\displaystyle k=1}
, are the prime numbers themselves.
2-almost-primes, where
k
=
2
{\displaystyl... | #VBScript | VBScript |
For k = 1 To 5
count = 0
increment = 1
WScript.StdOut.Write "K" & k & ": "
Do Until count = 10
If PrimeFactors(increment) = k Then
WScript.StdOut.Write increment & " "
count = count + 1
End If
increment = increment + 1
Loop
WScript.StdOut.WriteLine
Next
Function PrimeFactors(n)
PrimeFactors = 0
... | Give a code snippet in #VBScript
A k-Almost-prime is a natural number
n
{\displaystyle n}
that is the product of
k
{\displaystyle k}
(possibly identical) primes.
Example
1-almost-primes, where
k
=
1
{\displaystyle k=1}
, are the prime numbers themselves.
2-almost-primes, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hostname | Hostname | Task
Find the name of the host on which the routine is running.
| #Modula-3 | Modula-3 | MODULE Hostname EXPORTS Main;
IMPORT IO, OSConfig;
BEGIN
IO.Put(OSConfig.HostName() & "\n");
END Hostname. | Give a code snippet in #Modula-3
Task
Find the name of the host on which the routine is running.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/4-rings_or_4-squares_puzzle | 4-rings or 4-squares puzzle | 4-rings or 4-squares puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Replace a, b, c, d, e, f, and
g with the decimal
digits LOW ───► HIGH
such that the sum of the letters inside of each of the four large squares add up to
t... | #PL.2FSQL | PL/SQL |
CREATE TABLE allints (v NUMBER);
CREATE TABLE results
(
a NUMBER,
b NUMBER,
c NUMBER,
d NUMBER,
e NUMBER,
f NUMBER,
g NUMBER
);
CREATE OR REPLACE PROCEDURE foursquares(lo NUMBER,hi NUMBER,uniq BOOLEAN,show BOOLEAN)
AS
a NUMBER;
b NUMBER;
c NUMBER;
d NUMBER;
e NUMBER;
f NUMBER;
g NUMBER;... | Give a code snippet in #PL.2FSQL
4-rings or 4-squares puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Replace a, b, c, d, e, f, and
g with the decimal
digits LOW ───► HIGH
such that the sum of the letters inside of each of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_input_device_is_a_terminal | Check input device is a terminal | Task
Demonstrate how to check whether the input device is a terminal or not.
Related task
Check output device is a terminal
| #Racket | Racket |
(terminal-port? (current-input-port))
| Give a code snippet in #Racket
Task
Demonstrate how to check whether the input device is a terminal or not.
Related task
Check output device is a terminal
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sudoku | Sudoku | Task
Solve a partially filled-in normal 9x9 Sudoku grid and display the result in a human-readable format.
references
Algorithmics of Sudoku may help implement this.
Python Sudoku Solver Computerphile video.
| #Prolog | Prolog | :- use_module(library(clpfd)).
sudoku(Rows) :-
length(Rows, 9), maplist(length_(9), Rows),
append(Rows, Vs), Vs ins 1..9,
maplist(all_distinct, Rows),
transpose(Rows, Columns), maplist(all_distinct, Columns),
Rows = [A,B,C,D,E,F,G,H,I],
blocks(A, B, C), blocks(D, E, F),... | Give a code snippet in #Prolog
Task
Solve a partially filled-in normal 9x9 Sudoku grid and display the result in a human-readable format.
references
Algorithmics of Sudoku may help implement this.
Python Sudoku Solver Computerphile video.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Nth_root | Nth root | Task
Implement the algorithm to compute the principal nth root
A
n
{\displaystyle {\sqrt[{n}]{A}}}
of a positive real number A, as explained at the Wikipedia page.
| #Objeck | Objeck | class NthRoot {
function : Main(args : String[]) ~ Nil {
NthRoot(5, 34, .001)->PrintLine();
}
function : NthRoot(n : Int, A: Float, p : Float) ~ Float {
x := Float->New[2];
x[0] := A;
x[1] := A / n;
while((x[1] - x[0])->Abs() > p) {
x[0] := x[1];
x[1] := ((n - 1.0) * x[1] + A /... | Give a code snippet in #Objeck
Task
Implement the algorithm to compute the principal nth root
A
n
{\displaystyle {\sqrt[{n}]{A}}}
of a positive real number A, as explained at the Wikipedia page.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Extensible_prime_generator | Extensible prime generator | Task
Write a generator of prime numbers, in order, that will automatically adjust to accommodate the generation of any reasonably high prime.
The routine should demonstrably rely on either:
Being based on an open-ended counter set to count without upper limit other than system or programming language limits. In thi... | #BQN | BQN | # Function that returns a new prime generator
PrimeGen ← {𝕤
i ← 0 # Counter: index of next prime to be output
primes ← ↕0
next ← 2
Sieve ← { p 𝕊 i‿n:
E ← {↕∘⌈⌾(((𝕩|-i)+𝕩×⊢)⁼)n-i} # Indices of multiples of 𝕩
i + / (1⥊˜n-i) E⊸{0¨⌾(𝕨⊸⊏)𝕩}´ p # Primes in segment [i,n)
}
{𝕤
{ i=≠pri... | Give a code snippet in #BQN
Task
Write a generator of prime numbers, in order, that will automatically adjust to accommodate the generation of any reasonably high prime.
The routine should demonstrably rely on either:
Being based on an open-ended counter set to count without upper limit other than system or progra... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Color_wheel | Color wheel | Task
Write a function to draw a HSV color wheel completely with code.
This is strictly for learning purposes only. It's highly recommended that you use an image in an actual application to actually draw the color wheel (as procedurally drawing is super slow). This does help you understand how color wheels work and ... | #C.2B.2B | C++ | // colorwheelwidget.cpp
#include "colorwheelwidget.h"
#include <QPainter>
#include <QPaintEvent>
#include <cmath>
namespace {
QColor hsvToRgb(int h, double s, double v) {
double hp = h/60.0;
double c = s * v;
double x = c * (1 - std::abs(std::fmod(hp, 2) - 1));
double m = v - c;
double r = 0, g ... | Give a code snippet in #C.2B.2B
Task
Write a function to draw a HSV color wheel completely with code.
This is strictly for learning purposes only. It's highly recommended that you use an image in an actual application to actually draw the color wheel (as procedurally drawing is super slow). This does help you unde... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Atomic_updates | Atomic updates |
Task
Define a data type consisting of a fixed number of 'buckets', each containing a nonnegative integer value, which supports operations to:
get the current value of any bucket
remove a specified amount from one specified bucket and add it to another, preserving the total of all bucket values, and clamping the t... | #zkl | zkl | class B{
const N=10;
var [const]
buckets=(1).pump(N,List).copy(), //(1,2,3...)
lock=Atomic.Lock(), cnt=Atomic.Int();
fcn init{ "Initial sum: ".println(values().sum()); }
fcn transferArb{ // transfer arbitary amount from 1 bucket to another
b1:=(0).random(N); b2:=(0).random(N);
crit... | Give a code snippet in #zkl
Task
Define a data type consisting of a fixed number of 'buckets', each containing a nonnegative integer value, which supports operations to:
get the current value of any bucket
remove a specified amount from one specified bucket and add it to another, preserving the total of all buck... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #Fortran | Fortran | module FIFO
use fifo_nodes
! fifo_nodes must define the type fifo_node, with the two field
! next and valid, for queue handling, while the field datum depends
! on the usage (see [[FIFO (usage)]] for an example)
! type fifo_node
! integer :: datum
! ! the next part is not variable and must be present
! t... | Give a code snippet in #Fortran
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Currying | Currying |
This page uses content from Wikipedia. The original article was at Currying. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Create a simple demonstrative example of Currying in a specific la... | #Phix | Phix | with javascript_semantics
sequence curries = {}
function create_curried(integer rid, sequence partial_args)
curries = append(curries,{rid,partial_args})
return length(curries) -- (return an integer id)
end function
function call_curried(integer id, sequence args)
{integer rid, sequence partial_args} = cur... | Give a code snippet in #Phix
This page uses content from Wikipedia. The original article was at Currying. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Create a simple demonstrative exampl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Metered_concurrency | Metered concurrency | The goal of this task is to create a counting semaphore used to control the execution of a set of concurrent units. This task intends to demonstrate coordination of active concurrent units through the use of a passive concurrent unit. The operations for a counting semaphore are acquire, release, and count. Each active ... | #Rust | Rust |
//! Rust has a perfectly good Semaphore type already. It lacks count(), though, so we can't use it
//! directly.
use std::sync::atomic::AtomicUsize;
use std::sync::atomic::Ordering::SeqCst;
use std::sync::mpsc::channel;
use std::sync::Arc;
use std::thread::{self, spawn};
use std::time::Duration;
pub struct Counti... | Give a code snippet in #Rust
The goal of this task is to create a counting semaphore used to control the execution of a set of concurrent units. This task intends to demonstrate coordination of active concurrent units through the use of a passive concurrent unit. The operations for a counting semaphore are acquire, re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generate_random_chess_position | Generate random chess position | Task
Generate a random chess position in FEN format.
The position does not have to be realistic or even balanced, but it must comply to the following rules:
there is one and only one king of each color (one black king and one white king);
the kings must not be placed on adjacent squares;
there can not be any p... | #Scala | Scala | import scala.math.abs
import scala.util.Random
object RandomFen extends App {
val rand = new Random
private def createFen = {
val grid = Array.ofDim[Char](8, 8)
def placeKings(grid: Array[Array[Char]]): Unit = {
var r1, c1, r2, c2 = 0
do {
r1 = rand.nextInt(8)
c1 = rand.nex... | Give a code snippet in #Scala
Task
Generate a random chess position in FEN format.
The position does not have to be realistic or even balanced, but it must comply to the following rules:
there is one and only one king of each color (one black king and one white king);
the kings must not be placed on adjacent s... | 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... | #FurryScript | FurryScript | THE_LIST( <apple> <orange> )
COUNT[ 0 SW ~| COUNT_STEP# 0 SW SU ]
COUNT_STEP[ DR 1 SU ]
`THE_LIST COUNT# +<> | Give a code snippet in #FurryScript
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial | Factorial | Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a number.
Solutions can be iterat... | #LiveCode | LiveCode | // recursive
function factorialr n
if n < 2 then
return 1
else
return n * factorialr(n-1)
end if
end factorialr
// using accumulator
function factorialacc n acc
if n = 0 then
return acc
else
return factorialacc(n-1, n * acc)
end if
end factorialacc
function f... | Give a code snippet in #LiveCode
Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of ... | 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... | #Simula | Simula | BEGIN
INTEGER PROCEDURE COUNTSUBSTRING(T,TSUB); TEXT T,TSUB;
BEGIN
INTEGER N,I;
I := 1;
WHILE I+TSUB.LENGTH-1 <= T.LENGTH DO
IF T.SUB(I,TSUB.LENGTH) = TSUB THEN
BEGIN
N := N+1;
I := I+MAX(TSUB.LENGTH,1);
END ELSE I := I+1;
... | Give a code snippet in #Simula
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.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/While | Loops/While | Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For... | #ALGOL_68 | ALGOL 68 | INT i := 1024;
WHILE i > 0 DO
print(i);
i := i OVER 2
OD | Give a code snippet in #ALGOL_68
Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Down... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial | Factorial | Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a number.
Solutions can be iterat... | #Clojure | Clojure | (defn factorial [x]
(apply * (range 2 (inc x)))) | Give a code snippet in #Clojure
Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Delegates | Delegates | A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern.
Objects ... | #C.2B.2B | C++ |
#include <tr1/memory>
#include <string>
#include <iostream>
#include <tr1/functional>
using namespace std;
using namespace std::tr1;
using std::tr1::function;
// interface for all delegates
class IDelegate
{
public:
virtual ~IDelegate() {}
};
//interface for delegates supporting thing
class IThing
{
public... | Give a code snippet in #C.2B.2B
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also... | christopher/rosetta-code | |
http://rosettacode.org/wiki/JortSort | JortSort |
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
... | #BQN | BQN | JSort ← ≡⟜∧
JSort 3‿2‿1
0 | Give a code snippet in #BQN
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library | Call a function in a shared library | Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign language function where the focus is c... | #Jsish | Jsish | #!/usr/local/bin/jsish
load('byjsi.so'); | Give a code snippet in #Jsish
Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign languag... | 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... | #Microsoft_Small_Basic | Microsoft Small Basic | 'Permutations - sb
n=4
printem = "True"
For i = 1 To n
p[i] = i
EndFor
count = 0
Last = "False"
While Last = "False"
If printem Then
For t = 1 To n
TextWindow.Write(p[t])
EndFor
TextWindow.WriteLine("")
EndIf
count = count + 1
Last = "True"
i = n - 1
W... | Give a code snippet in #Microsoft_Small_Basic
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 per... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rename_a_file | Rename a file | Task
Rename:
a file called input.txt into output.txt and
a directory called docs into mydocs.
This should be done twice:
once "here", i.e. in the current working directory and once in the filesystem root.
It can be assumed that the user has the rights to do so.
(In unix-type s... | #Phixmonti | Phixmonti | _platform "windows" == if "\\" "ren " else "/" "mv " endif
var com var slash
com "input.txt output.txt" chain cmd
com "docs mydocs" chain cmd
com slash chain "input.txt " chain slash chain "output.txt" chain cmd
com slash chain "docs " chain slash chain "mydocs" chain cmd | Give a code snippet in #Phixmonti
Task
Rename:
a file called input.txt into output.txt and
a directory called docs into mydocs.
This should be done twice:
once "here", i.e. in the current working directory and once in the filesystem root.
It can be assumed that the user has th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Church_numerals | Church numerals | Task
In the Church encoding of natural numbers, the number N is encoded by a function that applies its first argument N times to its second argument.
Church zero always returns the identity function, regardless of its first argument. In other words, the first argument is not applied to the second argument at all.
C... | #Groovy | Groovy | class ChurchNumerals {
static void main(args) {
def zero = { f -> { a -> a } }
def succ = { n -> { f -> { a -> f(n(f)(a)) } } }
def add = { n -> { k -> { n(succ)(k) } } }
def mult = { f -> { g -> { a -> f(g(a)) } } }
def pow = { f -> { g -> g(f) } }
def toChurchNu... | Give a code snippet in #Groovy
Task
In the Church encoding of natural numbers, the number N is encoded by a function that applies its first argument N times to its second argument.
Church zero always returns the identity function, regardless of its first argument. In other words, the first argument is not applied t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Long_year | Long year | Most years have 52 weeks, some have 53, according to ISO8601.
Task
Write a function which determines if a given year is long (53 weeks) or not, and demonstrate it.
| #Haskell | Haskell | import Data.Time.Calendar (fromGregorian)
import Data.Time.Calendar.WeekDate (toWeekDate)
longYear :: Integer -> Bool
longYear y =
let (_, w, _) = toWeekDate $ fromGregorian y 12 28
in 52 < w
main :: IO ()
main = mapM_ print $ filter longYear [2000 .. 2100] | Give a code snippet in #Haskell
Most years have 52 weeks, some have 53, according to ISO8601.
Task
Write a function which determines if a given year is long (53 weeks) or not, and demonstrate it.
| christopher/rosetta-code |
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