task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
value |
|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Pseudo-random_numbers/Combined_recursive_generator_MRG32k3a | Pseudo-random numbers/Combined recursive generator MRG32k3a | MRG32k3a Combined recursive generator (pseudo-code)
/* Constants */
/* First generator */
a1 = [0, 1403580, -810728]
m1 = 2**32 - 209
/* Second Generator */
a2 = [527612, 0, -1370589]
m2 = 2**32 - 22853
d = m1 + 1
class MRG32k3a
x1 = [0, 0, 0] /* list of three last values of... | #Perl | Perl | use strict;
use warnings;
use feature 'say';
package MRG32k3a {
use constant {
m1 => 2**32 - 209,
m2 => 2**32 - 22853
};
use Const::Fast;
const my @a1 => < 0 1403580 -810728>;
const my @a2 => <527612 0 -1370589>;
sub new {
my ($class,undef,$seed) = @_;
... | Give a code snippet in #Perl
MRG32k3a Combined recursive generator (pseudo-code)
/* Constants */
/* First generator */
a1 = [0, 1403580, -810728]
m1 = 2**32 - 209
/* Second Generator */
a2 = [527612, 0, -1370589]
m2 = 2**32 - 22853
d = m1 + 1
class MRG32k3a
x1 = [0, 0, 0] /... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Leap_year | Leap year | Task
Determine whether a given year is a leap year in the Gregorian calendar.
See also
Leap year (wiki)
| #C.2B.2B | C++ | g++ -std=c++11 leap_year.cpp
| Give a code snippet in #C.2B.2B
Task
Determine whether a given year is a leap year in the Gregorian calendar.
See also
Leap year (wiki)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Creation | Associative array/Creation | Task
The goal is to create an associative array (also known as a dictionary, map, or hash).
Related tasks:
Associative arrays/Iteration
Hash from two arrays
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element ins... | #Tcl | Tcl | # Create one element at a time:
set hash(foo) 5
# Create in bulk:
array set hash {
foo 5
bar 10
baz 15
}
# Access one element:
set value $hash(foo)
# Output all values:
foreach key [array names hash] {
puts $hash($key)
} | Give a code snippet in #Tcl
Task
The goal is to create an associative array (also known as a dictionary, map, or hash).
Related tasks:
Associative arrays/Iteration
Hash from two arrays
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, El... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Interactive_programming_(repl) | Interactive programming (repl) | Many language implementations come with an interactive mode.
This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a command mode, a read-eval-print loop (REPL), or a shell.
Task
Show how to start this... | #Perl | Perl | $ perl -de1
Loading DB routines from perl5db.pl version 1.3
Editor support available.
Enter h or `h h' for help, or `man perldebug' for more help.
main::(-e:1): 1
DB<1> sub f {my ($s1, $s2, $sep) = @_; $s1 . $sep . $sep . $s2}
DB<2> p f('Rosetta', 'Code', ':')
Rosetta::Code
DB<3> q | Give a code snippet in #Perl
Many language implementations come with an interactive mode.
This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a command mode, a read-eval-print loop (REPL), or a shell.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Comments | Comments | Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| #Scilab | Scilab | // this is a comment
i=i+1 // this is a comment | Give a code snippet in #Scilab
Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #C.23 | C# | int a = 0;
do
{
a += 1;
Console.WriteLine(a);
} while (a % 6 != 0); | Give a code snippet in #C.23
Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Do... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #XPL0 | XPL0 | include c:\cxpl\codesi;
real A, A1, G;
[Format(0, 16);
A:= 1.0; G:= 1.0/sqrt(2.0);
repeat A1:= (A+G)/2.0;
G:= sqrt(A*G);
A:= A1;
RlOut(0, A); RlOut(0, G); RlOut(0, A-G); CrLf(0);
until A=G;
] | Give a code snippet in #XPL0
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #PicoLisp | PicoLisp | (make
(in '(host "www.kame.net")
(while (from "address ")
(link (till "^J" T)) ) ) ) | Give a code snippet in #PicoLisp
DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within l... | #Erlang | Erlang |
-module (main).
-export ([main/0]).
main() ->
io:fwrite( "SPAM~n" ),
main().
| Give a code snippet in #Erlang
Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loo... | 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... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "float.s7i";
const array float: numbers is [] (1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0);
const func proc: main is func
local
var float: number is 0.0;
var float: sum is 0.0;
var float: product is 1.0;
var float: reciprocalSum is 0.0;
begin
for nu... | Give a code snippet in #Seed7
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},\ldo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Kosaraju | Kosaraju |
This page uses content from Wikipedia. The original article was at Graph. 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)
Kosaraju's algorithm (also known as the Kosaraju–Sharir algorithm) is a lin... | #Racket | Racket | #lang racket
(require racket/dict)
;; G is a dictionary of vertex -> (list vertex)
(define (Kosuraju G)
(letrec
((vertices (remove-duplicates (append (dict-keys G) (append* (dict-values G)))))
(visited?-dict (make-hash)) ; or any mutable dict type
(assigned-dict (make-hash)) ; or any mutable d... | Give a code snippet in #Racket
This page uses content from Wikipedia. The original article was at Graph. 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)
Kosaraju's algorithm (also known as the Kos... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence_of_primes_by_trial_division | Sequence of primes by trial division | Sequence of primes by trial division
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate a sequence of primes by means of trial division.
Trial division is an algorithm where a candidate number is tested for being a prime by trying to divide it by... | #Phix | Phix | function is_prime_by_trial_division(integer n)
if n<2 then return 0 end if
if n=2 then return 1 end if
if remainder(n,2)=0 then return 0 end if
for i=3 to floor(sqrt(n)) by 2 do
if remainder(n,i)=0 then
return 0
end if
end for
return 1
end function
?filter(tagset(32),... | Give a code snippet in #Phix
Sequence of primes by trial division
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate a sequence of primes by means of trial division.
Trial division is an algorithm where a candidate number is tested for being a p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_digits_of_an_integer | Sum digits of an integer | Task
Take a Natural Number in a given base and return the sum of its digits:
110 sums to 1
123410 sums to 10
fe16 sums to 29
f0e16 sums to 29
| #PicoLisp | PicoLisp | (de sumDigits (N Base)
(or
(=0 N)
(+ (% N Base) (sumDigits (/ N Base) Base)) ) ) | Give a code snippet in #PicoLisp
Task
Take a Natural Number in a given base and return the sum of its digits:
110 sums to 1
123410 sums to 10
fe16 sums to 29
f0e16 sums to 29
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sockets | Sockets | For this exercise a program is open a socket to localhost on port 256 and send the message "hello socket world" before closing the socket.
Catching any exceptions or errors is not required.
| #Cind | Cind |
var libsocket = @("lib","socket");
// connect
int socket = libsocket.connect("localhost",256);
// send data
{
sheet data = (sheet)"hello socket world";
int datalen = data.size();
int was = libsocket.send(socket,data,0,datalen);
// assuming here that all data has been sent (if not, send them in some loop)
... | Give a code snippet in #Cind
For this exercise a program is open a socket to localhost on port 256 and send the message "hello socket world" before closing the socket.
Catching any exceptions or errors is not required.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #ALGOL_W | ALGOL W | begin
% return the nth Fibonacci number %
integer procedure Fibonacci( integer value n ) ;
begin
integer fn, fn1, fn2;
fn2 := 1;
fn1 := 0;
fn := 0;
for i := 1 until n do begin
fn := fn1 + fn2;
fn2 := fn1;
... | Give a code snippet in #ALGOL_W
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mastermind | Mastermind | Create a simple version of the board game: Mastermind.
It must be possible to:
choose the number of colors will be used in the game (2 - 20)
choose the color code length (4 - 10)
choose the maximum number of guesses the player has (7 - 20)
choose whether or not colors may be repeated in the code
The (... | #Perl | Perl | use List::Util qw(any);
print 'Enter pool size, puzzle size, attempts allowed: ';
($pool,$length,$tries) = split /\s+/, <>;
$length = 4 if $length eq '' or $length < 3 or $length > 11;
$pool = 6 if $pool eq '' or $pool < 2 or $pool > 21;
$tries = 10 if $tries eq '' or $tries < 7 or $tries > 21;
@vali... | Give a code snippet in #Perl
Create a simple version of the board game: Mastermind.
It must be possible to:
choose the number of colors will be used in the game (2 - 20)
choose the color code length (4 - 10)
choose the maximum number of guesses the player has (7 - 20)
choose whether or not colors may b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Haversine_formula | Haversine formula |
This page uses content from Wikipedia. The original article was at Haversine formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The haversine formula is an equation important in navigation, g... | #Lua | Lua | local function haversine(x1, y1, x2, y2)
r=0.017453292519943295769236907684886127;
x1= x1*r; x2= x2*r; y1= y1*r; y2= y2*r; dy = y2-y1; dx = x2-x1;
a = math.pow(math.sin(dx/2),2) + math.cos(x1) * math.cos(x2) * math.pow(math.sin(dy/2),2); c = 2 * math.asin(math.sqrt(a)); d = 6372.8 * c;
return d;
end | Give a code snippet in #Lua
This page uses content from Wikipedia. The original article was at Haversine formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The haversine formula is an equati... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Recursively | Walk a directory/Recursively | Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk a directory/Non-recursively ... | #Oz | Oz | declare
[Path] = {Module.link ['x-oz://system/os/Path.ozf']}
[Regex] = {Module.link ['x-oz://contrib/regex']}
proc {WalkDirTree Root Pattern Proc}
proc {Walk R}
Entries = {Path.readdir R}
Files = {Filter Entries Path.isFile}
MatchingFiles = {Filter Files fun {$ File} {Regex.search P... | Give a code snippet in #Oz
Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Text_processing/Max_licenses_in_use | Text processing/Max licenses in use | A company currently pays a fixed sum for the use of a particular licensed software package. In determining if it has a good deal it decides to calculate its maximum use of the software from its license management log file.
Assume the software's licensing daemon faithfully records a checkout event when a copy of the ... | #MAXScript | MAXScript | fn licencesInUse =
(
local logFile = openFile "mlijobs.txt"
local out = 0
local maxOut = -1
local maxTimes = #()
while not EOF logFile do
(
line = readLine logFile
if findString line "OUT" != undefined then
(
out += 1
)
else
(
... | Give a code snippet in #MAXScript
A company currently pays a fixed sum for the use of a particular licensed software package. In determining if it has a good deal it decides to calculate its maximum use of the software from its license management log file.
Assume the software's licensing daemon faithfully records a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Kernighans_large_earthquake_problem | Kernighans large earthquake problem | Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example lines from the file would be lines li... | #Klingphix | Klingphix | arg pop nip len dup
( [get nip]
[drop drop "data.txt"]
) if
%f
dup "r" fopen !f
$f 0 < ( [drop "Could not open '" print print "' for reading" print -1 end ] [drop] ) if
[dup split 3 get tonum 6 > ( [drop print nl] [drop drop] ) if]
[$f fgets dup -1 #]
while
drop
$f fclose
"End " input | Give a code snippet in #Klingphix
Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example li... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Text | Hello world/Text | Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
| #ERRE | ERRE |
! Hello World in ERRE language
PROGRAM HELLO
BEGIN
PRINT("Hello world!")
END PROGRAM
| Give a code snippet in #ERRE
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Goldbach%27s_comet | Goldbach's comet |
This page uses content from Wikipedia. The original article was at Goldbach's comet. 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)
Goldbach's comet is the name given to a plot of the function g(E),... | #ALGOL_68 | ALGOL 68 | BEGIN # calculate values of the Goldbach function G where G(n) is the number #
# of prime pairs that sum to n, n even and > 2 #
# generates an ASCII scatter plot of G(n) up to G(2000) #
# (Goldbach's Comet) #
... | Give a code snippet in #ALGOL_68
This page uses content from Wikipedia. The original article was at Goldbach's comet. 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)
Goldbach's comet is the name giv... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric | Determine if a string is numeric | Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
Array length
String length
Cop... | #Sidef | Sidef | say "0.1E-5".looks_like_number; #=> true | Give a code snippet in #Sidef
Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
A... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Formatted_numeric_output | Formatted numeric output | Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| #Kotlin | Kotlin | // version 1.0.5-2
fun main(args: Array<String>) {
val num = 7.125
println("%09.3f".format(num))
} | Give a code snippet in #Kotlin
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Home_primes | Home primes |
This page uses content from Wikipedia. The original article was at Home 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 number theory, the home prime HP(n) of an integer n greater than 1 is... | #Sidef | Sidef | for n in (2..20, 65) {
var steps = []
var orig = n
for (var f = n.factor; true; f = n.factor) {
steps << f
n = Num(f.join)
break if n.is_prime
}
say ("HP(#{orig}) = ", steps.map { .join('_') }.join(' -> '))
} | Give a code snippet in #Sidef
This page uses content from Wikipedia. The original article was at Home 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 number theory, the home prime HP(n) of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Text_processing/2 | Text processing/2 | The following task concerns data that came from a pollution monitoring station with twenty-four instruments monitoring twenty-four aspects of pollution in the air. Periodically a record is added to the file, each record being a line of 49 fields separated by white-space, which can be one or more space or tab characters... | #VBScript | VBScript | Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFile = objFSO.OpenTextFile(objFSO.GetParentFolderName(WScript.ScriptFullName) &_
"\readings.txt",1)
Set objDateStamp = CreateObject("Scripting.Dictionary")
Total_Records = 0
Valid_Records = 0
Duplicate_TimeStamps = ""
Do Until objFile.AtEndOfStream
... | Give a code snippet in #VBScript
The following task concerns data that came from a pollution monitoring station with twenty-four instruments monitoring twenty-four aspects of pollution in the air. Periodically a record is added to the file, each record being a line of 49 fields separated by white-space, which can be o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rosetta_Code/Rank_languages_by_popularity | Rosetta Code/Rank languages by popularity | Rosetta Code/Rank languages by popularity
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Sort the most popular computer programming languages based in number of members in Rosetta Code categories.
Sample output on 01 juin 2022 at 14:13 +02
Rank: 1 (1,... | #Python | Python | import requests
import re
response = requests.get("http://rosettacode.org/wiki/Category:Programming_Languages").text
languages = re.findall('title="Category:(.*?)">',response)[:-3] # strip last 3
response = requests.get("http://rosettacode.org/mw/index.php?title=Special:Categories&limit=5000").text
response = re.su... | Give a code snippet in #Python
Rosetta Code/Rank languages by popularity
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Sort the most popular computer programming languages based in number of members in Rosetta Code categories.
Sample output on 01 juin... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dijkstra%27s_algorithm | Dijkstra's algorithm | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path pro... | #11l | 11l | T Edge
String start
String end
Int cost
F (start, end, cost)
.start = start
.end = end
.cost = cost
T Graph
[Edge] edges
Set[String] vertices
F (edges)
.edges = edges.map((s, e, c) -> Edge(s, e, c))
.vertices = Set(.edges.map(e -> e.start)).union(Set(.edges.map(e... | Give a code snippet in #11l
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the si... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Angles_(geometric),_normalization_and_conversion | Angles (geometric), normalization and conversion | This task is about the normalization and/or conversion of (geometric) angles using
some common scales.
The angular scales that will be used in this task are:
degree
gradian
mil
radian
Definitions
The angular scales used or referenced here:
turn is a full turn or 360 degrees, also shown as 360º
... | #Factor | Factor | USING: accessors combinators formatting inverse kernel math
math.constants quotations qw sequences units.si ;
IN: rosetta-code.angles
ALIAS: degrees arc-deg
: gradiens ( n -- d ) 9/10 * degrees ;
: mils ( n -- d ) 9/160 * degrees ;
: normalize ( d -- d' ) [ 2 pi * mod ] change-value ;
CONSTANT: units { degrees gradie... | Give a code snippet in #Factor
This task is about the normalization and/or conversion of (geometric) angles using
some common scales.
The angular scales that will be used in this task are:
degree
gradian
mil
radian
Definitions
The angular scales used or referenced here:
turn is a full turn or ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Equilibrium_index | Equilibrium index | An equilibrium index of a sequence is an index into the sequence such that the sum of elements at lower indices is equal to the sum of elements at higher indices.
For example, in a sequence
A
{\displaystyle A}
:
A
0
=
−
7
{\displaystyle A_{0}=-7}
A
1
=
1
{\displaystyle A_{1}=1}
... | #AutoHotkey | AutoHotkey | Equilibrium_index(list, BaseIndex=0){
StringSplit, A, list, `,
Loop % A0 {
i := A_Index , Pre := Post := 0
loop, % A0
if (A_Index < i)
Pre += A%A_Index%
else if (A_Index > i)
Post += A%A_Index%
if (Pre = Post)
Res .= (Res?", ":"") i - (BaseIndex?0:1)
}
return Res
} | Give a code snippet in #AutoHotkey
An equilibrium index of a sequence is an index into the sequence such that the sum of elements at lower indices is equal to the sum of elements at higher indices.
For example, in a sequence
A
{\displaystyle A}
:
A
0
=
−
7
{\displaystyle A_{0}=-7}
A... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Metered_concurrency | Metered concurrency | The goal of this task is to create a counting semaphore used to control the execution of a set of concurrent units. This task intends to demonstrate coordination of active concurrent units through the use of a passive concurrent unit. The operations for a counting semaphore are acquire, release, and count. Each active ... | #Scala | Scala | class CountingSemaphore(var maxCount: Int) {
private var lockCount = 0
def acquire(): Unit = {
while ( {
lockCount >= maxCount
}) wait()
lockCount += 1
}
def release(): Unit = {
if (lockCount > 0) {
lockCount -= 1
notifyAll()
}
}
def getCount: Int = lockCount
}
... | Give a code snippet in #Scala
The goal of this task is to create a counting semaphore used to control the execution of a set of concurrent units. This task intends to demonstrate coordination of active concurrent units through the use of a passive concurrent unit. The operations for a counting semaphore are acquire, r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Infinity | Infinity | Task
Write a function which tests if infinity is supported for floating point numbers (this step should be omitted for languages where the language specification already demands the existence of infinity, e.g. by demanding IEEE numbers), and if so, returns positive infinity. Otherwise, return the largest possible po... | #Lambdatalk | Lambdatalk |
{/ 1 0}
-> Infinity
{/ 1 Infinity}
-> 0
{< {pow 10 100} Infinity}
-> true
{< {pow 10 1000} Infinity}
-> false
| Give a code snippet in #Lambdatalk
Task
Write a function which tests if infinity is supported for floating point numbers (this step should be omitted for languages where the language specification already demands the existence of infinity, e.g. by demanding IEEE numbers), and if so, returns positive infinity. Other... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dining_philosophers | Dining philosophers | The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra.
Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a rou... | #REXX | REXX | /*REXX program demonstrates a solution in solving the dining philosophers problem. */
signal on halt /*branches to HALT: (on Ctrl─break).*/
parse arg seed diners /*obtain optional arguments from the CL*/
if datatype(seed, 'W') then call random ,, see... | Give a code snippet in #REXX
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra.
Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eatin... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zumkeller_numbers | Zumkeller numbers | Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the divisors are partitioned, only that ... | #Go | Go | package main
import "fmt"
func getDivisors(n int) []int {
divs := []int{1, n}
for i := 2; i*i <= n; i++ {
if n%i == 0 {
j := n / i
divs = append(divs, i)
if i != j {
divs = append(divs, j)
}
}
}
return divs
}
func sum(... | Give a code snippet in #Go
Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the divisors... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Text_processing/1 | Text processing/1 | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another pr... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | FileName = "Readings.txt"; data = Import[FileName,"TSV"];
Scan[(a=Position[#[[3;;All;;2]],1];
Print["Line:",#[[1]] ,"\tReject:", 24 - Length[a], "\t Accept:", Length[a], "\tLine_tot:",
Total@Part[#, Flatten[2*a]] , "\tLine_avg:", Total@Part[#, Flatten[2*a]]/Length[a]])&, data]
GlobalSum = Nb = Running = MaxRunRecorde... | Give a code snippet in #Mathematica.2FWolfram_Language
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Often data is produced by one program, in the wrong format for later use by a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Largest_proper_divisor_of_n | Largest proper divisor of n | Task
a(1) = 1; for n > 1, a(n) = largest proper divisor of n, where n < 101 .
| #J | J | lpd =: (1 |.!.1 ])&.q: | Give a code snippet in #J
Task
a(1) = 1; for n > 1, a(n) = largest proper divisor of n, where n < 101 .
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #Go | Go | func fib(a int) int {
if a < 2 {
return a
}
return fib(a - 1) + fib(a - 2)
} | Give a code snippet in #Go
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are ge... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Holidays_related_to_Easter | Holidays related to Easter | Task
Calculate the dates of:
Easter
Ascension Thursday
Pentecost
Trinity Sunday
Corpus Christi feast (for Catholic)
All Saints' Sunday (for Orthodox)
As an example, calculate for the first year of each century from;
years 400 to 2100 CE and for
years 2010 to 2020 CE.
Note
... | #F.C5.8Drmul.C3.A6 | Fōrmulæ | package main
import (
"fmt"
"time"
)
type holiday struct {
time.Time
}
func easter(y int) holiday {
c := y / 100
n := mod(y, 19)
i := mod(c-c/4-(c-(c-17)/25)/3+19*n+15, 30)
i -= (i / 28) * (1 - (i/28)*(29/(i+1))*((21-n)/11))
l := i - mod(y+y/4+i+2-c+c/4, 7)
m := 3 + (l+40)/44
... | Give a code snippet in #F.C5.8Drmul.C3.A6
Task
Calculate the dates of:
Easter
Ascension Thursday
Pentecost
Trinity Sunday
Corpus Christi feast (for Catholic)
All Saints' Sunday (for Orthodox)
As an example, calculate for the first year of each century from;
years 400 to 2100 CE and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Minimum_multiple_of_m_where_digital_sum_equals_m | Minimum multiple of m where digital sum equals m | Generate the sequence a(n) when each element is the minimum integer multiple m such that the digit sum of n times m is equal to n.
Task
Find the first 40 elements of the sequence.
Stretch
Find the next 30 elements of the sequence.
See also
OEIS:A131382 - Minimal number m such that Sum_digits(n*m)=n
| #APL | APL | {n←⍵ ⋄ (+∘1)⍣{n=+/10⊥⍣¯1⊢⍺×n}⊢0 } ¨ 7 10⍴⍳70 | Give a code snippet in #APL
Generate the sequence a(n) when each element is the minimum integer multiple m such that the digit sum of n times m is equal to n.
Task
Find the first 40 elements of the sequence.
Stretch
Find the next 30 elements of the sequence.
See also
OEIS:A131382 - Minimal number m such that... | 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
| #Plain_English | Plain English | To run:
Start up.
Write "Goodbye, world!" on the console without advancing.
Wait for the escape key.
Shut down. | Give a code snippet in #Plain_English
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 wor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorions | Factorions |
Definition
A factorion is a natural number that equals the sum of the factorials of its digits.
Example
145 is a factorion in base 10 because:
1! + 4! + 5! = 1 + 24 + 120 = 145
It can be shown (see talk page) that no factorion in base 10 can exceed 1,499,999.
Task
Write a progr... | #J | J |
index=: $ #: I.@:,
factorion=: 10&$: :(] = [: +/ [: ! #.^:_1)&>
FACTORIONS=: 9 0 +"1 index Q=: 9 10 11 12 factorion/ i. 1500000
NB. base, factorion expressed in bases 10, and base
(,. ".@:((Num_j_,26}.Alpha_j_) {~ #.inv/)"1) FACTORIONS
9 1 1
9 2 2
9 41282 62558
10 1 1
10 ... | Give a code snippet in #J
Definition
A factorion is a natural number that equals the sum of the factorials of its digits.
Example
145 is a factorion in base 10 because:
1! + 4! + 5! = 1 + 24 + 120 = 145
It can be shown (see talk page) that no factorion in base 10 can exceed 1,499,... | 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... | #Euphoria | Euphoria | function mean(sequence s)
atom sum
if length(s) = 0 then
return 0
else
sum = 0
for i = 1 to length(s) do
sum += s[i]
end for
return sum/length(s)
end if
end function
sequence test
test = {1.0, 2.0, 5.0, -5.0, 9.5, 3.14159}
? mean(test) | Give a code snippet in #Euphoria
Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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
| #Common_Lisp | Common Lisp |
VAR
b,c: BOOLEAN;
...
b := TRUE;
c := FALSE;
...
| Give a code snippet in #Common_Lisp
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/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... | #Axe | Axe | Lbl BSEARCH
0→L
r₃-1→H
While L≤H
(L+H)/2→M
If {L+M}>r₂
M-1→H
ElseIf {L+M}<r₂
M+1→L
Else
M
Return
End
End
-1
Return | Give a code snippet in #Axe
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 num... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Musical_scale | Musical scale | Task
Output the 8 notes of the C major diatonic scale to the default musical sound device on the system. Specifically, pitch must be tuned to 12-tone equal temperament (12TET) with the modern standard A=440Hz.
These are the notes "C, D, E, F, G, A, B, C(1 octave higher)", or "Do, Re, Mi, Fa, Sol, La, Si/Ti, Do(1 octa... | #Racket | Racket |
#lang racket
(require ffi/unsafe ffi/unsafe/define)
(define-ffi-definer defmm (ffi-lib "Winmm"))
(defmm midiOutOpen (_fun [h : (_ptr o _int32)] [_int = -1] [_pointer = #f]
[_pointer = #f] [_int32 = 0] -> _void -> h))
(defmm midiOutShortMsg (_fun _int32 _int32 -> _void))
(define M (midiOutOpen... | Give a code snippet in #Racket
Task
Output the 8 notes of the C major diatonic scale to the default musical sound device on the system. Specifically, pitch must be tuned to 12-tone equal temperament (12TET) with the modern standard A=440Hz.
These are the notes "C, D, E, F, G, A, B, C(1 octave higher)", or "Do, Re, M... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Get_system_command_output | Get system command output | Task
Execute a system command and get its output into the program. The output may be stored in any kind of collection (array, list, etc.).
Related task
Execute a system command
| #Kotlin | Kotlin | // version 1.0.6
import java.util.Scanner
fun main(args: Array<String>) {
val command = "cmd /c chcp"
val p = Runtime.getRuntime().exec(command)
val sc = Scanner(p.inputStream)
println(sc.nextLine())
sc.close()
} | Give a code snippet in #Kotlin
Task
Execute a system command and get its output into the program. The output may be stored in any kind of collection (array, list, etc.).
Related task
Execute a system command
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Subtractive_generator | Subtractive generator | A subtractive generator calculates a sequence of random numbers, where each number is congruent to the subtraction of two previous numbers from the sequence.
The formula is
r
n
=
r
(
n
−
i
)
−
r
(
n
−
j
)
(
mod
m
)
{\displaystyle r_{n}=r_{(n-i)}-r_{(n-j)}{\pmod {m}}}
for some fixed values of... | #Racket | Racket | #lang racket
(define (make-initial-state a-list max-i)
(for/fold ((state a-list))
((i (in-range (length a-list) max-i)))
(append state (list (- (list-ref state (- i 2)) (list-ref state (- i 1))))))) ;from the seed and 1 creates the initial state
(define (shuffle a-list)
(for/list ((i (in-range (le... | Give a code snippet in #Racket
A subtractive generator calculates a sequence of random numbers, where each number is congruent to the subtraction of two previous numbers from the sequence.
The formula is
r
n
=
r
(
n
−
i
)
−
r
(
n
−
j
)
(
mod
m
)
{\displaystyle r_{n}=r_{(n-i)}-r_{(n-j)}{\pmod ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Penney%27s_game | Penney's game | Penney's game is a game where two players bet on being the first to see a particular sequence of heads or tails in consecutive tosses of a fair coin.
It is common to agree on a sequence length of three then one player will openly choose a sequence, for example:
Heads, Tails, Heads, or HTH for short.
The other pla... | #BBC_BASIC | BBC BASIC | REM >penney
PRINT "*** Penney's Game ***"
REPEAT
PRINT ' "Heads you pick first, tails I pick first."
PRINT "And it is... ";
WAIT 100
ht% = RND(0 - TIME) AND 1
IF ht% THEN
PRINT "heads!"
PROC_player_chooses(player$)
computer$ = FN_optimal(player$)
PRINT "I choose "; computer$; "."
ELSE
PR... | Give a code snippet in #BBC_BASIC
Penney's game is a game where two players bet on being the first to see a particular sequence of heads or tails in consecutive tosses of a fair coin.
It is common to agree on a sequence length of three then one player will openly choose a sequence, for example:
Heads, Tails, Head... | 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, ... | #PARI.2FGP | PARI/GP | v=concat(concat([48..57],[65..90]),concat([97..122],95));
apply(Strchr,v) | Give a code snippet in #PARI.2FGP
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 compu... | 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... | #J | J | 12 *. 18
36
12 *. 18 22
36 132
*./ 12 18 22
396
0 1 0 1 *. 0 0 1 1 NB. for truth valued arguments (0 and 1) it is equivalent to "and"
0 0 0 1
*./~ 0 1
0 0
0 1 | Give a code snippet in #J
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 bot... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Closures/Value_capture | Closures/Value capture | Task
Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, i 2.
Display the result of runnin... | #Java | Java | import java.util.function.Supplier;
import java.util.ArrayList;
public class ValueCapture {
public static void main(String[] args) {
ArrayList<Supplier<Integer>> funcs = new ArrayList<>();
for (int i = 0; i < 10; i++) {
int j = i;
funcs.add(() -> j * j);
}
Supplier<Integer> foo = funcs.get(3);
Sy... | Give a code snippet in #Java
Task
Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, i 2.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ray-casting_algorithm | Ray-casting algorithm |
This page uses content from Wikipedia. The original article was at Point_in_polygon. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Given a point and a polygon, check if the point is inside or out... | #R | R | point_in_polygon <- function(polygon, p) {
count <- 0
for(side in polygon) {
if ( ray_intersect_segment(p, side) ) {
count <- count + 1
}
}
if ( count %% 2 == 1 )
"INSIDE"
else
"OUTSIDE"
}
ray_intersect_segment <- function(p, side) {
eps <- 0.0001
a <- side$A
b <- side$B
if ( a... | Give a code snippet in #R
This page uses content from Wikipedia. The original article was at Point_in_polygon. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Given a point and a polygon, check if... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brownian_tree | Brownian tree | Brownian tree
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw a Brownian Tree.
A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes.
The initial "seed" is placed somewhere wi... | #Processing | Processing | boolean SIDESTICK = false;
boolean[][] isTaken;
void setup() {
size(512, 512);
background(0);
isTaken = new boolean[width][height];
isTaken[width/2][height/2] = true;
}
void draw() {
int x = floor(random(width));
int y = floor(random(height));
if (isTaken[x][y]) {
return;
}
while (true) {
... | Give a code snippet in #Processing
Brownian tree
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw a Brownian Tree.
A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes.
The i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Search_a_list | Search a list | Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle that has multiple occurrences in ... | #Raku | Raku | my @haystack = <Zig Zag Wally Ronald Bush Krusty Charlie Bush Bozo>;
for <Washington Bush> -> $needle {
say "$needle -- { @haystack.first($needle, :k) // 'not in haystack' }";
} | Give a code snippet in #Raku
Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle tha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorions | Factorions |
Definition
A factorion is a natural number that equals the sum of the factorials of its digits.
Example
145 is a factorion in base 10 because:
1! + 4! + 5! = 1 + 24 + 120 = 145
It can be shown (see talk page) that no factorion in base 10 can exceed 1,499,999.
Task
Write a progr... | #C | C | #include <stdio.h>
int main() {
int n, b, d;
unsigned long long i, j, sum, fact[12];
// cache factorials from 0 to 11
fact[0] = 1;
for (n = 1; n < 12; ++n) {
fact[n] = fact[n-1] * n;
}
for (b = 9; b <= 12; ++b) {
printf("The factorions for base %d are:\n", b);
... | Give a code snippet in #C
Definition
A factorion is a natural number that equals the sum of the factorials of its digits.
Example
145 is a factorion in base 10 because:
1! + 4! + 5! = 1 + 24 + 120 = 145
It can be shown (see talk page) that no factorion in base 10 can exceed 1,499,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #Action.21 | Action! | DEFINE MAXSIZE="200"
BYTE ARRAY queue(MAXSIZE)
BYTE queueFront=[0],queueRear=[0]
BYTE FUNC IsEmpty()
IF queueFront=queueRear THEN
RETURN (1)
FI
RETURN (0)
PROC Push(BYTE v)
BYTE rear
rear=queueRear+1
IF rear=MAXSIZE THEN
rear=0
FI
IF rear=queueFront THEN
PrintE("Error: queue is full!")
... | Give a code snippet in #Action.21
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #Slate | Slate | define: #Fruit &parents: {Cloneable}.
Fruit traits define: #Apple -> Fruit clone.
Fruit traits define: #Banana -> Fruit clone.
Fruit traits define: #Cherry -> Fruit clone. | Give a code snippet in #Slate
Task
Create an enumeration of constants with and without explicit values.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #PARI.2FGP | PARI/GP | sha256(s)=extern("echo \"Str(`echo -n '"Str(s)"'|sha256sum|cut -d' ' -f1`)\"") | Give a code snippet in #PARI.2FGP
SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa54271396... | 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... | #Java | Java | /* Query.java */
public class Query {
public static boolean call(byte[] data, int[] length)
throws java.io.UnsupportedEncodingException
{
String message = "Here am I";
byte[] mb = message.getBytes("utf-8");
if (length[0] < mb.length)
return false;
length[0] = mb.length;
System.arraycopy(mb, 0, data, ... | Give a code snippet in #Java
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, s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Four_bit_adder | Four bit adder | Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made using two nots, two ands ... | #JavaScript | JavaScript |
function acceptedBinFormat(bin) {
if (bin == 1 || bin === 0 || bin === '0')
return true;
else
return bin;
}
function arePseudoBin() {
var args = [].slice.call(arguments), len = args.length;
while(len--)
if (acceptedBinFormat(args[len]) !== true)
throw new Error('a... | Give a code snippet in #JavaScript
Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fraction_reduction | Fraction reduction | There is a fine line between numerator and denominator. ─── anonymous
A method to "reduce" some reducible fractions is to cross out a digit from the
numerator and the denominator. An example is:
16 16
──── and then (simp... | #Lua | Lua | function indexOf(haystack, needle)
for idx,straw in pairs(haystack) do
if straw == needle then
return idx
end
end
return -1
end
function getDigits(n, le, digits)
while n > 0 do
local r = n % 10
if r == 0 or indexOf(digits, r) > 0 then
return fa... | Give a code snippet in #Lua
There is a fine line between numerator and denominator. ─── anonymous
A method to "reduce" some reducible fractions is to cross out a digit from the
numerator and the denominator. An example is:
16 16
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/K-d_tree | K-d tree |
This page uses content from Wikipedia. The original article was at K-d tree. 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)
A k-d tree (short for k-dimensional tree) is a space-partitioning data str... | #Racket | Racket |
#lang racket
; A tree consists of a point, a left and a right subtree.
(struct tree (p l r) #:transparent)
; If the node is in depth d, then the points in l has
; the (d mod k)'th coordinate less than the same coordinate in p.
(define (kdtree d k ps)
(cond [(empty? ps) #f] ; #f represents an empty subtree
... | Give a code snippet in #Racket
This page uses content from Wikipedia. The original article was at K-d tree. 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)
A k-d tree (short for k-dimensional tree) ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Nim_game | Nim game | Nim game
You are encouraged to solve this task according to the task description, using any language you may know.
Nim is a simple game where the second player ─── if they know the trick ─── will always win.
The game has only 3 rules:
start with 12 tokens
each player takes 1, 2, or 3 tokens in tur... | #BlooP | BlooP |
DEFINE PROCEDURE ''DIVIDE'' [A,B]:
BLOCK 0: BEGIN
IF A < B, THEN:
QUIT BLOCK 0;
CELL(0) <= 1;
OUTPUT <= 1;
LOOP AT MOST A TIMES:
BLOCK 2: BEGIN
IF OUTPUT * B = A, THEN:
QUIT BLOCK 0;
OUTPUT <= OUTPUT + 1;
IF OUTPUT * B > A, THEN:
BLOCK 3: BEGIN
OUTPUT <= CELL(0);
QUIT BLO... | Give a code snippet in #BlooP
Nim game
You are encouraged to solve this task according to the task description, using any language you may know.
Nim is a simple game where the second player ─── if they know the trick ─── will always win.
The game has only 3 rules:
start with 12 tokens
each player takes ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #FALSE | FALSE | Give a code snippet in #FALSE
Task
Create the simplest possible program that is still considered "correct."
| christopher/rosetta-code | ||
http://rosettacode.org/wiki/Greatest_common_divisor | Greatest common divisor | Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greatest common measure.
Related tas... | #Simula | Simula | BEGIN
INTEGER PROCEDURE GCD(a, b); INTEGER a, b;
BEGIN
IF a = 0 THEN a := b
ELSE
WHILE 0 < b DO BEGIN INTEGER i;
i := MOD(a, b); a := b; b := i;
END;
GCD := a
END;
INTEGER a, b;
!outint(SYSOUT.IMAGE.MAIN.LENGTH, 0);!OUTIMAGE;!OUTIMAGE... | Give a code snippet in #Simula
Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greates... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #68000_Assembly | 68000 Assembly | forever:
MOVE.B D0,$300001
JMP forever | Give a code snippet in #68000_Assembly
Task
Create the simplest possible program that is still considered "correct."
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations | Permutations | Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations generation tasks.
Order Uni... | #PureBasic | PureBasic | Macro reverse(firstIndex, lastIndex)
first = firstIndex
last = lastIndex
While first < last
Swap cur(first), cur(last)
first + 1
last - 1
Wend
EndMacro
Procedure nextPermutation(Array cur(1))
Protected first, last, elementCount = ArraySize(cur())
If elementCount < 1
ProcedureReturn #False... | Give a code snippet in #PureBasic
Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Python | Python | '''
Bulls and cows. A game pre-dating, and similar to, Mastermind.
'''
import random
digits = '123456789'
size = 4
chosen = ''.join(random.sample(digits,size))
#print chosen # Debug
print '''I have chosen a number from %s unique digits from 1 to 9 arranged in a random order.
You need to input a %i digit, unique di... | Give a code snippet in #Python
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roman_numerals/Encode | Roman numerals/Encode | Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a value of zero.
In Roman numeral... | #Befunge | Befunge | &>0\0>00p:#v_$ >:#,_ $ @
4-v >5+#:/#<\55+%:5/\5%:
vv_$9+00g+5g\00g8+>5g\00
g>\20p>:10p00g \#v _20gv
> 2+ v^-1g01\g5+8<^ +9 _
IVXLCDM | Give a code snippet in #Befunge
Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a v... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zumkeller_numbers | Zumkeller numbers | Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the divisors are partitioned, only that ... | #Visual_Basic_.NET | Visual Basic .NET | Module Module1
Function GetDivisors(n As Integer) As List(Of Integer)
Dim divs As New List(Of Integer) From {
1, n
}
Dim i = 2
While i * i <= n
If n Mod i = 0 Then
Dim j = n \ i
divs.Add(i)
If i <> j Then
... | Give a code snippet in #Visual_Basic_.NET
Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on h... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Program_termination | Program termination |
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers/destructors, run-on-exit hooks... | #Unlambda | Unlambda | `ei | Give a code snippet in #Unlambda
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finaliz... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Playing_cards | Playing cards | Task
Create a data structure and the associated methods to define and manipulate a deck of playing cards.
The deck should contain 52 unique cards.
The methods must include the ability to:
make a new deck
shuffle (randomize) the deck
deal from the deck
print the current contents of a deck
Each card mu... | #Logo | Logo | make "suits {Diamonds Hearts Clubs Spades}
make "pips {Ace Two Three Four Five Six Seven Eight Nine Ten Jack Queen King}
to card :n
output (sentence item 1 + modulo :n 13 :pips "of item 1 + int quotient :n 13 :suits)
end
to new.deck
make "deck listtoarray iseq 0 51
make "top 1
end
to swap :i :j :a
local... | Give a code snippet in #Logo
Task
Create a data structure and the associated methods to define and manipulate a deck of playing cards.
The deck should contain 52 unique cards.
The methods must include the ability to:
make a new deck
shuffle (randomize) the deck
deal from the deck
print the current co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_strings | Binary strings | Many languages have powerful and useful (binary safe) string manipulation functions, while others don't, making it harder for these languages to accomplish some tasks.
This task is about creating functions to handle binary strings (strings made of arbitrary bytes, i.e. byte strings according to Wikipedia) for those la... | #Go | Go | package main
import (
"bytes"
"fmt"
)
// Strings in Go allow arbitrary bytes. They are implemented basically as
// immutable byte slices and syntactic sugar. This program shows functions
// required by the task on byte slices, thus it mostly highlights what
// happens behind the syntactic sugar. The prog... | Give a code snippet in #Go
Many languages have powerful and useful (binary safe) string manipulation functions, while others don't, making it harder for these languages to accomplish some tasks.
This task is about creating functions to handle binary strings (strings made of arbitrary bytes, i.e. byte strings accordin... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_using_a_custom_comparator | Sort using a custom comparator |
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
... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | StringOrderQ[x_String, y_String] :=
If[StringLength[x] == StringLength[y],
OrderedQ[{x, y}],
StringLength[x] >StringLength[y]
]
words={"on","sunday","sander","sifted","and","sorted","sambaa","for","a","second"};
Sort[words,StringOrderQ] | Give a code snippet in #Mathematica.2FWolfram_Language
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 |... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conway%27s_Game_of_Life | Conway's Game of Life | The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, in an m-by-m (or m×m) sq... | #SQL | SQL |
-- save these lines in a file called
-- setupworld.sql
-- turn off feedback for cleaner display
SET feedback off
-- 3 x 3 world
-- alive has coordinates of living cells
DROP TABLE alive;
CREATE TABLE alive (x NUMBER,y NUMBER);
-- three alive up the middle
-- *
-- *
-- *
INSERT INTO alive VALUES (... | Give a code snippet in #SQL
The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exponentiation_order | Exponentiation order | This task will demonstrate the order of exponentiation (xy) when there are multiple exponents.
(Many programming languages, especially those with extended─precision integer arithmetic, usually support one of **, ^, ↑ or some such for exponentiation.)
Task requirements
Show the result of a language's eval... | #Swift | Swift | precedencegroup ExponentiationPrecedence {
associativity: left
higherThan: MultiplicationPrecedence
}
infix operator ** : ExponentiationPrecedence
@inlinable
public func ** <T: BinaryInteger>(lhs: T, rhs: T) -> T {
guard lhs != 0 else {
return 1
}
var x = lhs
var n = rhs
var y = T(1)
while n... | Give a code snippet in #Swift
This task will demonstrate the order of exponentiation (xy) when there are multiple exponents.
(Many programming languages, especially those with extended─precision integer arithmetic, usually support one of **, ^, ↑ or some such for exponentiation.)
Task requirements
Show ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Juggler_sequence | Juggler sequence | Background of the juggler sequence:
Juggler sequences were publicized by an American mathematician and author Clifford A. Pickover. The name of the sequence gets it's name from the similarity of the rising and falling nature of the numbers in the sequences, much like balls in the hands of a juggler.
Descrip... | #Factor | Factor | USING: combinators formatting generalizations io kernel math
math.extras math.functions.integer-logs math.order math.ranges
sequences strings tools.memory.private ;
: next ( m -- n )
dup odd? [ dup dup * * ] when integer-sqrt ;
: new-max ( l i h a -- l i h a )
[ drop dup ] 2dip nip dup ;
: (step) ( l i h ... | Give a code snippet in #Factor
Background of the juggler sequence:
Juggler sequences were publicized by an American mathematician and author Clifford A. Pickover. The name of the sequence gets it's name from the similarity of the rising and falling nature of the numbers in the sequences, much like balls in th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available,... | #Euphoria | Euphoria |
--Arrays task for Rosetta Code wiki
--User:Lnettnay
atom dummy
--Arrays are sequences
-- single dimensioned array of 10 elements
sequence xarray = repeat(0,10)
xarray[5] = 5
dummy = xarray[5]
? dummy
--2 dimensional array
--5 sequences of 10 elements each
sequence xyarray = repeat(repeat(0,10),5)
xyarray[3][6] = ... | Give a code snippet in #Euphoria
This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rename_a_file | Rename a file | Task
Rename:
a file called input.txt into output.txt and
a directory called docs into mydocs.
This should be done twice:
once "here", i.e. in the current working directory and once in the filesystem root.
It can be assumed that the user has the rights to do so.
(In unix-type s... | #Factor | Factor | "" "/" [
[ "input.txt" "output.txt" move-file "docs" "mydocs" move-file ] with-directory
] bi@ | Give a code snippet in #Factor
Task
Rename:
a file called input.txt into output.txt and
a directory called docs into mydocs.
This should be done twice:
once "here", i.e. in the current working directory and once in the filesystem root.
It can be assumed that the user has the r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_a_file | Create a file | In this task, the job is to create a new empty file called "output.txt" of size 0 bytes
and an empty directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| #Elena | Elena | import system'io;
public program()
{
File.assign("output.txt").textwriter().close();
File.assign("\output.txt").textwriter().close();
Directory.assign("docs").create();
Directory.assign("\docs").create();
} | Give a code snippet in #Elena
In this task, the job is to create a new empty file called "output.txt" of size 0 bytes
and an empty directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Snake | Snake |
This page uses content from Wikipedia. The original article was at Snake_(video_game). 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)
Snake is a game where the player maneuvers a line which grows i... | #JavaScript | JavaScript |
const L = 1, R = 2, D = 4, U = 8;
var block = 24, wid = 30, hei = 20, frameR = 7, fruit, snake;
function Snake() {
this.length = 1;
this.alive = true;
this.pos = createVector( 1, 1 );
this.posArray = [];
this.posArray.push( createVector( 1, 1 ) );
this.dir = R;
this.draw = function() {
... | Give a code snippet in #JavaScript
This page uses content from Wikipedia. The original article was at Snake_(video_game). 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)
Snake is a game where the p... | christopher/rosetta-code | |
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... | #Sidef | Sidef | module EC {
var A = 0
var B = 7
class Horizon {
method to_s {
"EC Point at horizon"
}
method *(_) {
self
}
method -(_) {
self
}
}
class Point(Number x, Number y) {
method to_s {
"EC Poin... | Give a code snippet in #Sidef
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 n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Filter | Filter | Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| #langur | langur | val .arr = series 7
writeln " array: ", .arr
writeln "filtered: ", where f .x div 2, .arr | Give a code snippet in #langur
Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/LZW_compression | LZW compression | The Lempel-Ziv-Welch (LZW) algorithm provides loss-less data compression.
You can read a complete description of it in the Wikipedia article on the subject. It was patented, but it entered the public domain in 2004.
| #J | J | encodeLZW =: 4 : 0
d=. ;/x
r=.0$0
wc=.w=.{.y
for_c. }.y do.
wc=.w,c
if. d e.~ <wc do. w=.wc else.
r=. r, d i.<w
d=.d,<wc
w=.c
end.
end.
r, d i.<w
) | Give a code snippet in #J
The Lempel-Ziv-Welch (LZW) algorithm provides loss-less data compression.
You can read a complete description of it in the Wikipedia article on the subject. It was patented, but it entered the public domain in 2004.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sierpinski_triangle | Sierpinski triangle | Task
Produce an ASCII representation of a Sierpinski triangle of order N.
Example
The Sierpinski triangle of order 4 should look like this:
*
* *
* *
* * * *
* *
* * * *
... | #PowerShell | PowerShell | function triangle($o) {
$n = [Math]::Pow(2, $o)
$line = ,' '*(2*$n+1)
$line[$n] = '█'
$OFS = ''
for ($i = 0; $i -lt $n; $i++) {
Write-Host $line
$u = '█'
for ($j = $n - $i; $j -lt $n + $i + 1; $j++) {
if ($line[$j-1] -eq $line[$j+1]) {
$t = ' '
... | Give a code snippet in #PowerShell
Task
Produce an ASCII representation of a Sierpinski triangle of order N.
Example
The Sierpinski triangle of order 4 should look like this:
*
* *
* *
* * * *
* *... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring/Top_and_tail | Substring/Top and tail | The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
If the program uses UTF-8 or UTF... | #LiveCode | LiveCode | put "pple" into x
answer char 2 to len(x) of x // pple
answer char 1 to -2 of x // ppl
answer char 2 to -2 of x // ppl | Give a code snippet in #LiveCode
The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calendar | Calendar | Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 display with accented characters). Target fo... | #Tcl | Tcl | package require Tcl 8.5
# Produce information about the days in a month, without any assumptions about
# what those days actually are.
proc calMonthDays {timezone locale year month} {
set days {}
set moment [clock scan [format "%04d-%02d-00 12:00" $year $month] \
-timezone $timezone -locale $locale -form... | Give a code snippet in #Tcl
Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 display with ac... | 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... | #Nim | Nim | import math, tables
type Quaternion* = object
a, b, c, d: float
func initQuaternion*(a, b, c, d = 0.0): Quaternion =
Quaternion(a: a, b: b, c: c, d: d)
func `-`*(q: Quaternion): Quaternion =
initQuaternion(-q.a, -q.b, -q.c, -q.d)
func `+`*(q: Quaternion; r: float): Quaternion =
initQuaternion(q.a + r, q... | Give a code snippet in #Nim
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 mi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Middle_three_digits | Middle three digits | Task
Write a function/procedure/subroutine that is called with an integer value and returns the middle three digits of the integer if possible or a clear indication of an error if this is not possible.
Note: The order of the middle digits should be preserved.
Your function should be tested with the following values;... | #Ruby | Ruby | def middle_three_digits(num)
# minus sign doesn't factor into digit count,
# and calling #abs acts as a duck-type assertion
num = num.abs
# convert to string and find length
length = (str = num.to_s).length
# check validity
raise ArgumentError, "Number must have at least three digits" if length < 3
... | Give a code snippet in #Ruby
Task
Write a function/procedure/subroutine that is called with an integer value and returns the middle three digits of the integer if possible or a clear indication of an error if this is not possible.
Note: The order of the middle digits should be preserved.
Your function should be tes... | 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... | #dc | dc | 0 si [i = 0]sz
[2Q]sA [A = code to break loop]sz
[
li 1 + p [print it = i + 1]sz
d si [i = it, leave it on stack]sz
6 % 0 =A [call A if 0 == it % 6]sz
0 0 =B [continue loop]sz
]sB 0 0 =B | Give a code snippet in #dc
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/Down... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Elementary_cellular_automaton/Infinite_length | Elementary cellular automaton/Infinite length | The purpose of this task is to create a version of an Elementary cellular automaton whose number of cells is only limited by the memory size of the computer.
To be precise, consider the state of the automaton to be made of an infinite number of cells, but with a bounded support. In other words, to describe the state o... | #Sidef | Sidef | func evolve(rule, bin) {
var offset = 0
var (l='', r='')
Inf.times {
bin.sub!(/^((.)\g2*)/, {|_s1, s2| l = s2; offset -= s2.len; s2*2 })
bin.sub!(/(.)\g1*$/, {|s1| r = s1; s1*2 })
printf("%5d| %s%s\n", offset, ' ' * (40 + offset), bin.tr('01','.#'))
bin = [l*3, 0.to(bin.len-3... | Give a code snippet in #Sidef
The purpose of this task is to create a version of an Elementary cellular automaton whose number of cells is only limited by the memory size of the computer.
To be precise, consider the state of the automaton to be made of an infinite number of cells, but with a bounded support. In other... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anti-primes | Anti-primes | The anti-primes
(or highly composite numbers, sequence A002182 in the OEIS)
are the natural numbers with more factors than any smaller than itself.
Task
Generate and show here, the first twenty anti-primes.
Related tasks
Factors of an integer
Sieve of Eratosthenes
| #Erlang | Erlang | divcount(N) -> divcount(N, 1, 0).
divcount(N, D, Count) when D*D > N -> Count;
divcount(N, D, Count) ->
Divs = case N rem D of
0 ->
case N - D*D of
0 -> 1;
_ -> 2
end;
_ -> 0
end,
divcount(N, D + 1, Count + Divs).
antiprimes(N) ->... | Give a code snippet in #Erlang
The anti-primes
(or highly composite numbers, sequence A002182 in the OEIS)
are the natural numbers with more factors than any smaller than itself.
Task
Generate and show here, the first twenty anti-primes.
Related tasks
Factors of an integer
Sieve of Eratosthenes
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Element_insertion | Doubly-linked list/Element insertion | Doubly-Linked List (element)
This is much like inserting into a Singly-Linked List, but with added assignments so that the backwards-pointing links remain correct.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element inse... | #Go | Go | package main
import "fmt"
type dlNode struct {
string
next, prev *dlNode
}
type dlList struct {
head, tail *dlNode
}
func (list *dlList) String() string {
if list.head == nil {
return fmt.Sprint(list.head)
}
r := "[" + list.head.string
for p := list.head.next; p != nil; p = p... | Give a code snippet in #Go
Doubly-Linked List (element)
This is much like inserting into a Singly-Linked List, but with added assignments so that the backwards-pointing links remain correct.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Elem... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_strings | Binary strings | Many languages have powerful and useful (binary safe) string manipulation functions, while others don't, making it harder for these languages to accomplish some tasks.
This task is about creating functions to handle binary strings (strings made of arbitrary bytes, i.e. byte strings according to Wikipedia) for those la... | #Picat | Picat | main => % - String assignment
S1 = "binary_string",
println(s1=S1),
% Picat has re-assignments (:=/2) as well,
S1 := "another string",
println(s1=S1),
% - String comparison
if S1 == "another string" then
println(same)
else
println(not_same)
end,
% - String cloning and copying
S2 =... | Give a code snippet in #Picat
Many languages have powerful and useful (binary safe) string manipulation functions, while others don't, making it harder for these languages to accomplish some tasks.
This task is about creating functions to handle binary strings (strings made of arbitrary bytes, i.e. byte strings accor... | 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... | #JavaScript | JavaScript | //Constructor function.
function Car(brand, weight) {
this.brand = brand;
this.weight = weight || 1000; // Resort to default value (with 'or' notation).
}
Car.prototype.getPrice = function() { // Method of Car.
return this.price;
}
function Truck(brand, size) {
this.car = Car;
this.car(brand, 2000); // Call... | Give a code snippet in #JavaScript
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 th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calendar | Calendar | Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 display with accented characters). Target fo... | #OCaml | OCaml | #load "unix.cma"
let lang = "en" (* language: English *)
let usage () =
Printf.printf "Usage:\n%s\n" Sys.argv.(0)
let month_pattern =
[
[ 0; 4; 8 ];
[ 1; 5; 9 ];
[ 2; 6; 10 ];
[ 3; 7; 11 ];
(*
[ 0; 1; 2; 3; 4; 5 ];
[ 6; 7; 8; 9; 10; 11 ];
[ 0; 1; 2; ... | Give a code snippet in #OCaml
Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 display with ... | 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 ... | #Prolog | Prolog | halve(X,Y) :- Y is X // 2.
double(X,Y) :- Y is 2*X.
is_even(X) :- 0 is X mod 2.
% columns(First,Second,Left,Right) is true if integers First and Second
% expand into the columns Left and Right, respectively
columns(1,Second,[1],[Second]).
columns(First,Second,[First|Left],[Second|Right]) :-
halve(First,Halved),
... | Give a code snippet in #Prolog
Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Collections | Collections | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Collections are abstractions to represent sets of values.
In statically-typed languages, the values are typically of a common data type.
Task
Create a collection, and add a fe... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols nobinary
myVals = [ 'zero', 'one', 'two', 'three', 'four', 'five' ]
mySet = Set
mySet = HashSet()
loop val over myVals
mySet.add(val)
end val
loop val over mySet
say val
end val
return
| Give a code snippet in #NetRexx
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Collections are abstractions to represent sets of values.
In statically-typed languages, the values are typically of a common data type.
Task
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Two_bullet_roulette | Two bullet roulette | The following is supposedly a question given to mathematics graduates seeking jobs on Wall Street:
A revolver handgun has a revolving cylinder with six chambers for bullets.
It is loaded with the following procedure:
1. Check the first chamber to the right of the trigger for a bullet. If a bullet
is seen, the cyli... | #REXX | REXX | /*REXX pgm simulates scenarios for a two─bullet Russian roulette game with a 6 cyl. gun.*/
parse arg cyls tests seed . /*obtain optional arguments from the CL*/
if cyls=='' | cyls=="," then cyls= 6 /*Not specified? Then use the default.*/
if tests=='' | tests=="," then tests= 100000 ... | Give a code snippet in #REXX
The following is supposedly a question given to mathematics graduates seeking jobs on Wall Street:
A revolver handgun has a revolving cylinder with six chambers for bullets.
It is loaded with the following procedure:
1. Check the first chamber to the right of the trigger for a bullet.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/GUI_component_interaction | GUI component interaction |
Almost every application needs to communicate with the user in some way.
Therefore, a substantial part of the code deals with the interaction
of program logic with GUI components.
Typically, the following is needed:
put values into input fields under program control
read and check input from the user
pop up dial... | #C | C | file main.c | Give a code snippet in #C
Almost every application needs to communicate with the user in some way.
Therefore, a substantial part of the code deals with the interaction
of program logic with GUI components.
Typically, the following is needed:
put values into input fields under program control
read and check input... | christopher/rosetta-code |
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