task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
value |
|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Chaocipher | Chaocipher | Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | ClearAll[ichaoalphabet, iMoveToFront, ChaoCipher]
ichaoalphabet = CharacterRange["A", "Z"];
iMoveToFront[l_List, sel_] := Module[{p},
p = FirstPosition[l, sel];
RotateLeft[l, p - 1]
]
ChaoCipher::wrongcipheralpha =
"The cipher alphabet `1` is not a permutation of \
\"A\"\[LongDash]\"Z\".";
ChaoCipher::wrongpla... | Give a code snippet in #Mathematica.2FWolfram_Language
Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Comments | Comments | Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| #Wren | Wren | // This is a line comment.
/* This is a single line block comment.*/
/* This is
a multi-line
block comment.*/
/* This is/* a nested */block comment.*/ | Give a code snippet in #Wren
Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Swift | Swift | func isPrime(_ n: Int) -> Bool {
if n < 2 {
return false
}
if n % 2 == 0 {
return n == 2
}
if n % 3 == 0 {
return n == 3
}
var p = 5
while p * p <= n {
if n % p == 0 {
return false
}
p += 2
if n % p == 0 {
re... | Give a code snippet in #Swift
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-truncatab... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #Sidef | Sidef | class Quaternion(r, i, j, k) {
func qu(*r) { Quaternion(r...) }
method to_s { "#{r} + #{i}i + #{j}j + #{k}k" }
method reals { [r, i, j, k] }
method conj { qu(r, -i, -j, -k) }
method norm { self.reals.map { _*_ }.sum.sqrt }
method ==(Quaternion b) { self.reals == b.reals }
method +... | Give a code snippet in #Sidef
Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap | Bitmap | Show a basic storage type to handle a simple RGB raster graphics image,
and some primitive associated functions.
If possible provide a function to allocate an uninitialised image,
given its width and height, and provide 3 additional functions:
one to fill an image with a plain RGB color,
one to set a given pixe... | #Pascal | Pascal | Interface
uses crt, { GetDir }
graph; { function GetPixel }
type { integer numbers }
{ from unit bitmaps XPERT software production Tamer Fakhoury }
_bit = $00000000..$00000001; {number 1 bit without sign = (0..1) }
_byte = $00000000..$000000FF; {number 1 byte without sign = (0..255)}
_word ... | Give a code snippet in #Pascal
Show a basic storage type to handle a simple RGB raster graphics image,
and some primitive associated functions.
If possible provide a function to allocate an uninitialised image,
given its width and height, and provide 3 additional functions:
one to fill an image with a plain RGB c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/String | Literals/String | Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
Here document
Other tasks r... | #V | V | 'hello world' puts | Give a code snippet in #V
Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
Her... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Comma_quibbling | Comma quibbling | Comma quibbling is a task originally set by Eric Lippert in his blog.
Task
Write a function to generate a string output which is the concatenation of input words from a list/sequence where:
An input of no words produces the output string of just the two brace characters "{}".
An input of just one word, e.g. ["AB... | #XLISP | XLISP | (defun quibble (inputs &optional oxford-comma)
(define final
(if (and (caddr inputs) oxford-comma)
", and "
" and " ) )
(defun comma-quibble (words)
(cond
((null words) "")
((null (cdr words)) (car words))
(t (begin
(str... | Give a code snippet in #XLISP
Comma quibbling is a task originally set by Eric Lippert in his blog.
Task
Write a function to generate a string output which is the concatenation of input words from a list/sequence where:
An input of no words produces the output string of just the two brace characters "{}".
An in... | christopher/rosetta-code | |
http://rosettacode.org/wiki/One_of_n_lines_in_a_file | One of n lines in a file | A method of choosing a line randomly from a file:
Without reading the file more than once
When substantial parts of the file cannot be held in memory
Without knowing how many lines are in the file
Is to:
keep the first line of the file as a possible choice, then
Read the second line of the file if possible and m... | #Wren | Wren | import "random" for Random
import "/fmt" for Fmt
var rand = Random.new()
var oneOfN = Fn.new { |n|
var choice = 1
for (i in 2..n) {
if (rand.float() < 1/i) choice = i
}
return choice
}
var n = 10
var freqs = List.filled(n, 0)
var reps = 1e6
for (i in 0...reps) {
var num = oneOfN.call(n... | Give a code snippet in #Wren
A method of choosing a line randomly from a file:
Without reading the file more than once
When substantial parts of the file cannot be held in memory
Without knowing how many lines are in the file
Is to:
keep the first line of the file as a possible choice, then
Read the second line... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Palindrome_detection | Palindrome detection | A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly as a wrapper to the first) which ... | #BaCon | BaCon |
OPTION COMPARE TRUE
INPUT "Enter your line... ", word$
IF word$ = REVERSE$(word$) THEN
PRINT "This is an exact palindrome!"
ELIF EXTRACT$(word$, "[[:punct:]]|[[:blank:]]", TRUE) = REVERSE$(EXTRACT$(word$, "[[:punct:]]|[[:blank:]]", TRUE)) THEN
PRINT "This is an inexact palindrome!"
ELSE
PRINT "Not a p... | Give a code snippet in #BaCon
A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly as... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generic_swap | Generic swap | Task
Write a generic swap function or operator which exchanges the values of two variables (or, more generally, any two storage places that can be assigned), regardless of their types.
If your solution language is statically typed please describe the way your language provides genericity.
If variables are typed in t... | #Harbour | Harbour | PROCEDURE Swap( /*@*/v1, /*@*/v2 )
LOCAL xTmp
xTmp := v1
v1 := v2
v2 := xTmp
RETURN
| Give a code snippet in #Harbour
Task
Write a generic swap function or operator which exchanges the values of two variables (or, more generally, any two storage places that can be assigned), regardless of their types.
If your solution language is statically typed please describe the way your language provides generic... | christopher/rosetta-code | |
http://rosettacode.org/wiki/S-expressions | S-expressions | S-Expressions are one convenient way to parse and store data.
Task
Write a simple reader and writer for S-Expressions that handles quoted and unquoted strings, integers and floats.
The reader should read a single but nested S-Expression from a string and store it in a suitable datastructure (list, array, etc).
... | #Nim | Nim | import strutils
const Input = """
((data "quoted data" 123 4.5)
(data (!@# (4.5) "(more" "data)")))
"""
type
TokenKind = enum
tokInt, tokFloat, tokString, tokIdent
tokLPar, tokRPar
tokEnd
Token = object
case kind: TokenKind
of tokString: stringVal: string
of tokInt: intVal: int
of t... | Give a code snippet in #Nim
S-Expressions are one convenient way to parse and store data.
Task
Write a simple reader and writer for S-Expressions that handles quoted and unquoted strings, integers and floats.
The reader should read a single but nested S-Expression from a string and store it in a suitable datast... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Split_a_character_string_based_on_change_of_character | Split a character string based on change of character |
Task
Split a (character) string into comma (plus a blank) delimited
strings based on a change of character (left to right).
Show the output here (use the 1st example below).
Blanks should be treated as any other character (except
they are problematic to display clearly). The same applies
to commas.
Fo... | #Pike | Pike |
string input = "gHHH5YY++///\\"; // \ needs escaping
string last_char;
foreach(input/1, string char) {
if(last_char && char != last_char)
write(", ");
write(char);
last_char = char;
}
| Give a code snippet in #Pike
Task
Split a (character) string into comma (plus a blank) delimited
strings based on a change of character (left to right).
Show the output here (use the 1st example below).
Blanks should be treated as any other character (except
they are problematic to display clearly). The... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_squares | Sum of squares | Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| #Frink | Frink |
f = {|x| x^2} // Anonymous function which squares its argument
a = [1,2,3,5,7]
println[sum[map[f,a], 0]]
| Give a code snippet in #Frink
Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Pentagram | Pentagram |
A pentagram is a star polygon, consisting of a central pentagon of which each side forms the base of an isosceles triangle. The vertex of each triangle, a point of the star, is 36 degrees.
Task
Draw (or print) a regular pentagram, in any orientation. Use a different color (or token) for stroke and fill, and backg... | #C | C | #include<graphics.h>
#include<stdio.h>
#include<math.h>
#define pi M_PI
int main(){
char colourNames[][14] = { "BLACK", "BLUE", "GREEN", "CYAN", "RED", "MAGENTA", "BROWN", "LIGHTGRAY", "DARKGRAY",
"LIGHTBLUE", "LIGHTGREEN", "LIGHTCYAN", "LIGHTRED", "LIGHTMAGENTA", "YELLOW", "WHITE" };
int stroke... | Give a code snippet in #C
A pentagram is a star polygon, consisting of a central pentagon of which each side forms the base of an isosceles triangle. The vertex of each triangle, a point of the star, is 36 degrees.
Task
Draw (or print) a regular pentagram, in any orientation. Use a different color (or token) for... | 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 ... | #Run_BASIC | Run BASIC | ' Boolean Evaluations
'
' > Greater Than
' < Less Than
' >= Greater Than Or Equal To
' <= Less Than Or Equal To
' = Equal to
x = 0
if x = 0 then print "Zero"
' --------------------------
' if/then/else
if x = 0 then
print "Zero"
else
print "Nonzero"
end if
' --------------------------
' not
if x then
print "x h... | Give a code snippet in #Run_BASIC
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.
Com... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Floyd-Warshall_algorithm | Floyd-Warshall algorithm | The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been checked for loops, parallel ... | #SequenceL | SequenceL | import <Utilities/Sequence.sl>;
import <Utilities/Math.sl>;
ARC ::= (To: int, Weight: float);
arc(t,w) := (To: t, Weight: w);
VERTEX ::= (Label: int, Arcs: ARC(1));
vertex(l,arcs(1)) := (Label: l, Arcs: arcs);
getArcsFrom(vertex, graph(1)) :=
let
index := firstIndexOf(graph.Label, vertex);
in
... | Give a code snippet in #SequenceL
The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has alread... | 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... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | Do[
Print[i],
{i, 1, 20, 4}] | Give a code snippet in #Mathematica.2FWolfram_Language
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
L... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Non-decimal_radices/Convert | Non-decimal radices/Convert | Number base conversion is when you express a stored integer in an integer base, such as in octal (base 8) or binary (base 2). It also is involved when you take a string representing a number in a given base and convert it to the stored integer form. Normally, a stored integer is in binary, but that's typically invisibl... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols nobinary
import java.math.BigInteger
numeric digits 200
parse arg input -- input should be val, radix; no input results in using default test data
-- test data - number pairs where 1st is value and 2nd is target radix
inputs = [ -
'1234, ... | Give a code snippet in #NetRexx
Number base conversion is when you express a stored integer in an integer base, such as in octal (base 8) or binary (base 2). It also is involved when you take a string representing a number in a given base and convert it to the stored integer form. Normally, a stored integer is in bina... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_squares | Sum of squares | Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| #Oz | Oz | declare
fun {SumOfSquares Xs}
for X in Xs sum:S do
{S X*X}
end
end
in
{Show {SumOfSquares [3 1 4 1 5 9]}} | Give a code snippet in #Oz
Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/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... | #ALGOL-M | ALGOL-M | BEGIN
INTEGER I;
FOR I := 1 STEP 3 UNTIL 19 DO
WRITE( I );
END | Give a code snippet in #ALGOL-M
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/I... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truth_table | Truth table | A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function.
Task
Input a Boolean function from the user as a string then calculate and print a formatted truth table for the g... | #D.C3.A9j.C3.A0_Vu | Déjà Vu | print-line lst end:
for v in reversed copy lst:
print\( v chr 9 )
print end
(print-truth-table) t n func:
if n:
(print-truth-table) push-through copy t 0 -- n @func
(print-truth-table) push-through copy t 1 -- n @func
else:
print-line t func for in copy t
print-truth-... | Give a code snippet in #D.C3.A9j.C3.A0_Vu
A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function.
Task
Input a Boolean function from the user as a string then calculate ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Magic_squares_of_odd_order | Magic squares of odd order | A magic square is an NxN square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column, and both long (main) diagonals are equal to the same sum (which is called the magic number or magic constant).
The numbers are usually (but not always) t... | #Oforth | Oforth | : magicSquare(n)
| i j wd |
n sq log asInteger 1+ ->wd
n loop: i [
n loop: j [
i j + 1- n 2 / + n mod n *
i j + j + 2 - n mod 1 + +
System.Out swap <<w(wd) " " << drop
]
printcr
]
System.Out "Magic constant is : " << n sq 1 + 2 / n * << cr ; | Give a code snippet in #Oforth
A magic square is an NxN square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column, and both long (main) diagonals are equal to the same sum (which is called the magic number or magic constant).
The number... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pangram_checker | Pangram checker | Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
Write a function or method to chec... | #APL | APL |
a←'abcdefghijklmnopqrstuvwxyz'
A←'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
Panagram←{∧/ ∨⌿ 2 26⍴(a,A) ∊ ⍵}
Panagram 'This should fail'
0
Panagram 'The quick brown fox jumps over the lazy dog'
1
| Give a code snippet in #APL
Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
Write... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Order_two_numerical_lists | Order two numerical lists | sorting
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
She... | #F.23 | F# | let inline cmp x y = if x < y then -1 else if x = y then 0 else 1
let before (s1 : seq<'a>) (s2 : seq<'a>) = (Seq.compareWith cmp s1 s2) < 0
[
([0], []);
([], []);
([], [0]);
([-1], [0]);
([0], [0]);
([0], [-1]);
([0], [0; -1]);
([0], [0; 0]);
([0], [0; 1]);
([0; -1], [0]);
... | Give a code snippet in #F.23
sorting
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Q... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dinesman%27s_multiple-dwelling_problem | Dinesman's multiple-dwelling problem | Task
Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below.
Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of... | #PowerShell | PowerShell |
# Floors are numbered 1 (ground) to 5 (top)
# Baker, Cooper, Fletcher, Miller, and Smith live on different floors:
$statement1 = '$baker -ne $cooper -and $baker -ne $fletcher -and $baker -ne $miller -and
$baker -ne $smith -and $cooper -ne $fletcher -and $cooper -ne $miller -and
... | Give a code snippet in #PowerShell
Task
Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below.
Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Grayscale_image | Grayscale image | Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
To get luminance of a color u... | #11l | 11l | T Colour
Byte r, g, b
F (r, g, b)
.r = r
.g = g
.b = b
F ==(other)
R .r == other.r & .g == other.g & .b == other.b
V black = Colour(0, 0, 0)
V white = Colour(255, 255, 255)
T Bitmap
Int width, height
Colour background
[[Colour]] map
F (width = 40, height = 40, back... | Give a code snippet in #11l
Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_sequence | Integer sequence | Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations limits. For example, if integer... | #Go | Go | package main
import "fmt"
func main() {
for i := 1;; i++ {
fmt.Println(i)
}
} | Give a code snippet in #Go
Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations limit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compare_a_list_of_strings | Compare a list of strings | Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or false value, which could be used as t... | #FreeBASIC | FreeBASIC |
' FB 1.05.0 Win64
Function AllEqual(strings() As String) As Boolean
Dim length As Integer = UBound(strings) - LBound(strings) + 1
If length < 2 Then Return False
For i As Integer = LBound(strings) + 1 To UBound(strings)
If strings(i - 1) <> strings(i) Then Return False
Next
Return True
End Funct... | Give a code snippet in #FreeBASIC
Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or fa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Semiprime | Semiprime | Semiprime numbers are natural numbers that are products of exactly two (possibly equal) prime numbers.
Semiprimes are also known as:
semi-primes
biprimes
bi-primes
2-almost primes
or simply: P2
Example
1679 = 23 × 73
(This particular number was chosen as the length of the Arecib... | #Swift | Swift | import Foundation
func primes(n: Int) -> AnyGenerator<Int> {
var (seive, i) = ([Int](0..<n), 1)
let lim = Int(sqrt(Double(n)))
return anyGenerator {
while ++i < n {
if seive[i] != 0 {
if i <= lim {
for notPrime in stride(from: i*i, to: n, by: i) {
seive[notPrime] = 0
... | Give a code snippet in #Swift
Semiprime numbers are natural numbers that are products of exactly two (possibly equal) prime numbers.
Semiprimes are also known as:
semi-primes
biprimes
bi-primes
2-almost primes
or simply: P2
Example
1679 = 23 × 73
(This particular number was cho... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Distributed_programming | Distributed programming | Write two programs (or one program with two modes) which run on networked computers, and send some messages between them.
The protocol used may be language-specific or not, and should be suitable for general distributed programming; that is, the protocol should be generic (not designed just for the particular example ... | #Tcl | Tcl | proc main {} {
global connections
set connections [dict create]
socket -server handleConnection 12345
vwait dummyVar ;# enter the event loop
}
proc handleConnection {channel clientaddr clientport} {
global connections
dict set connections $channel address "$clientaddr:$clientport"
fconfigu... | Give a code snippet in #Tcl
Write two programs (or one program with two modes) which run on networked computers, and send some messages between them.
The protocol used may be language-specific or not, and should be suitable for general distributed programming; that is, the protocol should be generic (not designed jus... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calculating_the_value_of_e | Calculating the value of e | Task
Calculate the value of e.
(e is also known as Euler's number and Napier's constant.)
See details: Calculating the value of e
| #Clojure | Clojure |
;; Calculating the number e, euler-napier number.
;; We will use two methods
;; First method: the forumula (1 + 1/n)^n
;; Second method: the series partial sum 1/(p!)
;;first method
(defn inverse-plus-1 [n]
(+ 1 (/ 1 n)))
(defn e-return [n]
(Math/pow (inverse-plus-1 n) n))
(time (e-return 100000.))
;;... | Give a code snippet in #Clojure
Task
Calculate the value of e.
(e is also known as Euler's number and Napier's constant.)
See details: Calculating the value of e
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #AWK | AWK |
# syntax: GAWK -f YIN_AND_YANG.AWK
# converted from PHL
BEGIN {
yin_and_yang(16)
yin_and_yang(8)
exit(0)
}
function yin_and_yang(radius, black,white,scale_x,scale_y,sx,sy,x,y) {
black = "#"
white = "."
scale_x = 2
scale_y = 1
for (sy = radius*scale_y; sy >= -(radius*scale_y); sy--) {
... | Give a code snippet in #AWK
One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #AutoHotkey | AutoHotkey | RunWait %comspec% /c cls | Give a code snippet in #AutoHotkey
Task
Clear the terminal window.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Percentage_difference_between_images | Percentage difference between images | basic bitmap storage
Useful for comparing two JPEG images saved with a different compression ratios.
You can use these pictures for testing (use the full-size version of each):
50% quality JPEG
100% quality JPEG
link to full size 50% image
link to full size 100% image
The expected difference for these two... | #J | J | require 'media/image3'
'Lenna50.jpg' (+/@,@:|@:- % 2.55 * */@$@])&read_image 'Lenna100.jpg'
1.62559 | Give a code snippet in #J
basic bitmap storage
Useful for comparing two JPEG images saved with a different compression ratios.
You can use these pictures for testing (use the full-size version of each):
50% quality JPEG
100% quality JPEG
link to full size 50% image
link to full size 100% image
The expect... | christopher/rosetta-code | |
http://rosettacode.org/wiki/MD5 | MD5 | Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the Wikipedia article.
Warning:... | #OCaml | OCaml | # Digest.to_hex(Digest.string "The quick brown fox jumped over the lazy dog's back") ;;
- : string = "e38ca1d920c4b8b8d3946b2c72f01680" | Give a code snippet in #OCaml
Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_from_two_arrays | Hash from two arrays | Task
Using two Arrays of equal length, create a Hash object
where the elements from one array (the keys) are linked
to the elements of the other (the values)
Related task
Associative arrays/Creation
| #Elixir | Elixir | iex(1)> keys = [:one, :two, :three]
[:one, :two, :three]
iex(2)> values = [1, 2, 3]
[1, 2, 3]
iex(3)> Enum.zip(keys, values) |> Enum.into(Map.new)
%{one: 1, three: 3, two: 2} | Give a code snippet in #Elixir
Task
Using two Arrays of equal length, create a Hash object
where the elements from one array (the keys) are linked
to the elements of the other (the values)
Related task
Associative arrays/Creation
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Nonoblock | Nonoblock | Nonoblock is a chip off the old Nonogram puzzle.
Given
The number of cells in a row.
The size of each, (space separated), connected block of cells to fit in the row, in left-to right order.
Task
show all possible positions.
show the number of positions of the blocks for the following cases within the row. ... | #Racket | Racket | #lang racket
(require racket/trace)
(define add1-to-car (match-lambda [(cons (app add1 p1) t) (cons p1 t)]))
;; inputs:
;; cells -- available cells
;; blocks -- list of block widths
;; output:
;; gap-block+gaps
;; where gap-block+gaps is:
;; (list gap) -- a single gap
;; (lis... | Give a code snippet in #Racket
Nonoblock is a chip off the old Nonogram puzzle.
Given
The number of cells in a row.
The size of each, (space separated), connected block of cells to fit in the row, in left-to right order.
Task
show all possible positions.
show the number of positions of the blocks for the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Look-and-say_sequence | Look-and-say sequence | The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway.
The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 11122... | #ALGOL-M | ALGOL-M | begin
string(1) function digit(n);
integer n;
case n of begin
digit := "0"; digit := "1"; digit := "2";
digit := "3"; digit := "4"; digit := "5";
digit := "6"; digit := "7"; digit := "8";
digit := "9";
end;
string(1) array cur[1:128];
string(1) array... | Give a code snippet in #ALGOL-M
The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway.
The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequen... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic_evaluation | Arithmetic evaluation | Create a program which parses and evaluates arithmetic expressions.
Requirements
An abstract-syntax tree (AST) for the expression must be created from parsing the input.
The AST must be used in evaluation, also, so the input may not be directly evaluated (e.g. by calling eval or a similar language feature.)
The ... | #Icon_and_Unicon | Icon and Unicon | procedure main() #: simple arithmetical parser / evaluator
write("Usage: Input expression = Abstract Syntax Tree = Value, ^Z to end.")
repeat {
writes("Input expression : ")
if not writes(line := read()) then break
if map(line) ? { (x := E()) & pos(... | Give a code snippet in #Icon_and_Unicon
Create a program which parses and evaluates arithmetic expressions.
Requirements
An abstract-syntax tree (AST) for the expression must be created from parsing the input.
The AST must be used in evaluation, also, so the input may not be directly evaluated (e.g. by calling ev... | christopher/rosetta-code | |
http://rosettacode.org/wiki/List_comprehensions | List comprehensions | A list comprehension is a special syntax in some programming languages to describe lists. It is similar to the way mathematicians describe sets, with a set comprehension, hence the name.
Some attributes of a list comprehension are:
They should be distinct from (nested) for loops and the use of map and filter functio... | #Swift | Swift | typealias F1 = (Int) -> [(Int, Int, Int)]
typealias F2 = (Int) -> Bool
func pythagoreanTriples(n: Int) -> [(Int, Int, Int)] {
(1...n).flatMap({x in
(x...n).flatMap({y in
(y...n).filter({z in
x * x + y * y == z * z
} as F2).map({ (x, y, $0) })
} as F1)
} as F1)
}
print(pythagoreanTrip... | Give a code snippet in #Swift
A list comprehension is a special syntax in some programming languages to describe lists. It is similar to the way mathematicians describe sets, with a set comprehension, hence the name.
Some attributes of a list comprehension are:
They should be distinct from (nested) for loops and th... | 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 ... | #Forth | Forth | ( condition ) IF ( true statements ) THEN
( condition ) IF ( true statements ) ELSE ( false statements ) THEN | Give a code snippet in #Forth
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Emirp_primes | Emirp primes | An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th emirp
In each list, the numbe... | #Python | Python | from __future__ import print_function
from prime_decomposition import primes, is_prime
from heapq import *
from itertools import islice
def emirp():
largest = set()
emirps = []
heapify(emirps)
for pr in primes():
while emirps and pr > emirps[0]:
yield heappop(emirps)
if pr ... | Give a code snippet in #Python
An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring | Substring |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #LabVIEW | LabVIEW |
{S.slice 1 2 hello brave new world}
-> brave new
{W.slice 4 11 www.rosetta.org}
-> rosetta
| Give a code snippet in #LabVIEW
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Order_disjoint_list_items | Order disjoint list items |
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
... | #J | J | disjorder=:3 :0&.;:
:
clusters=. (</. i.@#) x
order=. x i.&~. y
need=. #/.~ y
from=. ;need (#{.)each (/:~order){clusters
to=. ;need {.!._ each order{clusters
(from{x) to} x
) | Give a code snippet in #J
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brownian_tree | Brownian tree | Brownian tree
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw a Brownian Tree.
A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes.
The initial "seed" is placed somewhere wi... | #Visual_Basic_.NET | Visual Basic .NET |
Imports System.Drawing.Imaging
Public Class Form1
ReadOnly iCanvasColor As Integer = Color.Black.ToArgb
ReadOnly iSeedColor As Integer = Color.White.ToArgb
Dim iCanvasWidth As Integer = 0
Dim iCanvasHeight As Integer = 0
Dim iPixels() As Integer = Nothing
Private Sub BrownianTree()
Dim oCa... | Give a code snippet in #Visual_Basic_.NET
Brownian tree
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw a Brownian Tree.
A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Benford%27s_law | Benford's law |
This page uses content from Wikipedia. The original article was at Benford's_law. 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)
Benford's law, also called the first-digit law, refers to the freque... | #PicoLisp | PicoLisp |
(scl 4)
(load "@lib/misc.l")
(load "@lib/math.l")
(setq LOG10E 0.4343)
(de fibo (N)
(let (A 0 B 1 C NIL)
(make
(link B)
(do (dec N)
(setq C (+ A B) A B B C)
(link B)))))
(setq Actual
(let (
Digits (sort (mapcar '((N) (format (car (chop N)))) (fibo... | Give a code snippet in #PicoLisp
This page uses content from Wikipedia. The original article was at Benford's_law. 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)
Benford's law, also called the fir... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Statistics/Basic | Statistics/Basic | Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldots ,n\,\!}
, the mean is
x
¯... | #PureBasic | PureBasic | Procedure.f randomf()
#RNG_max_resolution = 2147483647
ProcedureReturn Random(#RNG_max_resolution) / #RNG_max_resolution
EndProcedure
Procedure sample(n)
Protected i, nBins, binNumber, tickMarks, maxBinValue
Protected.f sum, sumSq, mean
Dim dat.f(n)
For i = 1 To n
dat(i) = randomf()
Next
;show... | Give a code snippet in #PureBasic
Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldot... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Time_a_function | Time a function | Task
Write a program which uses a timer (with the least granularity available
on your system) to time how long a function takes to execute.
Whenever possible, use methods which measure only the processing time used
by the current process; instead of the difference in system time
between start and finish, which could ... | #Python | Python | import sys, timeit
def usec(function, arguments):
modname, funcname = __name__, function.__name__
timer = timeit.Timer(stmt='%(funcname)s(*args)' % vars(),
setup='from %(modname)s import %(funcname)s; args=%(arguments)r' % vars())
try:
t, N = 0, 1
while t < 0.2: ... | Give a code snippet in #Python
Task
Write a program which uses a timer (with the least granularity available
on your system) to time how long a function takes to execute.
Whenever possible, use methods which measure only the processing time used
by the current process; instead of the difference in system time
betwee... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/With_multiple_ranges | Loops/With multiple ranges | Loops/With multiple ranges
You are encouraged to solve this task according to the task description, using any language you may know.
Some languages allow multiple loop ranges, such as the PL/I example (snippet) below.
/* all variables are DECLARED as integers. */
prod=... | #Java | Java |
import java.util.ArrayList;
import java.util.List;
public class LoopsWithMultipleRanges {
private static long sum = 0;
private static long prod = 1;
public static void main(String[] args) {
long x = 5;
long y = -5;
long z = -2;
long one = 1;
long three = 3;
... | Give a code snippet in #Java
Loops/With multiple ranges
You are encouraged to solve this task according to the task description, using any language you may know.
Some languages allow multiple loop ranges, such as the PL/I example (snippet) below.
/* all variables are DECLARED a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/OpenGL | OpenGL |
Task
Display a smooth shaded triangle with OpenGL.
Triangle created using C example compiled with GCC 4.1.2 and freeglut3.
| #Haskell | Haskell | import Graphics.Rendering.OpenGL
import Graphics.UI.GLUT
main = do
getArgsAndInitialize
createWindow "Triangle"
displayCallback $= display
matrixMode $= Projection
loadIdentity
ortho2D 0 30 0 30
matrixMode $= Modelview 0
mainLoop
display = do
clear [ColorBuffer]
renderPrimitive Triangles $ d... | Give a code snippet in #Haskell
Task
Display a smooth shaded triangle with OpenGL.
Triangle created using C example compiled with GCC 4.1.2 and freeglut3.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Compare_a_list_of_strings | Compare a list of strings | Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or false value, which could be used as t... | #11l | 11l | L(strings_s) [‘AA AA AA AA’, ‘AA ACB BB CC’]
V strings = strings_s.split(‘ ’)
print(strings)
print(all(zip(strings, strings[1..]).map(a -> a[0] == a[1])))
print(all(zip(strings, strings[1..]).map(a -> a[0] < a[1])))
print() | Give a code snippet in #11l
Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or false va... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Command-line_arguments | Command-line arguments | Command-line arguments is part of Short Circuit's Console Program Basics selection.
Scripted main
See also Program name.
For parsing command line arguments intelligently, see Parsing command-line arguments.
Example command line:
myprogram -c "alpha beta" -h "gamma"
| #Clean | Clean | import ArgEnv
Start = getCommandLine | Give a code snippet in #Clean
Command-line arguments is part of Short Circuit's Console Program Basics selection.
Scripted main
See also Program name.
For parsing command line arguments intelligently, see Parsing command-line arguments.
Example command line:
myprogram -c "alpha beta" -h "gamma"
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Foreach | Loops/Foreach | Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for... | #Lambdatalk_2 | Lambdatalk |
{def collection alpha beta gamma delta}
-> collection
{S.map {lambda {:i} {br}:i} {collection}}
->
alpha
beta
gamma
delta
or
{def S.foreach
{lambda {:s}
{if {S.empty? {S.rest :s}}
then {S.first :s}
else {S.first :s} {br}{S.foreach {S.rest :s}}}}}
{S.foreach {collection}}
->
alpha
beta
gamma
d... | Give a code snippet in #Lambdatalk_2
Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively | Walk a directory/Non-recursively | Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, not an entire directory tree.
... | #Forth | Forth | defer ls-filter ( name len -- ? )
: ls-all 2drop true ;
: ls-visible drop c@ [char] . <> ;
: ls ( dir len -- )
open-dir throw ( dirid )
begin
dup pad 256 rot read-dir throw
while
pad over ls-filter if
cr pad swap type
else drop then
repeat
drop close-dir throw ;
\ only show C language... | Give a code snippet in #Forth
Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring | Substring |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #ColdFusion | ColdFusion |
<cfoutput>
<cfset str = "abcdefg">
<cfset n = 2>
<cfset m = 3>
<!--- Note: In CF index starts at 1 rather than 0
starting from n characters in and of m length --->
#mid( str, n, m )#
<!--- starting from n characters in, up to the end of the string --->
<cfset countFromRight = Len( str ) - n + 1>
#right( st... | Give a code snippet in #ColdFusion
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 Operat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Formal_power_series | Formal power series | A power series is an infinite sum of the form
a
0
+
a
1
⋅
x
+
a
2
⋅
x
2
+
a
3
⋅
x
3
+
⋯
{\displaystyle a_{0}+a_{1}\cdot x+a_{2}\cdot x^{2}+a_{3}\cdot x^{3}+\cdots }
The ai are called the coefficients of the series. Such sums can be added, multiplied etc., where the new coefficients of ... | #Raku | Raku | class DerFPS { ... }
class IntFPS { ... }
role FPS {
method coeffs { ... }
method differentiate { DerFPS.new(:x(self)) }
method integrate { IntFPS.new(:x(self)) }
method pretty($n) {
sub super($i) { $i.trans('0123456789' => '⁰¹²³⁴⁵⁶⁷⁸⁹') }
my $str = $.coeffs[0];
fo... | Give a code snippet in #Raku
A power series is an infinite sum of the form
a
0
+
a
1
⋅
x
+
a
2
⋅
x
2
+
a
3
⋅
x
3
+
⋯
{\displaystyle a_{0}+a_{1}\cdot x+a_{2}\cdot x^{2}+a_{3}\cdot x^{3}+\cdots }
The ai are called the coefficients of the series. Such sums can be added, multiplied etc., ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Horizontal_sundial_calculations | Horizontal sundial calculations | Task
Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location.
For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit... | #Sather | Sather | class MAIN is
getvalue(s:STR):FLT is
#OUT + s + ": ";
return #FLT(#IN.get_line.str);
end;
dr(a:FLT):FLT is
return a * FLT::pi / 180.0;
end;
rd(a:FLT):FLT is
return a * 180.0 / FLT::pi;
end;
main is
lat ::= getvalue("Enter latitude");
lng ::= getvalue("Enter longitude");
... | Give a code snippet in #Sather
Task
Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location.
For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Islan... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Modular_exponentiation | Modular exponentiation | Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
235139930337346448646612254452369009474497523... | #Lambdatalk | Lambdatalk |
We will call the lib_BN library for big numbers:
{require lib_BN}
In this library {BN.compare a b} returns 1 if a > b, 0 if a = b and -1 if a < b.
For a better readability we define three small functions
{def BN.= {lambda {:a :b} {= {BN.compare :a :b} 0}}}
-> BN.=
{def BN.even? {lambda {:n} {= {BN.compare {B... | Give a code snippet in #Lambdatalk
Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
235139930... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_stability | Sort stability |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | mylist = {{1, 2, 3}, {4, 5, 6}, {5, 4, 3}, {9, 5, 1}};
Sort[mylist, (#1[[2]] < #2[[2]]) &]
#[[Ordering[#[[All, 2]]]]] &[mylist] | Give a code snippet in #Mathematica.2FWolfram_Language
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Simulate_input/Mouse | Simulate input/Mouse | #Common_Lisp | Common Lisp |
(defun sh (cmd)
#+clisp (shell cmd)
#+ecl (si:system cmd)
#+sbcl (sb-ext:run-program "/bin/sh" (list "-c" cmd) :input nil :output *standard-output*)
#+clozure (ccl:run-program "/bin/sh" (list "-c" cmd) :input nil :output *standard-output*))
(sh "xdotool mousemove 0 0 click 1")
(sleep 2)
(sh "xdotool mousemove 300 300... | Give a code snippet in #Common_Lisp
| christopher/rosetta-code | ||
http://rosettacode.org/wiki/Sorting_algorithms/Comb_sort | Sorting algorithms/Comb sort | Sorting algorithms/Comb sort
You are encouraged to solve this task according to the task description, using any language you may know.
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 algor... | #Go | Go | package main
import "fmt"
func main() {
a := []int{170, 45, 75, -90, -802, 24, 2, 66}
fmt.Println("before:", a)
combSort(a)
fmt.Println("after: ", a)
}
func combSort(a []int) {
if len(a) < 2 {
return
}
for gap := len(a); ; {
if gap > 1 {
gap = gap * 4 / 5
... | Give a code snippet in #Go
Sorting algorithms/Comb sort
You are encouraged to solve this task according to the task description, using any language you may know.
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 sort... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Department_numbers | Department numbers | There is a highly organized city that has decided to assign a number to each of their departments:
police department
sanitation department
fire department
Each department can have a number between 1 and 7 (inclusive).
The three department numbers are to be unique (different from each other) and mu... | #Go | Go | package main
import "fmt"
func main() {
fmt.Println("Police Sanitation Fire")
fmt.Println("------ ---------- ----")
count := 0
for i := 2; i < 7; i += 2 {
for j := 1; j < 8; j++ {
if j == i { continue }
for k := 1; k < 8; k++ {
if k == i || k == j ... | Give a code snippet in #Go
There is a highly organized city that has decided to assign a number to each of their departments:
police department
sanitation department
fire department
Each department can have a number between 1 and 7 (inclusive).
The three department numbers are to be unique (diffe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pig_the_dice_game | Pig the dice game | The game of Pig is a multiplayer game played with a single six-sided die. The
object of the game is to reach 100 points or more.
Play is taken in turns. On each person's turn that person has the option of either:
Rolling the dice: where a roll of two to six is added to their score for that turn and th... | #Pascal | Pascal | program Pig;
const
WinningScore = 100;
type
DieRoll = 1..6;
Score = integer;
Player = record
Name: string;
Points: score;
Victory: Boolean
end;
{ Assume a 2-player game. }
var Player1, Player2: Player;
function RollTheDie: DieRoll;
{ Return a random number 1 thru 6. }
begin
RollTheDie := random(... | Give a code snippet in #Pascal
The game of Pig is a multiplayer game played with a single six-sided die. The
object of the game is to reach 100 points or more.
Play is taken in turns. On each person's turn that person has the option of either:
Rolling the dice: where a roll of two to six is added to ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Show_the_epoch | Show the epoch | Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind the scenes by the implementers), b... | #NewLISP | NewLISP | (date 0)
->"Thu Jan 01 01:00:00 1970" | Give a code snippet in #NewLISP
Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Vector | Vector | Task
Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented.
The Vector may be initialized in any reasonable way.
Start and end points, and direction
Angular coefficient and value (length)
The four operations to... | #REXX | REXX | /*REXX program shows how to support mathematical functions for vectors using functions. */
s1 = 11 /*define the s1 scalar: eleven */
s2 = 2 /*define the s2 scalar: two */
x = '(5, 7)' ... | Give a code snippet in #REXX
Task
Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented.
The Vector may be initialized in any reasonable way.
Start and end points, and direction
Angular coefficient and value (le... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Boolean_values | Boolean values | Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| #LFE | LFE |
> 'true
true
> 'false
false
> (or 'false 'false)
false
> (or 'false 'true)
true
| Give a code snippet in #LFE
Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Trigonometric_functions | Trigonometric functions | Task
If your language has a library or built-in functions for trigonometry, show examples of:
sine
cosine
tangent
inverses (of the above)
using the same angle in radians and degrees.
For the non-inverse functions, each radian/degree pair should use arguments that evaluate to the same angle (that i... | #MAXScript | MAXScript | local radians = pi / 4
local degrees = 45.0
--sine
print (sin (radToDeg radians))
print (sin degrees)
--cosine
print (cos (radToDeg radians))
print (cos degrees)
--tangent
print (tan (radToDeg radians))
print (tan degrees)
--arcsine
print (asin (sin (radToDeg radians)))
print (asin (sin degrees))
--arccosine
print (a... | Give a code snippet in #MAXScript
Task
If your language has a library or built-in functions for trigonometry, show examples of:
sine
cosine
tangent
inverses (of the above)
using the same angle in radians and degrees.
For the non-inverse functions, each radian/degree pair should use arguments that e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Emirp_primes | Emirp primes | An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th emirp
In each list, the numbe... | #Ruby | Ruby | require 'prime'
emirp = Enumerator.new do |y|
Prime.each do |prime|
rev = prime.to_s.reverse.to_i
y << prime if rev.prime? and rev != prime
end
end
puts "First 20 emirps:", emirp.first(20).join(" ")
puts "Emirps between 7,700 and 8,000:"
emirp.with_index(1) do |prime,i|
print "#{prime} " if (7700..8... | Give a code snippet in #Ruby
An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_input/output | File input/output | File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file into a variable
how to write ... | #GAP | GAP | CopyFile := function(src, dst)
local f, g, line;
f := InputTextFile(src);
g := OutputTextFile(dst, false);
while true do
line := ReadLine(f);
if line = fail then
break
else
WriteLine(g, Chomp(line));
fi;
od;
CloseStream(f);
CloseStream(g);
end; | Give a code snippet in #GAP
File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file int... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations | Permutations | Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations generation tasks.
Order Uni... | #Rust | Rust | pub fn permutations(size: usize) -> Permutations {
Permutations { idxs: (0..size).collect(), swaps: vec![0; size], i: 0 }
}
pub struct Permutations {
idxs: Vec<usize>,
swaps: Vec<usize>,
i: usize,
}
impl Iterator for Permutations {
type Item = Vec<usize>;
fn next(&mut self) -> Option<Self:... | Give a code snippet in #Rust
Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations gener... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable_size/Get | Variable size/Get | Demonstrate how to get the size of a variable.
See also: Host introspection
| #Pop11 | Pop11 | ;;; Prints 0 because small integers need no heap storage
datasize(12) =>
;;; Prints 3: 3 character fits into single machine word, 1 word
;;; for tag, 1 for length
datasize('str') =>
;;; 3 element vector takes 5 words: 3 for values, 1 for tag, 1 for
;;; length
datasize({1 2 3}) =>
;;; Prints 3 because only first node co... | Give a code snippet in #Pop11
Demonstrate how to get the size of a variable.
See also: Host introspection
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Animation | Animation |
Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games. The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user. This task demonstrates this.
Task
Creat... | #Red | Red | Red ["Animation"]
rev: false
roule: does [e: back tail s: t/text either rev [move e s] [move s e]]
view [t: text "Hello world! " rate 5 [rev: not rev] on-time [roule]] | Give a code snippet in #Red
Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games. The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user. This task demo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Logical_operations | Logical operations |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Elixir | Elixir | iex(1)> true and false
false
iex(2)> false or true
true
iex(3)> not false
true | Give a code snippet in #Elixir
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Modular_inverse | Modular inverse | From Wikipedia:
In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that
a
x
≡
1
(
mod
m
)
.
{\displaystyle a\,x\equiv 1{\pmod {m}}.}
Or in other words, such that:
∃
k
∈
Z
,
a
x
=
1
+
k
m
{\displaystyle \exists k\in \math... | #XPL0 | XPL0 | code IntOut=11, Text=12;
int X;
def A=42, M=2017;
[for X:= 2 to M-1 do
if rem(A*X/M) = 1 then [IntOut(0, X); exit];
Text(0, "Does not exist");
] | Give a code snippet in #XPL0
From Wikipedia:
In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that
a
x
≡
1
(
mod
m
)
.
{\displaystyle a\,x\equiv 1{\pmod {m}}.}
Or in other words, such that:
∃
k
∈
Z
,
a
x
=
1
+
k
m
{\d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #Toka | Toka | needs enum
0 enum| apple banana carrot |
10 enum| foo bar baz | | Give a code snippet in #Toka
Task
Create an enumeration of constants with and without explicit values.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Comments | Comments | Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| #Run_BASIC | Run BASIC | 'This is a comment
REM This is a comment
print "Notice comment at the end of the line." 'This is a comment
print "Also notice this comment at the end of the line." : REM This is a comment
| Give a code snippet in #Run_BASIC
Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix-exponentiation_operator | Matrix-exponentiation operator | Most programming languages have a built-in implementation of exponentiation for integers and reals only.
Task
Demonstrate how to implement matrix exponentiation as an operator.
| #Python | Python | >>> from operator import mul
>>> def matrixMul(m1, m2):
return map(
lambda row:
map(
lambda *column:
sum(map(mul, row, column)),
*m2),
m1)
>>> def identity(size):
size = range(size)
return [[(i==j)*1 for i in size] for j in size]
>>> def matrixExp(m, pow):
assert pow>=0 ... | Give a code snippet in #Python
Most programming languages have a built-in implementation of exponentiation for integers and reals only.
Task
Demonstrate how to implement matrix exponentiation as an operator.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Comma_quibbling | Comma quibbling | Comma quibbling is a task originally set by Eric Lippert in his blog.
Task
Write a function to generate a string output which is the concatenation of input words from a list/sequence where:
An input of no words produces the output string of just the two brace characters "{}".
An input of just one word, e.g. ["AB... | #C.23 | C# | using System;
using System.Linq;
namespace CommaQuibbling
{
internal static class Program
{
#region Static Members
private static string Quibble(string[] input)
{
return
String.Format("{{{0}}}",
String.Join("",
input.Reverse().Z... | Give a code snippet in #C.23
Comma quibbling is a task originally set by Eric Lippert in his blog.
Task
Write a function to generate a string output which is the concatenation of input words from a list/sequence where:
An input of no words produces the output string of just the two brace characters "{}".
An inp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Nested | Loops/Nested | Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is met.
Specifically, this task als... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref savelog symbols nobinary
say
say 'Loops/Nested'
rnd = Random()
dim2 = int[10, 10]
-- build sample data
loop i1 = 0 for dim2.length
loop i2 = 0 for dim2[i1].length
dim2[i1, i2] = rnd.nextInt(20) + 1
end i2
end i1
-- run... | Give a code snippet in #NetRexx
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/K-means%2B%2B_clustering | K-means++ clustering | K-means++ clustering
K-means
This data was partitioned into 7 clusters using the K-means algorithm.
The task is to implement the K-means++ algorithm. Produce a function which takes two arguments: the number of clusters K, and the dataset to classify. K is a positive integer and the dataset is a list of points in the C... | #JavaScript | JavaScript |
/**
* kmeans module
*
* cluster(model, k, converged = assignmentsConverged)
* distance(p, q),
* distanceSquared(p, q),
* centroidsConverged(delta)
* assignmentsConverged(model, newModel)
* assignmentsToClusters(model)
*/
define(function () {
"use strict";
/**
* @public
* Calc... | Give a code snippet in #JavaScript
K-means++ clustering
K-means
This data was partitioned into 7 clusters using the K-means algorithm.
The task is to implement the K-means++ algorithm. Produce a function which takes two arguments: the number of clusters K, and the dataset to classify. K is a positive integer and the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Plasma_effect | Plasma effect | The plasma effect is a visual effect created by applying various functions, notably sine and cosine, to the color values of screen pixels. When animated (not a task requirement) the effect may give the impression of a colorful flowing liquid.
Task
Create a plasma effect.
See also
Computer Graphics Tutorial (lod... | #Ring | Ring |
# Project : Plasma effect
load "guilib.ring"
paint = null
new qapp
{
win1 = new qwidget()
{
setwindowtitle("Plasma effect")
setgeometry(100,100,500,600)
label1 = new qlabel(win1)
{
setgeometry(... | Give a code snippet in #Ring
The plasma effect is a visual effect created by applying various functions, notably sine and cosine, to the color values of screen pixels. When animated (not a task requirement) the effect may give the impression of a colorful flowing liquid.
Task
Create a plasma effect.
See also
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Angles_(geometric),_normalization_and_conversion | Angles (geometric), normalization and conversion | This task is about the normalization and/or conversion of (geometric) angles using
some common scales.
The angular scales that will be used in this task are:
degree
gradian
mil
radian
Definitions
The angular scales used or referenced here:
turn is a full turn or 360 degrees, also shown as 360º
... | #Python | Python | PI = 3.141592653589793
TWO_PI = 6.283185307179586
def normalize2deg(a):
while a < 0: a += 360
while a >= 360: a -= 360
return a
def normalize2grad(a):
while a < 0: a += 400
while a >= 400: a -= 400
return a
def normalize2mil(a):
while a < 0: a += 6400
while a >= 6400: a -= 6400
return a
def normaliz... | Give a code snippet in #Python
This task is about the normalization and/or conversion of (geometric) angles using
some common scales.
The angular scales that will be used in this task are:
degree
gradian
mil
radian
Definitions
The angular scales used or referenced here:
turn is a full turn or ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Crystal | Crystal | 10.step(to: 0, by: -1).each { |i|
puts i
}
| Give a code snippet in #Crystal
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/Incr... | 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... | #LiveCode | LiveCode | local x=10
repeat for 10 times
put x & return
add -1 to x ... | Give a code snippet in #LiveCode
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/Inc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within l... | #Visual_Basic | Visual Basic | Do
Debug.Print("SPAM")
Loop | Give a code snippet in #Visual_Basic
Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric | Determine if a string is numeric | Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
Array length
String length
Cop... | #E | E | def isNumeric(specimen :String) {
try {
<import:java.lang.makeDouble>.valueOf(specimen)
return true
} catch _ {
return false
}
} | Give a code snippet in #E
Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
Array... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tokenize_a_string | Tokenize a string | Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks related to string operations:
Me... | #PowerShell | PowerShell | $words = "Hello,How,Are,You,Today".Split(',')
[string]::Join('.', $words) | Give a code snippet in #PowerShell
Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tas... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Detect_division_by_zero | Detect division by zero | Task
Write a function to detect a divide by zero error without checking if the denominator is zero.
| #zkl | zkl | fcn f(x,y){try{x/y}catch(MathError){println(__exception)}} | Give a code snippet in #zkl
Task
Write a function to detect a divide by zero error without checking if the denominator is zero.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Playing_cards | Playing cards | Task
Create a data structure and the associated methods to define and manipulate a deck of playing cards.
The deck should contain 52 unique cards.
The methods must include the ability to:
make a new deck
shuffle (randomize) the deck
deal from the deck
print the current contents of a deck
Each card mu... | #Forth | Forth | require random.fs \ RANDOM ( n -- 0..n-1 ) is called CHOOSE in other Forths
create pips s" A23456789TJQK" mem,
create suits s" DHCS" mem, \ diamonds, hearts, clubs, spades
: .card ( c -- )
13 /mod swap
pips + c@ emit
suits + c@ emit ;
create deck 52 allot
variable dealt
: new-deck
52 0 ... | Give a code snippet in #Forth
Task
Create a data structure and the associated methods to define and manipulate a deck of playing cards.
The deck should contain 52 unique cards.
The methods must include the ability to:
make a new deck
shuffle (randomize) the deck
deal from the deck
print the current c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abbreviations,_easy | Abbreviations, easy | This task is an easier (to code) variant of the Rosetta Code task: Abbreviations, simple.
For this task, the following command table will be used:
Add ALTer BAckup Bottom CAppend Change SCHANGE CInsert CLAst COMPress COpy
COUnt COVerlay CURsor DELete CDelete Down DUPlicate Xedit EXPand EXTract Find
... | #Clojure | Clojure |
(defn words [str]
"Split string into words"
(.split str "\\s+"))
(defn join-words [strings]
"Join words into a single string"
(clojure.string/join " " strings))
(def cmd-table
"Command Table - List of words to match against"
(words
"Add ALTer BAckup Bottom CAppend Change SCHANGE CInsert CLAst CO... | Give a code snippet in #Clojure
This task is an easier (to code) variant of the Rosetta Code task: Abbreviations, simple.
For this task, the following command table will be used:
Add ALTer BAckup Bottom CAppend Change SCHANGE CInsert CLAst COMPress COpy
COUnt COVerlay CURsor DELete CDelete Down DUP... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic-geometric_mean | Arithmetic-geometric mean |
This page uses content from Wikipedia. The original article was at Arithmetic-geometric mean. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Write a function to compute the arithmetic-geomet... | #Racket | Racket |
#lang racket
(define (agm a g [ε 1e-15])
(if (<= (- a g) ε)
a
(agm (/ (+ a g) 2) (sqrt (* a g)) ε)))
(agm 1 (/ 1 (sqrt 2)))
| Give a code snippet in #Racket
This page uses content from Wikipedia. The original article was at Arithmetic-geometric mean. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Write a function ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Old_Russian_measure_of_length | Old Russian measure of length | Task
Write a program to perform a conversion of the old Russian measures of length to the metric system (and vice versa).
It is an example of a linear transformation of several variables.
The program should accept a single value in a selected unit of measurement, and convert and return it to the other units:
... | #Tcl | Tcl |
package require units
set russian_units {
arshin 1.40607
centimeter 100
diuym 39.3701
fut 3.28084
kilometer 0.001
liniya 393.701
meter 1
milia 0.000133912
piad 5.6243
sazhen 0.468691
tochka 3937.01
vershok 22.4972
versta 0.00... | Give a code snippet in #Tcl
Task
Write a program to perform a conversion of the old Russian measures of length to the metric system (and vice versa).
It is an example of a linear transformation of several variables.
The program should accept a single value in a selected unit of measurement, and convert and re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Cursor_movement | Terminal control/Cursor movement | Task
Demonstrate how to achieve movement of the terminal cursor:
how to move the cursor one position to the left
how to move the cursor one position to the right
how to move the cursor up one line (without affecting its horizontal position)
how to move the cursor down one line (without affecting its horizontal po... | #Befunge | Befunge |
#include<conio.h>
#include<dos.h>
char *strings[] = {"The cursor will move one position to the left",
"The cursor will move one position to the right",
"The cursor will move vetically up one line",
"The cursor will move vertically down one line",
"The cursor will move to the beginning of... | Give a code snippet in #Befunge
Task
Demonstrate how to achieve movement of the terminal cursor:
how to move the cursor one position to the left
how to move the cursor one position to the right
how to move the cursor up one line (without affecting its horizontal position)
how to move the cursor down one line (wi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/24_game/Solve | 24 game/Solve | task
Write a program that takes four digits, either from user input or by random generation, and computes arithmetic expressions following the rules of the 24 game.
Show examples of solutions generated by the program.
Related task
Arithmetic Evaluator
| #Perl | Perl | # Fischer-Krause ordered permutation generator
# http://faq.perl.org/perlfaq4.html#How_do_I_permute_N_e
sub permute (&@) {
my $code = shift;
my @idx = 0..$#_;
while ( $code->(@_[@idx]) ) {
my $p = $#idx;
--$p while $idx[$p-1] > $idx[$p];
my $q = $p or return;
push @idx, reverse splice @idx, $p;
++$... | Give a code snippet in #Perl
task
Write a program that takes four digits, either from user input or by random generation, and computes arithmetic expressions following the rules of the 24 game.
Show examples of solutions generated by the program.
Related task
Arithmetic Evaluator
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic_evaluation | Arithmetic evaluation | Create a program which parses and evaluates arithmetic expressions.
Requirements
An abstract-syntax tree (AST) for the expression must be created from parsing the input.
The AST must be used in evaluation, also, so the input may not be directly evaluated (e.g. by calling eval or a similar language feature.)
The ... | #Go | Go | enum Op {
ADD('+', 2),
SUBTRACT('-', 2),
MULTIPLY('*', 1),
DIVIDE('/', 1);
static {
ADD.operation = { a, b -> a + b }
SUBTRACT.operation = { a, b -> a - b }
MULTIPLY.operation = { a, b -> a * b }
DIVIDE.operation = { a, b -> a / b }
}
final String symbol
... | Give a code snippet in #Go
Create a program which parses and evaluates arithmetic expressions.
Requirements
An abstract-syntax tree (AST) for the expression must be created from parsing the input.
The AST must be used in evaluation, also, so the input may not be directly evaluated (e.g. by calling eval or a simil... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Map_range | Map range | Given two ranges:
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
and
[
b
1
,
b
2
]
{\displaystyle [b_{1},b_{2}]}
;
then a value
s
{\displaystyle s}
in range
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
is linearly mapped to a value
t
{\di... | #zkl | zkl | fcn mapRange([(a1,a2)], [(b1,b2)], s) // a1a2 is List(a1,a2)
{ b1 + ((s - a1) * (b2 - b1) / (a2 - a1)) }
r1:=T(0.0, 10.0); r2:=T(-1.0, 0.0);
foreach s in ([0.0 .. 10]){
"%2d maps to %5.2f".fmt(s,mapRange(r1,r2, s)).println();
} | Give a code snippet in #zkl
Given two ranges:
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
and
[
b
1
,
b
2
]
{\displaystyle [b_{1},b_{2}]}
;
then a value
s
{\displaystyle s}
in range
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
is linearly map... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations | Permutations | Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations generation tasks.
Order Uni... | #Lambdatalk | Lambdatalk |
{def inject
{lambda {:x :a}
{if {A.empty? :a}
then {A.new {A.new :x}}
else {let { {:c {{lambda {:a :b} {A.cons {A.first :a} :b}} :a}}
{:d {inject :x {A.rest :a}}}
{:e {A.cons :x :a}}
} {A.cons :e {A.map :c :d}}}}}}
-> inject
{def permut
{lambda {:a}
{if {A.e... | Give a code snippet in #Lambdatalk
Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-1 | SHA-1 | SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to identify commits.
A US government... | #Scala | Scala |
import java.nio._
case class Hash(message: List[Byte]) {
val defaultHashes = List(0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0)
val hash = {
val padded = generatePadding(message)
val chunks: List[List[Byte]] = messageToChunks(padded)
toHashForm(hashesFromChunks(chunks))
}
def g... | Give a code snippet in #Scala
SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to ide... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Element-wise_operations | Element-wise operations | This task is similar to:
Matrix multiplication
Matrix transposition
Task
Implement basic element-wise matrix-matrix and scalar-matrix operations, which can be referred to in other, higher-order tasks.
Implement:
addition
subtraction
multiplication
division
exponentiation
Extend the task if ... | #Julia | Julia | @show [1 2 3; 3 2 1] .+ [2 1 2; 0 2 1]
@show [1 2 3; 2 1 2] .+ 1
@show [1 2 3; 2 2 1] .- [1 1 1; 2 1 0]
@show [1 2 1; 1 2 3] .* [3 2 1; 1 0 1]
@show [1 2 3; 3 2 1] .* 2
@show [9 8 6; 3 2 3] ./ [3 1 2; 2 1 2]
@show [3 2 2; 1 2 3] .^ [1 2 3; 2 1 2] | Give a code snippet in #Julia
This task is similar to:
Matrix multiplication
Matrix transposition
Task
Implement basic element-wise matrix-matrix and scalar-matrix operations, which can be referred to in other, higher-order tasks.
Implement:
addition
subtraction
multiplication
division
expon... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Percentage_difference_between_images | Percentage difference between images | basic bitmap storage
Useful for comparing two JPEG images saved with a different compression ratios.
You can use these pictures for testing (use the full-size version of each):
50% quality JPEG
100% quality JPEG
link to full size 50% image
link to full size 100% image
The expected difference for these two... | #Frink | Frink |
img1 = new image["file:Lenna50.jpg"]
img2 = new image["file:Lenna100.jpg"]
[w1, h1] = img1.getSize[]
[w2, h2] = img2.getSize[]
sum = 0
for x=0 to w1-1
for y=0 to h1-1
{
[r1,g1,b1] = img1.getPixel[x,y]
[r2,g2,b2] = img2.getPixel[x,y]
sum = sum + abs[r1-r2] + abs[g1-g2] + abs[b1-b2]
}
e... | Give a code snippet in #Frink
basic bitmap storage
Useful for comparing two JPEG images saved with a different compression ratios.
You can use these pictures for testing (use the full-size version of each):
50% quality JPEG
100% quality JPEG
link to full size 50% image
link to full size 100% image
The ex... | christopher/rosetta-code |
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