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/Caesar_cipher | Caesar cipher |
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A).
So key 2 encrypts "HI" to... | #Tcl | Tcl | package require Tcl 8.6; # Or TclOO package for 8.5
oo::class create Caesar {
variable encryptMap decryptMap
constructor shift {
for {set i 0} {$i < 26} {incr i} {
# Play fast and loose with string/list duality for shorter code
append encryptMap [format "%c %c %c %c " \
[expr {$i+65}] [exp... | Give a code snippet in #Tcl
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Wieferich_primes | Wieferich primes |
This page uses content from Wikipedia. The original article was at Wieferich 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, a Wieferich prime is a prime number p such th... | #Sidef | Sidef | func is_wieferich_prime(p, base=2) {
powmod(base, p-1, p**2) == 1
}
say ("Wieferich primes less than 5000: ", 5000.primes.grep(is_wieferich_prime)) | Give a code snippet in #Sidef
This page uses content from Wikipedia. The original article was at Wieferich 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, a Wieferich prim... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Web_scraping | Web scraping | Task
Create a program that downloads the time from this URL: http://tycho.usno.navy.mil/cgi-bin/timer.pl and then prints the current UTC time by extracting just the UTC time from the web page's HTML. Alternatively, if the above url is not working, grab the first date/time off this page's talk page.
If possible,... | #Run_BASIC | Run BASIC | print word$(word$(httpget$("http://tycho.usno.navy.mil/cgi-bin/timer.pl"),1,"UTC"),2,"<BR>") | Give a code snippet in #Run_BASIC
Task
Create a program that downloads the time from this URL: http://tycho.usno.navy.mil/cgi-bin/timer.pl and then prints the current UTC time by extracting just the UTC time from the web page's HTML. Alternatively, if the above url is not working, grab the first date/time off thi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_three_variables | Sort three variables |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #M2000_Interpreter | M2000 Interpreter |
Module Sort3 {
Let X=77744, Y=-12, Z=0
Let X$ = "lions, tigers, and", Y$ = "bears, oh my!", Z$ = {(from the "Wizard of OZ")}
\\ & use for by reference pass
Module SortSome (&X$, &Y$, &Z$){
If Type$(X$)<>"String" Then {
Link X$,Y$, Z$ to X,Y,Z
... | Give a code snippet in #M2000_Interpreter
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 sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_modification_time | File modification time | Task
Get and set the modification time of a file.
| #Rust | Rust | use std::fs;
fn main() -> std::io::Result<()> {
let metadata = fs::metadata("foo.txt")?;
if let Ok(time) = metadata.accessed() {
println!("{:?}", time);
} else {
println!("Not supported on this platform");
}
Ok(())
}
| Give a code snippet in #Rust
Task
Get and set the modification time of a file.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Fermat_numbers | Fermat numbers | In mathematics, a Fermat number, named after Pierre de Fermat who first studied them, is a positive integer of the form Fn = 22n + 1 where n is a non-negative integer.
Despite the simplicity of generating Fermat numbers, they have some powerful mathematical properties and are extensively used in cryptography & pseudo-... | #Ruby | Ruby | This uses the `factor` function from the `coreutils` library
that comes standard with most GNU/Linux, BSD, and Unix systems.
https://www.gnu.org/software/coreutils/
https://en.wikipedia.org/wiki/GNU_Core_Utilities
| Give a code snippet in #Ruby
In mathematics, a Fermat number, named after Pierre de Fermat who first studied them, is a positive integer of the form Fn = 22n + 1 where n is a non-negative integer.
Despite the simplicity of generating Fermat numbers, they have some powerful mathematical properties and are extensively ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/MD5 | MD5 | Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the Wikipedia article.
Warning:... | #8th | 8th |
"md5" cr:hash! "Some text" cr:hash cr:hash>s
. cr bye
| Give a code snippet in #8th
Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the Wi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Complex | Arithmetic/Complex | A complex number is a number which can be written as:
a
+
b
×
i
{\displaystyle a+b\times i}
(sometimes shown as:
b
+
a
×
i
{\displaystyle b+a\times i}
where
a
{\displaystyle a}
and
b
{\displaystyle b}
are real numbers, and
i
{\displaystyle i}
is √ -1
Typica... | #Nemerle | Nemerle | using System;
using System.Console;
using System.Numerics;
using System.Numerics.Complex;
module RCComplex
{
PrettyPrint(this c : Complex) : string
{
mutable sign = '+';
when (c.Imaginary < 0) sign = '-';
$"$(c.Real) $sign $(Math.Abs(c.Imaginary))i"
}
Main() : void
{
... | Give a code snippet in #Nemerle
A complex number is a number which can be written as:
a
+
b
×
i
{\displaystyle a+b\times i}
(sometimes shown as:
b
+
a
×
i
{\displaystyle b+a\times i}
where
a
{\displaystyle a}
and
b
{\displaystyle b}
are real numbers, and
i
{\display... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Inverted_index | Inverted index | An Inverted Index is a data structure used to create full text search.
Task
Given a set of text files, implement a program to create an inverted index.
Also create a user interface to do a search using that inverted index which returns a list of files that contain the query term / terms.
The search index can be i... | #D | D | import std.stdio, std.algorithm, std.string, std.file, std.regex;
void main() {
string[][string] index;
void parseFile(in string fn) {
if (!exists(fn) || !isFile(fn))
throw new Exception("File not found");
foreach (word; readText(fn).splitter(regex(r"\W"))) {
word =... | Give a code snippet in #D
An Inverted Index is a data structure used to create full text search.
Task
Given a set of text files, implement a program to create an inverted index.
Also create a user interface to do a search using that inverted index which returns a list of files that contain the query term / terms.... | 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 ... | #Factor | Factor | : fib ( n -- m )
dup 2 < [
[ 0 1 ] dip [ swap [ + ] keep ] times
drop
] unless ; | Give a code snippet in #Factor
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 ar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #Amazing_Hopper | Amazing Hopper |
#include <hopper.h>
main:
s=""
load str ("archivo.txt") (s)
println ( "File loaded:\n",s )
exit(0)
| Give a code snippet in #Amazing_Hopper
Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplis... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sieve_of_Eratosthenes | Sieve of Eratosthenes | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algorithm, with the only allowed... | #Oz | Oz | declare
fun {Sieve N}
S = {Array.new 2 N true}
M = {Float.toInt {Sqrt {Int.toFloat N}}}
in
for I in 2..M do
if S.I then
for J in I*I..N;I do
S.J := false
end
end
end
S
end
fun {Primes N}
S = {Sieve N}
in
for I in 2..N collect:C do
if S.I then {C I} end
... | Give a code snippet in #Oz
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bin_given_limits | Bin given limits | You are given a list of n ascending, unique numbers which are to form limits
for n+1 bins which count how many of a large set of input numbers fall in the
range of each bin.
(Assuming zero-based indexing)
bin[0] counts how many inputs are < limit[0]
bin[1] counts how many inputs are >= limit[0] and < limit[1]
... | #Nim | Nim | import algorithm, strformat
func binIt(limits, data: openArray[int]): seq[Natural] =
result.setLen(limits.len + 1)
for d in data:
inc result[limits.upperBound(d)]
proc binPrint(limits: openArray[int]; bins: seq[Natural]) =
echo &" < {limits[0]:3} := {bins[0]:3}"
for i in 1..limits.high:
ech... | Give a code snippet in #Nim
You are given a list of n ascending, unique numbers which are to form limits
for n+1 bins which count how many of a large set of input numbers fall in the
range of each bin.
(Assuming zero-based indexing)
bin[0] counts how many inputs are < limit[0]
bin[1] counts how many inputs are... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abbreviations,_simple | Abbreviations, simple | The use of abbreviations (also sometimes called synonyms, nicknames, AKAs, or aliases) can be an
easy way to add flexibility when specifying or using commands, sub─commands, options, etc.
For this task, the following command table will be used:
add 1 alter 3 backup 2 bottom 1 Cappend 2 change 1 ... | #Ada | Ada | with Ada.Characters.Handling;
with Ada.Containers.Vectors;
with Ada.Strings.Fixed;
with Ada.Strings.Maps.Constants;
with Ada.Strings.Unbounded;
with Ada.Text_IO;
procedure Abbreviations_Simple is
use Ada.Strings.Unbounded;
subtype Ustring is Unbounded_String;
type Word_Entry is record
Word : Ustrin... | Give a code snippet in #Ada
The use of abbreviations (also sometimes called synonyms, nicknames, AKAs, or aliases) can be an
easy way to add flexibility when specifying or using commands, sub─commands, options, etc.
For this task, the following command table will be used:
add 1 alter 3 backup 2 bo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Almost_prime | Almost prime | A k-Almost-prime is a natural number
n
{\displaystyle n}
that is the product of
k
{\displaystyle k}
(possibly identical) primes.
Example
1-almost-primes, where
k
=
1
{\displaystyle k=1}
, are the prime numbers themselves.
2-almost-primes, where
k
=
2
{\displaystyl... | #EchoLisp | EchoLisp |
(define (almost-prime? p k)
(= k (length (prime-factors p))))
(define (almost-primes k nmax)
(take (filter (rcurry almost-prime? k) [2 ..]) nmax))
(define (task (kmax 6) (nmax 10))
(for ((k [1 .. kmax]))
(write 'k= k '|)
(for-each write (almost-primes k nmax))
(writeln)))
| Give a code snippet in #EchoLisp
A k-Almost-prime is a natural number
n
{\displaystyle n}
that is the product of
k
{\displaystyle k}
(possibly identical) primes.
Example
1-almost-primes, where
k
=
1
{\displaystyle k=1}
, are the prime numbers themselves.
2-almost-primes, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #JavaScript | JavaScript | function dot_product(ary1, ary2) {
if (ary1.length != ary2.length)
throw "can't find dot product: arrays have different lengths";
var dotprod = 0;
for (var i = 0; i < ary1.length; i++)
dotprod += ary1[i] * ary2[i];
return dotprod;
}
print(dot_product([1,3,-5],[4,-2,-1])); // ==> 3
prin... | Give a code snippet in #JavaScript
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Vector | Vector | Task
Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented.
The Vector may be initialized in any reasonable way.
Start and end points, and direction
Angular coefficient and value (length)
The four operations to... | #ALGOL_68 | ALGOL 68 | # the standard mode COMPLEX is a two element vector #
MODE VECTOR = COMPLEX;
# the operations required for the task plus many others are provided as standard for COMPLEX and REAL items #
# the two components are fields called "re" and "im" #
# we can define a "pretty-print" operator: #
# returns a formatted representat... | Give a code snippet in #ALGOL_68
Task
Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented.
The Vector may be initialized in any reasonable way.
Start and end points, and direction
Angular coefficient and value... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pi | Pi |
Create a program to continually calculate and output the next decimal digit of
π
{\displaystyle \pi }
(pi).
The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession.
The output should be a decimal sequence beginning 3.14159265 ...... | #Java | Java | import java.math.BigInteger ;
public class Pi {
final BigInteger TWO = BigInteger.valueOf(2) ;
final BigInteger THREE = BigInteger.valueOf(3) ;
final BigInteger FOUR = BigInteger.valueOf(4) ;
final BigInteger SEVEN = BigInteger.valueOf(7) ;
BigInteger q = BigInteger.ONE ;
BigInteger r = BigInteger.ZERO ... | Give a code snippet in #Java
Create a program to continually calculate and output the next decimal digit of
π
{\displaystyle \pi }
(pi).
The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession.
The output should be a decimal seque... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Animation | Animation |
Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games. The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user. This task demonstrates this.
Task
Creat... | #Quick_BASIC | Quick BASIC |
'here accordingly to the version, QB or QBX
REM $INCLUDE: 'QBX.BI'
DIM REGS AS REGTYPE
DIM C AS STRING, SIZ AS INTEGER
DIM I AS DOUBLE, DIRE AS INTEGER
C = "Hello World! "
SIZ = LEN(C)
SCREEN 12
'turn the cursor visible
REGS.AX = 1
INTERRUPT 51, REGS, REGS
DO
I = TIMER
LOCATE 1, 1
PRINT C
REGS.AX = 5 ... | Give a code snippet in #Quick_BASIC
Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games. The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user. This t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Singly-linked_list/Element_insertion | Singly-linked list/Element insertion | Singly-Linked List (element)
singly-linked list
Using this method, insert an element C into a list comprised of elements A->B, following element A.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Trav... | #Erlang | Erlang |
-module( singly_linked_list ).
-export( [append/2, foreach/2, free/1, insert/3, new/1, task/0] ).
append( New, Start ) -> Start ! {append, New}.
foreach( Fun, Start ) -> Start ! {foreach, Fun}.
free( Element ) -> Element ! {free}.
insert( New, After, Start ) -> Start ! {insert, New, After}.
new( Data ) ->... | Give a code snippet in #Erlang
Singly-Linked List (element)
singly-linked list
Using this method, insert an element C into a list comprised of elements A->B, following element A.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definiti... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_in_octal | Count in octal | Task
Produce a sequential count in octal, starting at zero, and using an increment of a one for each consecutive number.
Each number should appear on a single line, and the program should count until terminated, or until the maximum value of the numeric type in use is reached.
Related task
Integer sequ... | #Aime | Aime | integer o;
o = 0;
do {
o_xinteger(8, o);
o_byte('\n');
o += 1;
} while (0 < o); | Give a code snippet in #Aime
Task
Produce a sequential count in octal, starting at zero, and using an increment of a one for each consecutive number.
Each number should appear on a single line, and the program should count until terminated, or until the maximum value of the numeric type in use is reached.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/Integer | Literals/Integer | Some programming languages have ways of expressing integer literals in bases other than the normal base ten.
Task
Show how integer literals can be expressed in as many bases as your language allows.
Note: this should not involve the calling of any functions/methods, but should be interpreted by the compiler or... | #TI-89_BASIC | TI-89 BASIC | 0b10000001 = 129 = 0h81 | Give a code snippet in #TI-89_BASIC
Some programming languages have ways of expressing integer literals in bases other than the normal base ten.
Task
Show how integer literals can be expressed in as many bases as your language allows.
Note: this should not involve the calling of any functions/methods, but sho... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_an_integer_array | Sort an integer array |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Fantom | Fantom | fansh> a := [5, 1, 4, 2, 3]
[5, 1, 4, 2, 3]
fansh> a.sort
[1, 2, 3, 4, 5]
fansh> a
[1, 2, 3, 4, 5]
| Give a code snippet in #Fantom
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_length | String length | Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters.
F... | #6502_Assembly | 6502 Assembly | GetStringLength: ;$00 and $01 make up the pointer to the string's base address.
;(Of course, any two consecutive zero-page memory locations can fulfill this role.)
LDY #0 ;Y is both the index into the string and the length counter.
loop_getStringLength:
LDA ($00),y
BEQ exit
INY
JMP loop_ge... | Give a code snippet in #6502_Assembly
Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible graph... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Caesar_cipher | Caesar cipher |
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A).
So key 2 encrypts "HI" to... | #Forth | Forth | : ceasar ( c n -- c )
over 32 or [char] a -
dup 0 26 within if
over + 25 > if 26 - then +
else 2drop then ;
: ceasar-string ( n str len -- )
over + swap do i c@ over ceasar i c! loop drop ;
: ceasar-inverse ( n -- 'n ) 26 swap - 26 mod ;
2variable test
s" The five boxing wizards jump quickly!" test 2!... | Give a code snippet in #Forth
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to... | christopher/rosetta-code | |
http://rosettacode.org/wiki/MD4 | MD4 | Find the MD4 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Code” (without quotes).
You may either call an MD4 library, or implement MD4 in your language.
MD4 is an obsolete hash function that computes a 128-bit message digest that sometimes appears in obsolete protocols.
RFC 1320 specifi... | #FreeBASIC | FreeBASIC | ' version 19-10-2016
' translation of the (pseudo) code in RFC 1320
' compile with: fbc -s console
Function MD4(test_str As String) As String
Dim As String message = test_str ' string are passed as ByRef
' some macro's
#Macro F(X, Y, Z)
(((X) And (Y)) Or ((Not(X)) And (Z)))
#EndMacro
#Macro G(X, Y... | Give a code snippet in #FreeBASIC
Find the MD4 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Code” (without quotes).
You may either call an MD4 library, or implement MD4 in your language.
MD4 is an obsolete hash function that computes a 128-bit message digest that sometimes appears in ob... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_concatenation | String concatenation | String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another string literal.
To illustrate the operat... | #Nim | Nim | let str = "String"
echo str & " literal."
# -> String literal. | Give a code snippet in #Nim
String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another string liter... | christopher/rosetta-code | |
http://rosettacode.org/wiki/MD5 | MD5 | Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the Wikipedia article.
Warning:... | #Haskell | Haskell | import Data.Digest.OpenSSL.MD5 (md5sum)
import Data.ByteString (pack)
import Data.Char (ord)
main = do
let message = "The quick brown fox jumped over the lazy dog's back"
digest = (md5sum . pack . map (fromIntegral . ord)) message
putStrLn digest | Give a code snippet in #Haskell
Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brilliant_numbers | Brilliant numbers | Brilliant numbers are a subset of semiprime numbers. Specifically, they are numbers that are the product of exactly two prime numbers that both have the same number of digits when expressed in base 10.
Brilliant numbers are useful in cryptography and when testing prime factoring algorithms.
E.G.
3 × 3 (9) is a bri... | #Arturo | Arturo | brilliant?: function [x][
pf: factors.prime x
and? -> 2 = size pf
-> equal? size digits first pf
size digits last pf
]
brilliants: new []
i: 2
while [100 > size brilliants][
if brilliant? i -> 'brilliants ++ i
i: i + 1
]
print "First 100 brilliant numbers:"
loop split.eve... | Give a code snippet in #Arturo
Brilliant numbers are a subset of semiprime numbers. Specifically, they are numbers that are the product of exactly two prime numbers that both have the same number of digits when expressed in base 10.
Brilliant numbers are useful in cryptography and when testing prime factoring algorit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library | Call a function in a shared library | Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign language function where the focus is c... | #Delphi | Delphi | procedure DoSomething; external 'MYLIB.DLL'; | Give a code snippet in #Delphi
Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign langua... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compare_a_list_of_strings | Compare a list of strings | Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or false value, which could be used as t... | #ALGOL_W | ALGOL W | % returns true if all elements of the string array a are equal, false otherwise %
% As Algol W procedures cannot determine the bounds of an array, the bounds %
% must be specified in lo and hi %
logical procedure allStringsEqual ( string(256) array a ( ... | Give a code snippet in #ALGOL_W
Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or fals... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rock-paper-scissors | Rock-paper-scissors | Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The winner is decided by a set of rules:
... | #Wee_Basic | Wee Basic | let entered=0
let keycode=0
let rcounter=1
print 1 "Enter R for rock, P for paper, or S for scissors. (not case sensitive)"
while entered=0
input human$
if human=$="r"
let human$="rock"
let entered=1
elseif human=$="R"
let human$="rock"
let entered=1
elseif human=$="p"
let human$="paper"
let entered=1
elseif human=$="P... | Give a code snippet in #Wee_Basic
Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The wi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-1 | SHA-1 | SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to identify commits.
A US government... | #Liberty_BASIC | Liberty BASIC |
'--------------------------------------------------------------------------------
' FAST SHA1 CALCULATION BASED ON MS ADVAPI32.DLL BY CRYPTOMAN '
' BASED ON SHA256 EXAMPLE BY RICHARD T. RUSSEL AUTHOR OF LBB '
' http://lbb.conforums.com/ ... | Give a code snippet in #Liberty_BASIC
SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digest... | 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
| #REBOL | REBOL | prin "Goodbye, World!" | Give a code snippet in #REBOL
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/Stand... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multiplicative_order | Multiplicative order | The multiplicative order of a relative to m is the least positive integer n such that a^n is 1 (modulo m).
Example
The multiplicative order of 37 relative to 1000 is 100 because 37^100 is 1 (modulo 1000), and no number smaller than 100 would do.
One possible algorithm that is efficient also for large numbers is ... | #EchoLisp | EchoLisp |
(require 'bigint)
;; factor-exp returns a list ((p k) ..) : a = p1^k1 * p2^k2 ..
(define (factor-exp a)
(map (lambda (g) (list (first g) (length g)))
(group* (prime-factors a))))
;; copied from Ruby
(define (_mult_order a p k (x))
(define pk (expt p k))
(define t (* (1- p) (expt p (1- k))))
(define r 1... | Give a code snippet in #EchoLisp
The multiplicative order of a relative to m is the least positive integer n such that a^n is 1 (modulo m).
Example
The multiplicative order of 37 relative to 1000 is 100 because 37^100 is 1 (modulo 1000), and no number smaller than 100 would do.
One possible algorithm that is ef... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_three_variables | Sort three variables |
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
... | #F.C5.8Drmul.C3.A6 | Fōrmulæ | {$mode objFPC}
generic procedure sort<T>(var X, Y: T);
procedure swap;
var
Z: T;
begin
Z := X;
X := Y;
Y := Z
end;
begin
if X > Y then
begin
swap
end
end;
generic procedure sort<T>(var X, Y, Z: T);
begin
specialize sort<T>(X, Y);
specialize sort<T>(X, Z);
specialize sort<T>(Y, Z)
end;
generic ... | Give a code snippet in #F.C5.8Drmul.C3.A6
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 sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Copy_a_string | Copy a string | This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
W... | #Z80_Assembly | Z80 Assembly | ld hl,MyString
ld (PointerVariable),hl
MyString: ;assembler equates this label to a memory location at compile time
byte "Hello",0
PointerVariable:
word 0 ;placeholder for the address of the above string, gets written to by the code above. | Give a code snippet in #Z80_Assembly
This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bulls_and_cows/Player | Bulls and cows/Player | Task
Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts.
One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those numbers that would give an equ... | #MATLAB | MATLAB | function BullsAndCowsPlayer
% Plays the game Bulls and Cows as the player
% Generate list of all possible numbers
nDigits = 4;
lowVal = 1;
highVal = 9;
combs = nchoosek(lowVal:highVal, nDigits);
nCombs = size(combs, 1);
nPermsPerComb = factorial(nDigits);
gList = zeros(nCombs.*nPermsPe... | Give a code snippet in #MATLAB
Task
Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts.
One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only thos... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Palindrome_detection | Palindrome detection | A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly as a wrapper to the first) which ... | #Frink | Frink | isPalindrome[x] := x == reverse[x]
| Give a code snippet in #Frink
A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly as... | christopher/rosetta-code | |
http://rosettacode.org/wiki/A%2BB | A+B | A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separated by space(s):
(
−
1000
≤... | #Ursa | Ursa | #
# a + b
#
# read a string containing the two ints
decl string input
set input (in string console)
# determine the sum
decl int sum
set sum (int (+ sum (int (split input " ")<0>)))
set sum (int (+ sum (int (split input " ")<1>)))
# output the sum
out sum endl console | Give a code snippet in #Ursa
A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separated... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Sparkling | Sparkling | let f = fopen("foo.txt", "r");
if f != nil {
var line;
while (line = fgetline(f)) != nil {
print(line);
}
fclose(f);
} | Give a code snippet in #Sparkling
Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Verify_distribution_uniformity/Naive | Verify distribution uniformity/Naive | This task is an adjunct to Seven-sided dice from five-sided dice.
Task
Create a function to check that the random integers returned from a small-integer generator function have uniform distribution.
The function should take as arguments:
The function (or object) producing random integers.
The number of times ... | #Python | Python | from collections import Counter
from pprint import pprint as pp
def distcheck(fn, repeats, delta):
'''\
Bin the answers to fn() and check bin counts are within +/- delta %
of repeats/bincount'''
bin = Counter(fn() for i in range(repeats))
target = repeats // len(bin)
deltacount = int(delta / 1... | Give a code snippet in #Python
This task is an adjunct to Seven-sided dice from five-sided dice.
Task
Create a function to check that the random integers returned from a small-integer generator function have uniform distribution.
The function should take as arguments:
The function (or object) producing random... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Foreach | Loops/Foreach | Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for... | #Slate | Slate | c do: [| :obj | print: obj]. | Give a code snippet in #Slate
Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_matching | String matching |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Ksh | Ksh |
#!/bin/ksh
exec 2> /tmp/String_matching.err
# String matching
# # 1. Determine if the first string starts with second string.
# # 2. Determine if the first string contains the second string at any location
# # 3. Determine if the first string ends with the second string
# # 4. Print the location of the match for pa... | Give a code snippet in #Ksh
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/String | Literals/String | Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
Here document
Other tasks r... | #PHP | PHP | 'c'; # character
'hello'; # these two strings are the same
"hello";
'Hi $name. How are you?'; # result: "Hi $name. How are you?"
"Hi $name. How are you?"; # result: "Hi Bob. How are you?"
'\n'; # 2-character string with a backslash and "n"
"\n"; ... | Give a code snippet in #PHP
Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
H... | 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... | #Phix | Phix | without js -- (file i/o)
?rename_file("input.txt","output.txt")
?rename_file("docs","mydocs")
?rename_file("C:\\Copy.txt","Copy.xxx")
?rename_file("C:\\docs","C:\\mydocs")
| Give a code snippet in #Phix
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 rig... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Date_format | Date format | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Task
Display the current date in the formats of:
2007-11-23 and
Friday, November 23, 2007
| #Free_Pascal | Free Pascal | program Format_Date_Time;
uses
SysUtils;
begin
WriteLn(FormatDateTime('yyyy-mm-dd', Now) +#13#10+ FormatDateTime('dddd, mmmm dd, yyyy', Now));
end.
| Give a code snippet in #Free_Pascal
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Task
Display the current date in the formats of:
2007-11-23 and
Friday, November 23, 2007
| christopher/rosetta-code | |
http://rosettacode.org/wiki/History_variables | History variables | Storing the history of objects in a program is a common task.
Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging.
History variables are variables in a programming la... | #REXX | REXX | /*REXX program demonstrates a method to track history of assignments to a REXX variable.*/
varSet!.=0 /*initialize the all of the VARSET!'s. */
call varSet 'fluid',min(0,-5/2,-1) ; say 'fluid=' fluid
call varSet 'fluid',3.14159 ; say 'fluid=' fluid
call varSet ... | Give a code snippet in #REXX
Storing the history of objects in a program is a common task.
Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging.
History variables are... | christopher/rosetta-code | |
http://rosettacode.org/wiki/HTTP | HTTP | Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| #Ol | Ol |
(import (lib curl))
(define curl (make-curl))
(curl 'url "http://rosettacode.org/")
(curl 'perform)
| Give a code snippet in #Ol
Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sieve_of_Eratosthenes | Sieve of Eratosthenes | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algorithm, with the only allowed... | #E | E | def rangeFromBelowBy(start, limit, step) {
return def stepper {
to iterate(f) {
var i := start
while (i < limit) {
f(null, i)
i += step
}
}
}
}
| Give a code snippet in #E
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Evaluate_binomial_coefficients | Evaluate binomial coefficients | This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2
)
…
(
n
−
k
+
1
)
k
(
k
−
1... | #CoffeeScript | CoffeeScript |
binomial_coefficient = (n, k) ->
result = 1
for i in [0...k]
result *= (n - i) / (i + 1)
result
n = 5
for k in [0..n]
console.log "binomial_coefficient(#{n}, #{k}) = #{binomial_coefficient(n,k)}"
| Give a code snippet in #CoffeeScript
This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_size | File size | Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| #NewLISP | NewLISP | (println (first (file-info "input.txt")))
(println (first (file-info "/input.txt"))) | Give a code snippet in #NewLISP
Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
Fo... | #Bracmat | Bracmat | ( ( encode
= encoded exceptions octet string
. !arg:(?exceptions.?string)
& :?encoded
& @( !string
: ?
( %@?octet ?
& !encoded
( !octet
: ( ~<0:~>9
... | Give a code snippet in #Bracmat
Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encode... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_numbers | Perfect numbers | Write a function which says whether a number is perfect.
A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself.
Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself).
Note: The faster Luca... | #R | R | is.perf <- function(n){
if (n==0|n==1) return(FALSE)
s <- seq (1,n-1)
x <- n %% s
m <- data.frame(s,x)
out <- with(m, s[x==0])
return(sum(out)==n)
}
# Usage - Warning High Memory Usage
is.perf(28)
sapply(c(6,28,496,8128,33550336),is.perf) | Give a code snippet in #R
Write a function which says whether a number is perfect.
A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself.
Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself).
... | 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.)
| #Lilypond | Lilypond | % This is a comment
%{ This is a comment
spanning several lines %} | Give a code snippet in #Lilypond
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/Repeat_a_string | Repeat a string | Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").
Other tasks re... | #Visual_Basic | Visual Basic | Public Function StrRepeat(s As String, n As Integer) As String
Dim r As String, i As Integer
r = ""
For i = 1 To n
r = r & s
Next i
StrRepeat = r
End Function
Debug.Print StrRepeat("ha", 5) | Give a code snippet in #Visual_Basic
Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation | Horner's rule for polynomial evaluation | A fast scheme for evaluating a polynomial such as:
−
19
+
7
x
−
4
x
2
+
6
x
3
{\displaystyle -19+7x-4x^{2}+6x^{3}\,}
when
x
=
3
{\displaystyle x=3\;}
.
is to arrange the computation as follows:
(
(
(
(
0
)
x
+
6
)
x
+
(
−
4
)
)
x
+
7
)
x
+
(
−
19
)
{\displaystyle ((((0)x+6)x+(-4))x... | #E | E | def makeHornerPolynomial(coefficients :List) {
def indexing := (0..!coefficients.size()).descending()
return def hornerPolynomial(x) {
var acc := 0
for i in indexing {
acc := acc * x + coefficients[i]
}
return acc
}
} | Give a code snippet in #E
A fast scheme for evaluating a polynomial such as:
−
19
+
7
x
−
4
x
2
+
6
x
3
{\displaystyle -19+7x-4x^{2}+6x^{3}\,}
when
x
=
3
{\displaystyle x=3\;}
.
is to arrange the computation as follows:
(
(
(
(
0
)
x
+
6
)
x
+
(
−
4
)
)
x
+
7
)
x
+
(
−
19
)
{\disp... | 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... | #PL.2FI | PL/I | STOP; /* terminates the entire program */
/* PL/I does any required cleanup, such as closing files. */ | Give a code snippet in #PL.2FI
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 finalizer... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Optional_parameters | Optional parameters | Task
Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters:
ordering
A function specifying the ordering of strings; lexicographic by default.
column
... | #F.23 | F# | type Table(rows:string[][]) =
// in-place sorting of rows
member x.Sort(?ordering, ?column, ?reverse) =
let ordering = defaultArg ordering compare
let column = defaultArg column 0
let reverse = defaultArg reverse false
let factor = if reverse then -1 else 1
let comparer (row1... | Give a code snippet in #F.23
Task
Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters:
ordering
A function specifying the ordering of strings; lexi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #TXR | TXR | echo $RANDOM | Give a code snippet in #TXR
The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm ... | 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... | #Io | Io |
// rename file in current directory
f := File with("input.txt")
f moveTo("output.txt")
// rename file in root directory
f := File with("/input.txt")
f moveTo("/output.txt")
// rename directory in current directory
d := Directory with("docs")
d moveTo("mydocs")
// rename directory in root directory
d := Director... | Give a code snippet in #Io
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 right... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brilliant_numbers | Brilliant numbers | Brilliant numbers are a subset of semiprime numbers. Specifically, they are numbers that are the product of exactly two prime numbers that both have the same number of digits when expressed in base 10.
Brilliant numbers are useful in cryptography and when testing prime factoring algorithms.
E.G.
3 × 3 (9) is a bri... | #Raku | Raku | use Lingua::EN::Numbers;
# Find an abundance of primes to use to generate brilliants
my %primes = (2..100000).grep( &is-prime ).categorize: { .chars };
# Generate brilliant numbers
my @brilliant = lazy flat (1..*).map: -> $digits {
sort flat (^%primes{$digits}).race.map: { %primes{$digits}[$_] X× (flat %primes{... | Give a code snippet in #Raku
Brilliant numbers are a subset of semiprime numbers. Specifically, they are numbers that are the product of exactly two prime numbers that both have the same number of digits when expressed in base 10.
Brilliant numbers are useful in cryptography and when testing prime factoring algorithm... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Array_concatenation | Array concatenation | Task
Show how to concatenate two arrays in your language.
If this is as simple as array1 + array2, so be it.
| #Icon_and_Unicon | Icon and Unicon |
procedure main()
L1 := [1, 2, 3, 4]
L2 := [11, 12, 13, 14]
L3 := L1 ||| L2
sep := ""
every writes(sep, !L3) do
sep := ", "
write()
end
| Give a code snippet in #Icon_and_Unicon
Task
Show how to concatenate two arrays in your language.
If this is as simple as array1 + array2, so be it.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Date_manipulation | Date manipulation | Task
Given the date string "March 7 2009 7:30pm EST",
output the time 12 hours later in any human-readable format.
As extra credit, display the resulting time in a time zone different from your own.
| #Java | Java | import java.time.*;
import java.time.format.*;
class Main {
public static void main(String args[]) {
String dateStr = "March 7 2009 7:30pm EST";
DateTimeFormatter df = new DateTimeFormatterBuilder()
.parseCaseInsensitive()
.appendPattern("MMMM d yyyy h:mma zzz")
.toFormatter();
ZonedD... | Give a code snippet in #Java
Task
Given the date string "March 7 2009 7:30pm EST",
output the time 12 hours later in any human-readable format.
As extra credit, display the resulting time in a time zone different from your own.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number | Factors of a Mersenne number | A Mersenne number is a number in the form of 2P-1.
If P is prime, the Mersenne number may be a Mersenne prime
(if P is not prime, the Mersenne number is also not prime).
In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,... | #Python | Python | def is_prime(number):
return True # code omitted - see Primality by Trial Division
def m_factor(p):
max_k = 16384 / p # arbitrary limit; since Python automatically uses long's, it doesn't overflow
for k in xrange(max_k):
q = 2*p*k + 1
if not is_prime(q):
continue
elif q... | Give a code snippet in #Python
A Mersenne number is a number in the form of 2P-1.
If P is prime, the Mersenne number may be a Mersenne prime
(if P is not prime, the Mersenne number is also not prime).
In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Circular_primes | Circular primes | Definitions
A circular prime is a prime number with the property that the number generated at each intermediate step when cyclically permuting its (base 10) digits will also be prime.
For example:
1193 is a circular prime, since 1931, 9311 and 3119 are all also prime.
Note that a number which is a cyclic permutation ... | #F.23 | F# |
// Circular primes - Nigel Galloway: September 13th., 2021
let fG n g=let rec fG y=if y=g then true else if y>g && isPrime y then fG(10*(y%n)+y/n) else false in fG(10*(g%n)+g/n)
let rec fN g l=seq{let g=[for n in g do for g in [1;3;7;9] do let g=n*10+g in yield g] in yield! g|>List.filter(fun n->isPrime n && fG l n);... | Give a code snippet in #F.23
Definitions
A circular prime is a prime number with the property that the number generated at each intermediate step when cyclically permuting its (base 10) digits will also be prime.
For example:
1193 is a circular prime, since 1931, 9311 and 3119 are all also prime.
Note that a number ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_last_Sunday_of_each_month | Find the last Sunday of each month | Write a program or a script that returns the last Sundays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc).
Example of an expected output:
./last_sundays 2013
2013-01-27
2013-02-24
2013-03-31
2013-04-28
2013-05-26
2013-06-30
2013-07-28
2... | #11l | 11l | F last_sundays(year)
[String] sundays
L(month) 1..12
V last_day_of_month = I month < 12 {Time(year, month + 1)} E Time(year + 1)
L
last_day_of_month -= TimeDelta(days' 1)
I last_day_of_month.strftime(‘%w’) == ‘0’
sundays [+]= year‘-’(‘#02’.format(month))‘-’last_day_of_mon... | Give a code snippet in #11l
Write a program or a script that returns the last Sundays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc).
Example of an expected output:
./last_sundays 2013
2013-01-27
2013-02-24
2013-03-31
2013-04-28
2013-... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/String | Literals/String | Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
Here document
Other tasks r... | #Vim_Script | Vim Script | Debug.Print "Tom said, ""The fox ran away."""
Debug.Print "Tom said, 'The fox ran away.'" | Give a code snippet in #Vim_Script
Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characte... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mutual_recursion | Mutual recursion | Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n
)
=
n
−
M
(
F
(
n
−
1
)
)
,
... | #SPL | SPL | f(n)=
? n=0, <= 1
<= n-m(f(n-1))
.
m(n)=
? n=0, <= 0
<= n-f(m(n-1))
.
> i, 0..20
fs += " "+f(i)
ms += " "+m(i)
<
#.output("F:",fs)
#.output("M:",ms) | Give a code snippet in #SPL
Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n
)
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Euler%27s_sum_of_powers_conjecture | Euler's sum of powers conjecture | There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth power,
except for the trivial case... | #FreeBASIC | FreeBASIC | ' version 14-09-2015
' compile with: fbc -s console
' some constants calculated when the program is compiled
Const As UInteger max = 250
Const As ULongInt pow5_max = CULngInt(max) * max * max * max * max
' limit x1, x2, x3
Const As UInteger limit_x1 = (pow5_max / 4) ^ 0.2
Const As UInteger limit_x2 = (pow5_max / 3)... | Give a code snippet in #FreeBASIC
There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth pow... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Send_email | Send email | Task
Write a function to send an email.
The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details.
If appropriate, explain what notifications of problems/success are given.
Solutions using libraries or f... | #Ada | Ada | with AWS.SMTP, AWS.SMTP.Client, AWS.SMTP.Authentication.Plain;
with Ada.Text_IO;
use Ada, AWS;
procedure Sendmail is
Status : SMTP.Status;
Auth : aliased constant SMTP.Authentication.Plain.Credential :=
SMTP.Authentication.Plain.Initialize ("id", "password");
Isp : SMTP.Receiver;
begin
Isp :=
... | Give a code snippet in #Ada
Task
Write a function to send an email.
The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details.
If appropriate, explain what notifications of problems/success are given.
S... | 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... | #BCPL | BCPL | get "libhdr"
let gcd(m,n) = n=0 -> m, gcd(n, m rem n)
let show(m,n) be
writef("gcd(%N, %N) = %N*N", m, n, gcd(m, n))
let start() be
$( show(18,12)
show(1071,1029)
show(3528,3780)
$) | Give a code snippet in #BCPL
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Line_printer | Hello world/Line printer | Task
Cause a line printer attached to the computer to print a line containing the message: Hello World!
Note
A line printer is not the same as standard output.
A line printer was an older-style printer which prints one line at a time to a continuous ream of paper.
With some systems, a line printer can be... | #Maple | Maple | lprint("Hello World!") | Give a code snippet in #Maple
Task
Cause a line printer attached to the computer to print a line containing the message: Hello World!
Note
A line printer is not the same as standard output.
A line printer was an older-style printer which prints one line at a time to a continuous ream of paper.
With some... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_length | String length | Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters.
F... | #Ring | Ring |
aString = "Welcome to the Ring Programming Language"
aStringSize = len(aString)
see "Character lenghts : " + aStringSize
| Give a code snippet in #Ring
Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme conta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Show_ASCII_table | Show ASCII table | Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioin... | #Action.21 | Action! | PROC Main()
BYTE
count=[96],rows=[16],
first=[32],last=[127],
i,j
Put(125) ;clear screen
FOR i=0 TO rows-1
DO
Position(2,3+i)
FOR j=first+i TO last STEP rows
DO
IF j>=96 AND j<=99 THEN
Put(' )
FI
PrintB(j)
Put(' )
IF j=32 THEN
Print("... | Give a code snippet in #Action.21
Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stone... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Total_circles_area | Total circles area | Total circles area
You are encouraged to solve this task according to the task description, using any language you may know.
Example circles
Example circles filtered
Given some partially overlapping circles on the plane, compute and show the total area covered by them, with four or six (or a little more) decimal dig... | #Java | Java |
public class CirclesTotalArea {
/*
* Rectangles are given as 4-element arrays [tx, ty, w, h].
* Circles are given as 3-element arrays [cx, cy, r].
*/
private static double distSq(double x1, double y1, double x2, double y2) {
return (x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1);
... | Give a code snippet in #Java
Total circles area
You are encouraged to solve this task according to the task description, using any language you may know.
Example circles
Example circles filtered
Given some partially overlapping circles on the plane, compute and show the total area covered by them, with four or six ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Julia_set | Julia set |
Task
Generate and draw a Julia set.
Related tasks
Mandelbrot Set
| #AWK | AWK |
# syntax: GAWK -f JULIA_SET.AWK [real imaginary]
BEGIN {
c_real = (ARGV[1] != "") ? ARGV[1] : -0.8
c_imaginary = (ARGV[2] != "") ? ARGV[2] : 0.156
printf("%s %s\n",c_real,c_imaginary)
for (v=-100; v<=100; v+=10) {
for (h=-280; h<=280; h+=10) {
x = h / 200
y = v / 100
... | Give a code snippet in #AWK
Task
Generate and draw a Julia set.
Related tasks
Mandelbrot Set
| christopher/rosetta-code | |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial ... | #Haskell | Haskell | expand p = scanl (\z i -> z * (p-i+1) `div` i) 1 [1..p]
test p | p < 2 = False
| otherwise = and [mod n p == 0 | n <- init . tail $ expand p]
printPoly [1] = "1"
printPoly p = concat [ unwords [pow i, sgn (l-i), show (p!!(i-1))]
| i <- [l-1,l-2..1] ] where
l = length p
... | Give a code snippet in #Haskell
The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #AutoHotkey | AutoHotkey | FileRead, quine, %A_ScriptFullPath%
MsgBox % quine | Give a code snippet in #AutoHotkey
A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer progr... | 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... | #VBA | VBA | Dim coll As New Collection
coll.Add "apple"
coll.Add "banana" | Give a code snippet in #VBA
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
Crea... | christopher/rosetta-code | |
http://rosettacode.org/wiki/First_class_environments | First class environments | According to Wikipedia, "In computing, a first-class object ... is an entity that can be constructed at run-time, passed as a parameter, returned from a subroutine, or assigned into a variable".
Often this term is used in the context of "first class functions". In an analogous way, a programming language may support "... | #Erlang | Erlang | Note that using the Process Dictionary:
Destroys referencial transparency
Makes debugging difficult
Survives Catch/Throw
| Give a code snippet in #Erlang
According to Wikipedia, "In computing, a first-class object ... is an entity that can be constructed at run-time, passed as a parameter, returned from a subroutine, or assigned into a variable".
Often this term is used in the context of "first class functions". In an analogous way, a pr... | 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... | #Batch_File | Batch File |
@echo off & setlocal enabledelayedexpansion
:: Binary Chop Algorithm - Michael Sanders 2017
::
:: example output...
::
:: binary chop algorithm vs. standard for loop
::
:: number to find 941
:: for loop required 941 iterations
:: binchop required 10 iterations
:setup
set x=1
set y=999
set /a z=(%random... | Give a code snippet in #Batch_File
A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a sec... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generate_lower_case_ASCII_alphabet | Generate lower case ASCII alphabet | Task
Generate an array, list, lazy sequence, or even an indexable string of all the lower case ASCII characters, from a to z. If the standard library contains such a sequence, show how to access it, but don't fail to show how to generate a similar sequence.
For this basic task use a reliable style of coding, a sty... | #MATLAB_.2F_Octave | MATLAB / Octave | 'a':'z' | Give a code snippet in #MATLAB_.2F_Octave
Task
Generate an array, list, lazy sequence, or even an indexable string of all the lower case ASCII characters, from a to z. If the standard library contains such a sequence, show how to access it, but don't fail to show how to generate a similar sequence.
For this basic... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CSV_data_manipulation | CSV data manipulation | CSV spreadsheet files are suitable for storing tabular data in a relatively portable way.
The CSV format is flexible but somewhat ill-defined.
For present purposes, authors may assume that the data fields contain no commas, backslashes, or quotation marks.
Task
Read a CSV file, change some values and save the cha... | #F.23 | F# | open System.IO
[<EntryPoint>]
let main _ =
let input = File.ReadAllLines "test_in.csv"
let output =
input
|> Array.mapi (fun i line ->
if i = 0 then line + ",SUM"
else
let sum = Array.sumBy int (line.Split(','))
sprintf "%s,%i" line su... | Give a code snippet in #F.23
CSV spreadsheet files are suitable for storing tabular data in a relatively portable way.
The CSV format is flexible but somewhat ill-defined.
For present purposes, authors may assume that the data fields contain no commas, backslashes, or quotation marks.
Task
Read a CSV file, chang... | 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 ... | #Ursala | Ursala | #import std
#import nat
iterative_fib = ~&/(0,1); ~&r->ll ^|\predecessor ^/~&r sum
recursive_fib = {0,1}^?<a/~&a sum^|W/~& predecessor^~/~& predecessor
analytical_fib =
%np+ -+
mp..round; ..mp2str; sep`+; ^CNC/~&hh take^\~&htt %np@t,
(mp..div^|\~& mp..sub+ ~~ @rlX mp..pow_ui)^lrlPGrrPX/~& -+
^\~& ^(... | Give a code snippet in #Ursala
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 ar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_Machin-like_formulas | Check Machin-like formulas | Machin-like formulas are useful for efficiently computing numerical approximations for
π
{\displaystyle \pi }
Task
Verify the following Machin-like formulas are correct by calculating the value of tan (right hand side) for each equation using exact arithmetic and showing they equal 1:
π
4
=
ar... | #Nim | Nim | import bignum
type
# Description of a term.
Term = object
factor: int # Multiplier (may be negative).
fract: Rat # Argument of arc tangent.
Expression = seq[Term]
# Rational 1.
let One = newRat(1)
##########################################################################################... | Give a code snippet in #Nim
Machin-like formulas are useful for efficiently computing numerical approximations for
π
{\displaystyle \pi }
Task
Verify the following Machin-like formulas are correct by calculating the value of tan (right hand side) for each equation using exact arithmetic and showing the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Problem_of_Apollonius | Problem of Apollonius |
Task
Implement a solution to the Problem of Apollonius (description on Wikipedia) which is the problem of finding the circle that is tangent to three specified circles (colored black in the diagram below to the right).
There is an algebraic solution which is pretty straightforward.
The solutions to the ... | #C.23 | C# |
using System;
namespace ApolloniusProblemCalc
{
class Program
{
static float rs = 0;
static float xs = 0;
static float ys = 0;
public static void Main(string[] args)
{
float gx1;
float gy1;
float gr1;
float gx2;
... | Give a code snippet in #C.23
Task
Implement a solution to the Problem of Apollonius (description on Wikipedia) which is the problem of finding the circle that is tangent to three specified circles (colored black in the diagram below to the right).
There is an algebraic solution which is pretty straightfor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reflection/List_properties | Reflection/List properties | Task
The goal is to get the properties of an object, as names, values or both.
Some languages support dynamic properties, which in general can only be inspected if a class' public API includes a way of listing them.
| #Fortran | Fortran | package main
import (
"fmt"
"image"
"reflect"
)
// A type definition
type t struct {
X int
next *t
}
func main() {
report(t{})
report(image.Point{})
}
func report(x interface{}) {
t := reflect.TypeOf(x)
n := t.NumField()
fmt.Printf("Type %v has %d fields:\n", t, n)
fmt.Println("Name Type E... | Give a code snippet in #Fortran
Task
The goal is to get the properties of an object, as names, values or both.
Some languages support dynamic properties, which in general can only be inspected if a class' public API includes a way of listing them.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Fork | Fork | Task
Spawn a new process which can run simultaneously with, and independently of, the original parent process.
| #Java | Java |
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
public class RFork {
public static void main(String[] args) {
ProcessBuilder pb;
Process pp;
List<String> command;
Map<String, String... | Give a code snippet in #Java
Task
Spawn a new process which can run simultaneously with, and independently of, the original parent process.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Pancake_sort | Sorting algorithms/Pancake sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols nobinary
import java.util.List
runSample(arg)
return
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
method pancakeSort(tlist = List, debug = (1 == 0)) private static returns List
if tlist.size() > 1 then do
... | Give a code snippet in #NetRexx
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_that_file_exists | Check that file exists | Task
Verify that a file called input.txt and a directory called docs exist.
This should be done twice:
once for the current working directory, and
once for a file and a directory in the filesystem root.
Optional criteria (May 2015): verify it works with:
zero-length files
an ... | #Klingphix | Klingphix | include ..\Utilitys.tlhy
"foo.bar" "w" fopen
"Hallo !" over fputs
fclose
"fou.bar" "r" fopen
dup 0 < ( ["Could not open 'fou.bar' for reading" print drop] [fclose] ) if
" " input | Give a code snippet in #Klingphix
Task
Verify that a file called input.txt and a directory called docs exist.
This should be done twice:
once for the current working directory, and
once for a file and a directory in the filesystem root.
Optional criteria (May 2015): verify it works... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Circles_of_given_radius_through_two_points | Circles of given radius through two points |
Given two points on a plane and a radius, usually two circles of given radius can be drawn through the points.
Exceptions
r==0.0 should be treated as never describing circles (except in the case where the points are coincident).
If the points are coincident then an infinite number of circles with the point on thei... | #J | J | average =: +/ % #
circles =: verb define"1
'P0 P1 R' =. (j./"1)_2[\y NB. Use complex plane
C =. P0 average@:, P1
BAD =: ":@:+. C
SEPARATION =. P0 |@- P1
if. 0 = SEPARATION do.
if. 0 = R do. 'Degenerate point at ' , BAD
else. 'Any center at a distance ' , (":R) , ' from ' , BAD , ' works.'
end.
elseif. SEP... | Give a code snippet in #J
Given two points on a plane and a radius, usually two circles of given radius can be drawn through the points.
Exceptions
r==0.0 should be treated as never describing circles (except in the case where the points are coincident).
If the points are coincident then an infinite number of cir... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Langton%27s_ant | Langton's ant | Langton's ant is a cellular automaton that models an ant sitting on a plane of cells, all of which are white initially, the ant facing in one of four directions.
Each cell can either be black or white.
The ant moves according to the color of the cell it is currently sitting in, with the following rules:
If the ce... | #VBA | VBA |
Option Explicit
Sub Ant()
Dim TablDatas(1 To 200, 1 To 256) As String, sDir As String, sFile As String, Str As String
Dim ColA As Integer, LigA As Long, ColF As Integer, LigF As Long, i As Long, j As Integer, Num As Long
Dim Top As Boolean, Left As Boolean, Bottom As Boolean, Right As Boolean
'init variables
... | Give a code snippet in #VBA
Langton's ant is a cellular automaton that models an ant sitting on a plane of cells, all of which are white initially, the ant facing in one of four directions.
Each cell can either be black or white.
The ant moves according to the color of the cell it is currently sitting in, with the f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring | Substring |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Axe | Axe | Lbl SUB1
0→{r₁+r₂+r₃}
r₁+r₂
Return
Lbl SUB2
r₁+r₂
Return
Lbl SUB3
0→{r₁+length(r₁)-1}
r₁
Return
Lbl SUB4
inData(r₂,r₁)-1→I
0→{r₁+I+r₃}
r₁+I
Return | Give a code snippet in #Axe
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/JortSort | JortSort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Crystal | Crystal | def jort_sort(array)
array == array.sort
end | Give a code snippet in #Crystal
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Write_a_PPM_file | Bitmap/Write a PPM file | Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| #Aime | Aime | integer i, h, j, w;
file f;
w = 640;
h = 320;
f.create("out.ppm", 00644);
f.form("P6\n~ ~\n255\n", w, h);
j = 0;
do {
srand(j >> 4);
i = 0;
do {
16.times(f_bytes, f, drand(255), drand(255), drand(255));
} while ((i += 16) < w);
} while ((j += 1) < h); | Give a code snippet in #Aime
Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Logical_operations | Logical operations |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Fortran | Fortran | SUBROUTINE PRNLOG(A, B)
LOGICAL A, B
PRINT *, 'a and b is ', A .AND. B
PRINT *, 'a or b is ', A .OR. B
PRINT *, 'not a is ', .NOT. A
C You did not ask, but the following logical operators are also standard
C since ANSI FORTRAN 66
C ================================... | Give a code snippet in #Fortran
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #PureBasic | PureBasic | Procedure isDirEmpty(path$)
If Right(path$, 1) <> "\": path$ + "\": EndIf
Protected dirID = ExamineDirectory(#PB_Any, path$, "*.*")
Protected result
If dirID
result = 1
While NextDirectoryEntry(dirID)
If DirectoryEntryType(dirID) = #PB_DirectoryEntry_File Or (DirectoryEntryName(dirID) <> "." And... | Give a code snippet in #PureBasic
Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root | Digital root/Multiplicative digital root | The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
{\displaystyle i}
to
0
... | #Ruby | Ruby | def mdroot(n)
mdr, persist = n, 0
until mdr < 10 do
mdr = mdr.digits.inject(:*)
persist += 1
end
[mdr, persist]
end
puts "Number: MDR MP", "====== === =="
[123321, 7739, 893, 899998].each{|n| puts "%6d: %d %2d" % [n, *mdroot(n)]}
counter = Hash.new{|h,k| h[k]=[]}
0.step do |i|
counter[mdroot... | Give a code snippet in #Ruby
The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
{... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Phix | Phix | -- demo\rosetta\BrownianTree.exw
include pGUI.e
Ihandle dlg, canvas
cdCanvas cddbuffer, cdcanvas
function redraw_cb(Ihandle /*ih*/, integer /*posx*/, integer /*posy*/)
integer x,y,ox,oy
integer {width, height} = IupGetIntInt(canvas, "DRAWSIZE")
sequence grid = repeat(repeat(0,width),height)
integer xy = floor(width... | Give a code snippet in #Phix
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... | christopher/rosetta-code |
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