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
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http://rosettacode.org/wiki/Test_integerness | Test integerness | Mathematically,
the integers Z are included in the rational numbers Q,
which are included in the real numbers R,
which can be generalized to the complex numbers C.
This means that each of those larger sets, and the data types used to represent them, include some integers.
Task[edit]
Given a rational, real, or co... | #Julia | Julia | # v0.6.0
@show isinteger(25.000000)
@show isinteger(24.999999)
@show isinteger(25.000100)
@show isinteger(-2.1e120)
@show isinteger(-5e-2)
@show isinteger(NaN)
@show isinteger(Inf)
@show isinteger(complex(5.0, 0.0))
@show isinteger(complex(5, 5))
| Give a code snippet in #Julia
Mathematically,
the integers Z are included in the rational numbers Q,
which are included in the real numbers R,
which can be generalized to the complex numbers C.
This means that each of those larger sets, and the data types used to represent them, include some integers.
Task[edit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Collections | Collections | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Collections are abstractions to represent sets of values.
In statically-typed languages, the values are typically of a common data type.
Task
Create a collection, and add a fe... | #R | R | numeric(5)
1:10
c(1, 3, 6, 10, 7 + 8, sqrt(441)) | Give a code snippet in #R
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Collections are abstractions to represent sets of values.
In statically-typed languages, the values are typically of a common data type.
Task
Create... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exceptions | Exceptions | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions Through Nested Calls
| #Scala | Scala | //Defining exceptions
class AccountBlockException extends Exception
class InsufficientFundsException(val amount: Double) extends Exception
class CheckingAccount(number: Int, var blocked: Boolean = false, var balance: Double = 0.0) {
def deposit(amount: Double) { // Throwing an exception 1
if (blocked) throw new... | Give a code snippet in #Scala
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fusc_sequence | Fusc sequence |
Definitions
The fusc integer sequence is defined as:
fusc(0) = 0
fusc(1) = 1
for n>1, the nth term is defined as:
if n is even; fusc(n) = fusc(n/2)
if n is odd; fusc(n) = fusc((n-1)/2) + fusc((n+1)/2)
Note that MathWorld's definition starts with unity, not zero. Th... | #Processing | Processing | void setup() {
println("First 61 terms:");
for (int i = 0; i < 60; i++) {
print(fusc(i) + " ");
}
println(fusc(60));
println();
println("Sequence elements where number of digits of the value increase:");
int max_len = 0;
for (int i = 0; i < 700000; i++) {
int temp = fusc(i);
if (str(temp).le... | Give a code snippet in #Processing
Definitions
The fusc integer sequence is defined as:
fusc(0) = 0
fusc(1) = 1
for n>1, the nth term is defined as:
if n is even; fusc(n) = fusc(n/2)
if n is odd; fusc(n) = fusc((n-1)/2) + fusc((n+1)/2)
Note that MathWorld's definiti... | 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 |... | #Bracmat | Bracmat | ( ( Logic
= x y
. '$arg:(=?x,?y)
& str
$ ( "\n(x,y)="
!arg
( ":\n"
"x and y -> "
( (!x&!y)&true
| false
)
)
( \n
"x or y -> "
( (!x|!y)&true
| false... | Give a code snippet in #Bracmat
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/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
| #WDTE | WDTE | let io => import 'io';
let ex => switch 'this is irrelevant for this example' {
false => 'This is, obviously, not returned.';
'a string' => 'This is also not returned.';
true => 'This is returned.';
};
ex -- io.writeln io.stdout; | Give a code snippet in #WDTE
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/Roots_of_unity | Roots of unity | The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| #jq | jq | def nthroots(n):
(8 * (1|atan)) as $twopi
| range(0;n) | (($twopi * .) / n) as $angle | [ ($angle | cos), ($angle | sin) ];
nthroots(10) | Give a code snippet in #jq
The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Simple_moving_average | Averages/Simple moving average | Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average is a method for computing an avera... | #J | J | 5 (+/%#)\ 1 2 3 4 5 5 4 3 2 1 NB. not a solution for this task
3 3.8 4.2 4.2 3.8 3 | Give a code snippet in #J
Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average is a me... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Read_an_image_through_a_pipe | Bitmap/Read an image through a pipe | This task is the opposite of the PPM conversion through a pipe. In this task, using a delegate tool (like cjpeg, one of the netpbm package, or convert of the ImageMagick package) we read an image file and load it into the data storage type defined here. We can also use the code from Read ppm file, so that we can use PP... | #Lua | Lua | function Bitmap:loadPPM(filename, fp)
if not fp then fp = io.open(filename, "rb") end
if not fp then return end
local head, width, height, depth, tail = fp:read("*line", "*number", "*number", "*number", "*line")
self.width, self.height = width, height
self:alloc()
for y = 1, self.height do
for x = 1, se... | Give a code snippet in #Lua
This task is the opposite of the PPM conversion through a pipe. In this task, using a delegate tool (like cjpeg, one of the netpbm package, or convert of the ImageMagick package) we read an image file and load it into the data storage type defined here. We can also use the code from Read pp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_the_coins | Count the coins | There are four types of common coins in US currency:
quarters (25 cents)
dimes (10 cents)
nickels (5 cents), and
pennies (1 cent)
There are six ways to make change for 15 cents:
A dime and a nickel
A dime and 5 pennies
3 nickels
2 nickels and 5 pennies
A nickel and 10 pen... | #Perl | Perl | use 5.01;
use Memoize;
sub cc {
my $amount = shift;
return 0 if !@_ || $amount < 0;
return 1 if $amount == 0;
my $first = shift;
cc( $amount, @_ ) + cc( $amount - $first, $first, @_ );
}
memoize 'cc';
# Make recursive algorithm run faster by sorting coins descending by value:
sub cc_optimized {
... | Give a code snippet in #Perl
There are four types of common coins in US currency:
quarters (25 cents)
dimes (10 cents)
nickels (5 cents), and
pennies (1 cent)
There are six ways to make change for 15 cents:
A dime and a nickel
A dime and 5 pennies
3 nickels
2 nickels and 5 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/N-queens_problem | N-queens problem |
Solve the eight queens puzzle.
You can extend the problem to solve the puzzle with a board of size NxN.
For the number of solutions for small values of N, see OEIS: A000170.
Related tasks
A* search algorithm
Solve a Hidato puzzle
Solve a Holy Knight's tour
Knight's tour
Peaceful chess queen armie... | #APL | APL |
⍝Solution
accm←{⍺,((⍴⍵)=⍴⊃⍺)↑⊂⍵}
atk←{∪∊(⊂⍵)+¯1 0 1×⊂⌽⍳⍴⍵}
dfs←{⊃∇⍨/⌽(⊂⍺ ⍺⍺ ⍵),⍺ ⍵⍵ ⍵}
qfmt←{⍵∘.=⍳⍴⍵}
subs←{(⊂⍵),¨(⍳⍴⊃⍺)~atk ⍵}
queens←{qfmt¨(↓0 ⍵⍴0)accm dfs subs ⍬}
printqueens←{i←1⋄{⎕←'answer'i⋄⎕←⍵⋄i+←1}¨queens ⍵}
⍝Example
printqueens 6
| Give a code snippet in #APL
Solve the eight queens puzzle.
You can extend the problem to solve the puzzle with a board of size NxN.
For the number of solutions for small values of N, see OEIS: A000170.
Related tasks
A* search algorithm
Solve a Hidato puzzle
Solve a Holy Knight's tour
Knight's tou... | 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... | #AArch64_Assembly | AArch64 Assembly |
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program strTokenize64.s */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeConstantes... | Give a code snippet in #AArch64_Assembly
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.
Oth... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_sentence_type | Determine sentence type | Use these sentences:
"hi there, how are you today? I'd like to present to you the washing machine 9001. You have been nominated to win one of these! Just make sure you don't break it."
Task
Search for the last used punctuation in a sentence, and determine its type according to its punctuation.
Output one of these le... | #Python | Python | import re
txt = """
Hi there, how are you today? I'd like to present to you the washing machine 9001.
You have been nominated to win one of these! Just make sure you don't break it"""
def haspunctotype(s):
return 'S' if '.' in s else 'E' if '!' in s else 'Q' if '?' in s else 'N'
txt = re.sub('\n', '', txt)
pa... | Give a code snippet in #Python
Use these sentences:
"hi there, how are you today? I'd like to present to you the washing machine 9001. You have been nominated to win one of these! Just make sure you don't break it."
Task
Search for the last used punctuation in a sentence, and determine its type according to its punc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix | Sum of elements below main diagonal of matrix | Task
Find and display the sum of elements that are below the main diagonal of a matrix.
The matrix should be a square matrix.
─── Matrix to be used: ───
[[1,3,7,8,10],
[2,4,16,14,4],
[3,1,9,18,11],
[12,14,17,18,20],
[7,1,3,9,5]]
| #ALGOL_68 | ALGOL 68 | BEGIN # sum the elements below the main diagonal of a matrix #
# returns the sum of the elements below the main diagonal #
# of m, m must be a square matrix #
OP LOWERSUM = ( [,]INT m )INT:
IF 1 LWB m /= 2 LWB m OR 1 UPB m /= 2 UPB m THEN
# the matrix isn't sq... | Give a code snippet in #ALGOL_68
Task
Find and display the sum of elements that are below the main diagonal of a matrix.
The matrix should be a square matrix.
─── Matrix to be used: ───
[[1,3,7,8,10],
[2,4,16,14,4],
[3,1,9,18,11],
[12,14,17,18,20],
[7,1,3,9,5]]
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Problem_of_Apollonius | Problem of Apollonius |
Task
Implement a solution to the Problem of Apollonius (description on Wikipedia) which is the problem of finding the circle that is tangent to three specified circles (colored black in the diagram below to the right).
There is an algebraic solution which is pretty straightforward.
The solutions to the ... | #Elixir | Elixir | defmodule Circle do
def apollonius(c1, c2, c3, s1, s2, s3) do
{x1, y1, r1} = c1
{w12, w13, w14} = calc(c1, c2, s1, s2)
{u22, u23, u24} = calc(c2, c3, s2, s3)
{w22, w23, w24} = {u22 - w12, u23 - w13, u24 - w14}
p = -w23 / w22
q = w24 / w22
m = -w12 * p - w13
n = w14 - w12 * q
a ... | Give a code snippet in #Elixir
Task
Implement a solution to the Problem of Apollonius (description on Wikipedia) which is the problem of finding the circle that is tangent to three specified circles (colored black in the diagram below to the right).
There is an algebraic solution which is pretty straightf... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pascal%27s_triangle | Pascal's triangle | Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either 1 or the sum of the two elemen... | #Potion | Potion | printpascal = (n) :
if (n < 1) :
1 print
(1)
. else :
prev = printpascal(n - 1)
prev append(0)
curr = (1)
n times (i):
curr append(prev(i) + prev(i + 1))
.
"\n" print
curr join(", ") print
curr
.
.
printpascal(read number integer) | Give a code snippet in #Potion
Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is eithe... | 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... | #Icon_and_Unicon | Icon and Unicon | procedure main()
every 1 to 10 do
write(n := nextlooknsayseq(\n | 1))
end
procedure nextlooknsayseq(n) #: return next element in look and say sequence
n2 := ""
n ? until pos(0) do {
i := tab(any(&digits)) | fail # or fail if not digits
move(-1)
n2 ||:= *tab(many(i)) || i # accumulate count+digit
... | Give a code snippet in #Icon_and_Unicon
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 th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available,... | #TXR | TXR | (defvar li (list 1 2 3)) ;; (1 2 3)
(defvar ve (vec 1 2 3)) ;; make vector #(1 2 3)
;; (defvar ve (vector 3)) ;; make #(nil nil nil)
[ve 0] ;; yields 1
[li 0] ;; yields 1
[ve -1] ;; yields 3
[li 5] ;; yields nil
[li -50] ;; yields nil
[ve 50] ;; error
(set [ve 2] 4) ;; changes vector to #(1 2 4).
(... | Give a code snippet in #TXR
This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retriev... | 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... | #VBA | VBA |
Option Explicit
Sub Split_string_based_on_change_character()
Dim myArr() As String, T As String
Const STRINPUT As String = "gHHH5YY++///\"
Const SEP As String = ", "
myArr = Split_Special(STRINPUT)
T = Join(myArr, SEP)
Debug.Print Left(T, Len(T) - Len(SEP))
End Sub
Function Split_Special(Ch As Str... | Give a code snippet in #VBA
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/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.)
| #Julia | Julia | # single line
#=
Multi-
line
comment
=# | Give a code snippet in #Julia
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/Knapsack_problem/Bounded | Knapsack problem/Bounded | A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature. So he needs some items during the trip. Food, clothing, etc. He has a good knapsack for carrying the things, but he knows that he can carry only 4 kg weight in his knapsack, because th... | #Clojure | Clojure | (ns knapsack
(:gen-class))
(def groupeditems [
["map", 9, 150, 1]
["compass", 13, 35, 1]
["water", 153, 200, 3]
["sandwich", 50, 60, 2]
["glucose", 15, 60, 2]
["tin", 68, 45, 3]
["ban... | Give a code snippet in #Clojure
A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature. So he needs some items during the trip. Food, clothing, etc. He has a good knapsack for carrying the things, but he knows that he can carry only 4 kg w... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Halt_and_catch_fire | Halt and catch fire | Task
Create a program that crashes as soon as possible, with as few lines of code as possible. Be smart and don't damage your computer, ok?
The code should be syntactically valid. It should be possible to insert [a subset of] your submission into another program, presumably to help debug it, or perhaps for use when an... | #Julia | Julia | @assert false "Halt and catch fire." | Give a code snippet in #Julia
Task
Create a program that crashes as soon as possible, with as few lines of code as possible. Be smart and don't damage your computer, ok?
The code should be syntactically valid. It should be possible to insert [a subset of] your submission into another program, presumably to help debug... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Globally_replace_text_in_several_files | Globally replace text in several files | Task
Replace every occurring instance of a piece of text in a group of text files with another one.
For this task we want to replace the text "Goodbye London!" with "Hello New York!" for a list of files.
| #Erlang | Erlang |
-module( globally_replace_text ).
-export( [in_files/3, main/1] ).
in_files( Old, New, Files ) when is_list(Old) ->
in_files( binary:list_to_bin(Old), binary:list_to_bin(New), Files );
in_files( Old, New, Files ) -> [replace_in_file(Old, New, X, file:read_file(X)) || X <- Files].
main( [Old, New | Files... | Give a code snippet in #Erlang
Task
Replace every occurring instance of a piece of text in a group of text files with another one.
For this task we want to replace the text "Goodbye London!" with "Hello New York!" for a list of files.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Letter_frequency | Letter frequency | Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequen... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const type: charHash is hash [char] integer;
const proc: main is func
local
var charHash: numberOfChars is charHash.EMPTY_HASH;
var char: ch is ' ';
begin
ch := getc(IN);
while ch <> EOF do
if ch in numberOfChars then
incr(numberOfChars[ch]);
else
... | Give a code snippet in #Seed7
Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (ass... | 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... | #Standard_ML | Standard ML | val s = "hello"
val s1 = s ^ " literal\n"
val () =
print (s ^ " literal\n");
print s1 | Give a code snippet in #Standard_ML
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 stri... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Population_count | Population count | Population count
You are encouraged to solve this task according to the task description, using any language you may know.
The population count is the number of 1s (ones) in the binary representation of a non-negative integer.
Population count is also known as:
pop count
popcount
sideways sum
... | #Python | Python | >>> def popcount(n): return bin(n).count("1")
...
>>> [popcount(3**i) for i in range(30)]
[1, 2, 2, 4, 3, 6, 6, 5, 6, 8, 9, 13, 10, 11, 14, 15, 11, 14, 14, 17, 17, 20, 19, 22, 16, 18, 24, 30, 25, 25]
>>> evil, odious, i = [], [], 0
>>> while len(evil) < 30 or len(odious) < 30:
... p = popcount(i)
... if p % 2:... | Give a code snippet in #Python
Population count
You are encouraged to solve this task according to the task description, using any language you may know.
The population count is the number of 1s (ones) in the binary representation of a non-negative integer.
Population count is also known as:
pop coun... | 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.
... | #JavaScript | JavaScript | var fso = new ActiveXObject("Scripting.FileSystemObject");
var dir = fso.GetFolder('test_folder');
function walkDirectory(dir, re_pattern) {
WScript.Echo("Files in " + dir.name + " matching '" + re_pattern +"':");
walkDirectoryFilter(dir.Files, re_pattern);
WScript.Echo("Folders in " + dir.name + " matc... | Give a code snippet in #JavaScript
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 direct... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_entire_file | Write entire file | Task
(Over)write a file so that it contains a string.
The reverse of Read entire file—for when you want to update or create a file which you would read in its entirety all at once.
| #LiveCode | LiveCode |
put "this is a string" into URL "file:~/Desktop/TestFile.txt"
| Give a code snippet in #LiveCode
Task
(Over)write a file so that it contains a string.
The reverse of Read entire file—for when you want to update or create a file which you would read in its entirety all at once.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Penney%27s_game | Penney's game | Penney's game is a game where two players bet on being the first to see a particular sequence of heads or tails in consecutive tosses of a fair coin.
It is common to agree on a sequence length of three then one player will openly choose a sequence, for example:
Heads, Tails, Heads, or HTH for short.
The other pla... | #UNIX_Shell | UNIX Shell | #!/bin/bash
main() {
printf $'Penney\'s Game\n\n'
printf 'Flipping to see who goes first ... '
if [[ $(flip) == H ]]; then
printf 'I do.\n'
p2=$(choose_sequence)
printf 'I choose: %s\n' "$p2"
else
printf 'You do.\n'
fi
while true; do
read -p 'Enter your three-flip sequence: ' p1
... | Give a code snippet in #UNIX_Shell
Penney's game is a game where two players bet on being the first to see a particular sequence of heads or tails in consecutive tosses of a fair coin.
It is common to agree on a sequence length of three then one player will openly choose a sequence, for example:
Heads, Tails, Hea... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_element_of_a_list | Greatest element of a list | Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| #Logo | Logo | to max :a :b
output ifelse :a > :b [:a] [:b]
end
print reduce "max [...] | Give a code snippet in #Logo
Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| 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)
... | #Coco | Coco | for i from 1 to 100
console.log do
if i % 15 == 0 then 'FizzBuzz'
else if i % 3 == 0 then 'Fizz'
else if i % 5 == 0 then 'Buzz'
else i | Give a code snippet in #Coco
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 ... | 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... | #Dart | Dart |
main() {
while(true) {
print("SPAM");
}
}
| Give a code snippet in #Dart
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_three_variables | Sort three variables |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Rust | Rust | fn main() {
let mut array = [5, 1, 3];
array.sort();
println!("Sorted: {:?}", array);
array.sort_by(|a, b| b.cmp(a));
println!("Reverse sorted: {:?}", array);
}
| Give a code snippet in #Rust
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 sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Best_shuffle | Best shuffle | Task
Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible.
A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time is acceptable as an alternative... | #Ada | Ada | with Ada.Text_IO;
with Ada.Strings.Unbounded;
procedure Best_Shuffle is
function Best_Shuffle (S : String) return String;
function Best_Shuffle (S : String) return String is
T : String (S'Range) := S;
Tmp : Character;
begin
for I in S'Range loop
for J in S'Range loop
... | Give a code snippet in #Ada
Task
Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible.
A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time is... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Discordian_date | Discordian date |
Task
Convert a given date from the Gregorian calendar to the Discordian calendar.
| #Raku | Raku | my @seasons = << Chaos Discord Confusion Bureaucracy 'The Aftermath' >>;
my @days = << Sweetmorn Boomtime Pungenday Prickle-Prickle 'Setting Orange' >>;
sub ordinal ( Int $n ) { $n ~ ( $n % 100 == 11|12|13
?? 'th' !! < th st nd rd th th th th th th >[$n % 10] ) }
sub ddate ( Str $ymd ) {
my $d = DateTime.new:... | Give a code snippet in #Raku
Task
Convert a given date from the Gregorian calendar to the Discordian calendar.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Real_constants_and_functions | Real constants and functions | Task
Show how to use the following math constants and functions in your language (if not available, note it):
e (base of the natural logarithm)
π
{\displaystyle \pi }
square root
logarithm (any base allowed)
exponential (ex )
absolute value (a.k.a. "magnitude")
floor (largest ... | #Tcl | Tcl | expr {exp(1)} ;# e
expr {4 * atan(1)} ;# pi -- also, simpler: expr acos(-1)
expr {sqrt($x)} ;# square root
expr {log($x)} ;# natural logarithm, also log10
expr {exp($x)} ;# exponential
expr {abs($x)} ;# absolute value
expr {floor($x)} ;# floor
expr {ceil($x)} ;# ceiling
expr {$x**$y} ... | Give a code snippet in #Tcl
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/Gaussian_elimination | Gaussian elimination | Task
Solve Ax=b using Gaussian elimination then backwards substitution.
A being an n by n matrix.
Also, x and b are n by 1 vectors.
To improve accuracy, please use partial pivoting and scaling.
See also
the Wikipedia entry: Gaussian elimination
| #PL.2FI | PL/I | Solve: procedure options (main); /* 11 January 2014 */
declare n fixed binary;
put ('Program to solve n simultaneous equations of the form Ax = b. Please type n:' );
get (n);
begin;
declare (A(n, n), b(n), x(n)) float(18);
declare (SA(n,n), Sb(n)) float (18);
declare i fixed binary;
put sk... | Give a code snippet in #PL.2FI
Task
Solve Ax=b using Gaussian elimination then backwards substitution.
A being an n by n matrix.
Also, x and b are n by 1 vectors.
To improve accuracy, please use partial pivoting and scaling.
See also
the Wikipedia entry: Gaussian elimination
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Cantor_set | Cantor set | Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| #XPL0 | XPL0 | proc Cantor(N, LineSeg, Len); \Delete middle third of LineSeg
int N; char LineSeg; int Len, Third, I;
[if N>0 and Len>1 then
[Third:= Len/3;
for I:= Third, 2*Third-1 do LineSeg(I):= ^ ;
Cantor(N-1, LineSeg, Third);
Cantor(N-1, LineSeg+2*Third, Third);
];
];
char LineSeg, N;
[LineSeg:=
"########... | Give a code snippet in #XPL0
Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| 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... | #Ada | Ada | with Ada.Numerics.Discrete_Random;
with SDL.Video.Windows.Makers;
with SDL.Video.Renderers.Makers;
with SDL.Events.Events;
procedure Brownian_Tree is
Width : constant := 800;
Height : constant := 600;
Points : constant := 50_000;
subtype Width_Range is Integer range 1 .. Width;
subtype Heigh... | Give a code snippet in #Ada
Brownian tree
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw a Brownian Tree.
A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes.
The initial ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Power_set | Power set | A set is a collection (container) of certain values,
without any particular order, and no repeated values.
It corresponds with a finite set in mathematics.
A set can be implemented as an associative array (partial mapping)
in which the value of each key-value pair is ignored.
Given a set S, the power set (or pow... | #J | J | ps =: #~ 2 #:@i.@^ # | Give a code snippet in #J
A set is a collection (container) of certain values,
without any particular order, and no repeated values.
It corresponds with a finite set in mathematics.
A set can be implemented as an associative array (partial mapping)
in which the value of each key-value pair is ignored.
Given a s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Runtime_evaluation/In_an_environment | Runtime evaluation/In an environment | x
x
x
Do so in a way which:
does not involve string manipulation of the input source code
is plausibly extensible to a runtime-chosen set of bindings rather than just x
does not make x a global variable
or note that these are impossible.
See also
For more general examples and language-specific details, see... | #PHP | PHP | <?php
function eval_with_x($code, $a, $b) {
$x = $a;
$first = eval($code);
$x = $b;
$second = eval($code);
return $second - $first;
}
echo eval_with_x('return 3 * $x;', 5, 10), "\n"; # Prints "15".
?> | Give a code snippet in #PHP
x
x
x
Do so in a way which:
does not involve string manipulation of the input source code
is plausibly extensible to a runtime-chosen set of bindings rather than just x
does not make x a global variable
or note that these are impossible.
See also
For more general examples and l... | christopher/rosetta-code | |
http://rosettacode.org/wiki/N-queens_problem | N-queens problem |
Solve the eight queens puzzle.
You can extend the problem to solve the puzzle with a board of size NxN.
For the number of solutions for small values of N, see OEIS: A000170.
Related tasks
A* search algorithm
Solve a Hidato puzzle
Solve a Holy Knight's tour
Knight's tour
Peaceful chess queen armie... | #OCaml | OCaml | (* Authors: Nicolas Barnier, Pascal Brisset
Copyright 2004 CENA. All rights reserved.
This code is distributed under the terms of the GNU LGPL *)
open Facile
open Easy
(* Print a solution *)
let print queens =
let n = Array.length queens in
if n <= 10 then (* Pretty printing *)
for i = 0 to n - 1 do
... | Give a code snippet in #OCaml
Solve the eight queens puzzle.
You can extend the problem to solve the puzzle with a board of size NxN.
For the number of solutions for small values of N, see OEIS: A000170.
Related tasks
A* search algorithm
Solve a Hidato puzzle
Solve a Holy Knight's tour
Knight's t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/Floating_point | Literals/Floating point | Programming languages have different ways of expressing floating-point literals.
Task
Show how floating-point literals can be expressed in your language: decimal or other bases, exponential notation, and any other special features.
You may want to include a regular expression or BNF/ABNF/EBNF defining allowable fo... | #Maxima | Maxima | /* Maxima has machine floating point (usually double precision IEEE 754), and
arbitrary length "big floats" */
/* Here are ordinary floats */
3.14159
2.718e0
1.2345d10
1.2345e10
1.2345f10
/* And big floats (always with a "b" for the exponent) */
3.14159b0
2.718b0
1.2345b10
/* Before computing with big float, one ... | Give a code snippet in #Maxima
Programming languages have different ways of expressing floating-point literals.
Task
Show how floating-point literals can be expressed in your language: decimal or other bases, exponential notation, and any other special features.
You may want to include a regular expression or BNF... | 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 ... | #UNIX_Shell | UNIX Shell | multisplit() {
local str=$1
shift
local regex=$( IFS='|'; echo "$*" )
local sep
while [[ $str =~ $regex ]]; do
sep=${BASH_REMATCH[0]}
words+=( "${str%%${sep}*}" )
seps+=( "$sep" )
str=${str#*$sep}
done
words+=( "$str" )
}
words=() seps=()
original="a!===... | Give a code snippet in #UNIX_Shell
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 t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/Floating_point | Literals/Floating point | Programming languages have different ways of expressing floating-point literals.
Task
Show how floating-point literals can be expressed in your language: decimal or other bases, exponential notation, and any other special features.
You may want to include a regular expression or BNF/ABNF/EBNF defining allowable fo... | #PARI.2FGP | PARI/GP | [+-]?((\d*\.\d+\b)|(\d+(\.\d*)?[Ee][+-]?\d+\b)|-?(\.\d+[Ee][+-]?\d+\b)|(\d+\.)) | Give a code snippet in #PARI.2FGP
Programming languages have different ways of expressing floating-point literals.
Task
Show how floating-point literals can be expressed in your language: decimal or other bases, exponential notation, and any other special features.
You may want to include a regular expression or ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/QR_decomposition | QR decomposition | Any rectangular
m
×
n
{\displaystyle m\times n}
matrix
A
{\displaystyle {\mathit {A}}}
can be decomposed to a product of an orthogonal matrix
Q
{\displaystyle {\mathit {Q}}}
and an upper (right) triangular matrix
R
{\displaystyle {\mathit {R}}}
, as described in QR decompositi... | #BBC_BASIC | BBC BASIC | *FLOAT 64
@% = &2040A
INSTALL @lib$+"ARRAYLIB"
REM Test matrix for QR decomposition:
DIM A(2,2)
A() = 12, -51, 4, \
\ 6, 167, -68, \
\ -4, 24, -41
REM Do the QR decomposition:
DIM Q(2,2), R(2,2)
PROCqrdecompose(A(), Q(), R())
PRINT ... | Give a code snippet in #BBC_BASIC
Any rectangular
m
×
n
{\displaystyle m\times n}
matrix
A
{\displaystyle {\mathit {A}}}
can be decomposed to a product of an orthogonal matrix
Q
{\displaystyle {\mathit {Q}}}
and an upper (right) triangular matrix
R
{\displaystyle {\mathit {R}}... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Evaluate_binomial_coefficients | Evaluate binomial coefficients | This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2
)
…
(
n
−
k
+
1
)
k
(
k
−
1... | #Raku | Raku | say combinations(5, 3).elems; | Give a code snippet in #Raku
This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Balanced_ternary | Balanced ternary | Balanced ternary is a way of representing numbers. Unlike the prevailing binary representation, a balanced ternary integer is in base 3, and each digit can have the values 1, 0, or −1.
Examples
Decimal 11 = 32 + 31 − 30, thus it can be written as "++−"
Decimal 6 = 32 − 31 + 0 × 30, thus it can be written as "+−0"
... | #Common_Lisp | Common Lisp | ;;; balanced ternary
;;; represented as a list of 0, 1 or -1s, with least significant digit first
;;; convert ternary to integer
(defun bt-integer (b)
(reduce (lambda (x y) (+ x (* 3 y))) b :from-end t :initial-value 0))
;;; convert integer to ternary
(defun integer-bt (n)
(if (zerop n) nil
(case (mod n 3)
... | Give a code snippet in #Common_Lisp
Balanced ternary is a way of representing numbers. Unlike the prevailing binary representation, a balanced ternary integer is in base 3, and each digit can have the values 1, 0, or −1.
Examples
Decimal 11 = 32 + 31 − 30, thus it can be written as "++−"
Decimal 6 = 32 − 31 + 0 ×... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Gnome_sort | Sorting algorithms/Gnome 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
... | #J | J | position=: 0 {.@I.@, [
swap=: ] A.~ *@position * #@[ !@- <:@position
gnome=: swap~ 2 >/\ ]
gnomes=: gnome^:_ | 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/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #Visual_Basic | Visual Basic | Option Explicit
Function DotProduct(a() As Long, b() As Long) As Long
Dim l As Long, u As Long, i As Long
Debug.Assert DotProduct = 0 'return value automatically initialized with 0
l = LBound(a())
If l = LBound(b()) Then
u = UBound(a())
If u = UBound(b()) Then
For i = l To u
DotProduct = D... | Give a code snippet in #Visual_Basic
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Magic_8-ball | Magic 8-ball | Task
Create Magic 8-Ball.
See details at: Magic 8-Ball.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurren... | #Java | Java |
import java.util.Random;
import java.util.Scanner;
public class MagicEightBall {
public static void main(String[] args) {
new MagicEightBall().run();
}
private static String[] ANSWERS = new String[] {"It is certain.", "It is decidedly so.", "Without a doubt.", "Yes - definitely.",
... | Give a code snippet in #Java
Task
Create Magic 8-Ball.
See details at: Magic 8-Ball.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformat... | 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... | #Ada | Ada |
with Ada.Text_IO;
procedure Split is
procedure Print_Tokens (s : String) is
i, j : Integer := s'First;
begin
loop
while j<=s'Last and then s(j)=s(i) loop j := j + 1; end loop;
if i/=s'first then Ada.Text_IO.Put (", "); end if;
Ada.Text_IO.Put (s(i..j-1));
i := j;
exit when j... | Give a code snippet in #Ada
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/99_bottles_of_beer | 99 bottles of beer | Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one dow... | #Klingphix | Klingphix | include ..\Utilitys.tlhy
:bottles
dup 0 ==
(
["no more bottles of beer"]
[ dup 1 ==
(
["1 bottle of beer"]
[dup tostr " bottles of beer" chain]
) if
]
) if
;
( 99 1 -1 )
[ bottles print " on the wall," ?
bottles "," chain ?
"take one... | Give a code snippet in #Klingphix
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/Floating_point | Literals/Floating point | Programming languages have different ways of expressing floating-point literals.
Task
Show how floating-point literals can be expressed in your language: decimal or other bases, exponential notation, and any other special features.
You may want to include a regular expression or BNF/ABNF/EBNF defining allowable fo... | #Dyalect | Dyalect | var x = 42.02
var y = 0.174e-17 | Give a code snippet in #Dyalect
Programming languages have different ways of expressing floating-point literals.
Task
Show how floating-point literals can be expressed in your language: decimal or other bases, exponential notation, and any other special features.
You may want to include a regular expression or BN... | 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 ... | #Racket | Racket | (exp 1) ; e
pi ; pi
(sqrt x) ; square root
(log x) ; natural logarithm
(exp x) ; exponential
(abs x) ; absolute value
(floor x) ; floor
(ceiling x) ; ceiling
(expt x y) ; power | Give a code snippet in #Racket
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. "... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Convert_seconds_to_compound_duration | Convert seconds to compound duration | Task
Write a function or program which:
takes a positive integer representing a duration in seconds as input (e.g., 100), and
returns a string which shows the same duration decomposed into:
weeks,
days,
hours,
minutes, and
seconds.
This is detailed below (e.g., "2 hr, 59 sec").
Demonstrat... | #PicoLisp | PicoLisp | (for Sec (7259 86400 6000000)
(tab (-10 -30)
Sec
(glue ", "
(extract
'((N Str)
(when (gt0 (/ Sec N))
(setq Sec (% Sec N))
(pack @ " " Str) ) )
(604800 86400 3600 60 1)
'("wk" "d" "hr" "min" "sec") ) ) ) ) | Give a code snippet in #PicoLisp
Task
Write a function or program which:
takes a positive integer representing a duration in seconds as input (e.g., 100), and
returns a string which shows the same duration decomposed into:
weeks,
days,
hours,
minutes, and
seconds.
This is detailed below (e.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Graphical | Hello world/Graphical |
Task
Display the string Goodbye, World! on a GUI object (alert box, plain window, text area, etc.).
Related task
Hello world/Text
| #E | E | def <widget> := <swt:widgets.*>
def SWT := <swt:makeSWT>
def frame := <widget:makeShell>(currentDisplay)
frame.setText("Rosetta Code")
frame.setBounds(30, 30, 230, 60)
frame.addDisposeListener(def _ { to widgetDisposed(event) {
interp.continueAtTop()
}})
def label := <widget:makeLabel>(frame, SWT.getLEF... | Give a code snippet in #E
Task
Display the string Goodbye, World! on a GUI object (alert box, plain window, text area, etc.).
Related task
Hello world/Text
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial | Factorial | Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a number.
Solutions can be iterat... | #Verbexx | Verbexx | // ----------------
// recursive method (requires INTV_T input parm)
// ----------------
fact_r @FN [n]
{
@CASE
when:(n < 0iv) {-1iv }
when:(n == 0iv) { 1iv }
else: { n * (@fact_r n-1iv) }
};
// ----------------
// iterative method (requires ... | Give a code snippet in #Verbexx
Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rate_counter | Rate counter | Of interest is the code that performs the actual measurements. Any other code (such as job implementation or dispatching) that is required to demonstrate the rate tracking is helpful, but not the focus.
Multiple approaches are allowed (even preferable), so long as they can accomplish these goals:
Run N seconds worth... | #JavaScript | JavaScript | function millis() { // Gets current time in milliseconds.
return (new Date()).getTime();
}
/* Executes function 'func' n times, returns array of execution times. */
function benchmark(n, func, args) {
var times = [];
for (var i=0; i<n; i++) {
var m = millis();
func.apply(func, args);
times.push(mill... | Give a code snippet in #JavaScript
Of interest is the code that performs the actual measurements. Any other code (such as job implementation or dispatching) that is required to demonstrate the rate tracking is helpful, but not the focus.
Multiple approaches are allowed (even preferable), so long as they can accomplis... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Number_names | Number names | Task
Show how to spell out a number in English.
You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type, if that's less).
Support for inputs other than positive integers (like zero, negat... | #Vlang | Vlang | const (
small = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"]
tens = ["", "", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"]
illions... | Give a code snippet in #Vlang
Task
Show how to spell out a number in English.
You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type, if that's less).
Support for inputs other than posi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Range_consolidation | Range consolidation | Define a range of numbers R, with bounds b0 and b1 covering all numbers between and including both bounds.
That range can be shown as:
[b0, b1]
or equally as:
[b1, b0]
Given two ranges, the act of consolidation between them compares the two ranges:
If one range covers all of the other then t... | #C.2B.2B | C++ | #include <algorithm>
#include <iostream>
#include <utility>
#include <vector>
// A range is represented as std::pair<from, to>
template <typename iterator>
void normalize_ranges(iterator begin, iterator end) {
for (iterator i = begin; i != end; ++i) {
if (i->second < i->first)
std::swap(i->f... | Give a code snippet in #C.2B.2B
Define a range of numbers R, with bounds b0 and b1 covering all numbers between and including both bounds.
That range can be shown as:
[b0, b1]
or equally as:
[b1, b0]
Given two ranges, the act of consolidation between them compares the two ranges:
If one ran... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Queue/Usage | Queue/Usage |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Create a queue data structure and demonstrate its operations.
(For implementations of queues, see the FIFO task.)
Ope... | #6502_Assembly | 6502 Assembly |
queuePointerStart equ #$FD
queuePointerMinus1 equ #$FC ;make this equal whatever "queuePointerStart" is, minus 1.
pushQueue:
STA 0,x
DEX
RTS
popQueue:
STX temp
LDX #queuePointerStart
LDA 0,x ;get the item that's first in line
PHA
LDX #queuePointerMinus1
loop_popQueue:
LDA 0,X
STA 1,X
DEX
... | Give a code snippet in #6502_Assembly
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Create a queue data structure and demonstrate its operations.
(For implementation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_characters | Special characters | Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling it to be used as a normal charact... | #Lasso | Lasso | # defined local ie. #mylocal will fail if not defined
$ defined variable ie. $myvar will fail if not defined
= assignment
:= assign as return assigned value
? ternary conditional true ? this
| ternary else false ? this | that
|| or
&& and
! negative operator
{ open capture
} close capture
=> specify givenblock / captur... | Give a code snippet in #Lasso
Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling it... | 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.
| #Modula-3 | Modula-3 | MODULE FileCreation EXPORTS Main;
IMPORT FS, File, OSError, IO, Stdio;
VAR file: File.T;
BEGIN
TRY
file := FS.OpenFile("output.txt");
file.close();
FS.CreateDirectory("docs");
file := FS.OpenFile("/output.txt");
file.close();
FS.CreateDirectory("/docs");
EXCEPT
| OSError.E => IO.Put(... | Give a code snippet in #Modula-3
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/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 |... | #Lambdatalk | Lambdatalk |
{S.slice 1 2 hello brave new world}
-> brave new
{W.slice 4 11 www.rosetta.org}
-> rosetta
| Give a code snippet in #Lambdatalk
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/I_before_E_except_after_C | I before E except after C | The phrase "I before E, except after C" is a
widely known mnemonic which is supposed to help when spelling English words.
Task
Using the word list from http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
check if the two sub-clauses of the phrase are plausible individually:
"I before E when not pre... | #Kotlin | Kotlin | // version 1.0.6
import java.net.URL
import java.io.InputStreamReader
import java.io.BufferedReader
fun isPlausible(n1: Int, n2: Int) = n1 > 2 * n2
fun printResults(source: String, counts: IntArray) {
println("Results for $source")
println(" i before e except after c")
println(" for ${counts[0... | Give a code snippet in #Kotlin
The phrase "I before E, except after C" is a
widely known mnemonic which is supposed to help when spelling English words.
Task
Using the word list from http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
check if the two sub-clauses of the phrase are plausible individual... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Letter_frequency | Letter frequency | Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequen... | #F.23 | F# | let alphabet =
['A'..'Z'] |> Set.ofList
let letterFreq (text : string) =
text.ToUpper().ToCharArray()
|> Array.filter (fun x -> alphabet.Contains(x))
|> Seq.countBy (fun x -> x)
|> Seq.sort
let v = "Now is the time for all good men to come to the aid of the party"
let res = letterFreq v
for ... | Give a code snippet in #F.23
Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Run-length_encoding | Run-length encoding | Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a function to reverse the compression... | #Racket | Racket |
#lang racket
(define (encode str)
(regexp-replace* #px"(.)\\1*" str (λ (m c) (~a (string-length m) c))))
(define (decode str)
(regexp-replace* #px"([0-9]+)(.)" str (λ (m n c) (make-string (string->number n) (string-ref c 0)))))
| Give a code snippet in #Racket
Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a fun... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Periodic_table | Periodic table | Task
Display the row and column in the periodic table of the given atomic number.
The periodic table
Let us consider the following periodic table representation.
__________________________________________________________________________
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1... | #Wren | Wren | import "./fmt" for Fmt
var limits = [3..10, 11..18, 19..36, 37..54, 55..86, 87..118]
var periodicTable = Fn.new { |n|
if (n < 1 || n > 118) Fiber.abort("Atomic number is out of range.")
if (n == 1) return [1, 1]
if (n == 2) return [1, 18]
if (n >= 57 && n <= 71) return [8, n - 53]
if (n >= 89 &... | Give a code snippet in #Wren
Task
Display the row and column in the periodic table of the given atomic number.
The periodic table
Let us consider the following periodic table representation.
__________________________________________________________________________
| 1 2 3 4 5 6 7 8 9 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Cocktail_sort | Sorting algorithms/Cocktail 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
... | #Racket | Racket |
#lang racket
(require (only-in srfi/43 vector-swap!))
(define (cocktail-sort! xs)
(define (ref i) (vector-ref xs i))
(define (swap i j) (vector-swap! xs i j))
(define len (vector-length xs))
(define (bubble from to delta)
(for/fold ([swaps 0]) ([i (in-range from to delta)])
(cond [(> (ref i) (ref ... | Give a code snippet in #Racket
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/One-dimensional_cellular_automata | One-dimensional cellular automata | Assume an array of cells with an initial distribution of live and dead cells,
and imaginary cells off the end of the array having fixed values.
Cells in the next generation of the array are calculated based on the value of the cell and its left and right nearest neighbours in the current generation.
If, in the follow... | #DWScript | DWScript | const ngenerations = 10;
const table = [0, 0, 0, 1, 0, 1, 1, 0];
var a := [0, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0];
var b := a;
var i, j : Integer;
for i := 1 to ngenerations do begin
for j := a.low+1 to a.high-1 do begin
if a[j] = 0 then
Print('_')
else Print('#');... | Give a code snippet in #DWScript
Assume an array of cells with an initial distribution of live and dead cells,
and imaginary cells off the end of the array having fixed values.
Cells in the next generation of the array are calculated based on the value of the cell and its left and right nearest neighbours in the curr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Palindrome_dates | Palindrome dates | Today (2020-02-02, at the time of this writing) happens to be a palindrome, without the hyphens, not only for those countries which express their dates in the yyyy-mm-dd format but, unusually, also for countries which use the dd-mm-yyyy format.
Task
Write a program which calculates and shows th... | #Nim | Nim | import strformat, times
func digits(n: int): seq[int] =
var n = n
while n != 0:
result.add n mod 10
n = n div 10
echo "First 15 palindrome dates after 2020-02-02:"
var count = 0
var year = 2021
while count != 15:
let d = year.digits
let monthNum = 10 * d[0] + d[1]
let dayNum = 10 * d[2] + d[3]
i... | Give a code snippet in #Nim
Today (2020-02-02, at the time of this writing) happens to be a palindrome, without the hyphens, not only for those countries which express their dates in the yyyy-mm-dd format but, unusually, also for countries which use the dd-mm-yyyy format.
Task
Write a program ... | 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 |... | #Fermat | Fermat | Func Compare =
?a;
?b;
if a=b then !'Equal' fi;
if a<b then !'Less than' fi;
if a>b then !'Greater than' fi;
.; | Give a code snippet in #Fermat
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/Hickerson_series_of_almost_integers | Hickerson series of almost integers | The following function, due to D. Hickerson, is said to generate "Almost integers" by the
"Almost Integer" page of Wolfram MathWorld, (December 31 2013). (See formula numbered 51.)
The function is:
h
(
n
)
=
n
!
2
(
ln
2
)
n
+
1
{\displaystyle h(n)={\operatorname {n} ! \ove... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | h[n_] = n!/(2 (Log[2])^(n + 1));
firstdecimal[x_] := Floor[10 x] - 10 Floor[x];
almostIntegerQ[x_] := firstdecimal[x] == 0 || firstdecimal[x] == 9;
Table[{i, AccountingForm[N[h[i], 50], {Infinity, 5}], almostIntegerQ[N[h[i], 50]]}, {i, 1, 17}] // TableForm | Give a code snippet in #Mathematica_.2F_Wolfram_Language
The following function, due to D. Hickerson, is said to generate "Almost integers" by the
"Almost Integer" page of Wolfram MathWorld, (December 31 2013). (See formula numbered 51.)
The function is:
h
(
n
)
=
n
!
2
(
ln
2
)
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Go | Go | package main
import (
"bufio"
"fmt"
"log"
"os"
"strconv"
"strings"
)
func check(err error) {
if err != nil {
log.Fatal(err)
}
}
func main() {
scanner := bufio.NewScanner(os.Stdin)
n := 0
for n < 1 || n > 5 {
fmt.Print("How many integer variables do you w... | Give a code snippet in #Go
Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Pascal%27s_triangle | Pascal's triangle | Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either 1 or the sum of the two elemen... | #jq | jq | # pascal(n) for n>=0; pascal(0) emits an empty stream.
def pascal(n):
def _pascal: # input: the previous row
. as $in
| .,
if length >= n then empty
else
reduce range(0;length-1) as $i
([1]; . + [ $in[$i] + $in[$i + 1] ]) + [1] | _pascal
end;
if n <= 0 then empty else [1... | Give a code snippet in #jq
Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either 1 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Summarize_primes | Summarize primes | Task
Considering in order of length, n, all sequences of consecutive
primes, p, from 2 onwards, where p < 1000 and n>0, select those
sequences whose sum is prime, and for these display the length of the
sequence, the last item in the sequence, and the sum.
| #F.C5.8Drmul.C3.A6 | Fōrmulæ | package main
import (
"fmt"
"rcu"
)
func main() {
primes := rcu.Primes(999)
sum, n, c := 0, 0, 0
fmt.Println("Summing the first n primes (<1,000) where the sum is itself prime:")
fmt.Println(" n cumulative sum")
for _, p := range primes {
n++
sum += p
if rcu.IsP... | Give a code snippet in #F.C5.8Drmul.C3.A6
Task
Considering in order of length, n, all sequences of consecutive
primes, p, from 2 onwards, where p < 1000 and n>0, select those
sequences whose sum is prime, and for these display the length of the
sequence, the last item in the sequence, and the sum.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #Joy | Joy | DEFINE transpose == [ [null] [true] [[null] some] ifte ]
[ pop [] ]
[ [[first] map] [[rest] map] cleave ]
[ cons ]
linrec . | Give a code snippet in #Joy
Transpose an arbitrarily sized rectangular Matrix.
| 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... | #Unlambda | Unlambda | ``ci``s``s`kr``s``s``s``s`k.S`k.P`k.A`k.Mii | Give a code snippet in #Unlambda
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
L... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Web_server | Hello world/Web server | The browser is the new GUI !
Task
Serve our standard text Goodbye, World! to http://localhost:8080/ so that it can be viewed with a web browser.
The provided solution must start or implement a server that accepts multiple client connections and serves text as requested.
Note that starting a web browser or... | #Racket | Racket |
#lang racket
(require web-server/servlet web-server/servlet-env)
(define (start req) (response/xexpr "Goodbye, World!"))
(serve/servlet start #:port 8080 #:servlet-path "/")
| Give a code snippet in #Racket
The browser is the new GUI !
Task
Serve our standard text Goodbye, World! to http://localhost:8080/ so that it can be viewed with a web browser.
The provided solution must start or implement a server that accepts multiple client connections and serves text as requested.
Not... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pseudo-random_numbers/Xorshift_star | Pseudo-random numbers/Xorshift star | Some definitions to help in the explanation
Floor operation
https://en.wikipedia.org/wiki/Floor_and_ceiling_functions
Greatest integer less than or equal to a real number.
Bitwise Logical shift operators (c-inspired)
https://en.wikipedia.org/wiki/Bitwise_operation#Bit_shifts
Binary bits of value shifted left or ri... | #Haskell | Haskell | import Data.Bits
import Data.Word
import System.Random
import Data.List
newtype XorShift = XorShift Word64
instance RandomGen XorShift where
next (XorShift state) = (out newState, XorShift newState)
where
newState = (\z -> z `xor` (z `shiftR` 27)) .
(\z -> z `xor` (z `shiftL` 25)) .... | Give a code snippet in #Haskell
Some definitions to help in the explanation
Floor operation
https://en.wikipedia.org/wiki/Floor_and_ceiling_functions
Greatest integer less than or equal to a real number.
Bitwise Logical shift operators (c-inspired)
https://en.wikipedia.org/wiki/Bitwise_operation#Bit_shifts
Binary... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_a_series | Sum of a series | Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
n
1
k
2
{\displa... | #ActionScript | ActionScript | function partialSum(n:uint):Number
{
var sum:Number = 0;
for(var i:uint = 1; i <= n; i++)
sum += 1/(i*i);
return sum;
}
trace(partialSum(1000)); | Give a code snippet in #ActionScript
Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knuth_shuffle | Knuth shuffle | The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array.
Task
Implement the Knuth shuffle for an integer array (or, if possible, an array of any type).
Specification
Given an array items with indices ranging from 0 to last, the algorithm can be d... | #VBScript | VBScript |
function shuffle( a )
dim i
dim r
randomize timer
for i = lbound( a ) to ubound( a )
r = int( rnd * ( ubound( a ) + 1 ) )
if r <> i then
swap a(i), a(r)
end if
next
shuffle = a
end function
sub swap( byref a, byref b )
dim tmp
tmp = a
a = b
b = tmp
end sub | Give a code snippet in #VBScript
The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array.
Task
Implement the Knuth shuffle for an integer array (or, if possible, an array of any type).
Specification
Given an array items with indices ranging from... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parsing/Shunting-yard_algorithm | Parsing/Shunting-yard algorithm | Task
Given the operator characteristics and input from the Shunting-yard algorithm page and tables, use the algorithm to show the changes in the operator stack and RPN output
as each individual token is processed.
Assume an input of a correct, space separated, string of tokens representing an infix expression
Gener... | #Visual_Basic_.NET | Visual Basic .NET | Module Module1
Class SymbolType
Public ReadOnly symbol As String
Public ReadOnly precedence As Integer
Public ReadOnly rightAssociative As Boolean
Public Sub New(symbol As String, precedence As Integer, rightAssociative As Boolean)
Me.symbol = symbol
Me.prec... | Give a code snippet in #Visual_Basic_.NET
Task
Given the operator characteristics and input from the Shunting-yard algorithm page and tables, use the algorithm to show the changes in the operator stack and RPN output
as each individual token is processed.
Assume an input of a correct, space separated, string of tok... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Text | Hello world/Text | Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
| #8086_Assembly | 8086 Assembly | DOSSEG
.MODEL TINY
.DATA
TXT DB "Hello world!$"
.CODE
START:
MOV ax, @DATA
MOV ds, ax
MOV ah, 09h ; prepare output function
MOV dx, OFFSET TXT ; set offset
INT 21h ; output string TXT
MOV AX, 4C00h ; go back to DOS
INT 21h
END START | Give a code snippet in #8086_Assembly
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Run-length_encoding | Run-length encoding | Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a function to reverse the compression... | #Haskell | Haskell | import Data.List (group)
-- Datatypes
type Encoded = [(Int, Char)] -- An encoded String with form [(times, char), ...]
type Decoded = String
-- Takes a decoded string and returns an encoded list of tuples
rlencode :: Decoded -> Encoded
rlencode = fmap ((,) <$> length <*> head) . group
-- Takes an encoded list o... | Give a code snippet in #Haskell
Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a fu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Zsh | Zsh | read name
typeset $name=42 | Give a code snippet in #Zsh
Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| 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 ... | #Ioke | Ioke | Text isPalindrome? = method(self chars == self chars reverse) | Give a code snippet in #Ioke
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/Narcissistic_decimal_number | Narcissistic decimal number | A Narcissistic decimal number is a non-negative integer,
n
{\displaystyle n}
, that is equal to the sum of the
m
{\displaystyle m}
-th powers of each of the digits in the decimal representation of
n
{\displaystyle n}
, where
m
{\displaystyle m}
is the number of digits in... | #AWK | AWK |
# syntax: GAWK -f NARCISSISTIC_DECIMAL_NUMBER.AWK
BEGIN {
for (n=0;;n++) {
leng = length(n)
sum = 0
for (i=1; i<=leng; i++) {
c = substr(n,i,1)
sum += c ^ leng
}
if (n == sum) {
printf("%d ",n)
if (++count == 25) { break }
}
}
exit(0)
}
| Give a code snippet in #AWK
A Narcissistic decimal number is a non-negative integer,
n
{\displaystyle n}
, that is equal to the sum of the
m
{\displaystyle m}
-th powers of each of the digits in the decimal representation of
n
{\displaystyle n}
, where
m
{\displaystyle m}
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Elliptic_Curve_Digital_Signature_Algorithm | Elliptic Curve Digital Signature Algorithm | Elliptic curves.
An elliptic curve E over ℤp (p ≥ 5) is defined by an equation of the form
y^2 = x^3 + ax + b, where a, b ∈ ℤp and the discriminant ≢ 0 (mod p),
together with a special point 𝒪 called the point at infinity.
The set E(ℤp) consists of all points (x, y), with x, y ∈ ℤp,
which satisfy the above defining eq... | #C | C |
/*
subject: Elliptic curve digital signature algorithm,
toy version for small modulus N.
tested : gcc 4.6.3, tcc 0.9.27
*/
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
// 64-bit integer type
typedef long long int dlong;
// rational ec point
typedef struct {
dlong x, y;
} epnt;
// elliptic cu... | Give a code snippet in #C
Elliptic curves.
An elliptic curve E over ℤp (p ≥ 5) is defined by an equation of the form
y^2 = x^3 + ax + b, where a, b ∈ ℤp and the discriminant ≢ 0 (mod p),
together with a special point 𝒪 called the point at infinity.
The set E(ℤp) consists of all points (x, y), with x, y ∈ ℤp,
which sa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #RPL | RPL | <<
[ 1 3 -5 ]
[ 4 -2 -1 ]
DOT
>> | Give a code snippet in #RPL
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1] ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roman_numerals/Decode | Roman numerals/Decode | Task
Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer.
You don't need to validate the form of the Roman numeral.
Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately,
starting with the leftmost decima... | #Perl | Perl | use 5.10.0;
{
my @trans = (
[M => 1000], [CM => 900],
[D => 500], [CD => 400],
[C => 100], [XC => 90],
[L => 50], [XL => 40],
[X => 10], [IX => 9],
[V => 5], [IV => 4],
... | Give a code snippet in #Perl
Task
Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer.
You don't need to validate the form of the Roman numeral.
Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately,
sta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/First-class_functions | First-class functions | A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other functions
Use functions as retu... | #TXR | TXR | (defvar funlist [list sin
cos
(op expt @1 3)])
(defvar invlist [list asin
acos
(op expt @1 (/ 1 3))])
(each ((f funlist) (i invlist))
(prinl [(chain f i) 0.5])) | Give a code snippet in #TXR
A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other fun... | 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 ... | #Delphi | Delphi | Pi; // π (Pi)
LogN(BASE, x) // log of x for a specified base
Log2(x) // log of x for base 2
Log10(x) // log of x for base 10
Floor(x); // floor
Ceil(x); // ceiling
Power(x, y); // power | Give a code snippet in #Delphi
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. "... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Koch_curve | Koch curve | Draw a Koch curve. See details: Koch curve
| #AutoHotkey | AutoHotkey | gdip1()
KochX := 0, KochY := 0
Koch(0, 0, A_ScreenWidth, A_ScreenHeight, 4, Arr:=[])
xmin := xmax := ymin := ymax := 0
for i, point in Arr
{
xmin := A_Index = 1 ? point.x : xmin < point.x ? xmin : point.x
xmax := point.x > xmax ? point.x : xmax
ymin := A_Index = 1 ? point.y : ymin < point.y ? ymin : point.y
ymax :=... | Give a code snippet in #AutoHotkey
Draw a Koch curve. See details: Koch curve
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Number_names | Number names | Task
Show how to spell out a number in English.
You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type, if that's less).
Support for inputs other than positive integers (like zero, negat... | #Objective-C | Objective-C | #import <Foundation/Foundation.h>
int main() {
@autoreleasepool {
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
numberFormatter.numberStyle = NSNumberFormatterSpellOutStyle;
numberFormatter.locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US"];
for (NSNumber *n i... | Give a code snippet in #Objective-C
Task
Show how to spell out a number in English.
You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type, if that's less).
Support for inputs other tha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Price_fraction | Price fraction | A friend of mine runs a pharmacy. He has a specialized function in his Dispensary application which receives a decimal value of currency and replaces it to a standard value. This value is regulated by a government department.
Task
Given a floating point value between 0.00 and 1.00, rescale according to ... | #Elixir | Elixir | defmodule Price do
@table [ {0.06, 0.10}, {0.11, 0.18}, {0.16, 0.26}, {0.21, 0.32}, {0.26, 0.38},
{0.31, 0.44}, {0.36, 0.50}, {0.41, 0.54}, {0.46, 0.58}, {0.51, 0.62},
{0.56, 0.66}, {0.61, 0.70}, {0.66, 0.74}, {0.71, 0.78}, {0.76, 0.82},
{0.81, 0.86}, {0.86, 0.90}, {0.91, 0.94}, {0.96... | Give a code snippet in #Elixir
A friend of mine runs a pharmacy. He has a specialized function in his Dispensary application which receives a decimal value of currency and replaces it to a standard value. This value is regulated by a government department.
Task
Given a floating point value between 0.00 and... | 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... | #Vala | Vala | int main() {
bool doors_open[101];
for(int i = 1; i < doors_open.length; i++) {
for(int j = 1; i*j < doors_open.length; j++) {
doors_open[i*j] = !doors_open[i*j];
}
stdout.printf("%d: %s\n", i, (doors_open[i] ? "open" : "closed"));
}
return 0;
} | Give a code snippet in #Vala
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/Tarjan | Tarjan |
This page uses content from Wikipedia. The original article was at Graph. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Tarjan's algorithm is an algorithm in graph theory for finding the strongly... | #C.23 | C# | using System;
using System.Collections.Generic;
class Node
{
public int LowLink { get; set; }
public int Index { get; set; }
public int N { get; }
public Node(int n)
{
N = n;
Index = -1;
LowLink = 0;
}
}
class Graph
{
public HashSet<Node> V { get; }
public D... | Give a code snippet in #C.23
This page uses content from Wikipedia. The original article was at Graph. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Tarjan's algorithm is an algorithm in graph t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_configuration_file | Read a configuration file | The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a semicolon are ignored by the application
# pr... | #Python | Python | def readconf(fn):
ret = {}
with file(fn) as fp:
for line in fp:
# Assume whitespace is ignorable
line = line.strip()
if not line or line.startswith('#'): continue
boolval = True
# Assume leading ";" means a false boolean
if line.s... | Give a code snippet in #Python
The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a semicolon are... | christopher/rosetta-code |
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