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
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|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Elliptic_curve_arithmetic | Elliptic curve arithmetic | Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In a nutshell, an elliptic curve is a... | #Haskell | Haskell | import Data.Monoid
import Control.Monad (guard)
import Test.QuickCheck (quickCheck) | Give a code snippet in #Haskell
Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Use_another_language_to_call_a_function | Use another language to call a function | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
This task is inverse to the task Call foreign language function. Consider the following C program:
#include <stdio.h>
extern int Query (char * Data, size_t * Length);
int main (i... | #OCaml | OCaml | #include <stdio.h>
#include <string.h>
#include <caml/mlvalues.h>
#include <caml/callback.h>
extern int Query (char * Data, size_t * Length)
{
static value * closure_f = NULL;
if (closure_f == NULL) {
closure_f = caml_named_value("Query function cb");
}
value ret = caml_callback(*closure_f, Val_uni... | Give a code snippet in #OCaml
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
This task is inverse to the task Call foreign language function. Consider the following C program:
#include <stdio.h>
extern int Query (char * Data, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stem-and-leaf_plot | Stem-and-leaf plot | Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 11... | #Haskell | Haskell | import Data.List
import Control.Arrow
import Control.Monad
nlsRaw = "12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31"
++ " 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63"
++ " 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53"
++ " 114 96 25 109 7 31... | Give a code snippet in #Haskell
Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 3... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compound_data_type | Compound data type |
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.
Task
Create a compound data type:
Point(x,y)
A compound data type is one that holds multiple independent values.
Related task
Enumeration
S... | #Arturo | Arturo | point: #[
x: 10
y: 20
]
print point | Give a code snippet in #Arturo
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.
Task
Create a compound data type:
Point(x,y)
A compound data type is one that holds multiple independent values.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Entropy/Narcissist | Entropy/Narcissist |
Task
Write a computer program that computes and shows its own entropy.
Related Tasks
Fibonacci_word
Entropy
| #Erlang | Erlang | #! /usr/bin/escript
-define(LOG2E, 1.44269504088896340735992).
main(_) ->
Self = escript:script_name(),
{ok, Contents} = file:read_file(Self),
io:format("My entropy is ~p~n", [entropy(Contents)]).
entropy(Data) ->
Frq = count(Data),
maps:fold(fun(_, C, E) ->
P = C / byte_size... | Give a code snippet in #Erlang
Task
Write a computer program that computes and shows its own entropy.
Related Tasks
Fibonacci_word
Entropy
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
... | #Bracmat | Bracmat | ( get$("unixdict.txt",STR):?list
& 1:?product
& whl
' ( @(!list:(%?word:?w) \n ?list)
& :?sum
& whl
' ( @(!w:%?let ?w)
& (!let:~#|str$(N !let))+!sum:?sum
)
& !sum^!word*!product:?product
)
& lst$(product,"product.txt",NEW)
& 0:?max
& :?group
& ( !product
: ?
* ?... | Give a code snippet in #Bracmat
When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface | Catmull–Clark subdivision surface | Implement the Catmull-Clark surface subdivision (description on Wikipedia), which is an algorithm that maps from a surface (described as a set of points and a set of polygons with vertices at those points) to another more refined surface. The resulting surface will always consist of a mesh of quadrilaterals.
The proce... | #C | C | vertex face_point(face f)
{
int i;
vertex v;
if (!f->avg) {
f->avg = vertex_new();
foreach(i, v, f->v)
if (!i) f->avg->pos = v->pos;
else vadd(f->avg->pos, v->pos);
vdiv(f->avg->pos, len(f->v));
}
return f->avg;
}
#define hole_edge(e) (len(e->f)==1)
vertex edge_point(edge e)
{
int i;
face f;... | Give a code snippet in #C
Implement the Catmull-Clark surface subdivision (description on Wikipedia), which is an algorithm that maps from a surface (described as a set of points and a set of polygons with vertices at those points) to another more refined surface. The resulting surface will always consist of a mesh of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/XML/Input | XML/Input | Given the following XML fragment, extract the list of student names using whatever means desired. If the only viable method is to use XPath, refer the reader to the task XML and XPath.
<Students>
<Student Name="April" Gender="F" DateOfBirth="1989-01-02" />
<Student Name="Bob" Gender="M" DateOfBirth="1990-03-04" /... | #Wren | Wren | import "/pattern" for Pattern
import "/fmt" for Conv
var xml =
"<Students>
<Student Name=\"April\" Gender=\"F\" DateOfBirth=\"1989-01-02\" />
<Student Name=\"Bob\" Gender=\"M\" DateOfBirth=\"1990-03-04\" />
<Student Name=\"Chad\" Gender=\"M\" DateOfBirth=\"1991-05-06\" />
<Student Name=\"Dave\" Gender=\"M\... | Give a code snippet in #Wren
Given the following XML fragment, extract the list of student names using whatever means desired. If the only viable method is to use XPath, refer the reader to the task XML and XPath.
<Students>
<Student Name="April" Gender="F" DateOfBirth="1989-01-02" />
<Student Name="Bob" Gender="... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Erlang | Erlang |
os:getenv( "HOME" ).
| Give a code snippet in #Erlang
Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| christopher/rosetta-code | |
http://rosettacode.org/wiki/ABC_problem | ABC problem | ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet is guaranteed amongst all sid... | #CoffeeScript | CoffeeScript | blockList = [ 'BO', 'XK', 'DQ', 'CP', 'NA', 'GT', 'RE', 'TG', 'QD', 'FS', 'JW', 'HU', 'VI', 'AN', 'OB', 'ER', 'FS', 'LY', 'PC', 'ZM' ]
canMakeWord = (word="") ->
# Create a shallow clone of the master blockList
blocks = blockList.slice 0
# Check if blocks contains letter
checkBlocks = (letter) ->
... | Give a code snippet in #CoffeeScript
ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/The_sieve_of_Sundaram | The sieve of Sundaram | The sieve of Eratosthenes: you've been there; done that; have the T-shirt. The sieve of Eratosthenes was ancient history when Euclid was a schoolboy. You are ready for something less than 3000 years old. You are ready for The sieve of Sundaram.
Starting with the ordered set of +ve integers, mark every third starting a... | #Go | Go | package main
import (
"fmt"
"math"
"rcu"
"time"
)
func sos(n int) []int {
if n < 3 {
return []int{}
}
var primes []int
k := (n-3)/2 + 1
marked := make([]bool, k) // all false by default
limit := (int(math.Sqrt(float64(n)))-3)/2 + 1
for i := 0; i < limit; i++ {
... | Give a code snippet in #Go
The sieve of Eratosthenes: you've been there; done that; have the T-shirt. The sieve of Eratosthenes was ancient history when Euclid was a schoolboy. You are ready for something less than 3000 years old. You are ready for The sieve of Sundaram.
Starting with the ordered set of +ve integers,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Runtime_evaluation | Runtime evaluation | Task
Demonstrate a language's ability for programs to execute code written in the language provided at runtime.
Show what kind of program fragments are permitted (e.g. expressions vs. statements), and how to get values in and out (e.g. environments, arguments, return values), if applicable what lexical/static environ... | #Elena | Elena | import extensions'scripting;
public program()
{
lscript.interpret("system'console.writeLine(""Hello World"")");
} | Give a code snippet in #Elena
Task
Demonstrate a language's ability for programs to execute code written in the language provided at runtime.
Show what kind of program fragments are permitted (e.g. expressions vs. statements), and how to get values in and out (e.g. environments, arguments, return values), if applica... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stem-and-leaf_plot | Stem-and-leaf plot | Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 11... | #JavaScript | JavaScript | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<head>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8" >
<title>stem and leaf plot</title>
<script type='text/javascript'>
function has_property(obj, propname) {
return typeof(obj[propname]) === "u... | Give a code snippet in #JavaScript
Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 6... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_unity | Roots of unity | The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| #D | D | import std.stdio, std.range, std.algorithm, std.complex;
import std.math: PI;
auto nthRoots(in int n) pure nothrow {
return n.iota.map!(k => expi(PI * 2 * (k + 1) / n));
}
void main() {
foreach (immutable i; 1 .. 6)
writefln("#%d: [%(%5.2f, %)]", i, i.nthRoots);
} | Give a code snippet in #D
The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable_size/Get | Variable size/Get | Demonstrate how to get the size of a variable.
See also: Host introspection
| #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Dim i As Integer
Dim l As Long
Dim s As Short
Dim b As Byte
Print "An integer occupies "; SizeOf(i); " bytes"
Print "A long occupies "; SizeOf(l); " bytes"
Print "A short occupies "; SizeOf(s); " bytes"
Print "A byte occupies "; SizeOf(b); " byte"
' or use type directly rather than a va... | Give a code snippet in #FreeBASIC
Demonstrate how to get the size of a variable.
See also: Host introspection
| christopher/rosetta-code | |
http://rosettacode.org/wiki/MD5 | MD5 | Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the Wikipedia article.
Warning:... | #APL | APL |
md5←{
⍝ index origin zero
⎕IO←0
⍝ decoding UTF-8 & padding
M←(⊢,(0⍴⍨512|448-512|≢))1,⍨l←,⍉(8⍴2)⊤'UTF-8'⎕UCS ⍵
⍝ add length
M,←,⍉(8⍴2)⊤⌽(8⍴256)⊤≢l
⍝ init registers
A←16⊥6 7 4 5 2 3 0 1
B←16⊥14 15 12 13 10 11 8 9
C←16⊥9 8 11 10 13 12 15 14
D←16⊥1 0 3 2 5 4 7 6
... | Give a code snippet in #APL
Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the Wi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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 ... | #M2000_Interpreter | M2000 Interpreter |
Module Checkit {
\\ Iterative with two matrix rows
function LevenshteinDistance(s$,t$) {
if len(s$)<len(t$) then swap s$, t$
n=len(t$)
m=len(s$)
dim base 0, v0(n+1), v1(n+1)
Rem dim sw() ' we can use stack of values to make the swap.
for i=0 to n : v0(i)=i:next
for i=0 to m-1
v1(0)=i+1
for j=0 ... | Give a code snippet in #M2000_Interpreter
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 th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abbreviations,_easy | Abbreviations, easy | This task is an easier (to code) variant of the Rosetta Code task: Abbreviations, simple.
For this task, the following command table will be used:
Add ALTer BAckup Bottom CAppend Change SCHANGE CInsert CLAst COMPress COpy
COUnt COVerlay CURsor DELete CDelete Down DUPlicate Xedit EXPand EXTract Find
... | #Delphi | Delphi |
program Abbreviations_Easy;
{$APPTYPE CONSOLE}
uses
System.SysUtils;
const
_TABLE_ =
'Add ALTer BAckup Bottom CAppend Change SCHANGE CInsert CLAst COMPress COpy ' +
'COUnt COVerlay CURsor DELete CDelete Down DUPlicate Xedit EXPand EXTract Find ' +
'NFind NFINDUp NFUp CFind FINdup FUp FOrward ... | Give a code snippet in #Delphi
This task is an easier (to code) variant of the Rosetta Code task: Abbreviations, simple.
For this task, the following command table will be used:
Add ALTer BAckup Bottom CAppend Change SCHANGE CInsert CLAst COMPress COpy
COUnt COVerlay CURsor DELete CDelete Down DUPl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Validate_International_Securities_Identification_Number | Validate International Securities Identification Number | An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct format, and the embedded c... | #Visual_Basic | Visual Basic | Function IsValidISIN(ByVal ISIN As String) As Boolean
Dim s As String, c As String
Dim i As Long
If Len(ISIN) = 12 Then
For i = 1 To Len(ISIN)
c = UCase$(Mid(ISIN, i, 1))
Select Case c
Case "A" To "Z"
If i = 12 Then Exit Function
s = s & CStr(Asc(c) - 55)
Case "0"... | Give a code snippet in #Visual_Basic
An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Foreach | Loops/Foreach | Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for... | #Objective-C | Objective-C | NSArray *collect;
//...
for(Type i in collect){
NSLog(@"%@", i);
} | Give a code snippet in #Objective-C
Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Death_Star | Death Star |
Task
Display a region that consists of a large sphere with part of a smaller sphere removed from it as a result of geometric subtraction.
(This will basically produce a shape like a "death star".)
Related tasks
draw a sphere
draw a cuboid
draw a rotating cube
write language name in 3D ASCII
| #Julia | Julia | # run in REPL
using GLMakie
function deathstar()
n = 60
θ = [0; (0.5: n - 0.5) / n; 1]
φ = [(0: 2n - 2) * 2 / (2n - 1); 2]
# if x is +0.9 radius units, replace it with the coordinates of sphere surface
# at (1.2,0,0) center, radius 0.5 units
x = [(x1 = cospi(φ)*sinpi(θ)) > 0.9 ? 1.2 - x1 * 0.5... | Give a code snippet in #Julia
Task
Display a region that consists of a large sphere with part of a smaller sphere removed from it as a result of geometric subtraction.
(This will basically produce a shape like a "death star".)
Related tasks
draw a sphere
draw a cuboid
draw a rotating cube
write language na... | 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
... | #Smalltalk | Smalltalk |
(0 to: 4) combinations: 3 atATimeDo: [ :x | Transcript cr; show: x printString].
"output on Transcript:
#(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)"
| Give a code snippet in #Smalltalk
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Least_common_multiple | Least common multiple | Least common multiple
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Compute the least common multiple (LCM) of two integers.
Given m and n, the least common multiple is the smallest positive integer that has both m and n as factor... | #Qi | Qi |
(define gcd
A 0 -> A
A B -> (gcd B (MOD A B)))
(define lcm A B -> (/ (* A B) (gcd A B)))
| Give a code snippet in #Qi
Least common multiple
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Compute the least common multiple (LCM) of two integers.
Given m and n, the least common multiple is the smallest positive integer that has bo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic-geometric_mean | Arithmetic-geometric mean |
This page uses content from Wikipedia. The original article was at Arithmetic-geometric mean. 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
Write a function to compute the arithmetic-geomet... | #Sidef | Sidef | func agm(a, g) {
loop {
var (a1, g1) = ((a+g)/2, sqrt(a*g))
[a1,g1] == [a,g] && return a
(a, g) = (a1, g1)
}
}
say agm(1, 1/sqrt(2)) | Give a code snippet in #Sidef
This page uses content from Wikipedia. The original article was at Arithmetic-geometric mean. 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
Write a function t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_that_file_exists | Check that file exists | Task
Verify that a file called input.txt and a directory called docs exist.
This should be done twice:
once for the current working directory, and
once for a file and a directory in the filesystem root.
Optional criteria (May 2015): verify it works with:
zero-length files
an ... | #PureBasic | PureBasic | result = ReadFile(#PB_Any, "input.txt")
If result>0 : Debug "this local file exists"
Else : Debug "result=" +Str(result) +" so this local file is missing"
EndIf
result = ReadFile(#PB_Any, "/input.txt")
If result>0 : Debug "this root file exists"
Else : Debug "result=" +Str(result) +" so this root file is missing... | Give a code snippet in #PureBasic
Task
Verify that a file called input.txt and a directory called docs exist.
This should be done twice:
once for the current working directory, and
once for a file and a directory in the filesystem root.
Optional criteria (May 2015): verify it works... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Safe_addition | Safe addition | Implementation of interval arithmetic and more generally fuzzy number arithmetic require operations that yield safe upper and lower bounds of the exact result.
For example, for an addition, it is the operations +↑ and +↓ defined as: a +↓ b ≤ a + b ≤ a +↑ b.
Additionally it is desired that the widt... | #Raku | Raku | say "Floating points: (Nums)";
say "Error: " ~ (2**-53).Num;
sub infix:<±+> (Num $a, Num $b) {
my \ε = (2**-53).Num;
$a - ε + $b, $a + ε + $b,
}
printf "%4.16f .. %4.16f\n", (1.14e0 ±+ 2e3);
say "\nRationals:";
say ".1 + .2 is exactly equal to .3: ", .1 + .2 === .3;
say "\nLarge denominators require e... | Give a code snippet in #Raku
Implementation of interval arithmetic and more generally fuzzy number arithmetic require operations that yield safe upper and lower bounds of the exact result.
For example, for an addition, it is the operations +↑ and +↓ defined as: a +↓ b ≤ a + b ≤ a +↑ b.
Additional... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Safe_primes_and_unsafe_primes | Safe primes and unsafe primes | Definitions
A safe prime is a prime p and where (p-1)/2 is also prime.
The corresponding prime (p-1)/2 is known as a Sophie Germain prime.
An unsafe prime is a prime p and where (p-1)/2 isn't a prime.
An unsafe prime is a prime that isn't a safe prime.
Task
... | #Simula | Simula |
BEGIN
CLASS BOOLARRAY(N); INTEGER N;
BEGIN
BOOLEAN ARRAY DATA(0:N-1);
END BOOLARRAY;
CLASS INTARRAY(N); INTEGER N;
BEGIN
INTEGER ARRAY DATA(0:N-1);
END INTARRAY;
REF(BOOLARRAY) PROCEDURE SIEVE(LIMIT);
INTEGER LIMIT;
BEGIN
REF(BOOLARRAY) C;
... | Give a code snippet in #Simula
Definitions
A safe prime is a prime p and where (p-1)/2 is also prime.
The corresponding prime (p-1)/2 is known as a Sophie Germain prime.
An unsafe prime is a prime p and where (p-1)/2 isn't a prime.
An unsafe prime is a prime that isn... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Josephus_problem | Josephus problem | Josephus problem is a math puzzle with a grim description:
n
{\displaystyle n}
prisoners are standing on a circle, sequentially numbered from
0
{\displaystyle 0}
to
n
−
1
{\displaystyle n-1}
.
An executioner walks along the circle, starting from prisoner
0
{\displaystyle 0}
,
removing eve... | #Batch_File | Batch File | @echo off
setlocal enabledelayedexpansion
set "prison=41" %== Number of prisoners ==%
set "step=3" %== The step... ==%
set "survive=1" %== Number of survivors ==%
call :josephus
set "prison=41"
set "step=3"
set "survive=3"
call :josephus
pause
exit /b 0
%== The Procedure ==%
:josephus
set "surv_list="
for /l ... | Give a code snippet in #Batch_File
Josephus problem is a math puzzle with a grim description:
n
{\displaystyle n}
prisoners are standing on a circle, sequentially numbered from
0
{\displaystyle 0}
to
n
−
1
{\displaystyle n-1}
.
An executioner walks along the circle, starting from prisoner
0... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Longest_common_subsequence | Longest common subsequence | Introduction
Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string.
The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings.
Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be strings drawn from an alphabet Σ of ... | #F.23 | F# | open System
let longest xs ys = if List.length xs > List.length ys then xs else ys
let rec lcs a b =
match a, b with
| [], _
| _, [] -> []
| x::xs, y::ys ->
if x = y then
x :: lcs xs ys
else
longest (lcs a ys) (lcs xs b)
[<EntryPoint>]
let main argv ... | Give a code snippet in #F.23
Introduction
Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string.
The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings.
Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be string... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/Integer | Literals/Integer | Some programming languages have ways of expressing integer literals in bases other than the normal base ten.
Task
Show how integer literals can be expressed in as many bases as your language allows.
Note: this should not involve the calling of any functions/methods, but should be interpreted by the compiler or... | #BASIC | BASIC | PRINT 17
PRINT &O21
PRINT &H11 | Give a code snippet in #BASIC
Some programming languages have ways of expressing integer literals in bases other than the normal base ten.
Task
Show how integer literals can be expressed in as many bases as your language allows.
Note: this should not involve the calling of any functions/methods, but should be... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rendezvous | Rendezvous | Demonstrate the “rendezvous” communications technique by implementing a printer monitor.
| #Erlang | Erlang |
-module( rendezvous ).
-export( [task/0] ).
task() ->
Printer_pid = erlang:spawn( fun() -> printer(1, 5) end ),
Reserve_printer_pid = erlang:spawn( fun() -> printer(2, 5) end ),
Monitor_pid = erlang:spawn( fun() -> printer_monitor(Printer_pid, Reserve_printer_pid) end ),
erlang:spawn( fun() -> pri... | Give a code snippet in #Erlang
Demonstrate the “rendezvous” communications technique by implementing a printer monitor.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Runtime_evaluation | Runtime evaluation | Task
Demonstrate a language's ability for programs to execute code written in the language provided at runtime.
Show what kind of program fragments are permitted (e.g. expressions vs. statements), and how to get values in and out (e.g. environments, arguments, return values), if applicable what lexical/static environ... | #Cach.C3.A9_ObjectScript | Caché ObjectScript | USER>Set cmd="Write ""Hello, World!"""
USER>Xecute cmd
Hello, World!
USER>Set fnc="(num1, num2) Set res=num1+num2 Quit res"
USER>Write $Xecute(fnc, 2, 3)
5
| Give a code snippet in #Cach.C3.A9_ObjectScript
Task
Demonstrate a language's ability for programs to execute code written in the language provided at runtime.
Show what kind of program fragments are permitted (e.g. expressions vs. statements), and how to get values in and out (e.g. environments, arguments, return v... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Do-while | Loops/Do-while | Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loo... | #Delphi | Delphi | program Loop;
{$APPTYPE CONSOLE}
var
I: Integer;
begin
I:= 0;
repeat
Inc(I);
Write(I:2);
until I mod 6 = 0;
Writeln;
Readln;
end. | Give a code snippet in #Delphi
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/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... | #Wren | Wren | import "random" for Random
import "/set" for Set
import "/ioutil" for Input
var MAX_GUESSES = 20 // say
var r = Random.new()
var num
// generate a 4 digit random number from 1234 to 9876 with no zeros or repeated digits
while (true) {
num = (1234 + r.int(8643)).toString
if (!num.contains("0") && Set.new(num)... | Give a code snippet in #Wren
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 g... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #Axiom | Axiom | qi := quatern$Quaternion(Integer);
Type: ((Integer,Integer,Integer,Integer) -> Quaternion(Integer))
q := qi(1,2,3,4);
Type: Quaternion(Integer)
q1 := qi(2,3,4,5);
Type: Quaternion(Integer)
q2 := q... | Give a code snippet in #Axiom
Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Program_name | Program name | The task is to programmatically obtain the name used to invoke the program. (For example determine whether the user ran "python hello.py", or "python hellocaller.py", a program importing the code from "hello.py".)
Sometimes a multiline shebang is necessary in order to provide the script name to a language's internal A... | #Io | Io | #!/usr/bin/env io
main := method(
program := System args at(0)
("Program: " .. program) println
)
if (System args size > 0 and System args at(0) containsSeq("scriptname"), main) | Give a code snippet in #Io
The task is to programmatically obtain the name used to invoke the program. (For example determine whether the user ran "python hello.py", or "python hellocaller.py", a program importing the code from "hello.py".)
Sometimes a multiline shebang is necessary in order to provide the script nam... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_a_series | Sum of a series | Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
n
1
k
2
{\displa... | #GAP | GAP | # We will compute the sum exactly
# Computing an approximation of a rationnal (giving a string)
# Value is truncated toward zero
Approx := function(x, d)
local neg, a, b, n, m, s;
if x < 0 then
x := -x;
neg := true;
else
neg := false;
fi;
a := NumeratorRat(x);
b := DenominatorRat(x);
n := QuoInt(a, b);
... | Give a code snippet in #GAP
Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #ERRE | ERRE | PROGRAM ODD_EVEN
! works for -2^15 <= n% < 2^15
FUNCTION ISODD%(N%)
ISODD%=(N% AND 1)<>0
END FUNCTION
! works for -2^38 <= n# <= 2^38
FUNCTION ISODD#(N#)
ISODD#=N#<>2*INT(N#/2)
END FUNCTION
BEGIN
IF ISODD%(14) THEN PRINT("14 is odd") ELSE PRINT("14 is even") END IF
IF ISODD%(15) THEN PRINT("15 i... | Give a code snippet in #ERRE
Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divid... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_control_codes_and_extended_characters_from_a_string | Strip control codes and extended characters from a string | Task
Strip control codes and extended characters from a string.
The solution should demonstrate how to achieve each of the following results:
a string with control codes stripped (but extended characters not stripped)
a string with control codes and extended characters stripped
In ASCII, the control codes ... | #TXR | TXR | (defun strip-controls (str)
(regsub #/[\x0-\x1F\x7F]+/ "" str))
(defun strip-controls-and-extended (str)
(regsub #/[^\x20-\x7F]+/ "" str)) | Give a code snippet in #TXR
Task
Strip control codes and extended characters from a string.
The solution should demonstrate how to achieve each of the following results:
a string with control codes stripped (but extended characters not stripped)
a string with control codes and extended characters stripped
... | 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... | #Visual_Basic_.NET | Visual Basic .NET | Function BinarySearch(ByVal A() As Integer, ByVal value As Integer) As Integer
Dim low As Integer = 0
Dim high As Integer = A.Length - 1
Dim middle As Integer = 0
While low <= high
middle = (low + high) / 2
If A(middle) > value Then
high = middle - 1
ElseIf A(middle... | Give a code snippet in #Visual_Basic_.NET
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 ha... | 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... | #Vedit_macro_language | Vedit macro language | Buf_Switch(Buf_Free)
#90 = Time_Tick // seed for random number generator
#91 = 10 // random numbers in range 0 to 9
while (EOB_pos < 4) { // 4 digits needed
Call("RANDOM")
BOF Ins_Char(Return_Value + '0')
Replace("(.)(.*)\1", "\1\2", REGEXP+BEGIN+... | Give a code snippet in #Vedit_macro_language
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 play... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Self-describing_numbers | Self-describing numbers | Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when digit positions are labeled 0 to ... | #ooRexx | ooRexx |
-- REXX program to check if a number (base 10) is self-describing.
parse arg x y .
if x=='' then exit
if y=='' then y=x
-- 10 digits is the maximum size number that works here, so cap it
numeric digits 10
y=min(y, 9999999999)
loop number = x to y
loop i = 1 to number~length
digit = number~subchar(i)
-... | Give a code snippet in #ooRexx
Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when d... | 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... | #Raku | Raku | my @header = < X Y Z>;
my $rows = 5;
sub tag ($tag, $string, $param?) { return "<$tag" ~ ($param ?? " $param" !! '') ~ ">$string" ~ "</$tag>" };
my $table = tag('tr', ( tag('th', $_) for @header));
for 1 .. $rows -> $row {
$table ~= tag('tr', ( tag('td', $row, 'align="right"')
~ (tag('td', (^1000... | Give a code snippet in #Raku
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/Van_Eck_sequence | Van Eck sequence | The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured previously.
Example
Using ... | #Scala | Scala |
object VanEck extends App {
def vanEck(n: Int): List[Int] = {
def vanEck(values: List[Int]): List[Int] =
if (values.size < n)
vanEck(math.max(0, values.indexOf(values.head, 1)) :: values)
else
values
vanEck(List(0)).reverse
}
val vanEck1000 = vanEck(1000)
println(s"... | Give a code snippet in #Scala
The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured... | 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... | #Icon_and_Unicon | Icon and Unicon | procedure main() # demonstrate and describe function calling syntax and semantics
# normal procedure/function calling
f() # no arguments, also command context
f(x) # fixed number of arguments
f(x,h,w) # variable number of arguments (varargs)
y... | Give a code snippet in #Icon_and_Unicon
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Lucas-Lehmer_test | Lucas-Lehmer test | Lucas-Lehmer Test:
for
p
{\displaystyle p}
an odd prime, the Mersenne number
2
p
−
1
{\displaystyle 2^{p}-1}
is prime if and only if
2
p
−
1
{\displaystyle 2^{p}-1}
divides
S
(
p
−
1
)
{\displaystyle S(p-1)}
where
S
(
n
+
1
)
=
(
S
(
n
)
)
2
−
2
{\displaystyle S(n+1)=(... | #Scala | Scala | object LLT extends App {
import Stream._
def primeSieve(s: Stream[Int]): Stream[Int] =
s.head #:: primeSieve(s.tail filter { _ % s.head != 0 })
val primes = primeSieve(from(2))
def mersenne(p: Int): BigInt = (BigInt(2) pow p) - 1
def s(mp: BigInt, p: Int): BigInt = { if (p == 1) 4 else ((s(mp, p - 1... | Give a code snippet in #Scala
Lucas-Lehmer Test:
for
p
{\displaystyle p}
an odd prime, the Mersenne number
2
p
−
1
{\displaystyle 2^{p}-1}
is prime if and only if
2
p
−
1
{\displaystyle 2^{p}-1}
divides
S
(
p
−
1
)
{\displaystyle S(p-1)}
where
S
(
n
+
1
)
=
(
S
(
n
)
)
2
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sexy_primes | Sexy primes |
This page uses content from Wikipedia. The original article was at Sexy_prime. 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 mathematics, sexy primes are prime numbers that differ from each ot... | #zkl | zkl | var [const] BI=Import("zklBigNum"); // libGMP
const N=1_000_035, M=N+24; // M allows prime group to span N, eg N=100, (97,103)
const OVR=6; // 6 if prime group can NOT span N, else 0
ps,p := Data(M+50).fill(0), BI(1); // slop at the end (for reverse wrap around)
while(p.nextPrime()<=M){ ps[p]=1 } // bitmap of primes
... | Give a code snippet in #zkl
This page uses content from Wikipedia. The original article was at Sexy_prime. 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 mathematics, sexy primes are prime num... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Temperature_conversion | Temperature conversion | There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 kelvin.
0 kelvin is absolute z... | #11l | 11l | V k = 21.0
print(‘K ’k)
print(‘C ’(k - 273.15))
print(‘F ’(k * 1.8 - 459.67))
print(‘R ’(k * 1.8)) | Give a code snippet in #11l
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 ke... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pentagram | Pentagram |
A pentagram is a star polygon, consisting of a central pentagon of which each side forms the base of an isosceles triangle. The vertex of each triangle, a point of the star, is 36 degrees.
Task
Draw (or print) a regular pentagram, in any orientation. Use a different color (or token) for stroke and fill, and backg... | #Ring | Ring |
# Project : Pentagram
load "guilib.ring"
paint = null
new qapp
{
win1 = new qwidget() {
setwindowtitle("Pentagram")
setgeometry(100,100,500,600)
label1 = new qlabel(win1) {
setgeometry(10,10,400,400)
... | Give a code snippet in #Ring
A pentagram is a star polygon, consisting of a central pentagon of which each side forms the base of an isosceles triangle. The vertex of each triangle, a point of the star, is 36 degrees.
Task
Draw (or print) a regular pentagram, in any orientation. Use a different color (or token) ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Faulhaber%27s_triangle | Faulhaber's triangle | Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula:
∑
k
=
1
n
k
p
=
1
p
+
1
∑
j
=
0
p
(
p
+
1
j
)
B
j
n
p
+
1
−
j
{\displaystyle \sum _{k... | #JavaScript | JavaScript | (() => {
// Order of Faulhaber's triangle -> rows of Faulhaber's triangle
// faulHaberTriangle :: Int -> [[Ratio Int]]
const faulhaberTriangle = n =>
map(x => tail(
scanl((a, x) => {
const ys = map((nd, i) =>
ratioMult(nd, Ratio(x, i + 2)... | Give a code snippet in #JavaScript
Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula:
∑
k
=
1
n
k
p
=
1
p
+
1
∑
j
=
0
p
(
p
+
1
j
)
B
j
n
p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/First_class_environments | First class environments | According to Wikipedia, "In computing, a first-class object ... is an entity that can be constructed at run-time, passed as a parameter, returned from a subroutine, or assigned into a variable".
Often this term is used in the context of "first class functions". In an analogous way, a programming language may support "... | #Julia | Julia | const jobs = 12
mutable struct Environment
seq::Int
cnt::Int
Environment() = new(0, 0)
end
const env = [Environment() for i in 1:jobs]
const currentjob = [1]
seq() = env[currentjob[1]].seq
cnt() = env[currentjob[1]].cnt
seq(n) = (env[currentjob[1]].seq = n)
cnt(n) = (env[currentjob[1]].cnt = n)
func... | Give a code snippet in #Julia
According to Wikipedia, "In computing, a first-class object ... is an entity that can be constructed at run-time, passed as a parameter, returned from a subroutine, or assigned into a variable".
Often this term is used in the context of "first class functions". In an analogous way, a pro... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Move-to-front_algorithm | Move-to-front algorithm | Given a symbol table of a zero-indexed array of all possible input symbols
this algorithm reversibly transforms a sequence
of input symbols into an array of output numbers (indices).
The transform in many cases acts to give frequently repeated input symbols
lower indices which is useful in some compression algorithms... | #PicoLisp | PicoLisp | (de encode (Str)
(let Table (chop "abcdefghijklmnopqrstuvwxyz")
(mapcar
'((C)
(dec
(prog1
(index C Table)
(rot Table @) ) ) )
(chop Str) ) ) )
(de decode (Lst)
(let Table (chop "abcdefghijklmnopqrstuvwxyz")
(pack
... | Give a code snippet in #PicoLisp
Given a symbol table of a zero-indexed array of all possible input symbols
this algorithm reversibly transforms a sequence
of input symbols into an array of output numbers (indices).
The transform in many cases acts to give frequently repeated input symbols
lower indices which is use... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_case | String case | Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not reversable.
Show any additional... | #Phix | Phix | constant s = "alphaBETA"
?upper(s)
?lower(s)
| Give a code snippet in #Phix
Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pascal%27s_triangle | Pascal's triangle | Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either 1 or the sum of the two elemen... | #Rust | Rust |
fn pascal_triangle(n: u64)
{
for i in 0..n {
let mut c = 1;
for _j in 1..2*(n-1-i)+1 {
print!(" ");
}
for k in 0..i+1 {
print!("{:2} ", c);
c = c * (i-k)/(k+1);
}
println!();
}
}
| Give a code snippet in #Rust
Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Classes | Classes | In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of the class.
A class of types itself, a... | #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Type MyClass
Private:
myInt_ As Integer
Public:
Declare Constructor(myInt_ As Integer)
Declare Property MyInt() As Integer
Declare Function Treble() As Integer
End Type
Constructor MyClass(myInt_ As Integer)
This.myInt_ = myInt_
End Constructor
Property MyClass.MyInt() As ... | Give a code snippet in #FreeBASIC
In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/One-dimensional_cellular_automata | One-dimensional cellular automata | Assume an array of cells with an initial distribution of live and dead cells,
and imaginary cells off the end of the array having fixed values.
Cells in the next generation of the array are calculated based on the value of the cell and its left and right nearest neighbours in the current generation.
If, in the follow... | #Raku | Raku | class Automaton {
has $.rule;
has @.cells;
has @.code = $!rule.fmt('%08b').flip.comb».Int;
method gist { "|{ @!cells.map({+$_ ?? '#' !! ' '}).join }|" }
method succ {
self.new: :$!rule, :@!code, :cells(
@!code[
4 «*« @!cells.rotate(-1)
»+«... | Give a code snippet in #Raku
Assume an array of cells with an initial distribution of live and dead cells,
and imaginary cells off the end of the array having fixed values.
Cells in the next generation of the array are calculated based on the value of the cell and its left and right nearest neighbours in the current ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newline_omission | Hello world/Newline omission | Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standard error
Hello world/Text
| #Ring | Ring | see "Goodbye, World!" | Give a code snippet in #Ring
Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Runtime_evaluation/In_an_environment | Runtime evaluation/In an environment | x
x
x
Do so in a way which:
does not involve string manipulation of the input source code
is plausibly extensible to a runtime-chosen set of bindings rather than just x
does not make x a global variable
or note that these are impossible.
See also
For more general examples and language-specific details, see... | #Forth | Forth | : f-" ( a b snippet" -- )
[char] " parse ( code len )
2dup 2>r evaluate
swap 2r> evaluate
- . ;
2 3 f-" dup *" \ 5 (3*3 - 2*2) | Give a code snippet in #Forth
x
x
x
Do so in a way which:
does not involve string manipulation of the input source code
is plausibly extensible to a runtime-chosen set of bindings rather than just x
does not make x a global variable
or note that these are impossible.
See also
For more general examples and... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perlin_noise | Perlin noise | The Perlin noise is a kind of gradient noise invented by Ken Perlin around the end of the twentieth century and still currently heavily used in computer graphics, most notably to procedurally generate textures or heightmaps.
The Perlin noise is basically a pseudo-random mapping of
R
d
... | #Phix | Phix | with javascript_semantics
constant ph = x"97 A0 89 5B 5A 0F 83 0D C9 5F 60 35 C2 E9 07 E1"&
x"8C 24 67 1E 45 8E 08 63 25 F0 15 0A 17 BE 06 94"&
x"F7 78 EA 4B 00 1A C5 3E 5E FC DB CB 75 23 0B 20"&
x"39 B1 21 58 ED 95 38 57 AE 14 7D 88 AB A8 44 AF"&
x"4A A5 47 86 8B... | Give a code snippet in #Phix
The Perlin noise is a kind of gradient noise invented by Ken Perlin around the end of the twentieth century and still currently heavily used in computer graphics, most notably to procedurally generate textures or heightmaps.
The Perlin noise is basically a pseudo-random ... | 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... | #Common_Lisp | Common Lisp | CL-USER> (cffi:load-foreign-library "libX11.so")
#<CFFI::FOREIGN-LIBRARY {1004F4ECC1}>
CL-USER> (cffi:foreign-funcall "XOpenDisplay"
:string #+sbcl (sb-posix:getenv "DISPLAY")
#-sbcl ":0.0"
:pointer)
#.(SB-SYS:INT-SAP #... | Give a code snippet in #Common_Lisp
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 l... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Distributed_programming | Distributed programming | Write two programs (or one program with two modes) which run on networked computers, and send some messages between them.
The protocol used may be language-specific or not, and should be suitable for general distributed programming; that is, the protocol should be generic (not designed just for the particular example ... | #JavaScript | JavaScript | var net = require('net')
var server = net.createServer(function (c){
c.write('hello\r\n')
c.pipe(c) // echo messages back
})
server.listen(3000, 'localhost')
| Give a code snippet in #JavaScript
Write two programs (or one program with two modes) which run on networked computers, and send some messages between them.
The protocol used may be language-specific or not, and should be suitable for general distributed programming; that is, the protocol should be generic (not desig... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Numbers_with_equal_rises_and_falls | Numbers with equal rises and falls | When a number is written in base 10, adjacent digits may "rise" or "fall" as the number is read (usually from left to right).
Definition
Given the decimal digits of the number are written as a series d:
A rise is an index i such that d(i) < d(i+1)
A fall is an index i such that ... | #Wren | Wren | import "/fmt" for Fmt
var risesEqualsFalls = Fn.new { |n|
if (n < 10) return true
var rises = 0
var falls = 0
var prev = -1
while (n > 0) {
var d = n%10
if (prev >= 0) {
if (d < prev) {
rises = rises + 1
} else if (d > prev) {
... | Give a code snippet in #Wren
When a number is written in base 10, adjacent digits may "rise" or "fall" as the number is read (usually from left to right).
Definition
Given the decimal digits of the number are written as a series d:
A rise is an index i such that d(i) < d(i+1)
A fall ... | 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... | #FBSL | FBSL | #APPTYPE CONSOLE
FUNCTION Fibonacci(n)
IF n < 0 THEN
RETURN "Nuts!"
ELSE
RETURN Fib(n)
END IF
FUNCTION Fib(m)
IF m < 2 THEN
Fib = m
ELSE
Fib = Fib(m - 1) + Fib(m - 2)
END IF
END FUNCTION
END FUNCTION
PRINT Fibonacci(-1.5)
PRINT Fibonacci(1.5)
PRINT Fibonacci(13.666)
PAUSE | Give a code snippet in #FBSL
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 unwante... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively | Walk a directory/Non-recursively | Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, not an entire directory tree.
... | #TXR | TXR | (glob "/etc/*.conf") | Give a code snippet in #TXR
Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, no... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Heronian_triangles | Heronian triangles | Hero's formula for the area of a triangle given the length of its three sides a, b, and c is given by:
A
=
s
(
s
−
a
)
(
s
−
b
)
(
s
−
c
)
,
{\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},}
where s is half the perimeter of the triangle; that is,
s
=
a
+
b
+
c
2
.
{\displaystyle s... | #Java | Java | import java.util.ArrayList;
public class Heron {
public static void main(String[] args) {
ArrayList<int[]> list = new ArrayList<>();
for (int c = 1; c <= 200; c++) {
for (int b = 1; b <= c; b++) {
for (int a = 1; a <= b; a++) {
if (gcd(gcd(a, b),... | Give a code snippet in #Java
Hero's formula for the area of a triangle given the length of its three sides a, b, and c is given by:
A
=
s
(
s
−
a
)
(
s
−
b
)
(
s
−
c
)
,
{\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},}
where s is half the perimeter of the triangle; that is,
s
=
a
+
b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Pythagorean_means | Averages/Pythagorean means | Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldots ,x_{n})}
for this set of p... | #Ursala | Ursala | #import std
#import flo
data = ari10(1.,10.) # arithmetic progression, length 10 with endpoints 1 and 10
a = mean data
g = exp mean ln* data
h = div/1. mean div/*1. data
#cast %eLbX
main = ^(~&,ordered not fleq) <a,g,h> | Give a code snippet in #Ursala
Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ld... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Liberty_BASIC | Liberty BASIC |
FruitList$(0)="apple" 'assign 2 cells of a list array
FruitList$(1)="orange"
dimension=dimension(FruitList$()) 'first get the dimension of the array
if dimension>3 then
print "Sorry, program only written for array dimensions of 3 or less."
end
end if
call elements FruitList$(), dimension 'next get the size o... | Give a code snippet in #Liberty_BASIC
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
Lett... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Simple_moving_average | Averages/Simple moving average | Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average is a method for computing an avera... | #PARI.2FGP | PARI/GP | sma_per(n)={
sma_v=vector(n);
sma_i = 0;
n->if(sma_i++>#sma_v,sma_v[sma_i=1]=n;0,sma_v[sma_i]=n;0)+sum(i=1,#sma_v,sma_v[i])/#sma_v
}; | Give a code snippet in #PARI.2FGP
Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_subsequential_sum | Greatest subsequential sum | Task
Given a sequence of integers, find a continuous subsequence which maximizes the sum of its elements, that is, the elements of no other single subsequence add up to a value larger than this one.
An empty subsequence is considered to have the sum of 0; thus if all elements are negative, the result must be th... | #OCaml | OCaml | let maxsubseq =
let rec loop sum seq maxsum maxseq = function
| [] -> maxsum, List.rev maxseq
| x::xs ->
let sum = sum + x
and seq = x :: seq in
if sum < 0 then
loop 0 [] maxsum maxseq xs
else if sum > maxsum then
loop sum seq sum seq xs
el... | Give a code snippet in #OCaml
Task
Given a sequence of integers, find a continuous subsequence which maximizes the sum of its elements, that is, the elements of no other single subsequence add up to a value larger than this one.
An empty subsequence is considered to have the sum of 0; thus if all elements are ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Constrained_random_points_on_a_circle | Constrained random points on a circle | Task
Generate 100 <x,y> coordinate pairs such that x and y are integers sampled from the uniform distribution with the condition that
10
≤
x
2
+
y
2
≤
15
{\displaystyle 10\leq {\sqrt {x^{2}+y^{2}}}\leq 15}
.
Then display/plot them. The outcome should be a "fuzzy" circle. The actual number of point... | #Scala | Scala | import java.awt.{ Color, geom,Graphics2D ,Rectangle}
import scala.math.hypot
import scala.swing.{MainFrame,Panel,SimpleSwingApplication}
import scala.swing.Swing.pair2Dimension
import scala.util.Random
object CirculairConstrainedRandomPoints extends SimpleSwingApplication {
//min/max of display-x resp. y
val dx0,... | Give a code snippet in #Scala
Task
Generate 100 <x,y> coordinate pairs such that x and y are integers sampled from the uniform distribution with the condition that
10
≤
x
2
+
y
2
≤
15
{\displaystyle 10\leq {\sqrt {x^{2}+y^{2}}}\leq 15}
.
Then display/plot them. The outcome should be a "fuzzy" cir... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Last_letter-first_letter | Last letter-first letter | A certain children's game involves starting with a word in a particular category. Each participant in turn says a word, but that word must begin with the final letter of the previous word. Once a word has been given, it cannot be repeated. If an opponent cannot give a word in the category, they fall out of the ga... | #Elixir | Elixir | defmodule LastLetter_FirstLetter do
def search(names) do
first = Enum.group_by(names, &String.first/1)
sequences = Enum.reduce(names, [], fn name,acc -> add_name(first, acc, [name]) end)
max = Enum.max_by(sequences, &length/1) |> length
max_seqs = Enum.filter(sequences, fn seq -> length(seq) == max en... | Give a code snippet in #Elixir
A certain children's game involves starting with a word in a particular category. Each participant in turn says a word, but that word must begin with the final letter of the previous word. Once a word has been given, it cannot be repeated. If an opponent cannot give a word in the c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SEDOLs | SEDOLs | Task
For each number list of 6-digit SEDOLs, calculate and append the checksum digit.
That is, given this input:
710889
B0YBKJ
406566
B0YBLH
228276
B0YBKL
557910
B0YBKR
585284
B0YBKT
B00030
Produce this output:
7108899
B0YBKJ7
4065663
B0YBLH2
2282765
B0YBKL9
5579107
B0YBKR5
5852842
B0YBKT7
B000300
Extra credit
... | #Rust | Rust |
fn sedol(input: &str) -> Option<String> {
let weights = vec![1, 3, 1, 7, 3, 9, 1];
let valid_chars = "0123456789BCDFGHJKLMNPQRSTVWXYZ";
if input.len() != 6 {
return None;
}
// could be done by regex if needed
for c in input.chars() {
if !valid_chars.contains(c) {
... | Give a code snippet in #Rust
Task
For each number list of 6-digit SEDOLs, calculate and append the checksum digit.
That is, given this input:
710889
B0YBKJ
406566
B0YBLH
228276
B0YBKL
557910
B0YBKR
585284
B0YBKT
B00030
Produce this output:
7108899
B0YBKJ7
4065663
B0YBLH2
2282765
B0YBKL9
5579107
B0YBKR5
5852842
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knuth_shuffle | Knuth shuffle | The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array.
Task
Implement the Knuth shuffle for an integer array (or, if possible, an array of any type).
Specification
Given an array items with indices ranging from 0 to last, the algorithm can be d... | #AutoIt | AutoIt |
Dim $a[10]
ConsoleWrite('array before permutation:' & @CRLF)
For $i = 0 To 9
$a[$i] = Random(20,100,1)
ConsoleWrite($a[$i] & ' ')
Next
ConsoleWrite(@CRLF)
_Permute($a)
ConsoleWrite('array after permutation:' & @CRLF)
For $i = 0 To UBound($a) -1
ConsoleWrite($a[$i] & ' ')
Next
ConsoleWrite(@CRLF)
Func _Permut... | Give a code snippet in #AutoIt
The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array.
Task
Implement the Knuth shuffle for an integer array (or, if possible, an array of any type).
Specification
Given an array items with indices ranging from 0... | 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... | #PHP | PHP |
function strip_block_comments( $test_string ) {
$pattern = "/^.*?(\K\/\*.*?\*\/)|^.*?(\K\/\*.*?^.*\*\/)$/mXus";
return preg_replace( $pattern, '', $test_string );
}
echo "Result: '" . strip_block_comments( "
/**
* Some comments
* longer comments here that we can parse.
*
* Rahoo
*/
function subroutine() {
... | Give a code snippet in #PHP
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 a... | 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... | #AArch64_Assembly | AArch64 Assembly |
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program copystr64.s */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeConstantesARM6... | Give a code snippet in #AArch64_Assembly
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 stri... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Happy_numbers | Happy numbers | From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not inclu... | #Objeck | Objeck | use IO;
use Structure;
bundle Default {
class HappyNumbers {
function : native : IsHappy(n : Int) ~ Bool {
cache := IntVector->New();
sum := 0;
while(n <> 1) {
if(cache->Has(n)) {
return false;
};
cache->AddBack(n);
while(n <> 0) {
... | Give a code snippet in #Objeck
From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_append | String append |
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 |... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | (* mutable strings are not supported *)
s1 = "testing";
s1 = s1 <> " 123";
s1 | Give a code snippet in #Mathematica.2FWolfram_Language
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 |
L... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Color_of_a_screen_pixel | Color of a screen pixel | Task
Get color information from an arbitrary pixel on the screen, such as the current location of the mouse cursor.
The mouse cursor may or may not have to be active in a GUI created by your program. These functions are OS related.
| #C.2B.2B.2FCLI | C++/CLI | using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;
[STAThreadAttribute]
int main()
{
Point^ MousePoint = gcnew Point();
Control^ TempControl = gcnew Control();
MousePoint = TempControl->MousePosition;
Bitmap^ TempBitmap = gcnew Bitmap(1,1);
Graphics^ g = Graphics::Fr... | Give a code snippet in #C.2B.2B.2FCLI
Task
Get color information from an arbitrary pixel on the screen, such as the current location of the mouse cursor.
The mouse cursor may or may not have to be active in a GUI created by your program. These functions are OS related.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Idiomatically_determine_all_the_characters_that_can_be_used_for_symbols | Idiomatically determine all the characters that can be used for symbols | Idiomatically determine all the characters that can be used for symbols.
The word symbols is meant things like names of variables, procedures (i.e., named fragments of programs, functions, subroutines, routines), statement labels, events or conditions, and in general, anything a computer programmer can choose to name, ... | #Haskell | Haskell | varid → (small {small | large | digit | ' }) / reservedid
conid → large {small | large | digit | ' }
reservedid → case | class | data | default | deriving | do | else
| foreign | if | import | in | infix | infixl
| infixr | instance | let | module | newtype | of
| then | type ... | Give a code snippet in #Haskell
Idiomatically determine all the characters that can be used for symbols.
The word symbols is meant things like names of variables, procedures (i.e., named fragments of programs, functions, subroutines, routines), statement labels, events or conditions, and in general, anything a compute... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_comparison | String comparison |
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 |... | #Forth | Forth | : str-eq ( str len str len -- ? ) compare 0= ;
: str-neq ( str len str len -- ? ) compare 0<> ;
: str-lt ( str len str len -- ? ) compare 0< ;
: str-gt ( str len str len -- ? ) compare 0> ;
: str-le ( str len str len -- ? ) compare 0<= ;
: str-ge ( str len str len -- ? ) compare 0>= ; | Give a code snippet in #Forth
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/Merge_sort | Sorting algorithms/Merge sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Ruby | Ruby | def merge_sort(m)
return m if m.length <= 1
middle = m.length / 2
left = merge_sort(m[0...middle])
right = merge_sort(m[middle..-1])
merge(left, right)
end
def merge(left, right)
result = []
until left.empty? || right.empty?
result << (left.first<=right.first ? left.shift : right.shift)
end
re... | Give a code snippet in #Ruby
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/Roman_numerals/Decode | Roman numerals/Decode | Task
Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer.
You don't need to validate the form of the Roman numeral.
Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately,
starting with the leftmost decima... | #Delphi.2FPascal | Delphi/Pascal | program RomanNumeralsDecode;
{$APPTYPE CONSOLE}
function RomanToInteger(const aRoman: string): Integer;
function DecodeRomanDigit(aChar: Char): Integer;
begin
case aChar of
'M', 'm': Result := 1000;
'D', 'd': Result := 500;
'C', 'c': Result := 100;
'L', 'l': Result := 50;
'X', ... | Give a code snippet in #Delphi.2FPascal
Task
Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer.
You don't need to validate the form of the Roman numeral.
Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separ... | 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... | #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Open Lpt "Lpt:" As #1 '' prints to default printer
Print #1, "Hello World!"
Close #1 | Give a code snippet in #FreeBASIC
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Amb | Amb | Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton").
The Amb operator takes a v... | #ERRE | ERRE |
PROGRAM AMB
!
! for rosettacode.org
!
!$KEY
DIM SET1$[2],SET2$[2],SET3$[2],SET4$[2]
FUNCTION WORDS_OK(STRING1$,STRING2$)
WORDS_OK=(RIGHT$(STRING1$,1)=LEFT$(STRING2$,1))
END FUNCTION
PROCEDURE AMB(SET1$[],SET2$[],SET3$[],SET4$[]->RESULT$)
RESULT$="" ! Empty string, e.g. fail
FOR A=0 TO 2 DO
FOR B=0... | Give a code snippet in #ERRE
Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Man_or_boy_test | Man or boy test | Man or boy test
You are encouraged to solve this task according to the task description, using any language you may know.
Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguis... | #Phix | Phix | without js -- allocate()
forward function A(integer k, object x1, x2, x3, x4, x5)
function B(sequence s)
object {kptr,x1,x2,x3,x4} = s
integer k = peek4s(kptr)-1
poke4(kptr,k)
return A(k,{kptr,x1,x2,x3,x4},x1,x2,x3,x4)
end function
function A(integer k, object x1, x2, x3, x4, x5)
if k<=0 then
... | Give a code snippet in #Phix
Man or boy test
You are encouraged to solve this task according to the task description, using any language you may know.
Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim... | christopher/rosetta-code | |
http://rosettacode.org/wiki/FASTA_format | FASTA format | In bioinformatics, long character strings are often encoded in a format called FASTA.
A FASTA file can contain several strings, each identified by a name marked by a > (greater than) character at the beginning of the line.
Task
Write a program that reads a FASTA file such as:
>Rosetta_Example_1
THERECANBENOSPACE
... | #Julia | Julia | for line in eachline("data/fasta.txt")
if startswith(line, '>')
print(STDOUT, "\n$(line[2:end]): ")
else
print(STDOUT, "$line")
end
end | Give a code snippet in #Julia
In bioinformatics, long character strings are often encoded in a format called FASTA.
A FASTA file can contain several strings, each identified by a name marked by a > (greater than) character at the beginning of the line.
Task
Write a program that reads a FASTA file such as:
>Roset... | 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... | #Maxima | Maxima | load("descriptive");
mean([2, 7, 11, 17]); | Give a code snippet in #Maxima
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 est... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_comparison | Integer comparison |
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 |... | #Axe | Axe | Lbl FUNC
If r₁<r₂
Disp "LESS THAN",i
End
If r₁=r₂
Disp "EQUAL TO",i
End
If r₁>r₂
Disp "GREATER THAN",i
End
Return | Give a code snippet in #Axe
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
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/FizzBuzz | FizzBuzz | Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuzz (instead of the number)
... | #Clojure | Clojure |
(doseq [x (range 1 101)] (println x (str (when (zero? (mod x 3)) "fizz") (when (zero? (mod x 5)) "buzz"))))
| Give a code snippet in #Clojure
Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tokenize_a_string | Tokenize a string | Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks related to string operations:
Me... | #Pascal | Pascal | program TokenizeString;
{$mode objfpc}{$H+}
uses
SysUtils, Classes;
const
TestString = 'Hello,How,Are,You,Today';
var
Tokens: TStringList;
I: Integer;
begin
// Uses FCL facilities, "harder" algorithm not implemented
Tokens := TStringList.Create;
try
Tokens.Delimiter := ',';
Tokens.DelimitedTex... | Give a code snippet in #Pascal
Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks r... | 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 ... | #CoffeeScript | CoffeeScript |
halve = (n) -> Math.floor n / 2
double = (n) -> n * 2
is_even = (n) -> n % 2 == 0
multiply = (a, b) ->
prod = 0
while a > 0
prod += b if !is_even a
a = halve a
b = double b
prod
# tests
do ->
for i in [0..100]
for j in [0..100]
throw Error("broken for #{i} * #{j}") if multiply(i,j) !... | Give a code snippet in #CoffeeScript
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_Algorithms/Circle_Sort | Sorting Algorithms/Circle 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
... | #Forth | Forth | [UNDEFINED] cell- [IF] : cell- 1 cells - ; [THEN]
defer precedes ( addr addr -- flag )
variable (sorted?) \ is the array sorted?
: (compare) ( a1 a2 -- a1 a2)
over @ over @ precedes \ flag if swapped
if over over over @ over @ ... | Give a code snippet in #Forth
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 so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Algebraic_data_types | Algebraic data types | Some languages offer direct support for algebraic data types and pattern matching on them. While this of course can always be simulated with manual tagging and conditionals, it allows for terse code which is easy to read, and can represent the algorithm directly.
Task
As an example, implement insertion in a red-bla... | #Racket | Racket |
#lang racket
;; Using short names to make the code line up nicely
(struct N (color left value right) #:prefab)
(define (balance t)
(match t
[(N 'B (N 'R (N 'R a x b) y c) z d) (N 'R (N 'B a x b) y (N 'B c z d))]
[(N 'B (N 'R a x (N 'R b y c)) z d) (N 'R (N 'B a x b) y (N 'B c z d))]
[(N 'B a x (N 'R... | Give a code snippet in #Racket
Some languages offer direct support for algebraic data types and pattern matching on them. While this of course can always be simulated with manual tagging and conditionals, it allows for terse code which is easy to read, and can represent the algorithm directly.
Task
As an example, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #Idris | Idris | module Main
import Data.Vect
dotProduct : (Num a) => Vect n a -> Vect n a -> a
dotProduct = (sum .) . zipWith (*)
main : IO ()
main = printLn $ dotProduct [1,2,3] [1,2,3]
| Give a code snippet in #Idris
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Biorhythms | Biorhythms | For a while in the late 70s, the pseudoscience of biorhythms was popular enough to rival astrology, with kiosks in malls that would give you your weekly printout. It was also a popular entry in "Things to Do with your Pocket Calculator" lists. You can read up on the history at Wikipedia, but the main takeaway is that u... | #FreeBASIC | FreeBASIC | #define floor(x) ((x*2.0-0.5) Shr 1)
#define pi (4 * Atn(1))
Function Gregorian(db As String) As Integer
Dim As Integer M, Y, D
Y = Valint(Left(db,4)) : M = Valint(Mid(db,6,2)) : D = Valint(Right(db,2))
Dim As Integer N = (M+9) - Int((M+9)/12) * 12
Dim As Integer W = Y - Int(N/10)
Dim As Integer ... | Give a code snippet in #FreeBASIC
For a while in the late 70s, the pseudoscience of biorhythms was popular enough to rival astrology, with kiosks in malls that would give you your weekly printout. It was also a popular entry in "Things to Do with your Pocket Calculator" lists. You can read up on the history at Wikiped... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Boolean_values | Boolean values | Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| #Brainf.2A.2A.2A | Brainf*** | bool? value = null | Give a code snippet in #Brainf.2A.2A.2A
Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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 ... | #Nim | Nim | proc halve(x: int): int = x div 2
proc double(x: int): int = x * 2
proc odd(x: int): bool = x mod 2 != 0
proc ethiopian(x, y: int): int =
var x = x
var y = y
while x >= 1:
if odd(x):
result += y
x = halve x
y = double y
echo ethiopian(17, 34) | Give a code snippet in #Nim
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 wri... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Test_a_function | Test a function |
Task
Using a well-known testing-specific library/module/suite for your language, write some tests for your language's entry in Palindrome.
If your language does not have a testing specific library well known to the language's community then state this or omit the language.
| #Phix | Phix | with javascript_semantics
requires("0.8.2")
function is_palindrome(sequence s)
return s==reverse(s)
end function
--set_test_verbosity(TEST_QUIET) -- default, no output when third call removed
--set_test_verbosity(TEST_SUMMARY) -- first and last line only [w or w/o ""]
--set_test_verb... | Give a code snippet in #Phix
Task
Using a well-known testing-specific library/module/suite for your language, write some tests for your language's entry in Palindrome.
If your language does not have a testing specific library well known to the language's community then state this or omit the language.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Pick_random_element | Pick random element | Demonstrate how to pick a random element from a list.
| #BASIC | BASIC | 'setup
DIM foo(10) AS LONG
DIM n AS LONG, x AS LONG
FOR n = LBOUND(foo) TO UBOUND(foo)
foo(n) = INT(RND*99999)
NEXT
RANDOMIZE TIMER
'random selection
x = INT(RND * ((UBOUND(foo) - LBOUND(foo)) + 1))
'output
PRINT x, foo(x) | Give a code snippet in #BASIC
Demonstrate how to pick a random element from a list.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Temperature_conversion | Temperature conversion | There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 kelvin.
0 kelvin is absolute z... | #Swift | Swift |
func KtoC(kelvin : Double)->Double{
return kelvin-273.15
}
func KtoF(kelvin : Double)->Double{
return ((kelvin-273.15)*1.8)+32
}
func KtoR(kelvin : Double)->Double{
return ((kelvin-273.15)*1.8)+491.67
}
var k// input
print("\(k) Kelvin")
var c=KtoC(kelvin : k)
print("\(c) Celsius")
var f=KtoF(... | Give a code snippet in #Swift
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 ... | christopher/rosetta-code |
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