task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
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|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Input_loop | Input loop | Input loop is part of Short Circuit's Console Program Basics selection.
Task
Read from a text stream either word-by-word or line-by-line until the stream runs out of data.
The stream will have an unknown amount of data on it.
| #M2000_Interpreter | M2000 Interpreter |
Document A$={1st Line
2nd line
3rd line
}
Save.Doc A$, "test.txt", 0 ' 0 for utf16-le
\\ we use Wide for utf16-le \\ without it we open using ANSI
Open "test.txt" For Wide Input Exclusive as #N
While Not Eof(#N) {
Line Input #N, ThisLine$
Print ThisLine$
}
Close... | Give a code snippet in #M2000_Interpreter
Input loop is part of Short Circuit's Console Program Basics selection.
Task
Read from a text stream either word-by-word or line-by-line until the stream runs out of data.
The stream will have an unknown amount of data on it.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_word | Fibonacci word | The Fibonacci Word may be created in a manner analogous to the Fibonacci Sequence as described here:
Define F_Word1 as 1
Define F_Word2 as 0
Form F_Word3 as F_Word2 concatenated with F_Word1 i.e.: 01
Form F_Wordn as F_Wordn-1 concatenated with F_wordn-... | #REXX | REXX | /*REXX program displays the number of chars in a fibonacci word, and the word's entropy.*/
d= 21; de= d + 6; numeric digits de /*use more precision (the default is 9)*/
parse arg N . /*get optional argument from the C.L. */
if N=='' | N=="," then N= 42 ... | Give a code snippet in #REXX
The Fibonacci Word may be created in a manner analogous to the Fibonacci Sequence as described here:
Define F_Word1 as 1
Define F_Word2 as 0
Form F_Word3 as F_Word2 concatenated with F_Word1 i.e.: 01
Form F_Wordn as F_Wordn-1 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sailors,_coconuts_and_a_monkey_problem | Sailors, coconuts and a monkey problem | Five sailors are shipwrecked on an island and collect a large pile of coconuts during the day.
That night the first sailor wakes up and decides to take his first share early so tries to divide the pile of coconuts equally into five piles but finds that there is one coconut left over, so he tosses it to a monkey and th... | #Tcl | Tcl | proc assert {expr {msg ""}} { ;# for "static" assertions that throw nice errors
if {![uplevel 1 [list expr $expr]]} {
if {$msg eq ""} {
catch {set msg "{[uplevel 1 [list subst -noc $expr]]}"}
}
throw {ASSERT ERROR} "{$expr} $msg"
}
}
proc divmod {a b} {
list [expr {$... | Give a code snippet in #Tcl
Five sailors are shipwrecked on an island and collect a large pile of coconuts during the day.
That night the first sailor wakes up and decides to take his first share early so tries to divide the pile of coconuts equally into five piles but finds that there is one coconut left over, so he... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #Ada | Ada | type Restricted is range 1..10;
My_Var : Restricted;
if My_Var = 5 then
-- do something
elsif My_Var > 5 then
-- do something
else
-- do something
end if; | Give a code snippet in #Ada
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers | Luhn test of credit card numbers | The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order of the digits in the number.
Tak... | #REXX | REXX | /*REXX program validates credit card numbers using the Luhn algorithm. */
#.=; #.1= 49927398716 /*the 1st sample credit card number. */
#.2= 49927398717 /* " 2nd " " " " */
#.3= 1234567812345678 ... | Give a code snippet in #REXX
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Set | Set |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A set is a collection of elements, without duplicates and without order.
Task
Show each of these set operations:
Set creation
Test m ∈ S -- "m is an... | #F.23 | F# | [<EntryPoint>]
let main args =
// Create some sets (of int):
let s1 = Set.ofList [1;2;3;4;3]
let s2 = Set.ofArray [|3;4;5;6|]
printfn "Some sets (of int):"
printfn "s1 = %A" s1
printfn "s2 = %A" s2
printfn "Set operations:"
printfn "2 ∈ s1? %A" (s1.Contains 2)
printfn "10 ∈ s1? %A"... | Give a code snippet in #F.23
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A set is a collection of elements, without duplicates and without order.
Task
Show each of these set operations:
Set cr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
... | #FutureBasic | FutureBasic |
include "NSLog.incl"
local fn Ackerman( m as NSInteger, n as NSInteger ) as NSInteger
NSInteger result
select
case m == 0 : result = ( n + 1 )
case n == 0 : result = fn Ackerman( ( m - 1 ), 1 )
case else : result = fn Ackerman( ( m - 1 ), fn Ackerman( m, ( n - 1 ) ) )
end select
end fn = result
NSIntege... | Give a code snippet in #FutureBasic
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Real_constants_and_functions | Real constants and functions | Task
Show how to use the following math constants and functions in your language (if not available, note it):
e (base of the natural logarithm)
π
{\displaystyle \pi }
square root
logarithm (any base allowed)
exponential (ex )
absolute value (a.k.a. "magnitude")
floor (largest ... | #PHP | PHP | M_E; //e
M_PI; //pi
sqrt(x); //square root
log(x); //natural logarithm--log base 10 also available (log10)
exp(x); //exponential
abs(x); //absolute value
floor(x); //floor
ceil(x); //ceiling
pow(x,y); //power | Give a code snippet in #PHP
Task
Show how to use the following math constants and functions in your language (if not available, note it):
e (base of the natural logarithm)
π
{\displaystyle \pi }
square root
logarithm (any base allowed)
exponential (ex )
absolute value (a.k.a. "mag... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable_declaration_reset | Variable declaration reset | A decidely non-challenging task to highlight a potential difference between programming languages.
Using a straightforward longhand loop as in the JavaScript and Phix examples below, show the locations of elements which are identical to the immediately preceding element in {1,2,2,3,4,4,5}. The (non-blank) results may ... | #Go | Go | package main
import "fmt"
func main() {
s := []int{1, 2, 2, 3, 4, 4, 5}
// There is no output as 'prev' is created anew each time
// around the loop and set implicitly to zero.
for i := 0; i < len(s); i++ {
curr := s[i]
var prev int
if i > 0 && curr == prev {
fm... | Give a code snippet in #Go
A decidely non-challenging task to highlight a potential difference between programming languages.
Using a straightforward longhand loop as in the JavaScript and Phix examples below, show the locations of elements which are identical to the immediately preceding element in {1,2,2,3,4,4,5}. ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Remove_duplicate_elements | Remove duplicate elements |
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 | ary = [1, 1, 2, 2, "a", [1, 2, 3], [1, 2, 3], "a"]
p ary.uniq | 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/Write_to_Windows_event_log | Write to Windows event log | Task
Write script status to the Windows Event Log
| #PicoLisp | PicoLisp | : (call 'logger "This is a test")
-> T
: (call 'logger "This" 'is "another" 'test)
-> T | Give a code snippet in #PicoLisp
Task
Write script status to the Windows Event Log
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Thiele%27s_interpolation_formula | Thiele's interpolation formula |
This page uses content from Wikipedia. The original article was at Thiele's interpolation formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Thiele's interpolation formula is an interpolation ... | #PicoLisp | PicoLisp | (scl 17)
(load "@lib/math.l")
(setq
*X-Table (range 0.0 1.55 0.05)
*SinTable (mapcar sin *X-Table)
*CosTable (mapcar cos *X-Table)
*TanTable (mapcar tan *X-Table)
*TrigRows (length *X-Table) )
(let N2 (>> 1 (* *TrigRows (dec *TrigRows)))
(setq
*InvSinTable (need N2)
*InvCosTable (need ... | Give a code snippet in #PicoLisp
This page uses content from Wikipedia. The original article was at Thiele's interpolation formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Thiele's interpol... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Babbage_problem | Babbage problem |
Charles Babbage, looking ahead to the sorts of problems his Analytical Engine would be able to solve, gave this example:
What is the smallest positive integer whose square ends in the digits 269,696?
— Babbage, letter to Lord Bowden, 1837; see Hollingdale and Tootill, Electronic Computers, second edition, 1970, p.... | #Clojure | Clojure | ; Defines function named babbage? that returns true if the
; square of the provided number leaves a remainder of 269,696 when divided
; by a million
(defn babbage? [n]
(let [square (* n n)]
(= 269696 (mod square 1000000))))
; Use the above babbage? to find the first positive integer that returns true
; (We're e... | Give a code snippet in #Clojure
Charles Babbage, looking ahead to the sorts of problems his Analytical Engine would be able to solve, gave this example:
What is the smallest positive integer whose square ends in the digits 269,696?
— Babbage, letter to Lord Bowden, 1837; see Hollingdale and Tootill, Electronic Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_whitespace_from_a_string/Top_and_tail | Strip whitespace from a string/Top and tail | Task
Demonstrate how to strip leading and trailing whitespace from a string.
The solution should demonstrate how to achieve the following three results:
String with leading whitespace removed
String with trailing whitespace removed
String with both leading and trailing whitespace removed
For the purposes of thi... | #Factor | Factor | USE: unicode
" test string " [ blank? ] trim ! leading and trailing
" test string " [ blank? ] trim-head ! only leading
" test string " [ blank? ] trim-tail ! only trailing | Give a code snippet in #Factor
Task
Demonstrate how to strip leading and trailing whitespace from a string.
The solution should demonstrate how to achieve the following three results:
String with leading whitespace removed
String with trailing whitespace removed
String with both leading and trailing whitespace r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Character_codes | Character codes |
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out... | #Elena | Elena | import extensions;
public program()
{
var ch := $97;
console.printLine:ch;
console.printLine(ch.toInt())
} | Give a code snippet in #Elena
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conv... | christopher/rosetta-code | |
http://rosettacode.org/wiki/24_game | 24 game | The 24 Game tests one's mental arithmetic.
Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those four digits, used exactly once each. T... | #Tcl | Tcl | # Four random non-zero digits
proc choose4 {} {
set digits {}
foreach x {1 2 3 4} {lappend digits [expr {int(1+rand()*9)}]}
return [lsort $digits]
}
# Print out a welcome message
proc welcome digits {
puts [string trim "
The 24 Game
Given any four digits in the range 1 to 9, which may have repetitio... | Give a code snippet in #Tcl
The 24 Game tests one's mental arithmetic.
Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those four digi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Equilibrium_index | Equilibrium index | An equilibrium index of a sequence is an index into the sequence such that the sum of elements at lower indices is equal to the sum of elements at higher indices.
For example, in a sequence
A
{\displaystyle A}
:
A
0
=
−
7
{\displaystyle A_{0}=-7}
A
1
=
1
{\displaystyle A_{1}=1}
... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols nobinary
numeric digits 20
runSample(arg)
return
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- @see http://www.geeksforgeeks.org/equilibrium-index-of-an-array/
method equilibriumIndex(sequence) private static
... | Give a code snippet in #NetRexx
An equilibrium index of a sequence is an index into the sequence such that the sum of elements at lower indices is equal to the sum of elements at higher indices.
For example, in a sequence
A
{\displaystyle A}
:
A
0
=
−
7
{\displaystyle A_{0}=-7}
A
1... | 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
| #Elena | Elena | public program()
{
//print will not append a newline
console.write("Goodbye, World!")
} | Give a code snippet in #Elena
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/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #J | J | ]matrix=: (^/ }:) >:i.5 NB. make and show example matrix
1 1 1 1
2 4 8 16
3 9 27 81
4 16 64 256
5 25 125 625
|: matrix
1 2 3 4 5
1 4 9 16 25
1 8 27 64 125
1 16 81 256 625 | Give a code snippet in #J
Transpose an arbitrarily sized rectangular Matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #Ruby | Ruby | require 'digest/sha2'
puts Digest::SHA256.hexdigest('Rosetta code') | Give a code snippet in #Ruby
SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Summarize_and_say_sequence | Summarize and say sequence | There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits:
0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ...
The terms generat... | #F.23 | F# |
// Summarize and say sequence . Nigel Galloway: April 23rd., 2021
let rec fN g=let n=let n,g=List.head g|>List.countBy id|>List.unzip in n@(g|>List.collect(fun g->if g<10 then [g] else [g/10;g%10]))
if List.contains n g then g.Tail|>List.rev else fN(n::g)
let rec fG n g=seq{yield! n; if g>1 then yield! f... | Give a code snippet in #F.23
There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits:
0, 10, 1110, 3110, 132110, 1113122110, 31131... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fractal_tree | Fractal tree | Generate and draw a fractal tree.
Draw the trunk
At the end of the trunk, split by some angle and draw two branches
Repeat at the end of each branch until a sufficient level of branching is reached
Related tasks
Pythagoras Tree
| #jq | jq | # width and height define the outer dimensions;
# len defines the trunk size;
# scale defines the branch length relative to the trunk;
def main(width; height; len; scale):
def PI: (1|atan)*4;
def precision(n):
def pow(k): . as $in | reduce range(0;k) as $i (1; .*$in);
if . < 0 then - (-. | precision(n))... | Give a code snippet in #jq
Generate and draw a fractal tree.
Draw the trunk
At the end of the trunk, split by some angle and draw two branches
Repeat at the end of each branch until a sufficient level of branching is reached
Related tasks
Pythagoras Tree
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Spiral_matrix | Spiral matrix | Task
Produce a spiral array.
A spiral array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you go around the edges of the array spiraling inwards.
For example, given 5, produce this array:
0 1 2 3 4
15 16 17 18 5
14 23 24 19 6
13 22 21 ... | #Visual_Basic | Visual Basic | Option Explicit
Sub Main()
print2dArray getSpiralArray(5)
End Sub
Function getSpiralArray(dimension As Integer) As Integer()
ReDim spiralArray(dimension - 1, dimension - 1) As Integer
Dim numConcentricSquares As Integer
numConcentricSquares = dimension \ 2
If (dimension Mod 2) Then numConcentr... | Give a code snippet in #Visual_Basic
Task
Produce a spiral array.
A spiral array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you go around the edges of the array spiraling inwards.
For example, given 5, produce this array:
0 1 2 3 4
1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations | Combinations | Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
0 3 4
1 2 3
1 2 4
1 3 4
2 3 4
... | #PicoLisp | PicoLisp | (de comb (M Lst)
(cond
((=0 M) '(NIL))
((not Lst))
(T
(conc
(mapcar
'((Y) (cons (car Lst) Y))
(comb (dec M) (cdr Lst)) )
(comb M (cdr Lst)) ) ) ) )
(comb 3 (1 2 3 4 5)) | Give a code snippet in #PicoLisp
Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3
0 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Extensible_prime_generator | Extensible prime generator | Task
Write a generator of prime numbers, in order, that will automatically adjust to accommodate the generation of any reasonably high prime.
The routine should demonstrably rely on either:
Being based on an open-ended counter set to count without upper limit other than system or programming language limits. In thi... | #Julia | Julia | using Primes
sum = 2
currentprime = 2
for i in 2:100000
currentprime = nextprime(currentprime + 1)
sum += currentprime
end
println("The sum of the first 100,000 primes is $sum")
curprime = 1
arr = zeros(Int, 20)
for i in 1:20
curprime = nextprime(curprime + 1)
arr[i] = curprime
end
println("The firs... | Give a code snippet in #Julia
Task
Write a generator of prime numbers, in order, that will automatically adjust to accommodate the generation of any reasonably high prime.
The routine should demonstrably rely on either:
Being based on an open-ended counter set to count without upper limit other than system or prog... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Word_frequency | Word frequency | Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define what a letter is.
Undersc... | #TMG | TMG | /* Input format: N text */
/* Only lowercase letters can constitute a word in text. */
/* (c) 2020, Andrii Makukha, 2-clause BSD licence. */
progrm: readn/error
table(freq) table(chain) [firstword = ~0]
loop: not(!<<>>) output
| [j=777] batch... | Give a code snippet in #TMG
Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define what... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_shuffle | Perfect shuffle | A perfect shuffle (or faro/weave shuffle) means splitting a deck of cards into equal halves, and perfectly interleaving them - so that you end up with the first card from the left half, followed by the first card from the right half, and so on:
7♠ 8♠ 9♠ J♠ Q♠ K♠→7♠ 8♠ 9♠
J♠ Q♠ K♠→7♠ J♠ 8♠ Q♠ 9♠ K♠
When you ... | #Kotlin | Kotlin | // version 1.1.2
fun areSame(a: IntArray, b: IntArray): Boolean {
for (i in 0 until a.size) if (a[i] != b[i]) return false
return true
}
fun perfectShuffle(a: IntArray): IntArray {
var b = IntArray(a.size)
val hSize = a.size / 2
for (i in 0 until hSize) b[i * 2] = a[i]
var j = 1
for (i i... | Give a code snippet in #Kotlin
A perfect shuffle (or faro/weave shuffle) means splitting a deck of cards into equal halves, and perfectly interleaving them - so that you end up with the first card from the left half, followed by the first card from the right half, and so on:
7♠ 8♠ 9♠ J♠ Q♠ K♠→7♠ 8♠ 9♠
J♠ Q♠ ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Merge_sort | Sorting algorithms/Merge sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Sub copyArray(a() As Integer, iBegin As Integer, iEnd As Integer, b() As Integer)
Redim b(iBegin To iEnd - 1) As Integer
For k As Integer = iBegin To iEnd - 1
b(k) = a(k)
Next
End Sub
' Left source half is a(iBegin To iMiddle-1).
' Right source half is a(iMiddle To iEnd-1).
' Result is... | Give a code snippet in #FreeBASIC
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/Continued_fraction | Continued fraction | continued fraction
Mathworld
a
0
+
b
1
a
1
+
b
2
a
2
+
b
3
a
3
+
⋱
{\displaystyle a_{0}+{\cfrac {b_{1}}{a_{1}+{\cfrac {b_{2}}{a_{2}+{\cfrac {b_{3}}{a_{3}+\ddots }}}}}}}
The task is to write a program which generates su... | #Arturo | Arturo | calc: function [f, n][
[a, b, temp]: 0.0
loop n..1 'i [
[a, b]: call f @[i]
temp: b // a + temp
]
[a, b]: call f @[0]
return a + temp
]
sqrt2: function [n][
(n > 0)? -> [2.0, 1.0] -> [1.0, 1.0]
]
napier: function [n][
a: (n > 0)? -> to :floating n -> 2.0
b: (n > 1)?... | Give a code snippet in #Arturo
continued fraction
Mathworld
a
0
+
b
1
a
1
+
b
2
a
2
+
b
3
a
3
+
⋱
{\displaystyle a_{0}+{\cfrac {b_{1}}{a_{1}+{\cfrac {b_{2}}{a_{2}+{\cfrac {b_{3}}{a_{3}+\ddots }}}}}}}
The task is to wr... | 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 ... | #Nim | Nim | import algorithm, strutils
proc median(xs: seq[float]): float =
var ys = xs
sort(ys, system.cmp[float])
0.5 * (ys[ys.high div 2] + ys[ys.len div 2])
var a = @[4.1, 5.6, 7.2, 1.7, 9.3, 4.4, 3.2]
echo formatFloat(median(a), precision = 0)
a = @[4.1, 7.2, 1.7, 9.3, 4.4, 3.2]
echo formatFloat(median(a), precisio... | Give a code snippet in #Nim
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.
... | 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
| #6502_Assembly | 6502 Assembly | org $1200
SoundRam equ $1200 ;some assemblers require equ directives to not be indented.
SoundChannel_One equ $1200
SoundChannel_Two equ $1201
SoundChannel_Three equ $1202
LDA #$FF ;this still gets assembled starting at $1200, since equ directives don't take up space! | Give a code snippet in #6502_Assembly
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/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #HicEst | HicEst | CHARACTER c, txt='abc? XYZ!', cod*100
DO i = 1, LEN_TRIM(txt)
c = txt(i)
n = ICHAR(txt(i))
IF( (c >= 'a') * (c <= 'm') + (c >= 'A') * (c <= 'M') ) THEN
c = CHAR( ICHAR(c) + 13 )
ELSEIF( (c >= 'n') * (c <= 'z') + (c >= 'N') * (c <= 'Z') ) THEN
c = CHAR( ICHAR(c) - 13 )
ENDIF
... | Give a code snippet in #HicEst
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Smith_numbers | Smith numbers | Smith numbers are numbers such that the sum of the decimal digits of the integers that make up that number is the same as the sum of the decimal digits of its prime factors excluding 1.
By definition, all primes are excluded as they (naturally) satisfy this condition!
Smith numbers are also known as joke numbers.... | #PARI.2FGP | PARI/GP | isSmith(n)=my(f=factor(n)); if(#f~==1 && f[1,2]==1, return(0)); sum(i=1, #f~, sumdigits(f[i, 1])*f[i, 2]) == sumdigits(n);
select(isSmith, [1..9999]) | Give a code snippet in #PARI.2FGP
Smith numbers are numbers such that the sum of the decimal digits of the integers that make up that number is the same as the sum of the decimal digits of its prime factors excluding 1.
By definition, all primes are excluded as they (naturally) satisfy this condition!
Smith numbers ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_missing_permutation | Find the missing permutation | ABCD
CABD
ACDB
DACB
BCDA
ACBD
ADCB
CDAB
DABC
BCAD
CADB
CDBA
... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | ProvidedSet = {"ABCD" , "CABD" , "ACDB" , "DACB" , "BCDA" , "ACBD",
"ADCB" , "CDAB", "DABC", "BCAD" , "CADB", "CDBA" , "CBAD" , "ABDC",
"ADBC" , "BDCA", "DCBA" , "BACD", "BADC", "BDAC" , "CBDA", "DBCA", "DCAB"};
Complement[StringJoin /@ Permutations@Characters@First@#, #] &@ProvidedSet
->{"DBAC"} | Give a code snippet in #Mathematica_.2F_Wolfram_Language
ABCD
CABD
ACDB
DACB
BCDA
ACBD
ADCB
CDAB
DABC
BCAD
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/JSON | JSON | Load a JSON string into a data structure.
Also, create a new data structure and serialize it into JSON.
Use objects and arrays (as appropriate for your language)
and make sure your JSON is valid (https://jsonformatter.org).
| #Sidef | Sidef | var json = require('JSON').new;
var data = json.decode('{"blue": [1, 2], "ocean": "water"}');
say data;
data{:ocean} = Hash.new(water => %w[fishy salty]);
say json.encode(data); | Give a code snippet in #Sidef
Load a JSON string into a data structure.
Also, create a new data structure and serialize it into JSON.
Use objects and arrays (as appropriate for your language)
and make sure your JSON is valid (https://jsonformatter.org).
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Pierpont_primes | Pierpont primes | A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v .
A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v .
The term "Pierpont primes" is generally understood to mean the first definition, but will be c... | #Sidef | Sidef | func smooth_generator(primes) {
var s = primes.len.of { [1] }
{
var n = s.map { .first }.min
{ |i|
s[i].shift if (s[i][0] == n)
s[i] << (n * primes[i])
} * primes.len
n
}
}
func pierpont_primes(n, k = 1) {
var g = smooth_generator([2,3])
1..I... | Give a code snippet in #Sidef
A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v .
A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v .
The term "Pierpont primes" is generally understood to mean the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Input_loop | Input loop | Input loop is part of Short Circuit's Console Program Basics selection.
Task
Read from a text stream either word-by-word or line-by-line until the stream runs out of data.
The stream will have an unknown amount of data on it.
| #C.2B.2B | C++ |
#include <istream>
#include <string>
#include <vector>
#include <algorithm>
#include <iostream>
#include <iterator>
// word by word
template<class OutIt>
void read_words(std::istream& is, OutIt dest)
{
std::string word;
while (is >> word)
{
// send the word to the output iterator
*dest = word;
}
}
... | Give a code snippet in #C.2B.2B
Input loop is part of Short Circuit's Console Program Basics selection.
Task
Read from a text stream either word-by-word or line-by-line until the stream runs out of data.
The stream will have an unknown amount of data on it.
| 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... | #Go | Go | package main
import "fmt"
func main() {
for _, n := range []int{0, 1, 2, 3, 4, 5, 10, 40, -1} {
f, ok := arFib(n)
if ok {
fmt.Printf("fib %d = %d\n", n, f)
} else {
fmt.Println("fib undefined for negative numbers")
}
}
}
func arFib(n int) (int, bool)... | Give a code snippet in #Go
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/Nth_root | Nth root | Task
Implement the algorithm to compute the principal nth root
A
n
{\displaystyle {\sqrt[{n}]{A}}}
of a positive real number A, as explained at the Wikipedia page.
| #jq | jq | # An iterative algorithm for finding: self ^ (1/n) to the given
# absolute precision if "precision" > 0, or to within the precision
# allowed by IEEE 754 64-bit numbers.
# The following implementation handles underflow caused by poor estimates.
def iterative_nth_root(n; precision):
def abs: if . < 0 then -. else .... | Give a code snippet in #jq
Task
Implement the algorithm to compute the principal nth root
A
n
{\displaystyle {\sqrt[{n}]{A}}}
of a positive real number A, as explained at the Wikipedia page.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
... | #PARI.2FGP | PARI/GP | num_first_last_digits(a=5,b=4^3^2,n=20)={ my(L = b*log(a)/log(10), m=Mod(a,10^n)^b);
[L\1+1, 10^frac(L)\10^(1-n), lift(m)] \\ where x\y = floor(x/y) but more efficient
}
print("Length, first and last 20 digits of 5^4^3^2: ", num_first_last_digits()) \\ uses default values a=5, b=4^3^2, n=20 | Give a code snippet in #PARI.2FGP
Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abbreviations,_automatic | Abbreviations, automatic | 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.
It would make a list of words easier to maintain (as words are added, changed, and/or deleted) if
the minimum abbrevia... | #AArch64_Assembly | AArch64 Assembly |
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program abbrAuto64.s */
/* store list of day in a file listDays.txt*/
/* and run the program abbrAuto64 listDays.txt */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for t... | Give a code snippet in #AArch64_Assembly
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.
It would make a list of words easier to maintain (as words are added, changed,... | 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... | #Nim | Nim | proc `^`[T: float|int](base: T; exp: int): T =
var (base, exp) = (base, exp)
result = 1
if exp < 0:
when T is int:
if base * base != 1: return 0
elif (exp and 1) == 0: return 1
else: return base
else:
base = 1.0 / base
exp = -exp
while exp != 0:
if (exp and 1) != 0:... | Give a code snippet in #Nim
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 proce... | 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 |... | #C | C | #include <string.h>
#include <stdio.h>
int startsWith(const char* container, const char* target)
{
size_t clen = strlen(container), tlen = strlen(target);
if (clen < tlen)
return 0;
return strncmp(container, target, tlen) == 0;
}
int endsWith(const char* container, const char* target)
{
size_t clen = st... | Give a code snippet in #C
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
Conc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Aliquot_sequence_classifications | Aliquot sequence classifications | An aliquot sequence of a positive integer K is defined recursively as the first member
being K and subsequent members being the sum of the Proper divisors of the previous term.
If the terms eventually reach 0 then the series for K is said to terminate.
There are several classifications for non termination:
If the s... | #Ruby | Ruby | def aliquot(n, maxlen=16, maxterm=2**47)
return "terminating", [0] if n == 0
s = []
while (s << n).size <= maxlen and n < maxterm
n = n.proper_divisors.inject(0, :+)
if s.include?(n)
case n
when s[0]
case s.size
when 1 then return "perfect", s
when 2 then return... | Give a code snippet in #Ruby
An aliquot sequence of a positive integer K is defined recursively as the first member
being K and subsequent members being the sum of the Proper divisors of the previous term.
If the terms eventually reach 0 then the series for K is said to terminate.
There are several classifications ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Semordnilap | Semordnilap | A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total number of unique semordnilap ... | #Stata | Stata | set seed 17760704
import delimited http://www.puzzlers.org/pub/wordlists/unixdict.txt, clear
save temp, replace
replace v1=strreverse(v1)
merge 1:1 v1 using temp, nogen keep(3)
drop if v1>=strreverse(v1)
count
158
sample 5, count
gen v2=strreverse(v1)
list, noheader noobs
+-------------+
| evil live |
| pat ... | Give a code snippet in #Stata
A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the tota... | 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... | #Trith | Trith | 10 inc iota reverse [print] each | Give a code snippet in #Trith
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/Increm... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SEDOLs | SEDOLs | Task
For each number list of 6-digit SEDOLs, calculate and append the checksum digit.
That is, given this input:
710889
B0YBKJ
406566
B0YBLH
228276
B0YBKL
557910
B0YBKR
585284
B0YBKT
B00030
Produce this output:
7108899
B0YBKJ7
4065663
B0YBLH2
2282765
B0YBKL9
5579107
B0YBKR5
5852842
B0YBKT7
B000300
Extra credit
... | #Standard_ML | Standard ML | fun char2value c =
if List.exists (fn x => x = c) (explode "AEIOU") then raise Fail "no vowels"
else if Char.isDigit c then ord c - ord #"0"
else if Char.isUpper c then ord c - ord #"A" + 10
else raise Match
val sedolweight = [1,3,1,7,3,9]
fun checksum sedol = let
val tmp = ListPair.foldlEq (fn (ch, weigh... | Give a code snippet in #Standard_ML
Task
For each number list of 6-digit SEDOLs, calculate and append the checksum digit.
That is, given this input:
710889
B0YBKJ
406566
B0YBLH
228276
B0YBKL
557910
B0YBKR
585284
B0YBKT
B00030
Produce this output:
7108899
B0YBKJ7
4065663
B0YBLH2
2282765
B0YBKL9
5579107
B0YBKR5
5... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Image_noise | Image noise | Generate a random black and white 320x240 image continuously,
showing FPS (frames per second).
A sample image
| #Factor | Factor | USING: accessors calendar images images.viewer kernel math
math.parser models models.arrow random sequences threads timers
ui ui.gadgets ui.gadgets.labels ui.gadgets.packs ;
IN: rosetta-code.image-noise
: bits>pixels ( bits -- bits' pixels )
[ -1 shift ] [ 1 bitand ] bi 255 * ; inline
: ?generate-more-bits ( a ... | Give a code snippet in #Factor
Generate a random black and white 320x240 image continuously,
showing FPS (frames per second).
A sample image
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Here_document | Here document | A here document (or "heredoc") is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text.
Depending on the language being used, a here document is constructed using a command followed by "<<" (or some other symbol) followed by a token string.
The text ... | #Raku | Raku | my $color = 'green';
say qq :to 'END';
some line
color: $color
another line
END | Give a code snippet in #Raku
A here document (or "heredoc") is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text.
Depending on the language being used, a here document is constructed using a command followed by "<<" (or some other symbol) followed... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Image_noise | Image noise | Generate a random black and white 320x240 image continuously,
showing FPS (frames per second).
A sample image
| #Haskell | Haskell | cabal install glfw-b | Give a code snippet in #Haskell
Generate a random black and white 320x240 image continuously,
showing FPS (frames per second).
A sample image
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Inheritance/Single | Inheritance/Single | This task is about derived types; for implementation inheritance, see Polymorphism.
Inheritance is an operation of type algebra that creates a new type from one or several parent types.
The obtained type is called derived type.
It inherits some of the properties of its parent types.
Usually inherited properties... | #Scala | Scala | class Animal
class Dog extends Animal
class Cat extends Animal
class Lab extends Dog
class Collie extends Dog | Give a code snippet in #Scala
This task is about derived types; for implementation inheritance, see Polymorphism.
Inheritance is an operation of type algebra that creates a new type from one or several parent types.
The obtained type is called derived type.
It inherits some of the properties of its parent types... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mind_boggling_card_trick | Mind boggling card trick | Mind boggling card trick
You are encouraged to solve this task according to the task description, using any language you may know.
Matt Parker of the "Stand Up Maths channel" has a YouTube video of a card trick that creates a semblance of order from chaos.
The task is to simulate the trick in a way that mimics th... | #Phix | Phix | with javascript_semantics
constant n = 52,
pack = shuffle(repeat('r',n/2)&repeat('b',n/2))
string black = "", red = "", discard = ""
for i=1 to length(pack) by 2 do
integer top = pack[i],
next = pack[i+1]
if top=='b' then
black &= next
else
red &= next
end if
d... | Give a code snippet in #Phix
Mind boggling card trick
You are encouraged to solve this task according to the task description, using any language you may know.
Matt Parker of the "Stand Up Maths channel" has a YouTube video of a card trick that creates a semblance of order from chaos.
The task is to simulate the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mean_angle | Averages/Mean angle | When calculating the average or mean of an angle one has to take into account how angles wrap around so that any angle in degrees plus any integer multiple of 360 degrees is a measure of the same angle.
If one wanted an average direction of the wind over two readings where the first reading was of 350 degrees and the ... | #F.23 | F# | open System
open System.Numerics
let deg2rad d = d * Math.PI / 180.
let rad2deg r = r * 180. / Math.PI
[<EntryPoint>]
let main argv =
let makeComplex = fun r -> Complex.FromPolarCoordinates(1., r)
argv
|> Seq.map (Double.Parse >> deg2rad >> makeComplex)
|> Seq.fold (fun x y -> Complex.Add(x,y)) Com... | Give a code snippet in #F.23
When calculating the average or mean of an angle one has to take into account how angles wrap around so that any angle in degrees plus any integer multiple of 360 degrees is a measure of the same angle.
If one wanted an average direction of the wind over two readings where the first readi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_a_file | Create a file | In this task, the job is to create a new empty file called "output.txt" of size 0 bytes
and an empty directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| #BASIC | BASIC | OPEN "output.txt" FOR OUTPUT AS 1
CLOSE
OPEN "\output.txt" FOR OUTPUT AS 1
CLOSE | Give a code snippet in #BASIC
In this task, the job is to create a new empty file called "output.txt" of size 0 bytes
and an empty directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Singleton | Singleton | A Global Singleton is a class of which only one instance exists within a program.
Any attempt to use non-static members of the class involves performing operations on this one instance.
| #Raku | Raku | class Singleton {
# We create a lexical variable in the class block that holds our single instance.
my Singleton $instance = Singleton.bless; # You can add initialization arguments here.
method new {!!!} # Singleton.new dies.
method instance { $instance; }
} | Give a code snippet in #Raku
A Global Singleton is a class of which only one instance exists within a program.
Any attempt to use non-static members of the class involves performing operations on this one instance.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #SNOBOL4 | SNOBOL4 | output = host(4,'PATH')
end | Give a code snippet in #SNOBOL4
Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sexy_primes | Sexy primes |
This page uses content from Wikipedia. The original article was at Sexy_prime. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In mathematics, sexy primes are prime numbers that differ from each ot... | #Julia | Julia |
using Primes
function nextby6(n, a)
top = length(a)
i = n + 1
j = n + 2
k = n + 3
if n >= top
return n
end
possiblenext = a[n] + 6
if i <= top && possiblenext == a[i]
return i
elseif j <= top && possiblenext == a[j]
return j
elseif k <= top && possible... | Give a code snippet in #Julia
This page uses content from Wikipedia. The original article was at Sexy_prime. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In mathematics, sexy primes are prime n... | 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... | #Wren | Wren | import "io" for Stdin, Stdout
System.write("Do you want to terminate the program y/n ? ")
Stdout.flush()
var yn = Stdin.readLine()
if (yn == "y" || yn == "Y") {
System.print("OK, shutting down")
Fiber.suspend() // return to OS
}
System.print("OK, carrying on") | Give a code snippet in #Wren
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers/... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Lucas-Lehmer_test | Lucas-Lehmer test | Lucas-Lehmer Test:
for
p
{\displaystyle p}
an odd prime, the Mersenne number
2
p
−
1
{\displaystyle 2^{p}-1}
is prime if and only if
2
p
−
1
{\displaystyle 2^{p}-1}
divides
S
(
p
−
1
)
{\displaystyle S(p-1)}
where
S
(
n
+
1
)
=
(
S
(
n
)
)
2
−
2
{\displaystyle S(n+1)=(... | #Modula-3 | Modula-3 | MODULE LucasLehmer EXPORTS Main;
IMPORT IO, Fmt, Long;
PROCEDURE Mersenne(p: CARDINAL): BOOLEAN =
VAR
s := 4L;
m := Long.Shift(1L, p) - 1L; (* 2^p - 1 *)
BEGIN
IF p = 2 THEN
RETURN TRUE;
ELSE
FOR i := 3 TO p DO
s := (s * s - 2L) MOD m;
END;
RETURN s = 0L;
END... | Give a code snippet in #Modula-3
Lucas-Lehmer Test:
for
p
{\displaystyle p}
an odd prime, the Mersenne number
2
p
−
1
{\displaystyle 2^{p}-1}
is prime if and only if
2
p
−
1
{\displaystyle 2^{p}-1}
divides
S
(
p
−
1
)
{\displaystyle S(p-1)}
where
S
(
n
+
1
)
=
(
S
(
n
)
)
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stack_traces | Stack traces | Many programming languages allow for introspection of the current call stack environment. This can be for a variety of purposes such as enforcing security checks, debugging, or for getting access to the stack frame of callers.
Task
Print out (in a manner considered suitable for the platform) the current call stack.... | #C.23 | C# | using System;
using System.Diagnostics;
class Program
{
static void Inner()
{
Console.WriteLine(new StackTrace());
}
static void Middle()
{
Inner();
}
static void Outer()
{
Middle();
}
static void Main()
{
Outer();
}
} | Give a code snippet in #C.23
Many programming languages allow for introspection of the current call stack environment. This can be for a variety of purposes such as enforcing security checks, debugging, or for getting access to the stack frame of callers.
Task
Print out (in a manner considered suitable for the pla... | 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 ... | #Wren | Wren | import "io" for File
var lines = File.read("mlijobs.txt").replace("\r", "").split("\n")
var out = 0
var max = 0
var times = []
for (line in lines) {
if (line.startsWith("License OUT")) {
out = out + 1
if (out >= max) {
var sp = line.split(" ")
if (out > max) {
... | Give a code snippet in #Wren
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 chec... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
... | #Phixmonti | Phixmonti | def ack
var n var m
m 0 == if
n 1 +
else
n 0 == if
m 1 - 1 ack
else
m 1 - m n 1 - ack ack
endif
endif
enddef
3 6 ack print nl | Give a code snippet in #Phixmonti
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_an_HTML_table | Create an HTML table | Create an HTML table.
The table body should have at least three rows of three columns.
Each of these three columns should be labelled "X", "Y", and "Z".
An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled with sequential row numbers.
The... | #ALGOL_68 | ALGOL 68 | INT not numbered = 0; # possible values for HTMLTABLE row numbering #
INT numbered left = 1; # " " " " " " #
INT numbered right = 2; # " " " " " " #
INT align centre = 0; # possible values for HTMLTABLE column alignment #
INT align ... | Give a code snippet in #ALGOL_68
Create an HTML table.
The table body should have at least three rows of three columns.
Each of these three columns should be labelled "X", "Y", and "Z".
An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Remove_duplicate_elements | Remove duplicate elements |
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
... | #PicoLisp | PicoLisp | (uniq (2 4 6 1 2 3 4 5 6 1 3 5)) | Give a code snippet in #PicoLisp
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/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... | #Java | Java | public class Str{
public static void main(String[] args){
String s = "hello";
System.out.println(s + " literal");
String s2 = s + " literal";
System.out.println(s2);
}
} | Give a code snippet in #Java
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 lite... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #SPAD | SPAD | (1) -> originalMatrix := matrix [[1, 1, 1, 1],[2, 4, 8, 16], _
[3, 9, 27, 81],[4, 16, 64, 256], _
[5, 25, 125, 625]]
+1 1 1 1 +
| |
|2 4 8 16 |
| |
(1) |3 9 27 81 |
... | Give a code snippet in #SPAD
Transpose an arbitrarily sized rectangular Matrix.
| 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 ... | #Forth | Forth | ( ANSI terminal control lexicon Colored Text)
DECIMAL
( support routines)
27 CONSTANT ESC
: <##> ( n -- ) ( sends n, radix 10, no spaces)
BASE @ >R 0 <# #S #> TYPE R> BASE ! ;
: ESC[ ( -- ) ESC EMIT ." [" ;
( Attributes )
1 CONSTANT BOLD 2 CONSTANT DIM 3 CONSTANT ITALIC
5 CONSTANT BLINK ... | Give a code snippet in #Forth
Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Lingo | Lingo | ----------------------------------------
-- Simplified CSV parser (without escape character support etc.).
-- First line is interrepted as header with column names.
-- @param {string} csvStr
-- @param {string} [sep=","] - single char as string
-- @param {string} [eol=RETURN]
-- @return {propList}
----------------------... | Give a code snippet in #Lingo
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, chan... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rosetta_Code/Rank_languages_by_popularity | Rosetta Code/Rank languages by popularity | Rosetta Code/Rank languages by popularity
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Sort the most popular computer programming languages based in number of members in Rosetta Code categories.
Sample output on 01 juin 2022 at 14:13 +02
Rank: 1 (1,... | #Ruby | Ruby | require 'rosettacode'
langs = []
RosettaCode.category_members("Programming Languages") {|lang| langs << lang}
# API has trouble with long titles= values.
# To prevent skipping languages, use short slices of 20 titles.
langcount = {}
langs.each_slice(20) do |sublist|
url = RosettaCode.get_api_url({
"action" =>... | Give a code snippet in #Ruby
Rosetta Code/Rank languages by popularity
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Sort the most popular computer programming languages based in number of members in Rosetta Code categories.
Sample output on 01 juin 2... | 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... | #Fish | Fish | 1001-p01.
>0101-p02.
>101-g001-g+:::aa*)?v101-p03.
>02-g?v1}02-p02. >05.
>0}02-p02.
>~~~0101-p001-g:1+001-paa*)?v02.
>07.
>0101-p08.
>101-g::02-g?v >1+:101-paa*=?;
>n" "o^ | Give a code snippet in #Fish
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, ...... | 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 ... | #Lua | Lua |
-- None is represented by an empty table. Some is represented by any
-- array with one element. You SHOULD NOT compare maybe values with the
-- Lua operator == because it will give incorrect results. Use the
-- functions isMaybe(), isNone(), and isSome().
-- define once for efficiency, to avoid many different em... | Give a code snippet in #Lua
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/FizzBuzz | FizzBuzz | Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuzz (instead of the number)
... | #Clipper | Clipper | PROCEDURE Main()
LOCAL n
LOCAL cFB
FOR n := 1 TO 100
cFB := ""
AEval( { { 3, "Fizz" }, { 5, "Buzz" } }, {|x| cFB += iif( ( n % x[ 1 ] ) == 0, x[ 2 ], "" ) } )
?? iif( cFB == "", LTrim( Str( n ) ), cFB ) + iif( n == 100, ".", ", " )
NEXT
RETURN
| Give a code snippet in #Clipper
Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Maximum_triangle_path_sum | Maximum triangle path sum | Starting from the top of a pyramid of numbers like this, you can walk down going one step on the right or on the left, until you reach the bottom row:
55
94 48
95 30 96
77 71 26 67
One of such walks is 55 - 94 - 30 - 26.
You... | #Kotlin | Kotlin | // version 1.1.2
val tri = intArrayOf(
55,
94, 48,
95, 30, 96,
77, 71, 26, 67,
97, 13, 76, 38, 45,
7, 36, 79, 16, 37, 68,
48, 7, 9, 18, 70, 26, 6,
18, 72, 79, 46, 59, 79, 29, 90,
20, 76, 87, 11, 32, 7, 7, 49, 18,
27, 83, 58, 35, 71, 11, 25, 57, 29, 85,
14, 64, 36, 96,... | Give a code snippet in #Kotlin
Starting from the top of a pyramid of numbers like this, you can walk down going one step on the right or on the left, until you reach the bottom row:
55
94 48
95 30 96
77 71 26 67
One of such... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Monads/Writer_monad | Monads/Writer monad | The Writer monad is a programming design pattern which makes it possible to compose functions which return their result values paired with a log string. The final result of a composed function yields both a value, and a concatenation of the logs from each component function application.
Demonstrate in your programming... | #Python | Python | """A Writer Monad. Requires Python >= 3.7 for type hints."""
from __future__ import annotations
import functools
import math
import os
from typing import Any
from typing import Callable
from typing import Generic
from typing import List
from typing import TypeVar
from typing import Union
T = TypeVar("T")
cl... | Give a code snippet in #Python
The Writer monad is a programming design pattern which makes it possible to compose functions which return their result values paired with a log string. The final result of a composed function yields both a value, and a concatenation of the logs from each component function application.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_variables | Special variables | Special variables have a predefined meaning within a computer programming language.
Task
List the special variables used within the language.
| #Maxima | Maxima | /* There are many special variables in Maxima: more than 250 are used for options, for example */
fpprec; /* precision for big floats */
obase; /* number base for output */
/* Other variables are read-only, and give the list of user-defined variables, functions... */
infolists; /* give the names of all available l... | Give a code snippet in #Maxima
Special variables have a predefined meaning within a computer programming language.
Task
List the special variables used within the language.
| 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... | #TXR | TXR | This is the TXR Lisp interactive listener of TXR 176.
Use the :quit command or type Ctrl-D on empty line to exit.
1> (typedef utsarray (zarray 65 char))
#<ffi-type (zarray 65 char)>
2> (typedef utsname (struct utsname (sysname utsarray)
(nodename utsarray)
... | Give a code snippet in #TXR
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 ... | 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... | #Wren | Wren | /* send_email.wren */
foreign class Authority {
construct plainAuth(identity, username, password, host) {}
}
class SMTP {
foreign static sendMail(address, auth, from, to, msg)
}
class Message {
static check(host, user, pass) {
if (host == "") Fiber.abort("Bad host")
if (user == "") Fib... | Give a code snippet in #Wren
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.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rosetta_Code/Fix_code_tags | Rosetta Code/Fix code tags | Task
Fix Rosetta Code deprecated code tags, with these rules:
Change <%s> to <lang %s>
Change </%s> to </lang>
Change <code %s> to <lang %s>
Change </code> to </lang>
Usage
./convert.py < wikisource.txt > converted.txt
| #Perl | Perl | my @langs = qw(ada cpp-qt pascal lscript z80 visualprolog
html4strict cil objc asm progress teraterm hq9plus genero tsql
email pic16 tcl apt_sources io apache vhdl avisynth winbatch
vbnet ini scilab ocaml-brief sas actionscript3 qbasic perl bnf
cobol powershell php kixtart visualfoxpro mirc make javascript
cpp sdlbasic... | Give a code snippet in #Perl
Task
Fix Rosetta Code deprecated code tags, with these rules:
Change <%s> to <lang %s>
Change </%s> to </lang>
Change <code %s> to <lang %s>
Change </code> to </lang>
Usage
./convert.py < wikisource.txt > converted.txt
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Multisplit | Multisplit | It is often necessary to split a string into pieces
based on several different (potentially multi-character) separator strings,
while still retaining the information about which separators were present in the input.
This is particularly useful when doing small parsing tasks.
The task is to write code to demonstrate ... | #zkl | zkl | fcn multisplit(text, sep){
lastmatch := i := 0; matches := List();
while(i < text.len()){
foreach j,s in ([0..].zip(sep)){
if(i == text.find(s,i)){
if(i > lastmatch) matches.append(text[lastmatch,i-lastmatch]);
matches.append(T(j,i)); # Replace the string containing the matched separator... | Give a code snippet in #zkl
It is often necessary to split a string into pieces
based on several different (potentially multi-character) separator strings,
while still retaining the information about which separators were present in the input.
This is particularly useful when doing small parsing tasks.
The task is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/The_ISAAC_Cipher | The ISAAC Cipher | ISAAC is a cryptographically secure pseudo-random number generator (CSPRNG) and stream cipher. It was developed by Bob Jenkins from 1993 (http://burtleburtle.net/bob/rand/isaac.html) and placed in the Public Domain. ISAAC is fast - especially when optimised - and portable to most architectures in nearly all programming... | #Phix | Phix | --
-- demo\rosetta\ISAAC_Cipher.exw
--
with javascript_semantics
sequence randrsl = repeat(0,256)
integer randcnt
sequence mm
atom aa,bb,cc
function r32(object a)
if sequence(a) then
for i=1 to length(a) do
a[i] = r32(a[i])
end for
return a
end if
if a<0 then a+=#10000... | Give a code snippet in #Phix
ISAAC is a cryptographically secure pseudo-random number generator (CSPRNG) and stream cipher. It was developed by Bob Jenkins from 1993 (http://burtleburtle.net/bob/rand/isaac.html) and placed in the Public Domain. ISAAC is fast - especially when optimised - and portable to most architect... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reverse_a_string | Reverse a string | Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
... | #Cach.C3.A9_ObjectScript | Caché ObjectScript | USER>Write $Reverse("Hello, World")
dlroW ,olleH | Give a code snippet in #Cach.C3.A9_ObjectScript
Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stirling_numbers_of_the_first_kind | Stirling numbers of the first kind | Stirling numbers of the first kind, or Stirling cycle numbers, count permutations according to their number
of cycles (counting fixed points as cycles of length one).
They may be defined directly to be the number of permutations of n
elements with k disjoint cycles.
Stirling numbers of the first kind express coeffici... | #jq | jq | # For efficiency, define the helper function for `stirling1/2` as a
# top-level function so we can use it directly for constructing the table:
# input: [m,j,cache]
# output: [s, cache]
def stirling1:
. as [$m, $j, $cache]
| "\($m),\($j)" as $key
| $cache
| if has($key) then [.[$key], .]
e... | Give a code snippet in #jq
Stirling numbers of the first kind, or Stirling cycle numbers, count permutations according to their number
of cycles (counting fixed points as cycles of length one).
They may be defined directly to be the number of permutations of n
elements with k disjoint cycles.
Stirling numbers of the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Angle_difference_between_two_bearings | Angle difference between two bearings | Finding the angle between two bearings is often confusing.[1]
Task
Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings.
Input bearings are expressed in the range -180 to +180 degrees.
The result is also expressed in the range -180 to +180 degrees.
... | #APL | APL | [0] D←B1 DIFF B2
[1] D←180+¯360|180+B2-B1
| Give a code snippet in #APL
Finding the angle between two bearings is often confusing.[1]
Task
Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings.
Input bearings are expressed in the range -180 to +180 degrees.
The result is also expressed in the range -1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pernicious_numbers | Pernicious numbers | A pernicious number is a positive integer whose population count is a prime.
The population count is the number of ones in the binary representation of a non-negative integer.
Example
22 (which is 10110 in binary) has a population count of 3, which is prime, and therefore
22 is a pe... | #Clojure | Clojure | (defn counting-numbers
([] (counting-numbers 1))
([n] (lazy-seq (cons n (counting-numbers (inc n))))))
(defn divisors [n] (filter #(zero? (mod n %)) (range 1 (inc n))))
(defn prime? [n] (= (divisors n) (list 1 n)))
(defn pernicious? [n]
(prime? (count (filter #(= % \1) (Integer/toString n 2)))))
(println (take 25 (... | Give a code snippet in #Clojure
A pernicious number is a positive integer whose population count is a prime.
The population count is the number of ones in the binary representation of a non-negative integer.
Example
22 (which is 10110 in binary) has a population count of 3, which is pri... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Input_loop | Input loop | Input loop is part of Short Circuit's Console Program Basics selection.
Task
Read from a text stream either word-by-word or line-by-line until the stream runs out of data.
The stream will have an unknown amount of data on it.
| #Phix | Phix | without js -- (file i/o)
procedure process_line_by_line(integer fn)
object line
while 1 do
line = gets(fn)
if atom(line) then
exit
end if
-- process the line
end while
end procedure
| Give a code snippet in #Phix
Input loop is part of Short Circuit's Console Program Basics selection.
Task
Read from a text stream either word-by-word or line-by-line until the stream runs out of data.
The stream will have an unknown amount of data on it.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newbie | Hello world/Newbie | Task
Guide a new user of a language through the steps necessary
to install the programming language and selection of a text editor if needed,
to run the languages' example in the Hello world/Text task.
Assume the language-newbie is a programmer in another language.
Assume the language-newbie is competent in install... | #ARM_Assembly | ARM Assembly |
create file helloword.s
compile it with : as -o helloword.o helloword.s
link it with : ld -o helloword helloword.o -e main
execute it : helloword
| Give a code snippet in #ARM_Assembly
Task
Guide a new user of a language through the steps necessary
to install the programming language and selection of a text editor if needed,
to run the languages' example in the Hello world/Text task.
Assume the language-newbie is a programmer in another language.
Assume the l... | 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 ... | #Ada | Ada | generic
type Number is private;
Zero : Number;
One : Number;
Two : Number;
with function "+" (X, Y : Number) return Number is <>;
with function "*" (X, Y : Number) return Number is <>;
with function "/" (X, Y : Number) return Number is <>;
with function "mod" (X, Y : Number) return Numbe... | Give a code snippet in #Ada
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 pr... | 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... | #Action.21 | Action! | BYTE FUNC IsAlmostPrime(INT num BYTE k)
INT f,p,v
f=0 p=2 v=num
WHILE f<k AND p*p<=num
DO
WHILE v MOD p=0
DO
v==/p f==+1
OD
p==+1
OD
IF v>1 THEN
f==+1
FI
IF f=k THEN
RETURN (1)
FI
RETURN (0)
PROC Main()
BYTE count,k
INT i
FOR k=1 TO 5
DO
PrintF("k=%B:",k... | Give a code snippet in #Action.21
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/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... | #Visual_FoxPro | Visual FoxPro |
CLOSE DATABASES ALL
CREATE CURSOR pairs(id I, xcoord B(6), ycoord B(6))
INSERT INTO pairs VALUES (1, 0.654682, 0.925557)
INSERT INTO pairs VALUES (2, 0.409382, 0.619391)
INSERT INTO pairs VALUES (3, 0.891663, 0.888594)
INSERT INTO pairs VALUES (4, 0.716629, 0.996200)
INSERT INTO pairs VALUES (5, 0.477721, 0.946355)
I... | Give a code snippet in #Visual_FoxPro
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
Provi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #Ksh | Ksh |
#!/bin/ksh
# rot-13 function
# # Variables:
#
integer ROT_NUM=13 # Generalize to any ROT
string1="A2p" # Default "test"
string=${1:-${string1}} # Allow command line input
typeset -a lcalph=( a b c d e f g h i j k l m n o p q r s t u v w x y z )
typeset -a ucalph=( A B C D E F G H I J K L M N O P Q R S T... | Give a code snippet in #Ksh
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Move-to-front_algorithm | Move-to-front algorithm | Given a symbol table of a zero-indexed array of all possible input symbols
this algorithm reversibly transforms a sequence
of input symbols into an array of output numbers (indices).
The transform in many cases acts to give frequently repeated input symbols
lower indices which is useful in some compression algorithms... | #C.2B.2B | C++ |
#include <iostream>
#include <iterator>
#include <sstream>
#include <vector>
using namespace std;
class MTF
{
public:
string encode( string str )
{
fillSymbolTable();
vector<int> output;
for( string::iterator it = str.begin(); it != str.end(); it++ )
{
for( int i = 0; i < 26; i++ )
{
if( *... | Give a code snippet in #C.2B.2B
Given a symbol table of a zero-indexed array of all possible input symbols
this algorithm reversibly transforms a sequence
of input symbols into an array of output numbers (indices).
The transform in many cases acts to give frequently repeated input symbols
lower indices which is usef... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For_with_a_specified_step | Loops/For with a specified step |
Task
Demonstrate a for-loop where the step-value is greater than one.
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 b... | #Ada | Ada | with Loopers;
use Loopers;
procedure For_Main is
begin
Looper_1;
Looper_2;
Looper_3;
end For_Main;
package Loopers is
procedure Looper_1;
procedure Looper_2;
procedure Looper_3;
end Loopers;
with Ada.Text_IO, Ada.Integer_Text_IO;
use Ada.Text_IO, Ada.Integer_Tex... | Give a code snippet in #Ada
Task
Demonstrate a for-loop where the step-value is greater than one.
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/Incre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #Erlang | Erlang |
-module(catalin).
-compile(export_all).
mul(N,D,S,S)->
N2=N*(S+S),
D2=D*S,
K = N2 div D2 ;
mul(N,D,S,L)->
N2=N*(S+L),
D2=D*L,
K = mul(N2,D2,S,L+1).
catl(Ans,16) -> Ans;
catl(D,S)->
C=mul(1,1,S,2),
catl([D|C],S+1).
main()->
Ans=catl(1,2).
| Give a code snippet in #Erlang
Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that gen... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_case | String case | Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not reversable.
Show any additional... | #Fortran | Fortran | program example
implicit none
character(9) :: teststring = "alphaBETA"
call To_upper(teststring)
write(*,*) teststring
call To_lower(teststring)
write(*,*) teststring
contains
subroutine To_upper(str)
character(*), intent(in out) :: str
integer :: i
do i = 1, len(str)
... | Give a code snippet in #Fortran
Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #Z80_Assembly | Z80 Assembly | org &8000
ld hl,17
call Halve_Until_1
push bc
ld hl,34
call Double_Until_1
pop bc
call SumOddEntries
;returns Ethiopian product in IX.
call NewLine
call Primm
byte "0x",0
push ix
pop hl
ld a,H
call ShowHex
;Output should be in decimal but hex is easier.
ld a,L
call ShowHex
ret
H... | Give a code snippet in #Z80_Assembly
Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truncatable_primes | Truncatable primes | A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number.
Examples
The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime.
The number 7393 is a right-truncatable prime as the numbers 7393, 7... | #MATLAB | MATLAB | function largestTruncatablePrimes(boundary)
%Helper function for checking if a prime is left of right truncatable
function [leftTruncatable,rightTruncatable] = isTruncatable(prime,checkLeftTruncatable,checkRightTruncatable)
numDigits = ceil(log10(prime)); %calculate the number of digits in the prime... | Give a code snippet in #MATLAB
A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number.
Examples
The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime.
The number 7393 is a right-truncata... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Identity_matrix | Identity matrix | Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
0
1
⋯
0
⋮
⋮
⋮
⋱
... | #ALGOL_W | ALGOL W | begin
% set m to an identity matrix of size s %
procedure makeIdentity( real array m ( *, * )
; integer value s
) ;
for i := 1 until s do begin
for j := 1 until s do m( i, j ) := 0.0;
m( i, i ... | Give a code snippet in #ALGOL_W
Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
... | 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 |... | #ZX_Spectrum_Basic | ZX Spectrum Basic | 10 INPUT "Enter two integers: ";a;" ";b
20 PRINT a;" is ";("less than " AND (a<b));("equal to " AND (a=b));("greather than " AND (a>b));b | Give a code snippet in #ZX_Spectrum_Basic
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jacobi_symbol | Jacobi symbol | The Jacobi symbol is a multiplicative function that generalizes the Legendre symbol. Specifically, the Jacobi symbol (a | n) equals the product of the Legendre symbols (a | p_i)^(k_i), where n = p_1^(k_1)*p_2^(k_2)*...*p_i^(k_i) and the Legendre symbol (a | p) denotes the value of a ^ ((p-1)/2) (mod p)
(a | p) ≡ 1 ... | #Perl | Perl | use strict;
use warnings;
sub J {
my($k,$n) = @_;
$k %= $n;
my $jacobi = 1;
while ($k) {
while (0 == $k % 2) {
$k = int $k / 2;
$jacobi *= -1 if $n%8 == 3 or $n%8 == 5;
}
($k, $n) = ($n, $k);
$jacobi *= -1 if $n%4 == 3 and $k%4 == 3;
$k... | Give a code snippet in #Perl
The Jacobi symbol is a multiplicative function that generalizes the Legendre symbol. Specifically, the Jacobi symbol (a | n) equals the product of the Legendre symbols (a | p_i)^(k_i), where n = p_1^(k_1)*p_2^(k_2)*...*p_i^(k_i) and the Legendre symbol (a | p) denotes the value of a ^ ((p-... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Monty_Hall_problem | Monty Hall problem |
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for the time being.
The game show hos... | #Transact_SQL | Transact SQL |
---- BEGIN ------------
create table MONTY_HALL(
NOE int,
CAR int,
ALTERNATIVE int,
ORIGIN int,
[KEEP] int,
[CHANGE] int,
[RANDOM] int
)
-- INIT
truncate table MONTY_HALL
declare @N int , @i int -- No of Experiments and their counter
declare @rooms int , -- number of rooms
@origin int... | Give a code snippet in #Transact_SQL
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed ... | christopher/rosetta-code |
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