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/Box_the_compass | Box the compass | There be many a land lubber that knows naught of the pirate ways and gives direction by degree!
They know not how to box the compass!
Task description
Create a function that takes a heading in degrees and returns the correct 32-point compass heading.
Use the function to print and display a table of Index, Compass... | #Factor | Factor | USING: formatting kernel math sequences ;
CONSTANT: box
{
"North" "North by east" "North-northeast"
"Northeast by north" "Northeast" "Northeast by east"
"East-northeast" "East by north" "East" "East by south"
"East-southeast" "Southeast by east" "Southeast"
"Southeast by south" "South-southeast" "... | Give a code snippet in #Factor
There be many a land lubber that knows naught of the pirate ways and gives direction by degree!
They know not how to box the compass!
Task description
Create a function that takes a heading in degrees and returns the correct 32-point compass heading.
Use the function to print and d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Forest_fire | Forest fire |
This page uses content from Wikipedia. The original article was at Forest-fire model. 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
Implement the Drossel and Schwabl definition of the fores... | #MATLAB_.2F_Octave | MATLAB / Octave | function forest_fire(f,p,N,M)
% Forest fire
if nargin<4;
M=200;
end
if nargin<3;
N=200;
end
if nargin<2;
p=.03;
end
if nargin<1;
f=p*.0001;
end
% initialize;
F = (rand(M,N) < p)+1; % tree with probability p
S = ones(3); S(2,2)=0; % surrounding
textmap = ' T#';
colormap([.5,.5,.5;0,1,0;1,0,0]);
while(1)
... | Give a code snippet in #MATLAB_.2F_Octave
This page uses content from Wikipedia. The original article was at Forest-fire model. 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
Implement the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Best_shuffle | Best shuffle | Task
Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible.
A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time is acceptable as an alternative... | #Java | Java | import java.util.Random;
public class BestShuffle {
private final static Random rand = new Random();
public static void main(String[] args) {
String[] words = {"abracadabra", "seesaw", "grrrrrr", "pop", "up", "a"};
for (String w : words)
System.out.println(bestShuffle(w));
}
... | Give a code snippet in #Java
Task
Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible.
A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_block_comments | Strip block comments | A block comment begins with a beginning delimiter and ends with a ending delimiter, including the delimiters. These delimiters are often multi-character sequences.
Task
Strip block comments from program text (of a programming language much like classic C).
Your demos should at least handle simple, non-ne... | #Icon_and_Unicon | Icon and Unicon | procedure main()
every (unstripped := "") ||:= !&input || "\n" # Load file as one string
write(stripBlockComment(unstripped,"/*","*/"))
end
procedure stripBlockComment(s1,s2,s3) #: strip comments between s2-s3 from s1
result := ""
s1 ? {
while result ||:= tab(find(s2)) do {
move(*s2)
... | Give a code snippet in #Icon_and_Unicon
A block comment begins with a beginning delimiter and ends with a ending delimiter, including the delimiters. These delimiters are often multi-character sequences.
Task
Strip block comments from program text (of a programming language much like classic C).
Your de... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Chowla_numbers | Chowla numbers | Chowla numbers are also known as:
Chowla's function
chowla numbers
the chowla function
the chowla number
the chowla sequence
The chowla number of n is (as defined by Chowla's function):
the sum of the divisors of n excluding unity and n
where n is a positive integer
The s... | #C | C | #include <stdio.h>
unsigned chowla(const unsigned n) {
unsigned sum = 0;
for (unsigned i = 2, j; i * i <= n; i ++) if (n % i == 0) sum += i + (i == (j = n / i) ? 0 : j);
return sum;
}
int main(int argc, char const *argv[]) {
unsigned a;
for (unsigned n = 1; n < 38; n ++) printf("chowla(%u) = %u\n", n, cho... | Give a code snippet in #C
Chowla numbers are also known as:
Chowla's function
chowla numbers
the chowla function
the chowla number
the chowla sequence
The chowla number of n is (as defined by Chowla's function):
the sum of the divisors of n excluding unity and n
where n is... | 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... | #Perl | Perl | use List::Util qw(shuffle);
my $turn = 0;
my @jumble = shuffle 1..9;
while ( join('', @jumble) eq '123456789' ) {
@jumble = shuffle 1..9;
}
until ( join('', @jumble) eq '123456789' ) {
$turn++;
printf "%2d: @jumble - Flip how many digits ? ", $turn;
my $d = <>;
@jumble[0..$d-1] = reverse @... | Give a code snippet in #Perl
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 sco... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Singly-linked_list/Element_definition | Singly-linked list/Element definition | singly-linked list
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Definition, Usage
Set
Singly-linked list: Element definition, Element insertion, Lis... | #Elena | Elena | class Link
{
prop int Item;
prop Link Next;
constructor(int item, Link next)
{
Item := item;
Next := next
}
} | Give a code snippet in #Elena
singly-linked list
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Definition, Usage
Set
Singly-linked list: Element def... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brownian_tree | Brownian tree | Brownian tree
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw a Brownian Tree.
A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes.
The initial "seed" is placed somewhere wi... | #BBC_BASIC | BBC BASIC | SYS "SetWindowText", @hwnd%, "Brownian Tree"
SIZE = 400
VDU 23,22,SIZE;SIZE;8,16,16,0
GCOL 10
REM set the seed:
PLOT SIZE, SIZE
OFF
REPEAT
REM set particle's initial position:
REPEAT
X% = RND(SIZE)-1
Y% = RND(SIZE)-1
UNT... | Give a code snippet in #BBC_BASIC
Brownian tree
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw a Brownian Tree.
A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes.
The in... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric | Determine if a string is numeric | Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
Array length
String length
Cop... | #EasyLang | EasyLang | func is_numeric a$ . r .
h = number a$
r = 1 - error
# because every variable must be used
h = h
.
for s$ in [ "abc" "21a" "1234" "-13" "7.65" ]
call is_numeric s$ r
if r = 1
print s$ & " is numeric"
else
print s$ & " is not numeric"
.
. | Give a code snippet in #EasyLang
Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #Elena | Elena | import system'routines;
import extensions;
import extensions'text;
singleton rotConvertor
{
char convert(char ch)
{
if (($97 <= ch && ch <= $109) || ($65 <= ch && ch <= $77))
{
^ (ch.toInt() + 13).toChar()
};
if (($110 <= ch && ch <= $122) || ($78 <= ch && ch <= $90... | Give a code snippet in #Elena
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Program_termination | Program termination |
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers/destructors, run-on-exit hooks... | #Pop11 | Pop11 | if condition then
sysexit();
endif; | Give a code snippet in #Pop11
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Line_printer | Hello world/Line printer | Task
Cause a line printer attached to the computer to print a line containing the message: Hello World!
Note
A line printer is not the same as standard output.
A line printer was an older-style printer which prints one line at a time to a continuous ream of paper.
With some systems, a line printer can be... | #Phix | Phix | integer fn = open(iff(platform()=WIN32?"PRN":"/dev/lp0"),"w")
if fn=-1 then
puts(1,"some error")
else
puts(fn,"Hello World!")
close(fn)
puts(1,"success!")
end if
{} = wait_key()
| Give a code snippet in #Phix
Task
Cause a line printer attached to the computer to print a line containing the message: Hello World!
Note
A line printer is not the same as standard output.
A line printer was an older-style printer which prints one line at a time to a continuous ream of paper.
With some ... | 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... | #C | C | /* function with no argument */
f();
/* fix number of arguments */
g(1, 2, 3);
/* Optional arguments: err...
Feel free to make sense of the following. I can't. */
int op_arg();
int main()
{
op_arg(1);
op_arg(1, 2);
op_arg(1, 2, 3);
return 0;
}
int op_arg(int a, int b)
{
printf("%d %d %d\n", a, b, (&b)[1]);... | Give a code snippet in #C
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 variab... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within l... | #ARM_Assembly | ARM Assembly |
.global main
main:
loop:
ldr r0, =message
bl printf
b loop
message:
.asciz "SPAM\n"
| Give a code snippet in #ARM_Assembly
Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Man_or_boy_test | Man or boy test | Man or boy test
You are encouraged to solve this task according to the task description, using any language you may know.
Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguis... | #Ada | Ada | with Ada.Text_IO; use Ada.Text_IO;
procedure Man_Or_Boy is
function Zero return Integer is begin return 0; end Zero;
function One return Integer is begin return 1; end One;
function Neg return Integer is begin return -1; end Neg;
function A
( K : Integer;
X1, X2, X3, X4,... | Give a code snippet in #Ada
Man or boy test
You are encouraged to solve this task according to the task description, using any language you may know.
Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Long_multiplication | Long multiplication | Task
Explicitly implement long multiplication.
This is one possible approach to arbitrary-precision integer algebra.
For output, display the result of 264 * 264.
Optionally, verify your result against builtin arbitrary precision support.
The decimal representation of 264 is:
18,446,744,073,709,551,61... | #Ceylon | Ceylon | "run() is the main function of this module."
shared void run() {
function multiply(String|Integer|Integer[] top, String|Integer|Integer[] bottom, Integer base = 10) {
function fromString(String s) =>
s
.filter(not(','.equals))
.map((char) => Integer.pars... | Give a code snippet in #Ceylon
Task
Explicitly implement long multiplication.
This is one possible approach to arbitrary-precision integer algebra.
For output, display the result of 264 * 264.
Optionally, verify your result against builtin arbitrary precision support.
The decimal representation of 264 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Host_introspection | Host introspection | Print the word size and endianness of the host machine.
See also: Variable size/Get
| #Retro | Retro | needs variations'
^variations'size | Give a code snippet in #Retro
Print the word size and endianness of the host machine.
See also: Variable size/Get
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, o... | #Yabasic | Yabasic | theString$ = "Given$a$text$file$of$many$lines,$where$fields$within$a$line$"
theString$ = theString$ + "are$delineated$by$a$single$'dollar'$character,$write$a$program"
theString$ = theString$ + "that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$"
theString$ = theString$ + "column$are$separated$by$at$least... | Give a code snippet in #Yabasic
Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either l... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Gnome_sort | Sorting algorithms/Gnome 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
... | #Elixir | Elixir | defmodule Sort do
def gnome_sort([]), do: []
def gnome_sort([h|t]), do: gnome_sort([h], t)
defp gnome_sort(list, []), do: list
defp gnome_sort([prev|p], [next|n]) when next > prev, do: gnome_sort(p, [next,prev|n])
defp gnome_sort(p, [next|n]), do: gnome_sort([next|p], n)
end
IO.inspect Sort.gnome_sort([8,... | Give a code snippet in #Elixir
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/Continued_fraction | Continued fraction | continued fraction
Mathworld
a
0
+
b
1
a
1
+
b
2
a
2
+
b
3
a
3
+
⋱
{\displaystyle a_{0}+{\cfrac {b_{1}}{a_{1}+{\cfrac {b_{2}}{a_{2}+{\cfrac {b_{3}}{a_{3}+\ddots }}}}}}}
The task is to write a program which generates su... | #OCaml | OCaml | let pi = 3, fun n -> ((2*n-1)*(2*n-1), 6)
and nap = 2, fun n -> (max 1 (n-1), n)
and root2 = 1, fun n -> (1, 2) in
let eval (i,f) k =
let rec frac n =
let a, b = f n in
float a /. (float b +.
if n >= k then 0.0 else frac (n+1)) in
float i +. frac 1 in
Printf.printf "sqrt(2)\t= %.15f\n" (eval root2... | Give a code snippet in #OCaml
continued fraction
Mathworld
a
0
+
b
1
a
1
+
b
2
a
2
+
b
3
a
3
+
⋱
{\displaystyle a_{0}+{\cfrac {b_{1}}{a_{1}+{\cfrac {b_{2}}{a_{2}+{\cfrac {b_{3}}{a_{3}+\ddots }}}}}}}
The task is to wri... | 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... | #Befunge | Befunge | 84*:*> :v
^/2,*25.:_@ | Give a code snippet in #Befunge
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/Downw... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Primorial_numbers | Primorial numbers | Primorial numbers are those formed by multiplying successive prime numbers.
The primorial number series is:
primorial(0) = 1 (by definition)
primorial(1) = 2 (2)
primorial(2) = 6 (2×3)
primorial(3) = 30 (2×3×5)
primorial(4) = 210 (2×3×5×... | #C | C |
#include <inttypes.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <gmp.h>
/* Eratosthenes bit-sieve */
int es_check(uint32_t *sieve, uint64_t n)
{
if ((n != 2 && !(n & 1)) || (n < 2))
return 0;
else
return !(sieve[n >> 6] & (1 << ... | Give a code snippet in #C
Primorial numbers are those formed by multiplying successive prime numbers.
The primorial number series is:
primorial(0) = 1 (by definition)
primorial(1) = 2 (2)
primorial(2) = 6 (2×3)
primorial(3) = 30 (2×3×5)
primorial... | 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... | #Elm | Elm | module Main exposing (main)
import Html
main =
List.range 1 100
|> List.reverse
|> List.map
(\n ->
let
nString =
String.fromInt n
n1String =
String.fromInt (n - 1)
... | Give a code snippet in #Elm
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/Abbreviations,_simple | Abbreviations, simple | The use of abbreviations (also sometimes called synonyms, nicknames, AKAs, or aliases) can be an
easy way to add flexibility when specifying or using commands, sub─commands, options, etc.
For this task, the following command table will be used:
add 1 alter 3 backup 2 bottom 1 Cappend 2 change 1 ... | #J | J |
range=:<.+[:i.>.-<.
assert 2 3 4 -: 2 range 5
assert (i.0) -: 3 range 3
abbreviate =: 3 :0
NB. input is the abbreviation table
NB. output are the valid abbreviations
y =. toupper CRLF -.~ y
y =. ;: y
y =. (([: (,3":#)L:_1 {)`[`]}~ ([: I. [: -. {.@e.&Num_j_&>)) y
y =. [&.:(;:inv) y
y =. _2 ({. , <./@:".&.>@:{... | Give a code snippet in #J
The use of abbreviations (also sometimes called synonyms, nicknames, AKAs, or aliases) can be an
easy way to add flexibility when specifying or using commands, sub─commands, options, etc.
For this task, the following command table will be used:
add 1 alter 3 backup 2 bott... | 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... | #EchoLisp | EchoLisp |
(define (fact n)
(for/product ((f (in-range 2 (1+ n)))) f))
(fact 10)
→ 3628800
| Give a code snippet in #EchoLisp
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/Bitmap/Write_a_PPM_file | Bitmap/Write a PPM file | Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| #Action.21 | Action! | INCLUDE "H6:RGBIMAGE.ACT" ;from task Bitmap
PROC SaveHeader(RgbImage POINTER img
CHAR ARRAY format BYTE dev)
PrintDE(dev,format)
PrintBD(dev,img.w)
PutD(dev,32)
PrintBDE(dev,img.h)
PrintBDE(dev,255)
RETURN
PROC SavePPM3(RgbImage POINTER img CHAR ARRAY path)
BYTE dev=[1],x,y
RGB c
Close(dev)
... | Give a code snippet in #Action.21
Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations | Combinations | Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
0 3 4
1 2 3
1 2 4
1 3 4
2 3 4
... | #Oz | Oz | declare
fun {Comb M N}
proc {CombScript Comb}
%% Comb is a subset of [0..N-1]
Comb = {FS.var.upperBound {List.number 0 N-1 1}}
%% Comb has cardinality M
{FS.card Comb M}
%% enumerate all possibilities
{FS.distribute naive [Comb]}
end
in
%% Collect all s... | Give a code snippet in #Oz
Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
0 ... | 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... | #Haskell | Haskell | import Data.Version
import Control.Monad
import System.Info
minGHCVersion = Version [6, 8] []
main = when (compilerName == "ghc" && compilerVersion < minGHCVersion) $
fail "Compiler too old." | Give a code snippet in #Haskell
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 a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_a_file_on_magnetic_tape | Create a file on magnetic tape | The task is to create a new file called "TAPE.FILE" of any size on Magnetic Tape.
| #Seed7 | Seed7 | $ include "seed7_05.s7i";
const proc: main is func
local
var file: tapeFile is STD_NULL;
begin
tapeFile := open("/dev/tape", "w");
if tapeFile = STD_NULL then
tapeFile := open("tape.file", "w");
end if;
if tapeFile <> STD_NULL then
writeln(tapeFile, "Hello, world!");
close(ta... | Give a code snippet in #Seed7
The task is to create a new file called "TAPE.FILE" of any size on Magnetic Tape.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Compare_a_list_of_strings | Compare a list of strings | Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or false value, which could be used as t... | #OCaml | OCaml |
open List;;
let analyze cmp l =
let rec analyze' l prevs =
match l with
[] -> true
| [s] -> cmp prevs s
| s::rest -> (cmp prevs s) && (analyze' rest s)
in analyze' (List.tl l) (List.hd l)
;;
let isEqual = analyze (=) ;;
let isAscending = analyze (<) ;;
let test sample =
List.iter pri... | Give a code snippet in #OCaml
Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or false ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the f... | #Haskell | Haskell | fib :: Integer -> Maybe Integer
fib n
| n < 0 = Nothing
| otherwise = Just $ real n
where real 0 = 1
real 1 = 1
real n = real (n-1) + real (n-2) | Give a code snippet in #Haskell
While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_search | Binary search | A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret number, and will only tell the p... | #UNIX_Shell | UNIX Shell |
#!/bin/ksh
# This should work on any clone of Bourne Shell, ksh is the fastest.
value=$1; [ -z "$value" ] && exit
array=()
size=0
while IFS= read -r line; do
size=$(($size + 1))
array[${#array[*]}]=$line
done
| Give a code snippet in #UNIX_Shell
A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a sec... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Levenshtein_distance | Levenshtein distance |
This page uses content from Wikipedia. The original article was at Levenshtein distance. 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 information theory and computer science, the Levenshtein ... | #CLU | CLU | min = proc [T: type] (a, b: T) returns (T)
where T has lt: proctype (T,T) returns (bool)
if a<b
then return(a)
else return(b)
end
end min
levenshtein = proc (s, t: string) returns (int)
ai = array[int]
aai = array[array[int]]
m: int := string$size(s)
n: int := string$s... | Give a code snippet in #CLU
This page uses content from Wikipedia. The original article was at Levenshtein distance. 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 information theory and compu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sleep | Sleep | Task
Write a program that does the following in this order:
Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
Print "Sleeping..."
Sleep the main thread for the given amount of time.
... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols nobinary
runSample(arg)
return
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
method sleep(secs) public static binary
ms = (secs * 1000).format(null, 0) -- milliseconds, rounded to nearest integer
say 'Sleeping... | Give a code snippet in #NetRexx
Task
Write a program that does the following in this order:
Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
Print "Sleeping..."
Sleep the main thre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exceptions | Exceptions | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions Through Nested Calls
| #Modula-3 | Modula-3 | EXCEPTION EndOfFile;
EXCEPTION Error(TEXT); | Give a code snippet in #Modula-3
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Excepti... | 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... | #M2000_Interpreter | M2000 Interpreter |
\\ A is a pointer to array
A=("Apple", "Orange")
Print Len(A)=2 ' True
Print Dimension(A, 0) ' LBound (0 or 1), here 0
Print Dimension(A) ' No of Dimensions 1
Print Dimension(A, 1) ' for 1 dimension array this is also Length=2
\\ A$( ) is an Array (not a pointer to array)
Dim Base 1, A$(2)
A$(1)="Apple", "Orange"... | Give a code snippet in #M2000_Interpreter
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
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parsing/RPN_calculator_algorithm | Parsing/RPN calculator algorithm | Task
Create a stack-based evaluator for an expression in reverse Polish notation (RPN) that also shows the changes in the stack as each individual token is processed as a table.
Assume an input of a correct, space separated, string of tokens of an RPN expression
Test with the RPN expression generated from the... | #Go | Go | package main
import (
"fmt"
"math"
"strconv"
"strings"
)
var input = "3 4 2 * 1 5 - 2 3 ^ ^ / +"
func main() {
fmt.Printf("For postfix %q\n", input)
fmt.Println("\nToken Action Stack")
var stack []float64
for _, tok := range strings.Fields(input) {
act... | Give a code snippet in #Go
Task
Create a stack-based evaluator for an expression in reverse Polish notation (RPN) that also shows the changes in the stack as each individual token is processed as a table.
Assume an input of a correct, space separated, string of tokens of an RPN expression
Test with the RPN e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hailstone_sequence | Hailstone sequence | The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
The (unproven) Collatz conje... | #Wren | Wren | var hailstone = Fn.new { |n|
if (n < 1) Fiber.abort("Parameter must be a positive integer.")
var h = [n]
while (n != 1) {
n = (n%2 == 0) ? (n/2).floor : 3*n + 1
h.add(n)
}
return h
}
var h = hailstone.call(27)
System.print("For the Hailstone sequence starting with n = 27:")
Syste... | Give a code snippet in #Wren
The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Vector_products | Vector products | A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of numbers, (X, Y, Z) would repr... | #GAP | GAP | DotProduct := function(u, v)
return u*v;
end;
CrossProduct := function(u, v)
return [
u[2]*v[3] - u[3]*v[2],
u[3]*v[1] - u[1]*v[3],
u[1]*v[2] - u[2]*v[1] ];
end;
ScalarTripleProduct := function(u, v, w)
return DotProduct(u, CrossProduct(v, w));
end;
VectorTripleProduct := function(u, v, w)
return CrossP... | Give a code snippet in #GAP
A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of numb... | christopher/rosetta-code | |
http://rosettacode.org/wiki/S-expressions | S-expressions | S-Expressions are one convenient way to parse and store data.
Task
Write a simple reader and writer for S-Expressions that handles quoted and unquoted strings, integers and floats.
The reader should read a single but nested S-Expression from a string and store it in a suitable datastructure (list, array, etc).
... | #Tcl | Tcl | package require Tcl 8.5
proc fromSexp {str} {
set tokenizer {[()]|"(?:[^\\""]|\\.)*"|(?:[^()""\s\\]|\\.)+|[""]}
set stack {}
set accum {}
foreach token [regexp -inline -all $tokenizer $str] {
if {$token eq "("} {
lappend stack $accum
set accum {}
} elseif {$token eq ")"} {
if {![lleng... | Give a code snippet in #Tcl
S-Expressions are one convenient way to parse and store data.
Task
Write a simple reader and writer for S-Expressions that handles quoted and unquoted strings, integers and floats.
The reader should read a single but nested S-Expression from a string and store it in a suitable datast... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #AppleScript | AppleScript | try
find text ".*string$" in "I am a string" with regexp
on error message
return message
end try
try
change "original" into "modified" in "I am the original string" with regexp
on error message
return message
end try | Give a code snippet in #AppleScript
Task
match a string against a regular expression
substitute part of a string using a regular expression
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Higher-order_functions | Higher-order functions | Task
Pass a function as an argument to another function.
Related task
First-class functions
| #Nemerle | Nemerle | Twice[T] (f : T -> T, x : T) : T { f(f(x)) } | Give a code snippet in #Nemerle
Task
Pass a function as an argument to another function.
Related task
First-class functions
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Set_puzzle | Set puzzle | Set Puzzles are created with a deck of cards from the Set Game™. The object of the puzzle is to find sets of 3 cards in a rectangle of cards that have been dealt face up.
There are 81 cards in a deck.
Each card contains a unique variation of the following four features: color, symbol, number and shading.
there are... | #Ceylon | Ceylon | import ceylon.random {
Random,
DefaultRandom
}
abstract class Feature() of Color | Symbol | NumberOfSymbols | Shading {}
abstract class Color()
of red | green | purple
extends Feature() {}
object red extends Color() {
string => "red";
}
object green extends Color() {
string => "green... | Give a code snippet in #Ceylon
Set Puzzles are created with a deck of cards from the Set Game™. The object of the puzzle is to find sets of 3 cards in a rectangle of cards that have been dealt face up.
There are 81 cards in a deck.
Each card contains a unique variation of the following four features: color, symbol,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Narcissistic_decimal_number | Narcissistic decimal number | A Narcissistic decimal number is a non-negative integer,
n
{\displaystyle n}
, that is equal to the sum of the
m
{\displaystyle m}
-th powers of each of the digits in the decimal representation of
n
{\displaystyle n}
, where
m
{\displaystyle m}
is the number of digits in... | #Forth | Forth |
: dig.num \ returns input number and the number of its digits ( n -- n n1 )
dup
0 swap
begin
swap 1 + swap
dup 10 >= while
10 /
repeat
drop ;
: zero.divmod \ /mod that returns zero if number is zero
dup
0 = if drop 0 else
/... | Give a code snippet in #Forth
A Narcissistic decimal number is a non-negative integer,
n
{\displaystyle n}
, that is equal to the sum of the
m
{\displaystyle m}
-th powers of each of the digits in the decimal representation of
n
{\displaystyle n}
, where
m
{\displaystyle m}... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #AutoIt | AutoIt |
Func Halve($x)
Return Int($x/2)
EndFunc
Func Double($x)
Return ($x*2)
EndFunc
Func IsEven($x)
Return (Mod($x,2) == 0)
EndFunc
; this version also supports negative parameters
Func Ethiopian($nPlier, $nPlicand, $bTutor = True)
Local $nResult = 0
If ($nPlier < 0) Then
$nPlier =- $nPlier
$nPlicand =- $nPl... | Give a code snippet in #AutoIt
Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number/With_feedback | Guess the number/With feedback | Task
Write a game (computer program) that follows the following rules:
The computer chooses a number between given set limits.
The player is asked for repeated guesses until the the target number is guessed correctly
At each guess, the computer responds with whether the guess is:
higher than the target,
equal to... | #NS-HUBASIC | NS-HUBASIC | 10 NUMBER=RND(10)+1
20 INPUT "I'M THINKING OF A NUMBER BETWEEN 1 AND 10. WHAT IS IT? ",GUESS
30 IF GUESS>NUMBER THEN PRINT "MY NUMBER IS LOWER THAN THAT.": GOTO 20
40 IF GUESS<NUMBER THEN PRINT "MY NUMBER IS HIGHER THAN THAT.": GOTO 20
50 PRINT "THAT'S THE CORRECT NUMBER." | Give a code snippet in #NS-HUBASIC
Task
Write a game (computer program) that follows the following rules:
The computer chooses a number between given set limits.
The player is asked for repeated guesses until the the target number is guessed correctly
At each guess, the computer responds with whether the guess is... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat... | #Quackery | Quackery | [ tuck tally share ]this[ swap ] is accumulate ( n s --> [ n )
[ [ stack ] copy tuck put nested
' accumulate nested join ] is factory ( n --> [ ) | Give a code snippet in #Quackery
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_prototype | Function prototype | Some languages provide the facility to declare functions and subroutines through the use of function prototyping.
Task
Demonstrate the methods available for declaring prototypes within the language. The provided solutions should include:
An explanation of any placement restrictions for prototype declarations
A p... | #Raku | Raku | sub foo ( --> Int) {...} | Give a code snippet in #Raku
Some languages provide the facility to declare functions and subroutines through the use of function prototyping.
Task
Demonstrate the methods available for declaring prototypes within the language. The provided solutions should include:
An explanation of any placement restrictions f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Concurrent_computing | Concurrent computing | Task
Using either native language concurrency syntax or freely available libraries, write a program to display the strings "Enjoy" "Rosetta" "Code", one string per line, in random order.
Concurrency syntax must use threads, tasks, co-routines, or whatever concurrency is called in your language.
| #Lua | Lua | co = {}
co[1] = coroutine.create( function() print "Enjoy" end )
co[2] = coroutine.create( function() print "Rosetta" end )
co[3] = coroutine.create( function() print "Code" end )
math.randomseed( os.time() )
h = {}
i = 0
repeat
j = math.random(3)
if h[j] == nil then
coroutine.resume( co[j] )
h[... | Give a code snippet in #Lua
Task
Using either native language concurrency syntax or freely available libraries, write a program to display the strings "Enjoy" "Rosetta" "Code", one string per line, in random order.
Concurrency syntax must use threads, tasks, co-routines, or whatever concurrency is called in your lan... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_an_HTML_table | Create an HTML table | Create an HTML table.
The table body should have at least three rows of three columns.
Each of these three columns should be labelled "X", "Y", and "Z".
An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled with sequential row numbers.
The... | #11l | 11l | UInt32 seed = 0
F nonrandom(n)
:seed = 1664525 * :seed + 1013904223
R Int(:seed >> 16) % n
F rand9999()
R nonrandom(9000) + 1000
F tag(tag, txt, attr = ‘’)
R ‘<’tag‘’attr‘>’txt‘</’tag‘>’
V header = tag(‘tr’, ‘,X,Y,Z’.split(‘,’).map(txt -> tag(‘th’, txt)).join(‘’))"\n"
V rows = (1..5).map(i -> tag(‘tr’... | Give a code snippet in #11l
Create an HTML table.
The table body should have at least three rows of three columns.
Each of these three columns should be labelled "X", "Y", and "Z".
An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled with ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Graphical | Hello world/Graphical |
Task
Display the string Goodbye, World! on a GUI object (alert box, plain window, text area, etc.).
Related task
Hello world/Text
| #IWBASIC | IWBASIC |
DEF Win:WINDOW
DEF Close:CHAR
DEF ScreenSizeX,ScreenSizeY:UINT
GETSCREENSIZE(ScreenSizeX,ScreenSizeY)
OPENWINDOW Win,0,0,ScreenSizeX,ScreenSizeY,NULL,NULL,"Goodbye program",&MainHandler
PRINT Win,"Goodbye, World!"
'Prints in upper left corner of the window (position 0,0).
WAITUNTIL Close=1
CLOSEWINDOW Win
... | Give a code snippet in #IWBASIC
Task
Display the string Goodbye, World! on a GUI object (alert box, plain window, text area, etc.).
Related task
Hello world/Text
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number/With_feedback_(player) | Guess the number/With feedback (player) | Task
Write a player for the game that follows the following rules:
The scorer will choose a number between set limits. The computer player will print a guess of the target number. The computer asks for a score of whether its guess is higher than, lower than, or equal to the target. The computer guesses, and the score... | #Racket | Racket | #lang racket
(define (guess low high)
(define (input-loop available)
(define input (car (string->list (symbol->string (read)))))
(if (member input available)
input
(begin
(printf "Invalid Input\n") (input-loop available))))
(define (guess-loop low high)
(define guess (floor... | Give a code snippet in #Racket
Task
Write a player for the game that follows the following rules:
The scorer will choose a number between set limits. The computer player will print a guess of the target number. The computer asks for a score of whether its guess is higher than, lower than, or equal to the target. The... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Brat | Brat | 99.to 2 { n |
p "#{n} bottles of beer on the wall, #{n} bottles of beer!"
p "Take one down, pass it around, #{n - 1} bottle#{true? n > 2 's' ''} of beer on the wall."
}
p "One bottle of beer on the wall, one bottle of beer!"
p "Take one down, pass it around, no more bottles of beer on the wall." | Give a code snippet in #Brat
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas | The Twelve Days of Christmas | Task
Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas.
The lyrics can be found here.
(You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.)
Other tasks related to string operations:
Metrics
Array length
Stri... | #Bracmat | Bracmat | ( first
second
third
fourth
fifth
sixth
seventh
eighth
ninth
tenth
eleventh
twelveth
: ?days
& "A partridge in a pear tree."
"Two turtle doves and"
"Three french hens,"
"Four calling birds,"
"Five golden rings,"
"S... | Give a code snippet in #Bracmat
Task
Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas.
The lyrics can be found here.
(You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.)
Other tasks related to string operati... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_characters | Special characters | Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling it to be used as a normal charact... | #PowerShell | PowerShell | a=1 ; The ';' indicates that a comment starts
b=2*a: a=b*33 ; b will now be 2, and a=66 | Give a code snippet in #PowerShell
Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabli... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable-length_quantity | Variable-length quantity | Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable.
Task
With above operations,
convert these two numbers 0x200000 (209... | #C.23 | C# | namespace Vlq
{
using System;
using System.Collections.Generic;
using System.Linq;
public static class VarLenQuantity
{
public static ulong ToVlq(ulong integer)
{
var array = new byte[8];
var buffer = ToVlqCollection(integer)
.SkipWhile(b => b == 0)
.Reverse()
.To... | Give a code snippet in #C.23
Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable.
Task
With above operations,
convert t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exceptions | Exceptions | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions Through Nested Calls
| #Maple | Maple |
errorproc:=proc(n)
local a;
try
a:=1/n;
catch "numeric exception: division by zero":
error "Something went wrong when dividing."
end try;
end proc;
| Give a code snippet in #Maple
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Standard_error | Hello world/Standard error | Hello world/Standard error is part of Short Circuit's Console Program Basics selection.
A common practice in computing is to send error messages
to a different output stream than normal text console messages.
The normal messages print to what is called "standard output" or "standard out".
The error messages print to ... | #Ol | Ol |
(print-to stderr "Goodbye, World!")
| Give a code snippet in #Ol
Hello world/Standard error is part of Short Circuit's Console Program Basics selection.
A common practice in computing is to send error messages
to a different output stream than normal text console messages.
The normal messages print to what is called "standard output" or "standard out".
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pick_random_element | Pick random element | Demonstrate how to pick a random element from a list.
| #Ol | Ol |
(import (otus random!))
(define x '("Monday" "Tuesday" "Wednesday" "Thursday" "Friday" "Saturday" "Sunday"))
(print (list-ref x (rand! (length x))))
| Give a code snippet in #Ol
Demonstrate how to pick a random element from a list.
| 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... | #Kotlin | Kotlin | // version 1.1.2
import java.math.BigInteger
fun nextLeftTruncatablePrimes(n: BigInteger, radix: Int, certainty: Int): List<BigInteger> {
val probablePrimes = mutableListOf<BigInteger>()
val baseString = if (n == BigInteger.ZERO) "" else n.toString(radix)
for (i in 1 until radix) {
val p = BigIn... | Give a code snippet in #Kotlin
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/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if ... | #OCaml | OCaml | $ ocaml unix.cma -I +ANSITerminal ANSITerminal.cma
# open ANSITerminal ;;
# print_string [cyan; on_blue] "Hello\n" ;;
Hello
- : unit = () | Give a code snippet in #OCaml
Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_a_two-dimensional_array_at_runtime | Create a two-dimensional array at runtime |
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.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numbers, and which can be accessed ... | #REXX | REXX | /*REXX program allocates/populates/displays a two-dimensional array. */
call bloat /*the BLOAT procedure does all allocations.*/
/*no more array named @ at this point. */
exit /*stick a fork in it, we're all done honey.*/
/*──────────────────... | Give a code snippet in #REXX
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.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numbe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Topic_variable | Topic variable | Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable.
A topic variable is a special variable with a very short name which can also often be omitted.
Demonstrate the utilization and behaviour of the topic variable within the language and explain or demonstrate h... | #Perl | Perl | print sqrt . " " for (4, 16, 64) | Give a code snippet in #Perl
Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable.
A topic variable is a special variable with a very short name which can also often be omitted.
Demonstrate the utilization and behaviour of the topic variable within the languag... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For | Loops/For | “For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code.
Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers.
... | #TransFORTH | TransFORTH | : PRINTSTARS ( ROWS -- )
1 + 1 DO
I 0 DO
PRINT " * " LOOP
CR LOOP ;
5 PRINTSTARS | Give a code snippet in #TransFORTH
“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code.
Common extensions of this allow other counting patterns or iterating over abstract st... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Almkvist-Giullera_formula_for_pi | Almkvist-Giullera formula for pi | The Almkvist-Giullera formula for calculating 1/π2 is based on the Calabi-Yau
differential equations of order 4 and 5, which were originally used to describe certain manifolds
in string theory.
The formula is:
1/π2 = (25/3) ∑0∞ ((6n)! / (n!6))(532n2 + 126n + 9) / 10002n+1
This formula can be used to calcul... | #Visual_Basic_.NET | Visual Basic .NET | Imports System, BI = System.Numerics.BigInteger, System.Console
Module Module1
Function isqrt(ByVal x As BI) As BI
Dim t As BI, q As BI = 1, r As BI = 0
While q <= x : q <<= 2 : End While
While q > 1 : q >>= 2 : t = x - r - q : r >>= 1
If t >= 0 Then x = t : r += q
En... | Give a code snippet in #Visual_Basic_.NET
The Almkvist-Giullera formula for calculating 1/π2 is based on the Calabi-Yau
differential equations of order 4 and 5, which were originally used to describe certain manifolds
in string theory.
The formula is:
1/π2 = (25/3) ∑0∞ ((6n)! / (n!6))(532n2 + 126n + 9) / 10... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cistercian_numerals | Cistercian numerals | Cistercian numerals were used across Europe by Cistercian monks during the Late Medieval Period as an alternative to Roman numerals. They were used to represent base 10 integers from 0 to 9999.
How they work
All Cistercian numerals begin with a vertical line segment, which by itself represents the number 0. Then, glyp... | #Lua | Lua | function initN()
local n = {}
for i=1,15 do
n[i] = {}
for j=1,11 do
n[i][j] = " "
end
n[i][6] = "x"
end
return n
end
function horiz(n, c1, c2, r)
for c=c1,c2 do
n[r+1][c+1] = "x"
end
end
function verti(n, r1, r2, c)
for r=r1,r2 do
... | Give a code snippet in #Lua
Cistercian numerals were used across Europe by Cistercian monks during the Late Medieval Period as an alternative to Roman numerals. They were used to represent base 10 integers from 0 to 9999.
How they work
All Cistercian numerals begin with a vertical line segment, which by itself repres... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Floyd-Warshall_algorithm | Floyd-Warshall algorithm | The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been checked for loops, parallel ... | #Ada | Ada | --
-- Floyd-Warshall algorithm.
--
-- See https://en.wikipedia.org/w/index.php?title=Floyd%E2%80%93Warshall_algorithm&oldid=1082310013
--
with Ada.Containers.Vectors;
with Ada.Text_IO; use Ada.Text_IO;
with Interfaces; use Interfaces;
with Ada.Numerics.Generic_Elementary_Functions;
procedure floyd_warshall_task
... | Give a code snippet in #Ada
The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Smith_numbers | Smith numbers | Smith numbers are numbers such that the sum of the decimal digits of the integers that make up that number is the same as the sum of the decimal digits of its prime factors excluding 1.
By definition, all primes are excluded as they (naturally) satisfy this condition!
Smith numbers are also known as joke numbers.... | #PureBasic | PureBasic | DisableDebugger
#ECHO=#True ; #True: Print all results
Global NewList f.i()
Procedure.i ePotenz(Wert.i)
Define.i var=Wert, i
While var
i+1
var/10
Wend
ProcedureReturn i
EndProcedure
Procedure.i n_Element(Wert.i,Stelle.i=1)
If Stelle>0
ProcedureReturn (Wert%Int(Pow(10,Stelle))-Wer... | Give a code snippet in #PureBasic
Smith numbers are numbers such that the sum of the decimal digits of the integers that make up that number is the same as the sum of the decimal digits of its prime factors excluding 1.
By definition, all primes are excluded as they (naturally) satisfy this condition!
Smith numbers ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_missing_permutation | Find the missing permutation | ABCD
CABD
ACDB
DACB
BCDA
ACBD
ADCB
CDAB
DABC
BCAD
CADB
CDBA
... | #11l | 11l | V perms = [‘ABCD’, ‘CABD’, ‘ACDB’, ‘DACB’, ‘BCDA’, ‘ACBD’, ‘ADCB’, ‘CDAB’,
‘DABC’, ‘BCAD’, ‘CADB’, ‘CDBA’, ‘CBAD’, ‘ABDC’, ‘ADBC’, ‘BDCA’,
‘DCBA’, ‘BACD’, ‘BADC’, ‘BDAC’, ‘CBDA’, ‘DBCA’, ‘DCAB’]
V missing = ‘’
L(i) 4
V cnt = [0] * 4
L(j) 0 .< perms.len
cnt[perms[j][i].code - ‘A’.code... | Give a code snippet in #11l
ABCD
CABD
ACDB
DACB
BCDA
ACBD
ADCB
CDAB
DABC
BCAD
CADB
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_frequency | Function frequency | Display - for a program or runtime environment (whatever suits the style of your language) - the top ten most frequently occurring functions (or also identifiers or tokens, if preferred).
This is a static analysis: The question is not how often each function is
actually executed at runtime, but how often it is used by... | #Arturo | Arturo | source: to :block read arg\0
frequencies: #[]
inspectBlock: function [blk][
loop blk 'item [
case []
when? [word? item][
sItem: to :string item
if set? sItem ->
if function? var sItem [
if? key? frequencies sItem ->
... | Give a code snippet in #Arturo
Display - for a program or runtime environment (whatever suits the style of your language) - the top ten most frequently occurring functions (or also identifiers or tokens, if preferred).
This is a static analysis: The question is not how often each function is
actually executed at runt... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mind_boggling_card_trick | Mind boggling card trick | Mind boggling card trick
You are encouraged to solve this task according to the task description, using any language you may know.
Matt Parker of the "Stand Up Maths channel" has a YouTube video of a card trick that creates a semblance of order from chaos.
The task is to simulate the trick in a way that mimics th... | #AppleScript | AppleScript | use AppleScript version "2.5" -- OS X 10.11 (El Capitan) or later
use framework "Foundation"
use framework "GameplayKit" -- For randomising functions.
on cardTrick()
(* Create a pack of "cards" and shuffle it. *)
set suits to {"♥️", "♣️", "♦️", "♠️"}
set cards to {"A", "2", "3", "4", "5", "6", "7", "8", "... | Give a code snippet in #AppleScript
Mind boggling card trick
You are encouraged to solve this task according to the task description, using any language you may know.
Matt Parker of the "Stand Up Maths channel" has a YouTube video of a card trick that creates a semblance of order from chaos.
The task is to simul... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Arithmetic_mean | Averages/Arithmetic mean | Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin... | #REBOL | REBOL | rebol [
Title: "Arithmetic Mean (Average)"
URL: http://rosettacode.org/wiki/Average/Arithmetic_mean
]
average: func [v /local sum][
if empty? v [return 0]
sum: 0
forall v [sum: sum + v/1]
sum / length? v
]
; Note precision loss as spread increased.
print [mold x: [] "->" average x]
print [mold x: [3... | Give a code snippet in #REBOL
Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an esta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #Idris | Idris | Idris> transpose [[1,2],[3,4],[5,6]]
[[1, 3, 5], [2, 4, 6]] : List (List Integer) | Give a code snippet in #Idris
Transpose an arbitrarily sized rectangular Matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Memory_allocation | Memory allocation | Task
Show how to explicitly allocate and deallocate blocks of memory in your language.
Show access to different types of memory (i.e., heap, stack, shared, foreign) if applicable.
| #Ada | Ada | declare
X : Integer; -- Allocated on the stack
begin
...
end; -- X is freed | Give a code snippet in #Ada
Task
Show how to explicitly allocate and deallocate blocks of memory in your language.
Show access to different types of memory (i.e., heap, stack, shared, foreign) if applicable.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Monty_Hall_problem | Monty Hall problem |
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for the time being.
The game show hos... | #C.2B.2B | C++ | #include <iostream>
#include <cstdlib>
#include <ctime>
int randint(int n)
{
return (1.0*n*std::rand())/(1.0+RAND_MAX);
}
int other(int doorA, int doorB)
{
int doorC;
if (doorA == doorB)
{
doorC = randint(2);
if (doorC >= doorA)
++doorC;
}
else
{
for (doorC = 0; doorC == doorA || doo... | Give a code snippet in #C.2B.2B
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abstract_type | Abstract type | Abstract type is a type without instances or without definition.
For example in object-oriented programming using some languages, abstract types can be partial implementations of other types, which are to be derived there-from. An abstract type may provide implementation of some operations and/or components. Abstract ... | #Nim | Nim | type
Comparable = concept x, y
(x < y) is bool
Stack[T] = concept s, var v
s.pop() is T
v.push(T)
s.len is Ordinal
for value in s:
value is T | Give a code snippet in #Nim
Abstract type is a type without instances or without definition.
For example in object-oriented programming using some languages, abstract types can be partial implementations of other types, which are to be derived there-from. An abstract type may provide implementation of some operations... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #Dc | Dc | [ S1 S2 l2 l1 / L2 L1 % ] s~
1337 42 l~ x f | Give a code snippet in #Dc
Task
Show how to return more than one value from a function.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Gamma_function | Gamma function | Task
Implement one algorithm (or more) to compute the Gamma (
Γ
{\displaystyle \Gamma }
) function (in the real field only).
If your language has the function as built-in or you know a library which has it, compare your implementation's results with the results of the built-in/library function.
The Gamma funct... | #Vlang | Vlang | import math
fn main() {
println(" x math.Gamma Lanczos7")
for x in [-.5, .1, .5, 1, 1.5, 2, 3, 10, 140, 170] {
println("${x:5.1f} ${math.gamma(x):24.16} ${lanczos7(x):24.16}")
}
}
fn lanczos7(z f64) f64 {
t := z + 6.5
x := .99999999999980993 +
676.5... | Give a code snippet in #Vlang
Task
Implement one algorithm (or more) to compute the Gamma (
Γ
{\displaystyle \Gamma }
) function (in the real field only).
If your language has the function as built-in or you know a library which has it, compare your implementation's results with the results of the built-in/lib... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_a_set_of_characters_from_a_string | Strip a set of characters from a string | Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in the second argument:
print str... | #TUSCRIPT | TUSCRIPT |
$$ MODE TUSCRIPT,{}
string="She was a soul stripper. She took my heart!"
stringstrip=EXCHANGE (string,"_[aei]__")
print string
print stringstrip
| Give a code snippet in #TUSCRIPT
Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Remove_lines_from_a_file | Remove lines from a file | Task
Remove a specific line or a number of lines from a file.
This should be implemented as a routine that takes three parameters (filename, starting line, and the number of lines to be removed).
For the purpose of this task, line numbers and the number of lines start at one, so to remove the first two lines from th... | #Frink | Frink | removeLines[filename, start, len] :=
{
lines = array[lines[filenameToURL[filename]]]
modified = lines.removeLen[start-1, len]
if modified != len
println["Was only able to remove $modified lines due to end-of-file."]
w = new Writer[filename]
for line = lines
w.println[line]
w.close[]
} | Give a code snippet in #Frink
Task
Remove a specific line or a number of lines from a file.
This should be implemented as a routine that takes three parameters (filename, starting line, and the number of lines to be removed).
For the purpose of this task, line numbers and the number of lines start at one, so to rem... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Semiprime | Semiprime | Semiprime numbers are natural numbers that are products of exactly two (possibly equal) prime numbers.
Semiprimes are also known as:
semi-primes
biprimes
bi-primes
2-almost primes
or simply: P2
Example
1679 = 23 × 73
(This particular number was chosen as the length of the Arecib... | #Maple | Maple | SemiPrimes := proc( n )
local fact;
fact := NumberTheory:-Divisors( n ) minus {1, n};
if numelems( fact ) in {1,2} and not( member( 'false', isprime ~ ( fact ) ) ) then
return n;
else
return NULL;
end if;
end proc:
{ seq( SemiPrimes( i ), i = 1..100 ) }; | Give a code snippet in #Maple
Semiprime numbers are natural numbers that are products of exactly two (possibly equal) prime numbers.
Semiprimes are also known as:
semi-primes
biprimes
bi-primes
2-almost primes
or simply: P2
Example
1679 = 23 × 73
(This particular number was cho... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #UNIX_Shell | UNIX Shell | s="I am a string"
if [[ $s =~ str..g$ ]]; then
echo "the string ends with 'str..g'"
fi | Give a code snippet in #UNIX_Shell
Task
match a string against a regular expression
substitute part of a string using a regular expression
| 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
| #Go | Go | package main
import "fmt"
func gcd(n, k int) int {
if n < k || k < 1 {
panic("Need n >= k and k >= 1")
}
s := 1
for n&1 == 0 && k&1 == 0 {
n >>= 1
k >>= 1
s <<= 1
}
t := n
if n&1 != 0 {
t = -k
}
for t != 0 {
for t&1 == 0 {
... | Give a code snippet in #Go
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/Mutual_recursion | Mutual recursion | Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n
)
=
n
−
M
(
F
(
n
−
1
)
)
,
... | #PowerShell | PowerShell | function F($n) {
if ($n -eq 0) { return 1 }
return $n - (M (F ($n - 1)))
}
function M($n) {
if ($n -eq 0) { return 0 }
return $n - (F (M ($n - 1)))
} | Give a code snippet in #PowerShell
Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F... | christopher/rosetta-code | |
http://rosettacode.org/wiki/First-class_functions/Use_numbers_analogously | First-class functions/Use numbers analogously | In First-class functions, a language is showing how its manipulation of functions is similar to its manipulation of other types.
This tasks aim is to compare and contrast a language's implementation of first class functions, with its normal handling of numbers.
Write a program to create an ordered collection of a m... | #J | J | x =: 2.0
xi =: 0.5
y =: 4.0
yi =: 0.25
z =: x + y
zi =: 1.0 % (x + y) NB. / is spelled % in J
fwd =: x ,y ,z
rev =: xi,yi,zi
multiplier =: 2 : 'm * n * ]' | Give a code snippet in #J
In First-class functions, a language is showing how its manipulation of functions is similar to its manipulation of other types.
This tasks aim is to compare and contrast a language's implementation of first class functions, with its normal handling of numbers.
Write a program to create a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutation_test | Permutation test | Permutation test
You are encouraged to solve this task according to the task description, using any language you may know.
A new medical treatment was tested on a population of
n
+
m
{\displaystyle n+m}
volunteers, with each volunteer randomly assigned either to a group of
n
{\displaystyle n}
treatment... | #C | C | #include <stdio.h>
int data[] = { 85, 88, 75, 66, 25, 29, 83, 39, 97,
68, 41, 10, 49, 16, 65, 32, 92, 28, 98 };
int pick(int at, int remain, int accu, int treat)
{
if (!remain) return (accu > treat) ? 1 : 0;
return pick(at - 1, remain - 1, accu + data[at - 1], treat) +
... | Give a code snippet in #C
Permutation test
You are encouraged to solve this task according to the task description, using any language you may know.
A new medical treatment was tested on a population of
n
+
m
{\displaystyle n+m}
volunteers, with each volunteer randomly assigned either to a group of
n
{\... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Monty_Hall_problem | Monty Hall problem |
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for the time being.
The game show hos... | #COBOL | COBOL | IDENTIFICATION DIVISION.
PROGRAM-ID. monty-hall.
DATA DIVISION.
WORKING-STORAGE SECTION.
78 Num-Games VALUE 1000000.
*> These are needed so the values are passed to
*> get-rand-int correctly.
01 One PIC 9 VALUE 1.
01 ... | Give a code snippet in #COBOL
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/First_power_of_2_that_has_leading_decimal_digits_of_12 | First power of 2 that has leading decimal digits of 12 | (This task is taken from a Project Euler problem.)
(All numbers herein are expressed in base ten.)
27 = 128 and 7 is
the first power of 2 whose leading decimal digits are 12.
The next power of 2 whose leading decimal digits
are 12 is 80,
280 = 1208925819614629174706176.
Define ... | #Julia | Julia | function p(L, n)
@assert(L > 0 && n > 0)
places, logof2, nfound = trunc(log(10, L)), log(10, 2), 0
for i in 1:typemax(Int)
if L == trunc(10^(((i * logof2) % 1) + places)) && (nfound += 1) == n
return i
end
end
end
for (L, n) in [(12, 1), (12, 2), (123, 45), (123, 12345), (1... | Give a code snippet in #Julia
(This task is taken from a Project Euler problem.)
(All numbers herein are expressed in base ten.)
27 = 128 and 7 is
the first power of 2 whose leading decimal digits are 12.
The next power of 2 whose leading decimal digits
are 12 is 80,
280 = 120892... | christopher/rosetta-code | |
http://rosettacode.org/wiki/HTTP | HTTP | Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| #GML | GML | get = http_get("http://www.rosettacode.org/"); | Give a code snippet in #GML
Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitwise_operations | Bitwise operations |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #PARI.2FGP | PARI/GP | bo(a,b)={
print("And: "bitand(a,b));
print("Or: "bitor(a,b));
print("Not: "bitneg(a));
print("Xor: "bitxor(a,b));
print("Left shift: ",a<<b);
print("Right shift: ",a>>b);
} | Give a code snippet in #PARI.2FGP
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 Operati... | christopher/rosetta-code | |
http://rosettacode.org/wiki/McNuggets_problem | McNuggets problem | Wikipedia
The McNuggets version of the coin problem was introduced by Henri Picciotto,
who included it in his algebra textbook co-authored with Anita Wah. Picciotto
thought of the application in the 1980s while dining with his son at
McDonald's, working the problem out on a napkin. A McNugget number is
the total number... | #Draco | Draco | proc nonrec main() void:
byte LIMIT = 100;
[LIMIT+1] bool nugget;
byte a, b, c;
for a from 0 upto LIMIT do
nugget[a] := false
od;
for a from 0 by 6 upto LIMIT do
for b from a by 9 upto LIMIT do
for c from b by 20 upto LIMIT do
nugget[c] := true
... | Give a code snippet in #Draco
Wikipedia
The McNuggets version of the coin problem was introduced by Henri Picciotto,
who included it in his algebra textbook co-authored with Anita Wah. Picciotto
thought of the application in the 1980s while dining with his son at
McDonald's, working the problem out on a napkin. A McNu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Pancake_sort | Sorting algorithms/Pancake 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
... | #uBasic.2F4tH | uBasic/4tH | PRINT "Pancake sort:"
n = FUNC (_InitArray)
PROC _ShowArray (n)
PROC _Pancakesort (n)
PROC _ShowArray (n)
PRINT
END
_Flip PARAM(1)
LOCAL(1)
b@ = 0
DO WHILE b@ < a@
PROC _Swap (b@, a@)
b@ = b@ + 1
a@ = a@ - 1
LOOP
RETURN
_Pancakesort PARAM (1) ' Pancakesort
LOC... | Give a code snippet in #uBasic.2F4tH
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 |
Q... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Radix_sort | Sorting algorithms/Radix 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
... | #Rust | Rust |
fn merge(in1: &[i32], in2: &[i32], out: &mut [i32]) {
let (left, right) = out.split_at_mut(in1.len());
left.clone_from_slice(in1);
right.clone_from_slice(in2);
}
// least significant digit radix sort
fn radix_sort(data: &mut [i32]) {
for bit in 0..31 {
// types of small and big is Vec<i32>.
... | Give a code snippet in #Rust
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 sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Take_notes_on_the_command_line | Take notes on the command line | Take notes on the command line is part of Short Circuit's Console Program Basics selection.
Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists.
If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline.
Then al... | #OCaml | OCaml | #! /usr/bin/env ocaml
#load "unix.cma"
let notes_file = "notes.txt"
let take_notes() =
let gmt = Unix.gmtime (Unix.time()) in
let date =
Printf.sprintf "%d-%02d-%02d %02d:%02d:%02d"
(1900 + gmt.Unix.tm_year) (1 + gmt.Unix.tm_mon) gmt.Unix.tm_mday
gmt.Unix.tm_hour gmt.Unix.tm_min gmt.Unix.tm_sec
... | Give a code snippet in #OCaml
Take notes on the command line is part of Short Circuit's Console Program Basics selection.
Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists.
If NOTES has arguments, the current date and time are appended to the local NOTES.TXT... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Copy_a_string | Copy a string | This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
W... | #UNIX_Shell | UNIX Shell | foo="Hello"
bar=$foo # This is a copy of the string | Give a code snippet in #UNIX_Shell
This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Em... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Inverse_video | Terminal control/Inverse video | Task
Display a word in inverse video (or reverse video) followed by a word in normal video.
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | Run["tput mr"]
Run["echo foo"] (* is displayed in reverse mode *)
Run["tput me"]
Run["echo bar"] | Give a code snippet in #Mathematica.2FWolfram_Language
Task
Display a word in inverse video (or reverse video) followed by a word in normal video.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Elementary_cellular_automaton/Infinite_length | Elementary cellular automaton/Infinite length | The purpose of this task is to create a version of an Elementary cellular automaton whose number of cells is only limited by the memory size of the computer.
To be precise, consider the state of the automaton to be made of an infinite number of cells, but with a bounded support. In other words, to describe the state o... | #Julia | Julia | function ecainfinite(cells, rule, n)
notcell(cell) = (cell == '1') ? '0' : '1'
rulebits = reverse(string(rule, base = 2, pad = 8))
neighbors2next = Dict(string(n - 1, base=2, pad=3) => rulebits[n] for n in 1:8)
ret = String[]
for i in 1:n
push!(ret, cells)
cells = notcell(cells[1])^2... | Give a code snippet in #Julia
The purpose of this task is to create a version of an Elementary cellular automaton whose number of cells is only limited by the memory size of the computer.
To be precise, consider the state of the automaton to be made of an infinite number of cells, but with a bounded support. In other... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stack | Stack |
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.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is accessed through its top.
The ba... | #BBC_BASIC | BBC BASIC | STACKSIZE = 1000
FOR n = 3 TO 5
PRINT "Push ";n : PROCpush(n)
NEXT
PRINT "Pop " ; FNpop
PRINT "Push 6" : PROCpush(6)
REPEAT
PRINT "Pop " ; FNpop
UNTIL FNisempty
PRINT "Pop " ; FNpop
END
DEF PROCpush(n) : LOCAL f%
DEF FNpop : LOCAL f% ... | Give a code snippet in #BBC_BASIC
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.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_an_array_of_composite_structures | Sort an array of composite structures |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Pascal | Pascal | @people = (['joe', 120], ['foo', 31], ['bar', 51]);
@people = sort { $a->[0] cmp $b->[0] } @people; | Give a code snippet in #Pascal
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/Permutations/Derangements | Permutations/Derangements | A derangement is a permutation of the order of distinct items in which no item appears in its original place.
For example, the only two derangements of the three items (0, 1, 2) are (1, 2, 0), and (2, 0, 1).
The number of derangements of n distinct items is known as the subfactorial of n, sometimes written as !n.
The... | #jq | jq | def derangements:
# In order to reference the original array conveniently, define _derangements(ary):
def _derangements(ary):
# We cannot put the i-th element in the i-th place:
def deranged: # state: [i, available]
.[0] as $i | .[1] as $in
| if $i == (ary|length) then []
else
... | Give a code snippet in #jq
A derangement is a permutation of the order of distinct items in which no item appears in its original place.
For example, the only two derangements of the three items (0, 1, 2) are (1, 2, 0), and (2, 0, 1).
The number of derangements of n distinct items is known as the subfactorial of n, ... | christopher/rosetta-code |
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