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... | #Yabasic | Yabasic |
REM *** By changing the key and pattern, an encryption system that is difficult to break can be achieved. ***
text$ = "You are encouraged to solve this task according to the task description, using any language you may know."
key$ = "desoxirribonucleic acid" // With a single character you get a Caesar encryption. W... | Give a code snippet in #Yabasic
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truncate_a_file | Truncate a file | Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by creating a temporary file of a reduced... | #Powershell | Powershell | Function Truncate-File(fname) {
$null | Set-Content -Path "$fname"
}
| Give a code snippet in #Powershell
Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by cr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Globally_replace_text_in_several_files | Globally replace text in several files | Task
Replace every occurring instance of a piece of text in a group of text files with another one.
For this task we want to replace the text "Goodbye London!" with "Hello New York!" for a list of files.
| #XPL0 | XPL0 | include c:\cxpl\codes; \intrinsic 'code' declarations
string 0; \use zero-terminated strings
func StrLen(A); \Return number of characters in an ASCIIZ string
char A;
int I;
for I:= 0 to -1>>1-1 do
if A(I) = 0 then return I;
func StrFind(A, B); \Search ... | Give a code snippet in #XPL0
Task
Replace every occurring instance of a piece of text in a group of text files with another one.
For this task we want to replace the text "Goodbye London!" with "Hello New York!" for a list of files.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Ukkonen%E2%80%99s_suffix_tree_construction | Ukkonen’s suffix tree construction | Suffix Trees are very useful in numerous string processing and computational biology problems.
The task is to create a function which implements Ukkonen’s algorithm to create a useful Suffix Tree as described:
Part 1
Part 2
Part 3
Part 4
Part 5
Part 6
Using Arithmetic-geometric mean/Calculate Pi generate the first 1... | #Wren | Wren | import "/big" for BigRat
import "/dynamic" for Struct
import "/trait" for ByRef
import "io" for File
var maxChar = 128
var Node = Struct.create("Node", ["children", "suffixLink", "start", "pEnd", "suffixIndex"])
var text = ""
var root = null
var lastNewNode = null
var acti... | Give a code snippet in #Wren
Suffix Trees are very useful in numerous string processing and computational biology problems.
The task is to create a function which implements Ukkonen’s algorithm to create a useful Suffix Tree as described:
Part 1
Part 2
Part 3
Part 4
Part 5
Part 6
Using Arithmetic-geometric mean/Cal... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Median | Averages/Median | Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.
There are several approaches ... | #BBC_BASIC | BBC BASIC | INSTALL @lib$+"SORTLIB"
Sort% = FN_sortinit(0,0)
DIM a(6), b(5)
a() = 4.1, 5.6, 7.2, 1.7, 9.3, 4.4, 3.2
b() = 4.1, 7.2, 1.7, 9.3, 4.4, 3.2
PRINT "Median of a() is " ; FNmedian(a())
PRINT "Median of b() is " ; FNmedian(b())
END
DEF FNmedian(a())
LOCAL C%
... | Give a code snippet in #BBC_BASIC
Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle val... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pick_random_element | Pick random element | Demonstrate how to pick a random element from a list.
| #Elixir | Elixir | iex(1)> list = Enum.to_list(1..20)
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20]
iex(2)> Enum.random(list)
19
iex(3)> Enum.take_random(list,4)
[19, 20, 7, 15] | Give a code snippet in #Elixir
Demonstrate how to pick a random element from a list.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Cursor_positioning | Terminal control/Cursor positioning |
Task
Move the cursor to column 3, row 6, and display the word "Hello" (without the quotes), so that the letter H is in column 3 on row 6.
| #Scala | Scala | object Main extends App {
print("\u001Bc") // clear screen first
println("\u001B[6;3HHello")
} | Give a code snippet in #Scala
Task
Move the cursor to column 3, row 6, and display the word "Hello" (without the quotes), so that the letter H is in column 3 on row 6.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Subtractive_generator | Subtractive generator | A subtractive generator calculates a sequence of random numbers, where each number is congruent to the subtraction of two previous numbers from the sequence.
The formula is
r
n
=
r
(
n
−
i
)
−
r
(
n
−
j
)
(
mod
m
)
{\displaystyle r_{n}=r_{(n-i)}-r_{(n-j)}{\pmod {m}}}
for some fixed values of... | #Tcl | Tcl | package require Tcl 8.5
namespace eval subrand {
variable mod 1000000000 state [lrepeat 55 0] si 0 sj 0
proc seed p1 {
global subrand::mod subrand::state subrand::si subrand::sj
set p2 1
lset state 0 [expr {$p1 % $mod}]
for {set i 1; set j 21} {$i < 55} {incr i; incr j 21} {
if {$j >= 55} {incr j -55... | Give a code snippet in #Tcl
A subtractive generator calculates a sequence of random numbers, where each number is congruent to the subtraction of two previous numbers from the sequence.
The formula is
r
n
=
r
(
n
−
i
)
−
r
(
n
−
j
)
(
mod
m
)
{\displaystyle r_{n}=r_{(n-i)}-r_{(n-j)}{\pmod {m}... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Get_system_command_output | Get system command output | Task
Execute a system command and get its output into the program. The output may be stored in any kind of collection (array, list, etc.).
Related task
Execute a system command
| #PowerShell | PowerShell |
[string[]]$volume = cmd /c vol
$volume
| Give a code snippet in #PowerShell
Task
Execute a system command and get its output into the program. The output may be stored in any kind of collection (array, list, etc.).
Related task
Execute a system command
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Hailstone_sequence | Hailstone sequence | The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
The (unproven) Collatz conje... | #MATLAB_.2F_Octave | MATLAB / Octave | function x = hailstone(n)
x = n;
while n > 1
% faster than mod(n, 2)
if n ~= floor(n / 2) * 2
n = n * 3 + 1;
else
n = n / 2;
end
x(end + 1) = n; %#ok
end | Give a code snippet in #MATLAB_.2F_Octave
The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Narcissistic_decimal_number | Narcissistic decimal number | A Narcissistic decimal number is a non-negative integer,
n
{\displaystyle n}
, that is equal to the sum of the
m
{\displaystyle m}
-th powers of each of the digits in the decimal representation of
n
{\displaystyle n}
, where
m
{\displaystyle m}
is the number of digits in... | #Common_Lisp | Common Lisp |
(defun integer-to-list (n)
(map 'list #'digit-char-p (prin1-to-string n)))
(defun narcissisticp (n)
(let* ((lst (integer-to-list n))
(e (length lst)))
(= n
(reduce #'+ (mapcar (lambda (x) (expt x e)) lst)))))
(defun start ()
(loop for c from 0
while (< narcissistic 25)
c... | Give a code snippet in #Common_Lisp
A Narcissistic decimal number is a non-negative integer,
n
{\displaystyle n}
, that is equal to the sum of the
m
{\displaystyle m}
-th powers of each of the digits in the decimal representation of
n
{\displaystyle n}
, where
m
{\displayst... | 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... | #uBasic.2F4tH | uBasic/4tH | if set (a, open ("yourcsv.csv", "r")) < 0 then
print "Cannot open \qyourcsv.csv\q" ' open file a for reading
end ' abort on file opening errors
endif
if set (b, open ("mycsv.csv", "w")) < 0 then
print "Cannot open \qmycsv.csv\q" ' open file a for writing
end ... | Give a code snippet in #uBasic.2F4tH
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 fil... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Element_insertion | Doubly-linked list/Element insertion | Doubly-Linked List (element)
This is much like inserting into a Singly-Linked List, but with added assignments so that the backwards-pointing links remain correct.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element inse... | #J | J | (pred;succ;<data) conew 'DoublyLinkedListElement'
| Give a code snippet in #J
Doubly-Linked List (element)
This is much like inserting into a Singly-Linked List, but with added assignments so that the backwards-pointing links remain correct.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Eleme... | 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... | #Scala | Scala |
object StringLength extends App {
val s1 = "møøse"
val s3 = List("\uD835\uDD18", "\uD835\uDD2B", "\uD835\uDD26",
"\uD835\uDD20", "\uD835\uDD2C", "\uD835\uDD21", "\uD835\uDD22").mkString
val s4 = "J\u0332o\u0332s\u0332e\u0301\u0332"
List(s1, s3, s4).foreach(s => println(
s"The string: $s, chara... | Give a code snippet in #Scala
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 cont... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Twelve_statements | Twelve statements | This puzzle is borrowed from math-frolic.blogspot.
Given the following twelve statements, which of them are true?
1. This is a numbered list of twelve statements.
2. Exactly 3 of the last 6 statements are true.
3. Exactly 2 of the even-numbered statements are true.
4. If statement 5 is true, then statemen... | #Common_Lisp | Common Lisp |
(defparameter *state* (make-list 12))
(defparameter *statements* '(t ; 1
(= (count-true '(7 8 9 10 11 12)) 3) ; 2
(= (count-true '(2 4 6 8 10 12)) 2) ; 3
... | Give a code snippet in #Common_Lisp
This puzzle is borrowed from math-frolic.blogspot.
Given the following twelve statements, which of them are true?
1. This is a numbered list of twelve statements.
2. Exactly 3 of the last 6 statements are true.
3. Exactly 2 of the even-numbered statements are true.
4. ... | 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 ... | #Phix | Phix | with javascript_semantics
include mpfr.e
procedure multi_order(mpz res, a, sequence p_and_k)
mpz {pk,t,x,q,pz} = mpz_inits(5)
mpz_set_si(res,1)
if length(p_and_k)=1 then
string {ps} = p_and_k
mpz_set_str(pk,ps)
mpz_sub_ui(t,pk,1)
else
atom {p, k} = p_and_k
mpz_s... | Give a code snippet in #Phix
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 effici... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Text_processing/Max_licenses_in_use | Text processing/Max licenses in use | A company currently pays a fixed sum for the use of a particular licensed software package. In determining if it has a good deal it decides to calculate its maximum use of the software from its license management log file.
Assume the software's licensing daemon faithfully records a checkout event when a copy of the ... | #Factor | Factor | USING: kernel sequences splitting math accessors io.encodings.ascii
io.files math.parser io ;
IN: maxlicenses
TUPLE: maxlicense max-count current-count times ;
<PRIVATE
: <maxlicense> ( -- max ) -1 0 V{ } clone \ maxlicense boa ; inline
: out? ( line -- ? ) [ "OUT" ] dip subseq? ; inline
: line-time ( line --... | Give a code snippet in #Factor
A company currently pays a fixed sum for the use of a particular licensed software package. In determining if it has a good deal it decides to calculate its maximum use of the software from its license management log file.
Assume the software's licensing daemon faithfully records a ch... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pentagram | Pentagram |
A pentagram is a star polygon, consisting of a central pentagon of which each side forms the base of an isosceles triangle. The vertex of each triangle, a point of the star, is 36 degrees.
Task
Draw (or print) a regular pentagram, in any orientation. Use a different color (or token) for stroke and fill, and backg... | #Action.21 | Action! | INCLUDE "D2:REAL.ACT" ;from the Action! Tool Kit
DEFINE REALPTR="CARD"
TYPE PointR=[REALPTR x,y]
INT ARRAY SinTab=[
0 4 9 13 18 22 27 31 36 40 44 49 53 58 62 66 71 75 79 83
88 92 96 100 104 108 112 116 120 124 128 132 136 139 143
147 150 154 158 161 165 168 171 175 178 181 184 187 190
193 196 199 202 204 20... | Give a code snippet in #Action.21
A pentagram is a star polygon, consisting of a central pentagon of which each side forms the base of an isosceles triangle. The vertex of each triangle, a point of the star, is 36 degrees.
Task
Draw (or print) a regular pentagram, in any orientation. Use a different color (or to... | christopher/rosetta-code | |
http://rosettacode.org/wiki/99_bottles_of_beer | 99 bottles of beer | Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one dow... | #Malbolge | Malbolge | b'`;$9!=IlXFiVwwvtPO0)pon%IHGFDV|dd@Q=+^:('&Y$#m!1S|.QOO=v('98$65aCB}0i.Tw+QPU'7qK#I20jiDVgG
S(bt<%@#!7~|4{y1xv.us+rp(om%lj"ig}fd"cx``uz]rwvYnslkTonPfOjiKgJeG]\EC_X]@[Z<R;VU7S6QP2N1LK-I
,GF(D'BA#?>7~;:9y16w43s10)p-,l*#(i&%e#d!~``{tyxZpuXsrTTongOkdMhg`Hd]ba`_^W@[ZYXW9UNSRQPOHMLK
J-++FE''<A$?>=<;:387xw43s10/(-&m*)('&}${d... | Give a code snippet in #Malbolge
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
... | 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... | #Go | Go | package main
import (
"fmt"
"io/ioutil"
"log"
)
func main() {
empty, err := IsEmptyDir("/tmp")
if err != nil {
log.Fatalln(err)
}
if empty {
fmt.Printf("/tmp is empty\n")
} else {
fmt.Printf("/tmp is not empty\n")
}
}
func IsEmptyDir(name string) (bool, error) {
entries, err := ioutil.ReadDir(name... | Give a code snippet in #Go
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Miller%E2%80%93Rabin_primality_test | Miller–Rabin primality test |
This page uses content from Wikipedia. The original article was at Miller–Rabin primality test. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The Miller–Rabin primality test or Rabin–Miller prima... | #Smalltalk | Smalltalk | Integer extend [
millerRabinTest: kl [ |k| k := kl.
self <= 3
ifTrue: [ ^true ]
ifFalse: [
(self even)
ifTrue: [ ^false ]
ifFalse: [ |d s|
d := self - 1.
s := 0.
[ (d rem: 2) == 0 ]
whileTrue: [
... | Give a code snippet in #Smalltalk
This page uses content from Wikipedia. The original article was at Miller–Rabin primality test. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The Miller–Rabin p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_comments_from_a_string | Strip comments from a string | Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line.
Whitespace debacle: There is s... | #Icon_and_Unicon | Icon and Unicon | # strip_comments:
# return part of string up to first character in 'markers',
# or else the whole string if no comment marker is present
procedure strip_comments (str, markers)
return str ? tab(upto(markers) | 0)
end
procedure main ()
write (strip_comments ("apples, pears and bananas", cset ("#;")))
write (... | Give a code snippet in #Icon_and_Unicon
Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Order_by_pair_comparisons | Order by pair comparisons |
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
... | #Commodore_BASIC | Commodore BASIC | 100 REM SORT BY COMPARISON
110 DIM IN$(6), OU$(6)
120 FOR I=0 TO 6:READ IN$(I): NEXT I
130 DATA VIOLET,RED,GREEN,INDIGO,BLUE,YELLOW,ORANGE
140 OU$(0)=IN$(0):N=1
150 FOR I=1 TO 6
160 : IN$=IN$(I)
180 : GOSUB 390
190 : FOR J=0 TO N-1
200 : OU$ = OU$(J)
210 : GOSUB 340
220 : IF R>=0 THEN 280
230 : FOR K=N TO J+1 STEP ... | Give a code snippet in #Commodore_BASIC
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 ... | 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... | #ChucK | ChucK |
"Hello" => string A;
A + " World!" => string B;
<<< B >>>;
| Give a code snippet in #ChucK
String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another string lit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial | Factorial | Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a number.
Solutions can be iterat... | #PureBasic | PureBasic | Procedure factorial(n)
Protected i, f = 1
For i = 2 To n
f = f * i
Next
ProcedureReturn f
EndProcedure | Give a code snippet in #PureBasic
Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Miller%E2%80%93Rabin_primality_test | Miller–Rabin primality test |
This page uses content from Wikipedia. The original article was at Miller–Rabin primality test. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The Miller–Rabin primality test or Rabin–Miller prima... | #Tcl | Tcl | package require Tcl 8.5
proc miller_rabin {n k} {
if {$n <= 3} {return true}
if {$n % 2 == 0} {return false}
# write n - 1 as 2^s·d with d odd by factoring powers of 2 from n − 1
set d [expr {$n - 1}]
set s 0
while {$d % 2 == 0} {
set d [expr {$d / 2}]
incr s
}
whil... | Give a code snippet in #Tcl
This page uses content from Wikipedia. The original article was at Miller–Rabin primality test. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The Miller–Rabin primali... | 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... | #Perl | Perl | perl -n -0777 -e 'print "file len: ".length' stuff.txt | Give a code snippet in #Perl
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 increm... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the f... | #Sidef | Sidef | func fib(n) {
return NaN if (n < 0)
func (n) {
n < 2 ? n
: (__FUNC__(n-1) + __FUNC__(n-2))
}(n)
} | Give a code snippet in #Sidef
While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwant... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Amb | Amb | Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton").
The Amb operator takes a v... | #AutoHotkey | AutoHotkey | set1 := "the that a"
set2 := "frog elephant thing"
set3 := "walked treaded grows"
set4 := "slowly quickly"
MsgBox % amb( "", set1, set2, set3, set4 )
; this takes a total of 17 iterations to complete
amb( char = "", set1 = "", set2 = "", set3 = "", set4 = "" )
{ ; original call to amb must leave char param b... | Give a code snippet in #AutoHotkey
Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite auto... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #Action.21 | Action! | PROC CheckIsEmpty(CHAR ARRAY s)
PrintF("'%S' is empty? ",s)
IF s(0)=0 THEN
PrintE("True")
ELSE
PrintE("False")
FI
RETURN
PROC Main()
CHAR ARRAY str1,str2
str1=""
str2="text"
CheckIsEmpty(str1)
CheckIsEmpty(str2)
RETURN | Give a code snippet in #Action.21
Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Verify_distribution_uniformity/Chi-squared_test | Verify distribution uniformity/Chi-squared test | Task
Write a function to verify that a given distribution of values is uniform by using the
χ
2
{\displaystyle \chi ^{2}}
test to see if the distribution has a likelihood of happening of at least the significance level (conventionally 5%).
The function should return a boolean that is true if the distribut... | #VBA | VBA | Private Function Test4DiscreteUniformDistribution(ObservationFrequencies() As Variant, Significance As Single) As Boolean
'Returns true if the observed frequencies pass the Pearson Chi-squared test at the required significance level.
Dim Total As Long, Ei As Long, i As Integer
Dim ChiSquared As Double, Degr... | Give a code snippet in #VBA
Task
Write a function to verify that a given distribution of values is uniform by using the
χ
2
{\displaystyle \chi ^{2}}
test to see if the distribution has a likelihood of happening of at least the significance level (conventionally 5%).
The function should return a boolean ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exponentiation_operator | Exponentiation operator | Most programming languages have a built-in implementation of exponentiation.
Task
Re-implement integer exponentiation for both intint and floatint as both a procedure, and an operator (if your language supports operator definition).
If the language supports operator (or procedure) overloading, then an ov... | #ZX_Spectrum_Basic | ZX Spectrum Basic | 10 PRINT e(3,2): REM 3 ^ 2
20 PRINT e(1.5,2.7): REM 1.5 ^ 2.7
30 STOP
9950 DEF FN e(a,b)=a^b | Give a code snippet in #ZX_Spectrum_Basic
Most programming languages have a built-in implementation of exponentiation.
Task
Re-implement integer exponentiation for both intint and floatint as both a procedure, and an operator (if your language supports operator definition).
If the language supports oper... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cyclops_numbers | Cyclops numbers | A cyclops number is a number with an odd number of digits that has a zero in the center, but nowhere else. They are named so in tribute to the one eyed giants Cyclops from Greek mythology.
Cyclops numbers can be found in any base. This task strictly is looking for cyclops numbers in base 10.
There are many different ... | #Raku | Raku | use Lingua::EN::Numbers;
my @cyclops = 0, |flat lazy ^∞ .map: -> $exp {
my @oom = (exp($exp, 10) ..^ exp($exp + 1, 10)).grep: { !.contains: 0 }
|@oom.hyper.map: { $_ ~ 0 «~« @oom }
}
my @prime-cyclops = @cyclops.grep: { .is-prime };
for '', @cyclops,
'prime ', @prime-... | Give a code snippet in #Raku
A cyclops number is a number with an odd number of digits that has a zero in the center, but nowhere else. They are named so in tribute to the one eyed giants Cyclops from Greek mythology.
Cyclops numbers can be found in any base. This task strictly is looking for cyclops numbers in base ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Infinity | Infinity | Task
Write a function which tests if infinity is supported for floating point numbers (this step should be omitted for languages where the language specification already demands the existence of infinity, e.g. by demanding IEEE numbers), and if so, returns positive infinity. Otherwise, return the largest possible po... | #Slate | Slate | PositiveInfinity | Give a code snippet in #Slate
Task
Write a function which tests if infinity is supported for floating point numbers (this step should be omitted for languages where the language specification already demands the existence of infinity, e.g. by demanding IEEE numbers), and if so, returns positive infinity. Otherwise,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knuth_shuffle | Knuth shuffle | The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array.
Task
Implement the Knuth shuffle for an integer array (or, if possible, an array of any type).
Specification
Given an array items with indices ranging from 0 to last, the algorithm can be d... | #ACL2 | ACL2 | :set-state-ok t
(defun array-swap (name array i j)
(let ((ai (aref1 name array i))
(aj (aref1 name array j)))
(aset1 name
(aset1 name array j ai)
i aj)))
(defun shuffle-r (name array m state)
(if (zp m)
(mv array state)
(mv-let (i state)
(r... | Give a code snippet in #ACL2
The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array.
Task
Implement the Knuth shuffle for an integer array (or, if possible, an array of any type).
Specification
Given an array items with indices ranging from 0 t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Operator_precedence | Operator precedence |
This page uses content from Wikipedia. The original article was at Operators in C and C++. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Provide a list of precedence and associativity... | #PicoLisp | PicoLisp | q)3*2+1
9
q)(3*2)+1 / Brackets give the usual order of precedence
7
q)x:5
q)(x+5; x:20; x-5)
25 20 0 | Give a code snippet in #PicoLisp
This page uses content from Wikipedia. The original article was at Operators in C and C++. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Provide a list of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Closest-pair_problem | Closest-pair problem |
This page uses content from Wikipedia. The original article was at Closest pair of points problem. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Provide a function to find the closest two p... | #Java | Java | import java.util.*;
public class ClosestPair
{
public static class Point
{
public final double x;
public final double y;
public Point(double x, double y)
{
this.x = x;
this.y = y;
}
public String toString()
{ return "(" + x + ", " + y + ")"; }
}
public static cl... | Give a code snippet in #Java
This page uses content from Wikipedia. The original article was at Closest pair of points problem. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Provide a func... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable_size/Get | Variable size/Get | Demonstrate how to get the size of a variable.
See also: Host introspection
| #Scala | Scala | def nBytes(x: Double) = ((Math.log(x) / Math.log(2) + 1e-10).round + 1) / 8
val primitives: List[(Any, Long)] =
List((Byte, Byte.MaxValue),
(Short, Short.MaxValue),
(Int, Int.MaxValue),
(Long, Long.MaxValue))
primitives.foreach(t => println(f"A Scala ${t._1.toString.drop(13)}%-5s has ${n... | Give a code snippet in #Scala
Demonstrate how to get the size of a variable.
See also: Host introspection
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Primality_by_trial_division | Primality by trial division | Task
Write a boolean function that tells whether a given integer is prime.
Remember that 1 and all non-positive numbers are not prime.
Use trial division.
Even numbers greater than 2 may be eliminated right away.
A loop from 3 to √ n will suffice, but other loops are allowed.
Related tasks
... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref savelog symbols nobinary
parse arg nbr rangeBegin rangeEnd .
if nbr = '' | nbr = '.' then do
if rangeBegin = '' | rangeBegin = '.' then rangeBegin = 1
if rangeEnd = '' | rangeEnd = '.' then rangeEnd = 100
if rangeEnd > rangeBegin then directi... | Give a code snippet in #NetRexx
Task
Write a boolean function that tells whether a given integer is prime.
Remember that 1 and all non-positive numbers are not prime.
Use trial division.
Even numbers greater than 2 may be eliminated right away.
A loop from 3 to √ n will suffice, but other loo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multifactorial | Multifactorial | The factorial of a number, written as
n
!
{\displaystyle n!}
, is defined as
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(1)}
.
Multifactorials generalize factorials as follows:
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(... | #uBasic.2F4tH | uBasic/4tH | print "Degree | Multifactorials 1 to 10"
for x = 1 to 53 : print "-"; : next : print
for d = 1 to 5
print d;" ";"| ";
for n = 1 to 10
print FUNC(_multiFact(n, d));" ";
next
print
next
end
_multiFact param (2)
local (2)
c@ = 1
for d@ = a@ to 2 step -b@
c@ = c@ * d@
next
retur... | Give a code snippet in #uBasic.2F4tH
The factorial of a number, written as
n
!
{\displaystyle n!}
, is defined as
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(1)}
.
Multifactorials generalize factorials as follows:
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Feigenbaum_constant_calculation | Feigenbaum constant calculation | Task
Calculate the Feigenbaum constant.
See
Details in the Wikipedia article: Feigenbaum constant.
| #Lambdatalk | Lambdatalk |
{feigenbaum 11} // on my computer stackoverflow for values greater than 11
-> [3.2185114220380866,4.3856775985683365,4.600949276538056,4.6551304953919646,4.666111947822846,
4.668548581451485,4.66906066077106,4.669171554514976,4.669195154039278,4.669200256503637]
with:
{def feigenbaum
{lambda {:maxi}
{f3 :maxi... | Give a code snippet in #Lambdatalk
Task
Calculate the Feigenbaum constant.
See
Details in the Wikipedia article: Feigenbaum constant.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if ... | #Common_Lisp | Common Lisp | (defun coloured-text ()
(with-screen (scr :input-blocking t :input-echoing nil :cursor-visible nil)
(dolist (i '(:red :green :yellow :blue :magenta :cyan :white))
(add-string scr (format nil "~A~%" i) :fgcolor i))
(refresh scr)
;; wait for keypress
(get-char scr))) | Give a code snippet in #Common_Lisp
Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
H... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cut_a_rectangle | Cut a rectangle | A given rectangle is made from m × n squares. If m and n are not both odd, then it is possible to cut a path through the rectangle along the square edges such that the rectangle splits into two connected pieces with the same shape (after rotating one of the pieces by 180°). All such paths for 2 × 2 and 4 × 3 rectangles... | #Ruby | Ruby | def cut_it(h, w)
if h.odd?
return 0 if w.odd?
h, w = w, h
end
return 1 if w == 1
nxt = [[w+1, 1, 0], [-w-1, -1, 0], [-1, 0, -1], [1, 0, 1]] # [next,dy,dx]
blen = (h + 1) * (w + 1) - 1
grid = [false] * (blen + 1)
walk = lambda do |y, x, count=0|
return count+1 if y==0 or y==h or x==0 or... | Give a code snippet in #Ruby
A given rectangle is made from m × n squares. If m and n are not both odd, then it is possible to cut a path through the rectangle along the square edges such that the rectangle splits into two connected pieces with the same shape (after rotating one of the pieces by 180°). All such paths ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Monads/Maybe_monad | Monads/Maybe monad | Demonstrate in your programming language the following:
Construct a Maybe Monad by writing the 'bind' function and the 'unit' (sometimes known as 'return') function for that Monad (or just use what the language already has implemented)
Make two functions, each which take a number and return a monadic number, e.g. Int ... | #zkl | zkl | fcn bind(a,type,b){ if(type.isType(a)) b else Void }
fcn just(x){ if(Deferred.isType(x)) x() else x } // force lazy evaluation
fcn rtn(x) { just(x) } | Give a code snippet in #zkl
Demonstrate in your programming language the following:
Construct a Maybe Monad by writing the 'bind' function and the 'unit' (sometimes known as 'return') function for that Monad (or just use what the language already has implemented)
Make two functions, each which take a number and retur... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mad_Libs | Mad Libs |
This page uses content from Wikipedia. The original article was at Mad Libs. 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)
Mad Libs is a phrasal template word game where one player prompts another... | #11l | 11l | V template = ‘<name> went for a walk in the park. <he or she>
found a <noun>. <name> decided to take it home.’
F madlibs(template)
print("The story template is:\n"template)
V fields = sorted(Array(Set(re:‘<[^>]+>’.find_strings(template))))
V values = input("\nInput a comma-separated list of words to replace ... | Give a code snippet in #11l
This page uses content from Wikipedia. The original article was at Mad Libs. 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)
Mad Libs is a phrasal template word game whe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #Julia | Julia | #declaration/assignment, declaration is optional
x::Int32 = 1
#datatypes are inferred dynamically, but can also be set thru convert functions and datatype literals
x = 1 #x is inferred as Int, which is Int32 for 32-bit machines, Int64 for 64-bit machines
#variable reference
julia>x
1
x = int8(1) #x is of type Int8
x ... | Give a code snippet in #Julia
Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #min | min | (1 2 3 4) 0 '+ reduce puts! ; sum
(1 2 3 4) 1 '* reduce puts! ; product | Give a code snippet in #min
Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
S... | 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 ... | #APL | APL |
h ← ⎕fio['fopen'] 'input.txt'
h
7
⎕fio['fstat'] h
66311 803134 33188 1 1000 1000 0 11634 4096 24 1642047105 1642047105 1642047105
⎕fio['fclose'] h
0
h ← ⎕fio['fopen'] 'docs/'
h
7
⎕fio['fstat'] h
66311 3296858 16877 2 1000 1000 0 4096 4096 8 1642047108 1642047108 164204710... | Give a code snippet in #APL
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:... | 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.
| #Pascal | Pascal | my @arr1 = (1, 2, 3);
my @arr2 = (4, 5, 6);
my @arr3 = (@arr1, @arr2); | Give a code snippet in #Pascal
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/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 ... | #Fantom | Fantom |
class Palindrome
{
// Function to test if given string is a palindrome
public static Bool isPalindrome (Str str)
{
str == str.reverse
}
// Give it a test run
public static Void main ()
{
echo (isPalindrome(""))
echo (isPalindrome("a"))
echo (isPalindrome("aa"))
echo (isPalindrome(... | Give a code snippet in #Fantom
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 a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm | Trabb Pardo–Knuth algorithm | The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of... | #Racket | Racket |
#lang racket
(define input
(for/list ([i 11])
(printf "Enter a number (~a of 11): " (+ 1 i))
(read)))
(for ([x (reverse input)])
(define res (+ (sqrt (abs x)) (* 5 (expt x 3))))
(if (> res 400)
(displayln "Overflow!")
(printf "f(~a) = ~a\n" x res)))
| Give a code snippet in #Racket
The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Munchausen_numbers | Munchausen numbers | A Munchausen number is a natural number n the sum of whose digits (in base 10), each raised to the power of itself, equals n.
(Munchausen is also spelled: Münchhausen.)
For instance: 3435 = 33 + 44 + 33 + 55
Task
Find all Munchausen numbers between 1 and 5000.
Also see
The OEIS entry: A046253
The ... | #ALGOL_68 | ALGOL 68 | # Find Munchausen Numbers between 1 and 5000 #
# note that 6^6 is 46 656 so we only need to consider numbers consisting of 0 to 5 #
# table of Nth powers - note 0^0 is 0 for Munchausen numbers, not 1 #
[]INT nth power = ([]INT( 0, 1, 2 * 2, 3 * 3 * 3, 4 * 4 * 4... | Give a code snippet in #ALGOL_68
A Munchausen number is a natural number n the sum of whose digits (in base 10), each raised to the power of itself, equals n.
(Munchausen is also spelled: Münchhausen.)
For instance: 3435 = 33 + 44 + 33 + 55
Task
Find all Munchausen numbers between 1 and 5000.
Also se... | 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.)
| #NATURAL | NATURAL | * This is a comment and extends to the end of the line | Give a code snippet in #NATURAL
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/Sum_of_squares | Sum of squares | Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| #Cowgol | Cowgol | include "cowgol.coh";
include "argv.coh";
# Sum of squares
sub sumsquare(vec: [int32], len: intptr): (out: uint32) is
out := 0;
while len > 0 loop
var cur := [vec];
# make positive first so we can use extra range of uint32
if cur < 0 then cur := -cur; end if;
out := out +... | Give a code snippet in #Cowgol
Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Wilson_primes_of_order_n | Wilson primes of order n | Definition
A Wilson prime of order n is a prime number p such that p2 exactly divides:
(n − 1)! × (p − n)! − (− 1)n
If n is 1, the latter formula reduces to the more familiar: (p - n)! + 1 where the only known examples for p are 5, 13, and 563.
Task
Calculate and show on thi... | #Julia | Julia | using Primes
function wilsonprimes(limit = 11000)
sgn, facts = 1, accumulate(*, 1:limit, init = big"1")
println(" n: Wilson primes\n--------------------")
for n in 1:11
print(lpad(n, 2), ": ")
sgn = -sgn
for p in primes(limit)
if p > n && (facts[n < 2 ? 1 : n - 1] * f... | Give a code snippet in #Julia
Definition
A Wilson prime of order n is a prime number p such that p2 exactly divides:
(n − 1)! × (p − n)! − (− 1)n
If n is 1, the latter formula reduces to the more familiar: (p - n)! + 1 where the only known examples for p are 5, 13, and 563.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat... | #D.C3.A9j.C3.A0_Vu | Déjà Vu | accum n:
labda i:
set :n + n i
n
local :x accum 1
drop x 5
drop accum 3
!print x 2.3 | Give a code snippet in #D.C3.A9j.C3.A0_Vu
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeri... | 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:
... | #Ruby | Ruby | class RockPaperScissorsGame
CHOICES = %w[rock paper scissors quit]
BEATS = {
'rock' => 'paper',
'paper' => 'scissors',
'scissors' => 'rock',
}
def initialize()
@plays = {
'rock' => 1,
'paper' => 1,
'scissors' => 1,
}
@score = [0, 0, 0] # [0]:Hum... | Give a code snippet in #Ruby
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the f... | #Ela | Ela | fib n | n < 0 = fail "Negative n"
| else = fix (\f n -> if n < 2 then n else f (n - 1) + f (n - 2)) n | Give a code snippet in #Ela
While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_a_set_of_characters_from_a_string | Strip a set of characters from a string | Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in the second argument:
print str... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | stripchars[a_,b_]:=StringReplace[a,(#->"")&/@Characters[b]]
stripchars["She was a soul stripper. She took my heart!","aei"]
->Sh ws soul strppr. Sh took my hrt! | Give a code snippet in #Mathematica.2FWolfram_Language
Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ordered_partitions | Ordered partitions | In this task we want to find the ordered partitions into fixed-size blocks.
This task is related to Combinations in that it has to do with discrete mathematics and moreover a helper function to compute combinations is (probably) needed to solve this task.
p
a
r
t
i
t
i
o
n
s
(
a
r
g
1
,
a
r
g
2
,
... | #Ruby | Ruby | def partition(mask)
return [[]] if mask.empty?
[*1..mask.inject(:+)].permutation.map {|perm|
mask.map {|num_elts| perm.shift(num_elts).sort }
}.uniq
end | Give a code snippet in #Ruby
In this task we want to find the ordered partitions into fixed-size blocks.
This task is related to Combinations in that it has to do with discrete mathematics and moreover a helper function to compute combinations is (probably) needed to solve this task.
p
a
r
t
i
t
i
o
n
s
(
a
r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Chaos_game | Chaos game | The Chaos Game is a method of generating the attractor of an iterated function system (IFS).
One of the best-known and simplest examples creates a fractal, using a polygon and an initial point selected at random.
Task
Play the Chaos Game using the corners of an equilateral triangle as the reference points. Add a ... | #Nim | Nim | import random
import rapid/gfx
var
window = initRWindow()
.title("Rosetta Code - Chaos Game")
.open()
surface = window.openGfx()
sierpinski = window.newRCanvas()
points: array[3, Vec2[float]]
for i in 0..<3:
points[i] = vec2(cos(PI * 2 / 3 * i.float), sin(PI * 2 / 3 * i.float)) * 300
var point... | Give a code snippet in #Nim
The Chaos Game is a method of generating the attractor of an iterated function system (IFS).
One of the best-known and simplest examples creates a fractal, using a polygon and an initial point selected at random.
Task
Play the Chaos Game using the corners of an equilateral triangle as t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Van_Eck_sequence | Van Eck sequence | The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured previously.
Example
Using ... | #D | D | import std.stdio;
void vanEck(int firstIndex, int lastIndex) {
int[int] vanEckMap;
int last = 0;
if (firstIndex == 1) {
writefln("VanEck[%d] = %d", 1, 0);
}
for (int n = 2; n <= lastIndex; n++) {
int vanEck = last in vanEckMap ? n - vanEckMap[last] : 0;
vanEckMap[last] = n;... | Give a code snippet in #D
The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured pre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truncate_a_file | Truncate a file | Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by creating a temporary file of a reduced... | #Racket | Racket |
#lang racket
(define (truncate file size)
(unless (file-exists? file) (error 'truncat "missing file: ~a" file))
(when (> size (file-size file)) (printf "Warning: extending file size.\n"))
(call-with-output-file* file #:exists 'update
(λ(o) (file-truncate o size))))
| Give a code snippet in #Racket
Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by creati... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pascal%27s_triangle | Pascal's triangle | Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either 1 or the sum of the two elemen... | #q | q |
pascal:{(x-1){0+':x,0}\1}
pascal 5
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
| Give a code snippet in #q
Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either 1 o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Quicksort | Sorting algorithms/Quicksort |
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
... | #ARM_Assembly | ARM Assembly |
/* ARM assembly Raspberry PI */
/* program quickSort.s */
/* look pseudo code in wikipedia quicksort */
/************************************/
/* Constantes */
/************************************/
.equ STDOUT, 1 @ Linux output console
.equ EXIT, 1 @ Linux syscall
.equ WRITE, ... | Give a code snippet in #ARM_Assembly
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Q... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compiler/code_generator | Compiler/code generator | A code generator translates the output of the syntax analyzer and/or semantic analyzer
into lower level code, either assembly, object, or virtual.
Task[edit]
Take the output of the Syntax analyzer task - which is a flattened Abstract Syntax Tree (AST) - and convert it to virtual machine code, that can be run by the
Vi... | #C | C | #include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stdint.h>
#include <ctype.h>
typedef unsigned char uchar;
typedef enum {
nd_Ident, nd_String, nd_Integer, nd_Sequence, nd_If, nd_Prtc, nd_Prts, nd_Prti, nd_While,
nd_Assign, nd_Negate, nd_Not, nd_Mul, nd_Div, nd_Mod, nd... | Give a code snippet in #C
A code generator translates the output of the syntax analyzer and/or semantic analyzer
into lower level code, either assembly, object, or virtual.
Task[edit]
Take the output of the Syntax analyzer task - which is a flattened Abstract Syntax Tree (AST) - and convert it to virtual machine code... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #NetRexx | NetRexx | s_ = 'Hello'
s_ = s_', world!'
say s_ | Give a code snippet in #NetRexx
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/Function_composition | Function composition | Task
Create a function, compose, whose two arguments f and g, are both functions with one argument.
The result of compose is to be a function of one argument, (lets call the argument x), which works like applying function f to the result of applying function g to x.
Example
compose... | #Go | Go | // Go doesn't have generics, but sometimes a type definition helps
// readability and maintainability. This example is written to
// the following function type, which uses float64.
type ffType func(float64) float64
// compose function requested by task
func compose(f, g ffType) ffType {
return func(x float64) ... | Give a code snippet in #Go
Task
Create a function, compose, whose two arguments f and g, are both functions with one argument.
The result of compose is to be a function of one argument, (lets call the argument x), which works like applying function f to the result of applying function g t... | 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
... | #Nanoquery | Nanoquery | import sort
// sorting string literals
x = "lion, tigers, and"
y = "bears, oh my!"
z = "(from the \"Wizard of OZ\")"
varlist = sort({x,y,z})
x = varlist[0]
y = varlist[1]
z = varlist[2]
println x; println y; println z
// sorting integers
x = 77444
y = -12
z = 0
varlist = sort({x, y, z})
x = varlist[0]
y = v... | Give a code snippet in #Nanoquery
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 |
Quic... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the f... | #Rust | Rust | fn fib(n: i64) -> Option<i64> {
// A function declared inside another function does not pollute the outer namespace.
fn actual_fib(n: i64) -> i64 {
if n < 2 {
n
} else {
actual_fib(n - 1) + actual_fib(n - 2)
}
}
if n < 0 {
None
} else {
... | Give a code snippet in #Rust
While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwante... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring/Top_and_tail | Substring/Top and tail | The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
If the program uses UTF-8 or UTF... | #Phix | Phix | constant s = "(test)"
?s[2..-1]
?s[1..-2]
?s[2..-2]
| Give a code snippet in #Phix
The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
If... | 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... | #Rust | Rust | // Part 1: Inverted index structure
use std::{
borrow::Borrow,
collections::{BTreeMap, BTreeSet},
};
#[derive(Debug, Default)]
pub struct InvertedIndex<T> {
indexed: BTreeMap<String, BTreeSet<usize>>,
sources: Vec<T>,
}
impl<T> InvertedIndex<T> {
pub fn add<I, V>(&mut self, source: T, tokens: ... | Give a code snippet in #Rust
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 / ter... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Host_introspection | Host introspection | Print the word size and endianness of the host machine.
See also: Variable size/Get
| #MACRO-10 | MACRO-10 |
title Host Introspection
subttl PDP-10 assembly (MACRO-10 on TOPS-20). KJX 2022.
search monsym,macsym
comment \
The wordsize is detected by putting 1 into a re-
gister, counting the leading zeros (resulting in
wordsize-1) and adding 1 to the result.
Endianness doesn't really apply... | Give a code snippet in #MACRO-10
Print the word size and endianness of the host machine.
See also: Variable size/Get
| 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
| #PHP | PHP | echo "Goodbye, World !"; | Give a code snippet in #PHP
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/Standar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third... | #TI-89_BASIC | TI-89 BASIC | Define doors(fast) = Func
Local doors,i,j
seq(false,x,1,100) ? doors
If fast Then
For i,1,10,1
true ? doors[i^2]
EndFor
Else
For i,1,100,1
For j,i,100,i
not doors[j] ? doors[j]
EndFor
EndFor
EndIf
Return doors
EndFunc | Give a code snippet in #TI-89_BASIC
There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Password_generator | Password generator | Create a password generation program which will generate passwords containing random ASCII characters from the following groups:
lower-case letters: a ──► z
upper-case letters: A ──► Z
digits: 0 ──► 9
other printable characters: !"#$%&'()*+,-./:;<=>?@[]^_{|}~
(the above ch... | #Java | Java | import java.util.*;
public class PasswordGenerator {
final static Random rand = new Random();
public static void main(String[] args) {
int num, len;
try {
if (args.length != 2)
throw new IllegalArgumentException();
len = Integer.parseInt(args[0]);
... | Give a code snippet in #Java
Create a password generation program which will generate passwords containing random ASCII characters from the following groups:
lower-case letters: a ──► z
upper-case letters: A ──► Z
digits: 0 ──► 9
other printable characters: !"#$%&'()*+,-./:... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Leonardo_numbers | Leonardo numbers |
Leonardo numbers are also known as the Leonardo series.
The Leonardo numbers are a sequence of numbers defined by:
L(0) = 1 [1st equation]
L(1) = 1 [2nd equation]
L(n) = L(n-1) + L(n-2) + 1 ... | #Python | Python | def Leonardo(L_Zero, L_One, Add, Amount):
terms = [L_Zero,L_One]
while len(terms) < Amount:
new = terms[-1] + terms[-2]
new += Add
terms.append(new)
return terms
out = ""
print "First 25 Leonardo numbers:"
for term in Leonardo(1,1,1,25):
out += str(term) + " "
print out
out =... | Give a code snippet in #Python
Leonardo numbers are also known as the Leonardo series.
The Leonardo numbers are a sequence of numbers defined by:
L(0) = 1 [1st equation]
L(1) = 1 [2nd equation]
L(n) ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mad_Libs | Mad Libs |
This page uses content from Wikipedia. The original article was at Mad Libs. 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)
Mad Libs is a phrasal template word game where one player prompts another... | #Python | Python | import re
# Optional Python 2.x compatibility
#try: input = raw_input
#except: pass
template = '''<name> went for a walk in the park. <he or she>
found a <noun>. <name> decided to take it home.'''
def madlibs(template):
print('The story template is:\n' + template)
fields = sorted(set( re.findall('<[^>]+>'... | Give a code snippet in #Python
This page uses content from Wikipedia. The original article was at Mad Libs. 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)
Mad Libs is a phrasal template word game ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Call_a_function | Call a function | Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function with a variable number of arguments
C... | #8086_Assembly | 8086 Assembly | call foo | Give a code snippet in #8086_Assembly
Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function w... | christopher/rosetta-code | |
http://rosettacode.org/wiki/User_input/Graphical | User input/Graphical |
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| #Visual_Basic | Visual Basic | import "graphics" for Canvas, Color
import "input" for Keyboard, Clipboard
import "dome" for Window, Process
var X = 10
var Y = 28
class Main {
construct new() {}
init() {
_text = ""
_enterNum = false
Keyboard.handleText = true
Keyboard.textRegion(X, Y, 8, 8)
}
up... | Give a code snippet in #Visual_Basic
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sylvester%27s_sequence | Sylvester's sequence |
This page uses content from Wikipedia. The original article was at Sylvester's sequence. 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, Sylvester's sequence is an integer sequenc... | #Wren | Wren | import "/big" for BigInt, BigRat
var sylvester = [BigInt.two]
var prod = BigInt.two
var count = 1
while (true) {
var next = prod + 1
sylvester.add(next)
count = count + 1
if (count == 10) break
prod = prod * next
}
System.print("The first 10 terms in the Sylvester sequence are:")
System.print(sylv... | Give a code snippet in #Wren
This page uses content from Wikipedia. The original article was at Sylvester's sequence. 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, Sylvester's ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Standard_error | Hello world/Standard error | Hello world/Standard error is part of Short Circuit's Console Program Basics selection.
A common practice in computing is to send error messages
to a different output stream than normal text console messages.
The normal messages print to what is called "standard output" or "standard out".
The error messages print to ... | #Batch_File | Batch File | 1>&2 echo Goodbye, World! | Give a code snippet in #Batch_File
Hello world/Standard error is part of Short Circuit's Console Program Basics selection.
A common practice in computing is to send error messages
to a different output stream than normal text console messages.
The normal messages print to what is called "standard output" or "standard... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Stooge_sort | Sorting algorithms/Stooge 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
... | #jq | jq | def stoogesort:
def swap(i;j): .[i] as $t | .[i] = .[j] | .[j] = $t;
# for efficiency, define an auxiliary function
# that takes as input [L, i, j]
def ss: .[1] as $i | .[2] as $j
| .[0]
| if .[$j] < .[$i] then swap($i;$j) else . end
| if $j - $i > 1 then
(($j - $i + 1) / 3 | floor) a... | Give a code snippet in #jq
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_comparison | Integer comparison |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #ReScript | ReScript | let my_compare = (a, b) => {
if a < b { "A is less than B" } else
if a > b { "A is greater than B" } else
if a == b { "A equals B" }
else { "cannot compare NANs" }
}
let a = int_of_string(Sys.argv[2])
let b = int_of_string(Sys.argv[3])
Js.log(my_compare(a, b)) | Give a code snippet in #ReScript
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 Operatio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Filter | Filter | Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| #ActionScript | ActionScript | var arr:Array = new Array(1, 2, 3, 4, 5);
var evens:Array = new Array();
for (var i:int = 0; i < arr.length(); i++) {
if (arr[i] % 2 == 0)
evens.push(arr[i]);
} | Give a code snippet in #ActionScript
Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Iteration | Associative array/Iteration | Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked ... | #SNOBOL4 | SNOBOL4 | * # Create sample table
t = table()
t<'cat'> = 'meow'
t<'dog'> = 'woof'
t<'pig'> = 'oink'
* # Convert table to key/value array
a = convert(t,'array')
* # Iterate pairs
ploop i = i + 1; output = a<i,1> ' -> ' a<i,2> :s(ploop)
* # Iterate keys
kloop ... | Give a code snippet in #SNOBOL4
Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sleep | Sleep | Task
Write a program that does the following in this order:
Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
Print "Sleeping..."
Sleep the main thread for the given amount of time.
... | #PHP | PHP | $seconds = 42;
echo "Sleeping...\n";
sleep($seconds); # number is integer in seconds
echo "Awake!\n"; | Give a code snippet in #PHP
Task
Write a program that does the following in this order:
Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
Print "Sleeping..."
Sleep the main thread f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Arithmetic_mean | Averages/Arithmetic mean | Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | Unprotect[Mean];
Mean[{}] := 0 | Give a code snippet in #Mathematica_.2F_Wolfram_Language
Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the progr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so o... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | VanDerCorput[n_,base_:2]:=Table[
FromDigits[{Reverse[IntegerDigits[k,base]],0},base],
{k,n}]
VanDerCorput[10,2]
VanDerCorput[10,3]
VanDerCorput[10,4]
VanDerCorput[10,5]
| Give a code snippet in #Mathematica.2FWolfram_Language
When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Prime_decomposition | Prime decomposition | The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the prime decomposition of a given ... | #Haskell | Haskell | factorize n = [ d | p <- [2..n], isPrime p, d <- divs n p ]
-- [2..n] >>= (\p-> [p|isPrime p]) >>= divs n
where
divs n p | rem n p == 0 = p : divs (quot n p) p
| otherwise = [] | Give a code snippet in #Haskell
The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Array_length | Array length | Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I befo... | #UNIX_Shell | UNIX Shell | #!/bin/bash
array=("orange" "apple")
echo "${#array[@]}" | Give a code snippet in #UNIX_Shell
Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_float_arrays_to_a_text_file | Write float arrays to a text file | Task
Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.
The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.
For example, considering:
x = {1, 2, 3, 1e11};
y = {1, 1.41421356... | #RLaB | RLaB |
>> x = rand(10,1); y = rand(10,1);
>> writem("mytextfile.txt", [x,y]);
| Give a code snippet in #RLaB
Task
Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.
The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.
For example, considering:
x = {1, 2, 3... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_squares | Sum of squares | Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| #Logtalk | Logtalk | sum(List, Sum) :-
sum(List, 0, Sum).
sum([], Sum, Sum).
sum([X| Xs], Acc, Sum) :-
Acc2 is Acc + X,
sum(Xs, Acc2, Sum). | Give a code snippet in #Logtalk
Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Downward_for | Loops/Downward for | Task
Write a for loop which writes a countdown from 10 to 0.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop body... | #GAP | GAP | for i in [10, 9 .. 0] do
Print(i, "\n");
od; | Give a code snippet in #GAP
Task
Write a for loop which writes a countdown from 10 to 0.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Incremen... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Temperature_conversion | Temperature conversion | There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 kelvin.
0 kelvin is absolute z... | #J | J | NB. Temp conversions are all linear polynomials
K2K =: 0 1 NB. K = (1 *k) + 0
K2C =: _273 1 NB. C = (1 *k) - 273
K2F =: _459.67 1.8 NB. F = (1.8*k) - 459.67
K2R =: 0 1.8 NB. R = (1.8*k) + 0
NB. Do all conversions at once (eval
NB. polynomials in pa... | Give a code snippet in #J
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 kelv... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Percolation/Site_percolation | Percolation/Site percolation |
Percolation Simulation
This is a simulation of aspects of mathematical percolation theory.
For other percolation simulations, see Category:Percolation Simulations, or:
1D finite grid simulation
Mean run density
2D finite grid simulations
Site percolation | Bond percolation | Mean cluster density
Given an
M
×
N... | #Nim | Nim | import random, sequtils, strformat, strutils
type Grid = seq[string] # Row first, i.e. [y][x].
const
Full = '.'
Used = '#'
Empty = ' '
proc newGrid(p: float; xsize, ysize: Positive): Grid =
result = newSeqWith(ysize, newString(xsize))
for row in result.mitems:
for cell in row.mitems:
cel... | Give a code snippet in #Nim
Percolation Simulation
This is a simulation of aspects of mathematical percolation theory.
For other percolation simulations, see Category:Percolation Simulations, or:
1D finite grid simulation
Mean run density
2D finite grid simulations
Site percolation | Bond percolation | Mean cluste... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Gray_code | Gray code | Gray code
Karnaugh maps
Create functions to encode a number to and decode a number from Gray code.
Display the normal binary representations, Gray code representations, and decoded Gray code values for all 5-bit binary numbers (0-31 inclusive, leading 0's not necessary).
There are many possible Gray codes. The follow... | #bc | bc | scale = 0 /* to use integer division */
/* encode Gray code */
define e(i) {
auto h, r
if (i <= 0) return 0
h = i / 2
r = e(h) * 2 /* recurse */
if (h % 2 != i % 2) r += 1 /* xor low bits of h, i */
return r
}
/* decode Gray code */
define d(i) {
auto h, r
if (i <= 0) return 0
h = d(i ... | Give a code snippet in #bc
Gray code
Karnaugh maps
Create functions to encode a number to and decode a number from Gray code.
Display the normal binary representations, Gray code representations, and decoded Gray code values for all 5-bit binary numbers (0-31 inclusive, leading 0's not necessary).
There are many pos... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sierpinski_triangle | Sierpinski triangle | Task
Produce an ASCII representation of a Sierpinski triangle of order N.
Example
The Sierpinski triangle of order 4 should look like this:
*
* *
* *
* * * *
* *
* * * *
... | #Unlambda | Unlambda | ```ci``s``s`ks``s`k`s``s`kc``s``s``si`kr`k. `k.*k
`k``s``s``s``s`s`k`s``s`ksk`k``s``si`kk`k``s`kkk
`k``s`k`s``si`kk``s`kk``s``s``s``si`kk`k`s`k`s``s`ksk`k`s`k`s`k`si``si`k`ki
`k``s`k`s``si`k`ki``s`kk``s``s``s``si`kk`k`s`k`s`k`si`k`s`k`s``s`ksk``si`k`ki
`k`ki``s`k`s`k`si``s`kkk | Give a code snippet in #Unlambda
Task
Produce an ASCII representation of a Sierpinski triangle of order N.
Example
The Sierpinski triangle of order 4 should look like this:
*
* *
* *
* * * *
* *
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Statistics/Basic | Statistics/Basic | Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldots ,n\,\!}
, the mean is
x
¯... | #Liberty_BASIC | Liberty BASIC |
call sample 100
call sample 1000
call sample 10000
end
sub sample n
dim dat( n)
for i =1 to n
dat( i) =rnd( 1)
next i
'// show mean, standard deviation
sum =0
sSq =0
for i =1 to n
sum =sum +dat( i)
sSq =sSq +dat( i)^2
next i
print n; " data terms... | Give a code snippet in #Liberty_BASIC
Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sierpinski_triangle/Graphical | Sierpinski triangle/Graphical | Produce a graphical representation of a Sierpinski triangle of order N in any orientation.
An example of Sierpinski's triangle (order = 8) looks like this:
| #Perl | Perl | my $levels = 6;
my $side = 512;
my $height = get_height($side);
sub get_height { my($side) = @_; $side * sqrt(3) / 2 }
sub triangle {
my($x1, $y1, $x2, $y2, $x3, $y3, $fill, $animate) = @_;
my $svg;
$svg .= qq{<polygon points="$x1,$y1 $x2,$y2 $x3,$y3"};
$svg .= qq{ style="fill: $fill; stroke-width... | Give a code snippet in #Perl
Produce a graphical representation of a Sierpinski triangle of order N in any orientation.
An example of Sierpinski's triangle (order = 8) looks like this:
| christopher/rosetta-code |
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