task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
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|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/XML/Input | XML/Input | Given the following XML fragment, extract the list of student names using whatever means desired. If the only viable method is to use XPath, refer the reader to the task XML and XPath.
<Students>
<Student Name="April" Gender="F" DateOfBirth="1989-01-02" />
<Student Name="Bob" Gender="M" DateOfBirth="1990-03-04" /... | #REXX | REXX | /*REXX program extracts student names from an XML string(s). */
g.=
g.1 = '<Students> '
g.2 = ' <Student Name="April" Gender="F" DateOfBirth="1989-01-02" /> '
g.3 = ' <Student Name="Bob" Gender="M" DateOfBirth="1990-03-04"... | Give a code snippet in #REXX
Given the following XML fragment, extract the list of student names using whatever means desired. If the only viable method is to use XPath, refer the reader to the task XML and XPath.
<Students>
<Student Name="April" Gender="F" DateOfBirth="1989-01-02" />
<Student Name="Bob" Gender="... | christopher/rosetta-code | |
http://rosettacode.org/wiki/A%2BB | A+B | A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separated by space(s):
(
−
1000
≤... | #C | C | // Standard input-output streams
#include <stdio.h>
int main()
{
int a, b;
scanf("%d%d", &a, &b);
printf("%d\n", a + b);
return 0;
} | Give a code snippet in #C
A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separated by... | christopher/rosetta-code | |
http://rosettacode.org/wiki/List_rooted_trees | List rooted trees | You came back from grocery shopping. After putting away all the goods, you are left with a pile of plastic bags, which you want to save for later use, so you take one bag and stuff all the others into it, and throw it under the sink. In doing so, you realize that there are various ways of nesting the bags, with all... | #D | D | import std.stdio, std.conv;
alias Tree = ulong,
TreeList = Tree[],
Offset = uint[32];
void listTees(in uint n, in ref Offset offset, in TreeList list) nothrow @nogc @safe {
static void show(in Tree t, in uint len) nothrow @nogc @safe {
foreach (immutable i; 0 .. len)
putchar(t & ... | Give a code snippet in #D
You came back from grocery shopping. After putting away all the goods, you are left with a pile of plastic bags, which you want to save for later use, so you take one bag and stuff all the others into it, and throw it under the sink. In doing so, you realize that there are various ways of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Last_letter-first_letter | Last letter-first letter | A certain children's game involves starting with a word in a particular category. Each participant in turn says a word, but that word must begin with the final letter of the previous word. Once a word has been given, it cannot be repeated. If an opponent cannot give a word in the category, they fall out of the ga... | #VBScript | VBScript | ' Last letter-first letter - VBScript - 11/03/2019
names = array( _
"audino", "bagon", "baltoy", "banette", _
"bidoof", "braviary", "bronzor", "carracosta", "charmeleon", _
"cresselia", "croagunk", "darmanitan", "deino", "emboar", _
"emolga", "exeggcute", "gabite", "girafarig", "gulp... | Give a code snippet in #VBScript
A certain children's game involves starting with a word in a particular category. Each participant in turn says a word, but that word must begin with the final letter of the previous word. Once a word has been given, it cannot be repeated. If an opponent cannot give a word in the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #Pike | Pike | int main() {
string s;
if (!s == 1 || sizeof(s) == 0 || s == "") {
write("String is empty\n");
}
else {
write("String not empty\n");
}
return 0;
} | Give a code snippet in #Pike
Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Othe... | 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 |... | #jq | jq | # compare/0 compares the first two items if they are numbers,
# otherwise an "uncomparable" message is emitted.
def compare:
def english:
if .[0] < .[1] then "less than"
elif .[0] == .[1] then "equal to"
else "greater than"
end;
if (.[0]|type) == "number" and (.[1]|type) == "number" then
"... | Give a code snippet in #jq
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
Con... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Repeat_a_string | Repeat a string | Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").
Other tasks re... | #beeswax | beeswax | p <
p0~1<}~< d@<
_VT@1~>yg~9PKd@M'd; | Give a code snippet in #beeswax
Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arena_storage_pool | Arena storage pool | Dynamically allocated objects take their memory from a heap.
The memory for an object is provided by an allocator which maintains the storage pool used for the heap.
Often a call to allocator is denoted as
P := new T
where T is the type of an allocated object, and P is a reference to the object.
The stora... | #Rust | Rust | #![feature(rustc_private)]
extern crate arena;
use arena::TypedArena;
fn main() {
// Memory is allocated using the default allocator (currently jemalloc). The memory is
// allocated in chunks, and when one chunk is full another is allocated. This ensures that
// references to an arena don't become i... | Give a code snippet in #Rust
Dynamically allocated objects take their memory from a heap.
The memory for an object is provided by an allocator which maintains the storage pool used for the heap.
Often a call to allocator is denoted as
P := new T
where T is the type of an allocated object, and P is a refer... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Middle_three_digits | Middle three digits | Task
Write a function/procedure/subroutine that is called with an integer value and returns the middle three digits of the integer if possible or a clear indication of an error if this is not possible.
Note: The order of the middle digits should be preserved.
Your function should be tested with the following values;... | #ERRE | ERRE |
PROGRAM MIDDLE
!$DOUBLE
FUNCTION LUNG(N)
LUNG=LEN(STR$(INT(ABS(N))))+1
END FUNCTION
FUNCTION NCNT(N)
NCNT=VAL(MID$(STR$(INT(ABS(N))),(LUNG(N)-1)/2,3))
END FUNCTION
FUNCTION EVEN(N)
EVEN=INT(N/2)=N/2
END FUNCTION
PROCEDURE NUMBER_EXAM(N->R$)
R$="" LG%=LUNG(N)-2
IF EVEN(LG%) THEN R$="?EVE... | Give a code snippet in #ERRE
Task
Write a function/procedure/subroutine that is called with an integer value and returns the middle three digits of the integer if possible or a clear indication of an error if this is not possible.
Note: The order of the middle digits should be preserved.
Your function should be tes... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Trigonometric_functions | Trigonometric functions | Task
If your language has a library or built-in functions for trigonometry, show examples of:
sine
cosine
tangent
inverses (of the above)
using the same angle in radians and degrees.
For the non-inverse functions, each radian/degree pair should use arguments that evaluate to the same angle (that i... | #IDL | IDL | deg = 35 ; arbitrary number of degrees
rad = !dtor*deg ; system variables !dtor and !radeg convert between rad and deg | Give a code snippet in #IDL
Task
If your language has a library or built-in functions for trigonometry, show examples of:
sine
cosine
tangent
inverses (of the above)
using the same angle in radians and degrees.
For the non-inverse functions, each radian/degree pair should use arguments that evaluat... | 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]]
| #Julia | Julia | using LinearAlgebra
A = [ 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 ]
@show tril(A)
@show tril(A, -1)
@show sum(tril(A, -1)) # 69
| Give a code snippet in #Julia
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/ASCII_art_diagram_converter | ASCII art diagram converter | Given the RFC 1035 message diagram from Section 4.1.1 (Header section format) as a string:
http://www.ietf.org/rfc/rfc1035.txt
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| ID |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|QR| Opcode |AA|TC|RD|RA| Z | RC... | #Rust | Rust | use std::{borrow::Cow, io::Write};
pub type Bit = bool;
#[derive(Clone, Debug)]
pub struct Field {
name: String,
from: usize,
to: usize,
}
impl Field {
pub fn new(name: String, from: usize, to: usize) -> Self {
assert!(from < to);
Self { name, from, to }
}
pub fn name(&se... | Give a code snippet in #Rust
Given the RFC 1035 message diagram from Section 4.1.1 (Header section format) as a string:
http://www.ietf.org/rfc/rfc1035.txt
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| ID |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|QR| Opcod... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factors_of_an_integer | Factors of an integer |
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 |... | #Dyalect | Dyalect | func Iterator.Where(pred) {
for x in this when pred(x) {
yield x
}
}
func Integer.Factors() {
(1..this).Where(x => this % x == 0)
}
for x in 45.Factors() {
print(x)
} | Give a code snippet in #Dyalect
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/Sleeping_Beauty_problem | Sleeping Beauty problem | Background on the task
In decision theory, The Sleeping Beauty Problem
is a problem invented by Arnold Zoboff and first publicized on Usenet. The experimental
subject, named Sleeping Beauty, agrees to an experiment as follows:
Sleeping Beauty volunteers to be put into a deep sleep on a Sunday. There is then a fair coin... | #Swift | Swift | let experiments = 1000000
var heads = 0
var wakenings = 0
for _ in (1...experiments) {
wakenings += 1
switch (Int.random(in: 0...1)) {
case 0:
heads += 1
default:
wakenings += 1
}
}
print("Wakenings over \(experiments) experiments: \(wakenings)")
print("Sleeping Beauty should estimat... | Give a code snippet in #Swift
Background on the task
In decision theory, The Sleeping Beauty Problem
is a problem invented by Arnold Zoboff and first publicized on Usenet. The experimental
subject, named Sleeping Beauty, agrees to an experiment as follows:
Sleeping Beauty volunteers to be put into a deep sleep on a Su... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Dimensions | Terminal control/Dimensions | Determine the height and width of the terminal, and store this information into variables for subsequent use.
| #Julia | Julia |
julia> using Gtk
julia> screen_size()
(3840, 1080)
julia>
| Give a code snippet in #Julia
Determine the height and width of the terminal, and store this information into variables for subsequent use.
| 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... | #Ada | Ada | with Ada.Text_IO;
with Ada.Containers.Vectors;
procedure Range_Consolidation is
type Set_Type is record
Left, Right : Float;
end record;
package Set_Vectors is
new Ada.Containers.Vectors (Positive, Set_Type);
procedure Normalize (Set : in out Set_Vectors.Vector) is
function Less_... | Give a code snippet in #Ada
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 c... | 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.
| #Wren | Wren | import "/math" for Int
import "/fmt" for Fmt
var primes = Int.primeSieve(999)
var sum = 0
var n = 0
var c = 0
System.print("Summing the first n primes (<1,000) where the sum is itself prime:")
System.print(" n cumulative sum")
for (p in primes) {
n = n + 1
sum = sum + p
if (Int.isPrime(sum)) {
c... | Give a code snippet in #Wren
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/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.
| #Fortran | Fortran | PROGRAM Roots
COMPLEX :: root
INTEGER :: i, n
REAL :: angle, pi
pi = 4.0 * ATAN(1.0)
DO n = 2, 7
angle = 0.0
WRITE(*,"(I1,A)", ADVANCE="NO") n,": "
DO i = 1, n
root = CMPLX(COS(angle), SIN(angle))
WRITE(*,"(SP,2F7.4,A)", ADVANCE="NO") root, "j "
angle = angle + (2.0*pi / RE... | Give a code snippet in #Fortran
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/Sum_digits_of_an_integer | Sum digits of an integer | Task
Take a Natural Number in a given base and return the sum of its digits:
110 sums to 1
123410 sums to 10
fe16 sums to 29
f0e16 sums to 29
| #Oforth | Oforth | : sumDigits(n, base) 0 while( n ) [ n base /mod ->n + ] ; | Give a code snippet in #Oforth
Task
Take a Natural Number in a given base and return the sum of its digits:
110 sums to 1
123410 sums to 10
fe16 sums to 29
f0e16 sums to 29
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newbie | Hello world/Newbie | Task
Guide a new user of a language through the steps necessary
to install the programming language and selection of a text editor if needed,
to run the languages' example in the Hello world/Text task.
Assume the language-newbie is a programmer in another language.
Assume the language-newbie is competent in install... | #Raku | Raku | raku -e'say "Hello World!"'
| Give a code snippet in #Raku
Task
Guide a new user of a language through the steps necessary
to install the programming language and selection of a text editor if needed,
to run the languages' example in the Hello world/Text task.
Assume the language-newbie is a programmer in another language.
Assume the language-... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Munching_squares | Munching squares | Render a graphical pattern where each pixel is colored by the value of 'x xor y' from an arbitrary color table.
| #Icon_and_Unicon | Icon and Unicon | link printf
procedure main(A) #: XOR graphic
wsize := 512
cmax := 32768
wparms := ["Xmas Xor Graphic","g",sprintf("size=%d,%d",wsize),"bg=black"]
&window := open!wparms | stop("Unable to open window")
every y := 0 to wsize - 1 do
every x := 0 to wsize - 1 do {
c := cmax/wsize * iand... | Give a code snippet in #Icon_and_Unicon
Render a graphical pattern where each pixel is colored by the value of 'x xor y' from an arbitrary color table.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sleeping_Beauty_problem | Sleeping Beauty problem | Background on the task
In decision theory, The Sleeping Beauty Problem
is a problem invented by Arnold Zoboff and first publicized on Usenet. The experimental
subject, named Sleeping Beauty, agrees to an experiment as follows:
Sleeping Beauty volunteers to be put into a deep sleep on a Sunday. There is then a fair coin... | #Arturo | Arturo | sleepingBeauty: function [reps][
wakings: 0
heads: 0
do.times: reps [
coin: random 0 1
wakings: wakings + 1
if? coin = 0 -> heads: heads + 1
else -> wakings: wakings + 1
]
print ["Wakings over" reps "repetitions =" wakings]
return 100.0 * heads//wakings
]
pc: sl... | Give a code snippet in #Arturo
Background on the task
In decision theory, The Sleeping Beauty Problem
is a problem invented by Arnold Zoboff and first publicized on Usenet. The experimental
subject, named Sleeping Beauty, agrees to an experiment as follows:
Sleeping Beauty volunteers to be put into a deep sleep on a S... | christopher/rosetta-code | |
http://rosettacode.org/wiki/One_of_n_lines_in_a_file | One of n lines in a file | A method of choosing a line randomly from a file:
Without reading the file more than once
When substantial parts of the file cannot be held in memory
Without knowing how many lines are in the file
Is to:
keep the first line of the file as a possible choice, then
Read the second line of the file if possible and m... | #REXX | REXX | /*REXX program simulates reading a ten─line file, count the selection randomness. */
N= 10 /*the number of lines in pseudo-file. */
@.= 0 /*zero all the (ten) "buckets". */
do 1000000 ... | Give a code snippet in #REXX
A method of choosing a line randomly from a file:
Without reading the file more than once
When substantial parts of the file cannot be held in memory
Without knowing how many lines are in the file
Is to:
keep the first line of the file as a possible choice, then
Read the second line... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For_with_a_specified_step | Loops/For with a specified step |
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop b... | #Icon_and_Unicon | Icon and Unicon |
every 1 to 10 by 2 # the simplest case that satisfies the task, step by 2
every 1 to 10 # no to, step is by 1 by default
every EXPR1 to EXPR2 by EXPR3 do EXPR4 # general case - EXPRn can be complete expressions including other generators such as to-by, eve... | Give a code snippet in #Icon_and_Unicon
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Long_multiplication | Long multiplication | Task
Explicitly implement long multiplication.
This is one possible approach to arbitrary-precision integer algebra.
For output, display the result of 264 * 264.
Optionally, verify your result against builtin arbitrary precision support.
The decimal representation of 264 is:
18,446,744,073,709,551,61... | #Wren | Wren | import "/fmt" for Fmt
// argument validation
var d = Fn.new { |b|
if (b < 48 || b > 57) Fiber.abort("digit 0-9 expected")
return b - 48
}
// converts a list of bytes to a string
var b2s = Fn.new { |b| b.map { |e| String.fromByte(e) }.join() }
// add two numbers as strings
var add = Fn.new { |x, y|
if ... | Give a code snippet in #Wren
Task
Explicitly implement long multiplication.
This is one possible approach to arbitrary-precision integer algebra.
For output, display the result of 264 * 264.
Optionally, verify your result against builtin arbitrary precision support.
The decimal representation of 264 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pangram_checker | Pangram checker | Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
Write a function or method to chec... | #Clojure | Clojure | (defn pangram? [s]
(let [letters (into #{} "abcdefghijklmnopqrstuvwxyz")]
(= (->> s .toLowerCase (filter letters) (into #{})) letters))) | Give a code snippet in #Clojure
Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
W... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_block_comments | Strip block comments | A block comment begins with a beginning delimiter and ends with a ending delimiter, including the delimiters. These delimiters are often multi-character sequences.
Task
Strip block comments from program text (of a programming language much like classic C).
Your demos should at least handle simple, non-ne... | #Nim | Nim | import strutils
proc commentStripper(txt: string; delim: tuple[l, r: string] = ("/*", "*/")): string =
let i = txt.find(delim.l)
if i < 0: return txt
result = if i > 0: txt[0 ..< i] else: ""
let tmp = commentStripper(txt[i+delim.l.len .. txt.high], delim)
let j = tmp.find(delim.r)
assert j >= 0
result... | Give a code snippet in #Nim
A block comment begins with a beginning delimiter and ends with a ending delimiter, including the delimiters. These delimiters are often multi-character sequences.
Task
Strip block comments from program text (of a programming language much like classic C).
Your demos should a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_definition | Function definition | A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are ... | #Kaya | Kaya | program test;
// A function definition in Kaya:
Int multiply(Int a, Int b) {
return a * b;
}
// And calling a function:
Void main() {
putStrLn(string( multiply(2, 3) ));
} | Give a code snippet in #Kaya
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Square_form_factorization | Square form factorization | Task.
Daniel Shanks's Square Form Factorization (SquFoF).
Invented around 1975, ‘On a 32-bit computer, SquFoF is the clear champion factoring algorithm
for numbers between 1010 and 1018, and will likely remain so.’
An integral binary quadratic form is a polynomial
f(x,y) = ax2 + bxy + cy2
with integer coefficients ... | #Nim | Nim | import math, strformat
const M = [uint64 1, 3, 5, 7, 11]
template isqrt(n: uint64): uint64 = uint64(sqrt(float(n)))
template isEven(n: uint64): bool = (n and 1) == 0
proc squfof(n: uint64): uint64 =
if n.isEven: return 2
var h = uint64(sqrt(float(n)) + 0.5)
if h * h == n: return h
for m in M:
if m... | Give a code snippet in #Nim
Task.
Daniel Shanks's Square Form Factorization (SquFoF).
Invented around 1975, ‘On a 32-bit computer, SquFoF is the clear champion factoring algorithm
for numbers between 1010 and 1018, and will likely remain so.’
An integral binary quadratic form is a polynomial
f(x,y) = ax2 + bxy + c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generator/Exponential | Generator/Exponential | A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that the internal state of the objec... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | lastsquare = 1;
nextsquare = -1;
lastcube = -1;
midcube = 0;
nextcube = 1;
Gensquares[] := Module[{},
lastsquare += nextsquare;
nextsquare += 2;
squares = lastsquare;
squares
]
Gencubes[] := Module[{},
lastcube += nextcube;
nextcube += midcube;
midcube += 6;
cubes = lastcube
]
c = Gencubes[];
Do... | Give a code snippet in #Mathematica_.2F_Wolfram_Language
A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of cor... | 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
| #VBA | VBA | Sub foo1()
err.raise(vbObjectError + 1050)
End Sub
Sub foo2()
Error vbObjectError + 1051
End Sub
| Give a code snippet in #VBA
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 T... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jaro-Winkler_distance | Jaro-Winkler distance | The Jaro-Winkler distance is a metric for measuring the edit distance between words.
It is similar to the more basic Levenstein distance but the Jaro distance also accounts
for transpositions between letters in the words. With the Winkler modification to the Jaro
metric, the Jaro-Winkler distance also adds an increase ... | #Python | Python | """
Test Jaro-Winkler distance metric.
linuxwords.txt is from http://users.cs.duke.edu/~ola/ap/linuxwords
"""
WORDS = [s.strip() for s in open("linuxwords.txt").read().split()]
MISSPELLINGS = [
"accomodate",
"definately",
"goverment",
"occured",
"publically",
"recieve",
"seperate",
"... | Give a code snippet in #Python
The Jaro-Winkler distance is a metric for measuring the edit distance between words.
It is similar to the more basic Levenstein distance but the Jaro distance also accounts
for transpositions between letters in the words. With the Winkler modification to the Jaro
metric, the Jaro-Winkler... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Table_creation/Postal_addresses | Table creation/Postal addresses | Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zip... | #Go | Go | package main
import (
"database/sql"
"fmt"
"log"
_ "github.com/mattn/go-sqlite3"
)
func main() {
// task req: show database connection
db, err := sql.Open("sqlite3", "rc.db")
if err != nil {
log.Print(err)
return
}
defer db.Close()
// task req: create table ... | Give a code snippet in #Go
Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_definition | Function definition | A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are ... | #PureBasic | PureBasic | Procedure multiply(a,b)
ProcedureReturn a*b
EndProcedure | Give a code snippet in #PureBasic
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations_with_repetitions | Combinations with repetitions | The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of those sets is chosen from
S... | #REXX | REXX | /*REXX pgm displays combination sets with repetitions for X things taken Y at a time*/
call RcombN 3, 2, 'iced jam plain' /*The 1st part of Rosetta Code task. */
call RcombN -10, 3, 'Iced jam plain' /* " 2nd " " " " " */
exit ... | Give a code snippet in #REXX
The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Lua | Lua | local socket = require('socket')
local ip_tbl = socket.dns.getaddrinfo('www.kame.net')
for _, v in ipairs(ip_tbl) do
io.write(string.format('%s: %s\n', v.family, v.addr))
end
| Give a code snippet in #Lua
DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| 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... | #F.23 | F# |
let rec brk p lst =
match lst with
| [] -> (lst, lst)
| x::xs ->
if p x
then ([], lst)
else
let (ys, zs) = brk p xs
(x::ys, zs)
let span p lst = brk (not << p) lst
let rec groupBy eq lst =
match lst with
| [] -> []
| x::xs ->
let (ys,zs) = span (eq x) xs
(x::ys)::groupBy ... | Give a code snippet in #F.23
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jacobi_symbol | Jacobi symbol | The Jacobi symbol is a multiplicative function that generalizes the Legendre symbol. Specifically, the Jacobi symbol (a | n) equals the product of the Legendre symbols (a | p_i)^(k_i), where n = p_1^(k_1)*p_2^(k_2)*...*p_i^(k_i) and the Legendre symbol (a | p) denotes the value of a ^ ((p-1)/2) (mod p)
(a | p) ≡ 1 ... | #REXX | REXX | /*REXX pgm computes/displays the Jacobi symbol, the # of rows & columns can be specified*/
parse arg rows cols . /*obtain optional arguments from the CL*/
if rows='' | rows=="," then rows= 17 /*Not specified? Then use the default.*/
if cols='' | cols=="," then cols= 16 ... | Give a code snippet in #REXX
The Jacobi symbol is a multiplicative function that generalizes the Legendre symbol. Specifically, the Jacobi symbol (a | n) equals the product of the Legendre symbols (a | p_i)^(k_i), where n = p_1^(k_1)*p_2^(k_2)*...*p_i^(k_i) and the Legendre symbol (a | p) denotes the value of a ^ ((p-... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Non-continuous_subsequences | Non-continuous subsequences | Consider some sequence of elements. (It differs from a mere set of elements by having an ordering among members.)
A subsequence contains some subset of the elements of this sequence, in the same order.
A continuous subsequence is one in which no elements are missing between the first and last elements of the subseque... | #R | R | ncsub <- function(x)
{
n <- length(x)
a <- seq_len(n)
seqlist <- list()
for(i in 2:(n-1))
{
seqs <- combn(a, i) # Get all subseqs
ok <- apply(seqs, 2, function(x) any(diff(x)!=1)) # Find noncts ones
news... | Give a code snippet in #R
Consider some sequence of elements. (It differs from a mere set of elements by having an ordering among members.)
A subsequence contains some subset of the elements of this sequence, in the same order.
A continuous subsequence is one in which no elements are missing between the first and la... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Element_insertion | Doubly-linked list/Element insertion | Doubly-Linked List (element)
This is much like inserting into a Singly-Linked List, but with added assignments so that the backwards-pointing links remain correct.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element inse... | #FreeBASIC | FreeBASIC | #define FIL 1
#define DATO 2
#define LPREV 3
#define LNEXT 4
Dim Shared As Integer countNodes, Nodes
countNodes = 0
Nodes = 10
Dim Shared As Integer list(Nodes, 4)
list(0, LNEXT) = 1
Function searchNode(node As Integer) As Integer
Dim As Integer Node11
For i As Integer = 0 To node-1
Node1... | Give a code snippet in #FreeBASIC
Doubly-Linked List (element)
This is much like inserting into a Singly-Linked List, but with added assignments so that the backwards-pointing links remain correct.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newline_omission | Hello world/Newline omission | Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standard error
Hello world/Text
| #Harbour | Harbour | ?? "Goodbye, world"
or
QQout( "Goodbye, world" )
| Give a code snippet in #Harbour
Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Sta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_output_device_is_a_terminal | Check output device is a terminal | Task
Demonstrate how to check whether the output device is a terminal or not.
Related task
Check input device is a terminal
| #Crystal | Crystal | File.new("testfile").tty? #=> false
File.new("/dev/tty").tty? #=> true
STDOUT.tty? #=> true | Give a code snippet in #Crystal
Task
Demonstrate how to check whether the output device is a terminal or not.
Related task
Check input device is a terminal
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For_with_a_specified_step | Loops/For with a specified step |
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop b... | #Raku | Raku | for 2, 4 ... 8 {
print "$_, ";
}
say 'whom do we appreciate?'; | Give a code snippet in #Raku
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Incr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Do-while | Loops/Do-while | Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loo... | #Slate | Slate | [| val |
val: 0.
[val: val + 1.
print: val.
val \\ 6 ~= 0] whileTrue
] do. | Give a code snippet in #Slate
Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/D... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Prime_decomposition | Prime decomposition | The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the prime decomposition of a given ... | #Arturo | Arturo | decompose: function [num][
facts: to [:string] factors.prime num
print [
pad.right (to :string num) ++ " = " ++ join.with:" x " facts 30
"{"++ (join.with:", " unique facts) ++ "}"
]
]
loop 2..40 => decompose | Give a code snippet in #Arturo
The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/System_time | System time | Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
Date format
See also
Retr... | #Logo | Logo |
to time
output first first shell [date +%s]
end
make "start time
wait 300 ; 60ths of a second
print time - :start ; 5 | Give a code snippet in #Logo
Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
D... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rosetta_Code/Fix_code_tags | Rosetta Code/Fix code tags | Task
Fix Rosetta Code deprecated code tags, with these rules:
Change <%s> to <lang %s>
Change </%s> to </lang>
Change <code %s> to <lang %s>
Change </code> to </lang>
Usage
./convert.py < wikisource.txt > converted.txt
| #11l | 11l | V languages = [‘abap’, ‘actionscript’, ‘actionscript3’,
‘ada’, ‘apache’, ‘applescript’, ‘apt_sources’, ‘asm’, ‘asp’,
‘autoit’, ‘avisynth’, ‘bar’, ‘bash’, ‘basic4gl’, ‘bf’,
‘blitzbasic’, ‘bnf’, ‘boo’, ‘c’, ‘caddcl’, ‘cadlisp’, ‘cfdg’,
‘cfm’, ‘cil’, ‘c_mac’, ‘co... | Give a code snippet in #11l
Task
Fix Rosetta Code deprecated code tags, with these rules:
Change <%s> to <lang %s>
Change </%s> to </lang>
Change <code %s> to <lang %s>
Change </code> to </lang>
Usage
./convert.py < wikisource.txt > converted.txt
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Apply_a_callback_to_an_array | Apply a callback to an array | Task
Take a combined set of elements and apply a function to each element.
| #Clean | Clean | square x = x * x
values :: {#Int}
values = {x \\ x <- [1 .. 10]} | Give a code snippet in #Clean
Task
Take a combined set of elements and apply a function to each element.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Inverted_syntax | Inverted syntax | Inverted syntax with conditional expressions
In traditional syntax conditional expressions are usually shown before the action within a statement or code block:
IF raining=true THEN needumbrella=true
In inverted syntax, the action is listed before the conditional expression in the statement or code block:
needumb... | #Java | Java | do ... while(condition); | Give a code snippet in #Java
Inverted syntax with conditional expressions
In traditional syntax conditional expressions are usually shown before the action within a statement or code block:
IF raining=true THEN needumbrella=true
In inverted syntax, the action is listed before the conditional expression in the stat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zero_to_the_zero_power | Zero to the zero power | Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or 0^0 at compile time, ... | #Rust | Rust | fn main() {
println!("{}",0u32.pow(0));
} | Give a code snippet in #Rust
Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/String | Literals/String | Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
Here document
Other tasks r... | #Python | Python | 'c' == "c" # character
'text' == "text"
' " '
" ' "
'\x20' == ' '
u'unicode string'
u'\u05d0' # unicode literal | Give a code snippet in #Python
Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generator/Exponential | Generator/Exponential | A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that the internal state of the objec... | #Erlang | Erlang |
-module( generator ).
-export( [filter/2, next/1, power/1, task/0] ).
filter( Source_pid, Remove_pid ) ->
First_remove = next( Remove_pid ),
erlang:spawn( fun() -> filter_loop(Source_pid, Remove_pid, First_remove) end ).
next( Pid ) ->
Pid ! {next, erlang:self()},
receive X -> X end.
power( M... | Give a code snippet in #Erlang
A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generate_lower_case_ASCII_alphabet | Generate lower case ASCII alphabet | Task
Generate an array, list, lazy sequence, or even an indexable string of all the lower case ASCII characters, from a to z. If the standard library contains such a sequence, show how to access it, but don't fail to show how to generate a similar sequence.
For this basic task use a reliable style of coding, a sty... | #68000_Assembly | 68000 Assembly |
Ascii_Low:
MOVEM.L D0/A0,-(SP) ;store D0 and A0 on stack
LEA $00100000,A0 ;could also have used MOVE.L since the address is static
MOVE.B #$61,D0 ;ascii "a"
loop_AsciiLow:
MOVE.B D0,(A0)+ ;store letter in address and increment pointer by 1
ADDQ.B #1,D0 ;add 1 to D0 to get the next letter
CMP.B #$7B,D0 ;Are we... | Give a code snippet in #68000_Assembly
Task
Generate an array, list, lazy sequence, or even an indexable string of all the lower case ASCII characters, from a to z. If the standard library contains such a sequence, show how to access it, but don't fail to show how to generate a similar sequence.
For this basic ta... | 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... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | CellularAutomaton[{{0,0,_}->0,{0,1,0}->0,{0,1,1}->1,{1,0,0}->0,{1,0,1}->1,{1,1,0}->1,{1,1,1}->0},{{1,1,1,0,1,1,0,1,0,1,0,1,0,1,0,0,1},0},12]
Print @@@ (% /. {1 -> "#", 0 -> "."}); | Give a code snippet in #Mathematica_.2F_Wolfram_Language
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 neares... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Resistor_mesh | Resistor mesh |
Task
Given 10×10 grid nodes (as shown in the image) interconnected by 1Ω resistors as shown,
find the resistance between points A and B.
See also
(humor, nerd sniping) xkcd.com cartoon
| #Kotlin | Kotlin | // version 1.1.4-3
typealias List2D<T> = List<List<T>>
const val S = 10
class Node(var v: Double, var fixed: Int)
fun setBoundary(m: List2D<Node>) {
m[1][1].v = 1.0; m[1][1].fixed = 1
m[6][7].v = -1.0; m[6][7].fixed = -1
}
fun calcDiff(m: List2D<Node>, d: List2D<Node>, w: Int, h: Int): Double {
... | Give a code snippet in #Kotlin
Task
Given 10×10 grid nodes (as shown in the image) interconnected by 1Ω resistors as shown,
find the resistance between points A and B.
See also
(humor, nerd sniping) xkcd.com cartoon
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Closures/Value_capture | Closures/Value capture | Task
Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, i 2.
Display the result of runnin... | #PowerShell | PowerShell |
function Get-Closure ([double]$Number)
{
{param([double]$Sum) return $script:Number *= $Sum}.GetNewClosure()
}
| Give a code snippet in #PowerShell
Task
Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rep-string | Rep-string | Given a series of ones and zeroes in a string, define a repeated string or rep-string as a string which is created by repeating a substring of the first N characters of the string truncated on the right to the length of the input string, and in which the substring appears repeated at least twice in the original.
For e... | #CLU | CLU | rep_strings = iter (s: string) yields (string)
for len: int in int$from_to_by(string$size(s)/2, 1, -1) do
repstr: string := string$substr(s, 1, len)
attempt: string := ""
while string$size(attempt) < string$size(s) do
attempt := attempt || repstr
end
if s = string... | Give a code snippet in #CLU
Given a series of ones and zeroes in a string, define a repeated string or rep-string as a string which is created by repeating a substring of the first N characters of the string truncated on the right to the length of the input string, and in which the substring appears repeated at least ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Median | Averages/Median | Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.
There are several approaches ... | #BASIC | BASIC | DECLARE FUNCTION median! (vector() AS SINGLE)
DIM vec1(10) AS SINGLE, vec2(11) AS SINGLE, n AS INTEGER
RANDOMIZE TIMER
FOR n = 0 TO 10
vec1(n) = RND * 100
vec2(n) = RND * 100
NEXT
vec2(11) = RND * 100
PRINT median(vec1())
PRINT median(vec2())
FUNCTION median! (vector() AS SINGLE)
DIM lb AS INTEGER... | Give a code snippet in #BASIC
Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm | Trabb Pardo–Knuth algorithm | The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of... | #Nim | Nim | import math, rdstdin, strutils, algorithm, sequtils
proc f(x: float): float = x.abs.pow(0.5) + 5 * x.pow(3)
proc ask: seq[float] =
readLineFromStdin("11 numbers: ").strip.split[0..10].map(parseFloat)
var s = ask()
reverse s
for x in s:
let result = f(x)
echo x, ": ", if result > 400: "TOO LARGE!" else: $res... | Give a code snippet in #Nim
The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s, g... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Unicode_variable_names | Unicode variable names | Task
Describe, and give a pointer to documentation on your languages use of characters beyond those of the ASCII character set in the naming of variables.
Show how to:
Set a variable with a name including the 'Δ', (delta character), to 1
Increment it
Print its value.
Related task
Case-sensitivity of identif... | #JavaScript | JavaScript | var ᾩ = "something";
var ĦĔĽĻŎ = "hello";
var 〱〱〱〱 = "too less";
var जावास्क्रिप्ट = "javascript"; // ok that's JavaScript in hindi
var KingGeorgeⅦ = "Roman numerals.";
console.log([ᾩ, ĦĔĽĻŎ, 〱〱〱〱, जावास्क्रिप्ट, KingGeorgeⅦ]) | Give a code snippet in #JavaScript
Task
Describe, and give a pointer to documentation on your languages use of characters beyond those of the ASCII character set in the naming of variables.
Show how to:
Set a variable with a name including the 'Δ', (delta character), to 1
Increment it
Print its value.
Related... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Keyboard_input/Obtain_a_Y_or_N_response | Keyboard input/Obtain a Y or N response |
Task
Obtain a valid Y or N response from the keyboard.
The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing Y or N key-press from being evaluated.
The response should be obtained as soon as Y or N are pressed, and there should be no need t... | #Delphi | Delphi |
program Obtain_a_Y_or_N_response;
{$APPTYPE CONSOLE}
uses
System.Console;
function GetKey(acepted: string): Char;
var
key: Char;
begin
while True do
begin
if Console.KeyAvailable then
begin
key := UpCase(Console.ReadKey().KeyChar);
if pos(key, acepted) > 0 then
exit(key);
... | Give a code snippet in #Delphi
Task
Obtain a valid Y or N response from the keyboard.
The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing Y or N key-press from being evaluated.
The response should be obtained as soon as Y or N are presse... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rename_a_file | Rename a file | Task
Rename:
a file called input.txt into output.txt and
a directory called docs into mydocs.
This should be done twice:
once "here", i.e. in the current working directory and once in the filesystem root.
It can be assumed that the user has the rights to do so.
(In unix-type s... | #Fortran | Fortran | PROGRAM EX_RENAME
CALL RENAME('input.txt','output.txt')
CALL RENAME('docs','mydocs')
CALL RENAME('/input.txt','/output.txt')
CALL RENAME('/docs','/mydocs')
END | Give a code snippet in #Fortran
Task
Rename:
a file called input.txt into output.txt and
a directory called docs into mydocs.
This should be done twice:
once "here", i.e. in the current working directory and once in the filesystem root.
It can be assumed that the user has the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cullen_and_Woodall_numbers | Cullen and Woodall numbers | A Cullen number is a number of the form n × 2n + 1 where n is a natural number.
A Woodall number is very similar. It is a number of the form n × 2n - 1 where n is a natural number.
So for each n the associated Cullen number and Woodall number differ by 2.
Woodall numbers are sometimes referred to as Riesel numbers o... | #Raku | Raku | my @cullen = ^∞ .map: { $_ × 1 +< $_ + 1 };
my @woodall = ^∞ .map: { $_ × 1 +< $_ - 1 };
put "First 20 Cullen numbers: ( n × 2**n + 1)\n", @cullen[1..20]; # A002064
put "\nFirst 20 Woodall numbers: ( n × 2**n - 1)\n", @woodall[1..20]; # A003261
put "\nFirst 5 Cullen primes: (in terms of n)\n", @cullen.grep( ... | Give a code snippet in #Raku
A Cullen number is a number of the form n × 2n + 1 where n is a natural number.
A Woodall number is very similar. It is a number of the form n × 2n - 1 where n is a natural number.
So for each n the associated Cullen number and Woodall number differ by 2.
Woodall numbers are sometimes r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Call_a_foreign-language_function | Call a foreign-language function | Task
Show how a foreign language function can be called from the language.
As an example, consider calling functions defined in the C language. Create a string containing "Hello World!" of the string type typical to the language. Pass the string content to C's strdup. The content can be copied if necessary. Get the... | #BBC_BASIC | BBC BASIC | SYS "LoadLibrary", "MSVCRT.DLL" TO msvcrt%
SYS "GetProcAddress", msvcrt%, "_strdup" TO `strdup`
SYS "GetProcAddress", msvcrt%, "free" TO `free`
SYS `strdup`, "Hello World!" TO address%
PRINT $$address%
SYS `free`, address%
| Give a code snippet in #BBC_BASIC
Task
Show how a foreign language function can be called from the language.
As an example, consider calling functions defined in the C language. Create a string containing "Hello World!" of the string type typical to the language. Pass the string content to C's strdup. The content ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_search | Binary search | A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret number, and will only tell the p... | #Ada | Ada | with Ada.Text_IO; use Ada.Text_IO;
procedure Test_Recursive_Binary_Search is
Not_Found : exception;
generic
type Index is range <>;
type Element is private;
type Array_Of_Elements is array (Index range <>) of Element;
with function "<" (L, R : Element) return Boolean is <>;
functio... | Give a code snippet in #Ada
A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret num... | 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... | #Harbour | Harbour | #define ARRAY_ELEMENTS 100
PROCEDURE Main()
LOCAL aDoors := Array( ARRAY_ELEMENTS )
LOCAL i, j
AFill( aDoors, .F. )
FOR i := 1 TO ARRAY_ELEMENTS
FOR j := i TO ARRAY_ELEMENTS STEP i
aDoors[ j ] = ! aDoors[ j ]
NEXT
NEXT
AEval( aDoors, {|e, n| QQout( Padl(n,3) + " is " + Iif(aDoor... | Give a code snippet in #Harbour
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/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.)
| #MOO | MOO | "String literals are technically the only long-term comment format";
// Some compilers will, however, compile // one-liners to string literals as well (and vice-versa)
/* Classical C-style comments are removed entirely during compile */ | Give a code snippet in #MOO
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/Four_bit_adder | Four bit adder | Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made using two nots, two ands ... | #Ring | Ring |
###---------------------------
# Program: 4 Bit Adder - Ring
# Author: Bert Mariani
# Date: 2018-02-28
#
# Bit Adder: Input A B Cin
# Output S Cout
#
# A ^ B => axb XOR gate
# axb ^ C => Sout XOR gate
# axb & C => d AND gate
#
# A & B => anb ... | Give a code snippet in #Ring
Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made u... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/B%C3%A9zier_curves/Cubic | Bitmap/Bézier curves/Cubic | Using the data storage type defined on this page for raster images, and the draw_line function defined in this other one, draw a cubic bezier curve
(definition on Wikipedia).
| #PureBasic | PureBasic | Procedure cubic_bezier(img, p1x, p1y, p2x, p2y, p3x, p3y, p4x, p4y, Color, n_seg)
Protected i
Protected.f t, t1, a, b, c, d
Dim pts.POINT(n_seg)
For i = 0 To n_seg
t = i / n_seg
t1 = 1.0 - t
a = Pow(t1, 3)
b = 3.0 * t * Pow(t1, 2)
c = 3.0 * Pow(t, 2) * t1
d = Pow(t, 3)
pts(i)\x = a... | Give a code snippet in #PureBasic
Using the data storage type defined on this page for raster images, and the draw_line function defined in this other one, draw a cubic bezier curve
(definition on Wikipedia).
| 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 ... | #OCaml | OCaml | let dot = List.fold_left2 (fun z x y -> z +. x *. y) 0.
(*
# dot [1.0; 3.0; -5.0] [4.0; -2.0; -1.0];;
- : float = 3.
*) | Give a code snippet in #OCaml
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/Order_by_pair_comparisons | Order by pair comparisons |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Go | Go | package main
import (
"fmt"
"sort"
"strings"
)
var count int = 0
func interactiveCompare(s1, s2 string) bool {
count++
fmt.Printf("(%d) Is %s < %s? ", count, s1, s2)
var response string
_, err := fmt.Scanln(&response)
return err == nil && strings.HasPrefix(response, "y")
}
func m... | Give a code snippet in #Go
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Quicksort | Sorting algorithms/Quicksort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #ATS | ATS | (*------------------------------------------------------------------*)
(* Quicksort in ATS2, for non-linear lists. *)
(*------------------------------------------------------------------*)
#include "share/atspre_staload.hats"
#define NIL list_nil ()
#define :: list_cons
(*----------------... | Give a code snippet in #ATS
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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
| #Dc | Dc | [Hello world!]p | Give a code snippet in #Dc
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
H... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #Nim | Nim | proc transpose[X, Y; T](s: array[Y, array[X, T]]): array[X, array[Y, T]] =
for i in low(X)..high(X):
for j in low(Y)..high(Y):
result[i][j] = s[j][i]
let b = [[ 0, 1, 2, 3, 4],
[ 5, 6, 7, 8, 9],
[ 1, 0, 0, 0,42]]
let c = transpose(b)
for r in c:
for i in r:
stdout.write i, " "
ec... | Give a code snippet in #Nim
Transpose an arbitrarily sized rectangular Matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable-length_quantity | Variable-length quantity | Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable.
Task
With above operations,
convert these two numbers 0x200000 (209... | #XPL0 | XPL0 | func OctIn(Dev); \Input from device value of sequence of octets
int Dev, N, Oct;
[N:= 0;
repeat Oct:= HexIn(Dev);
N:= N<<7 + (Oct&$7F);
until (Oct&$80) = 0;
return N;
];
proc OctOut(Dev, Num, Lev); \Output value to device as sequence of octets
int Dev, Num, Lev, Rem;
[Rem:= Num & $7F;
... | Give a code snippet in #XPL0
Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable.
Task
With above operations,
convert t... | 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... | #Forth | Forth | : ?print dup 1 and if over args type space then ;
: .set begin dup while ?print >r 1+ r> 1 rshift repeat drop drop ;
: .powerset 0 do ." ( " 1 i .set ." )" cr loop ;
: check-none dup 2 < abort" Usage: powerset [val] .. [val]" ;
: check-size dup /cell 8 [*] >= abort" Set too large" ;
: powerset 1 argn check-none check-s... | Give a code snippet in #Forth
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bin_given_limits | Bin given limits | You are given a list of n ascending, unique numbers which are to form limits
for n+1 bins which count how many of a large set of input numbers fall in the
range of each bin.
(Assuming zero-based indexing)
bin[0] counts how many inputs are < limit[0]
bin[1] counts how many inputs are >= limit[0] and < limit[1]
... | #CLU | CLU | % Bin the given data, return an array of counts.
% CLU allows arrays to start at any index; the result array
% will have the same lower bound as the limit array.
% The datatype for the limits and data may be any type
% that allows the < comparator.
bin_count = proc [T: type] (limits, data: array[T]) returns (array[in... | Give a code snippet in #CLU
You are given a list of n ascending, unique numbers which are to form limits
for n+1 bins which count how many of a large set of input numbers fall in the
range of each bin.
(Assuming zero-based indexing)
bin[0] counts how many inputs are < limit[0]
bin[1] counts how many inputs are... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Introspection | Introspection | Task
verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old.
check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compute abs(bloop).
Extra credit
Repor... | #Erlang | Erlang |
-module( introspection ).
-export( [task/0] ).
task() ->
exit_if_too_old( erlang:system_info(otp_release) ),
Bloop = lists:keyfind( bloop, 1, ?MODULE:module_info(functions) ),
Abs = lists:keyfind( abs, 1, erlang:module_info(exports) ),
io:fwrite( "abs( bloop ) => ~p~n", [call_abs_with_bloop(Abs, B... | Give a code snippet in #Erlang
Task
verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old.
check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compute ab... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-1 | SHA-1 | SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to identify commits.
A US government... | #C.2B.2B | C++ | #include <string>
#include <iostream>
#include "Poco/SHA1Engine.h"
#include "Poco/DigestStream.h"
using Poco::DigestEngine ;
using Poco::SHA1Engine ;
using Poco::DigestOutputStream ;
int main( ) {
std::string myphrase ( "Rosetta Code" ) ;
SHA1Engine sha1 ;
DigestOutputStream outstr( sha1 ) ;
outstr << m... | Give a code snippet in #C.2B.2B
SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations | Permutations | Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations generation tasks.
Order Uni... | #m4 | m4 | divert(-1)
# 1-based indexing of a string's characters.
define(`get',`substr(`$1',decr(`$2'),1)')
define(`set',`substr(`$1',0,decr(`$2'))`'$3`'substr(`$1',`$2')')
define(`swap',
`pushdef(`_u',`get(`$1',`$2')')`'dnl
pushdef(`_v',`get(`$1',`$3')')`'dnl
set(set(`$1',`$2',_v),`$3',_u)`'dnl
popdef(`_u',`_v')')
# $1-fold... | Give a code snippet in #m4
Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations generat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_HQ9%2B | Execute HQ9+ | Task
Implement a HQ9+ interpreter or compiler.
| #Java | Java | function hq9plus(code) {
var out = '';
var acc = 0;
for (var i=0; i<code.length; i++) {
switch (code.charAt(i)) {
case 'H': out += "hello, world\n"; break;
case 'Q': out += code + "\n"; break;
case '9':
for (var j=99; j>1; j--) {
out += j + " bottles of beer on the wall, ... | Give a code snippet in #Java
Task
Implement a HQ9+ interpreter or compiler.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Undefined_values | Undefined values | #R | R |
exists("x")
| Give a code snippet in #R
| christopher/rosetta-code | ||
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the f... | #Racket | Racket |
#lang racket
;; Natural -> Natural
;; Calculate factorial
(define (fact n)
(define (fact-helper n acc)
(if (= n 0)
acc
(fact-helper (sub1 n) (* n acc))))
(unless (exact-nonnegative-integer? n)
(raise-argument-error 'fact "natural" n))
(fact-helper n 1))
;; Unit tests, works in v5.3 a... | Give a code snippet in #Racket
While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwan... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catalan_numbers | Catalan numbers | Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
for
n
≥
0.
{\displaystyle C... | #Rust | Rust | fn c_n(n: u64) -> u64 {
match n {
0 => 1,
_ => c_n(n - 1) * 2 * (2 * n - 1) / (n + 1)
}
}
fn main() {
for i in 1..16 {
println!("c_n({}) = {}", i, c_n(i));
}
} | Give a code snippet in #Rust
Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
f... | 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... | #EchoLisp | EchoLisp |
(define (set-cons a A)
(make-set (cons a A)))
(define (power-set e)
(cond ((null? e)
(make-set (list ∅)))
(else (let [(ps (power-set (cdr e)))]
(make-set
(append ps (map set-cons (circular-list (car e)) ps)))))))
(define B (make-set ' ( 🍎 🍇 🎂 🎄 )))
(power-set B)
→ { ∅ { �... | Give a code snippet in #EchoLisp
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.
Gi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Histogram | Bitmap/Histogram | Extend the basic bitmap storage defined on this page to support dealing with image histograms. The image histogram contains for each luminance the count of image pixels having this luminance. Choosing a histogram representation take care about the data type used for the counts. It must have range of at least 0..NxM, wh... | #PicoLisp | PicoLisp | (de histogram (Pgm)
(let H (need 256 0)
(for L Pgm
(for G L
(inc (nth H (inc G))) ) )
H ) ) | Give a code snippet in #PicoLisp
Extend the basic bitmap storage defined on this page to support dealing with image histograms. The image histogram contains for each luminance the count of image pixels having this luminance. Choosing a histogram representation take care about the data type used for the counts. It must... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Copy_stdin_to_stdout | Copy stdin to stdout | Create an executable file that copies stdin to stdout, or else a script that does so through the invocation of an interpreter at the command line.
| #Applesoft_BASIC | Applesoft BASIC | 0 GET C$ : PRINT C$; : GOTO | Give a code snippet in #Applesoft_BASIC
Create an executable file that copies stdin to stdout, or else a script that does so through the invocation of an interpreter at the command line.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Word_wrap | Word wrap | Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.
Basic task
The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or provided in a standard library, sho... | #Scala | Scala | import java.util.StringTokenizer
object WordWrap extends App {
final val defaultLineWidth = 80
final val spaceWidth = 1
def letsWrap(text: String, lineWidth: Int = defaultLineWidth) = {
println(s"\n\nWrapped at: $lineWidth")
println("." * lineWidth)
minNumLinesWrap(ewd, lineWidth)
}
final de... | Give a code snippet in #Scala
Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.
Basic task
The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or prov... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_Algorithms/Circle_Sort | Sorting Algorithms/Circle 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
... | #Haskell | Haskell | import Data.Bool (bool)
circleSort :: Ord a => [a] -> [a]
circleSort xs = if swapped then circleSort ks else ks
where
(swapped,ks) = go False xs (False,[])
go d [] sks = sks
go d [x] (s,ks) = (s,x:ks)
go d xs (s,ks) =
let (st,_,ls,rs) = halve d s xs xs
in go False ls (go True rs (st,... | Give a code snippet in #Haskell
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/A%2BB | A+B | A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separated by space(s):
(
−
1000
≤... | #Clojure | Clojure | (println (+ (Integer/parseInt (read-line)) (Integer/parseInt (read-line))))
3
4
=>7 | Give a code snippet in #Clojure
A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tree_datastructures | Tree datastructures | The following shows a tree of data with nesting denoted by visual levels of indentation:
RosettaCode
rocks
code
comparison
wiki
mocks
trolling
A common datastructure for trees is to define node structures having a name and a, (possibly empty), list of child nodes. The nesting of... | #C.2B.2B | C++ | #include <iomanip>
#include <iostream>
#include <list>
#include <string>
#include <vector>
#include <utility>
#include <vector>
class nest_tree;
bool operator==(const nest_tree&, const nest_tree&);
class nest_tree {
public:
explicit nest_tree(const std::string& name) : name_(name) {}
nest_tree& add_child(... | Give a code snippet in #C.2B.2B
The following shows a tree of data with nesting denoted by visual levels of indentation:
RosettaCode
rocks
code
comparison
wiki
mocks
trolling
A common datastructure for trees is to define node structures having a name and a, (possibly empty), li... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Subleq | Subleq | Subleq is an example of a One-Instruction Set Computer (OISC).
It is named after its only instruction, which is SUbtract and Branch if Less than or EQual to zero.
Task
Your task is to create an interpreter which emulates a SUBLEQ machine.
The machine's memory consists of an array of signed integers. These integers... | #Befunge | Befunge | 01-00p00g:0`*2/00p010p0>$~>:4v4:-1g02p+5/"P"\%"P":p01+1:g01+g00*p02+1_v#!`"/":<
\0_v#-"-":\1_v#!`\*84:_^#- *8< >\#%"P"/#:5#<+g00g-\1+:"P"%\"P"v>5+#\*#<+"0"-~>^
<~0>#<$#-0#\<>$0>:3+\::"P"%\"P"/5+g00g-:1+#^_$:~>00gvv0gp03:+5/"P"\p02:%"P":< ^
>>>>>> , >>>>>> ^$p+5/"P"\%"P":-g00g+5/"P"\%"P":+1\+<>0g-\-:0v>5+g00g-:1+>>#^_$
... | Give a code snippet in #Befunge
Subleq is an example of a One-Instruction Set Computer (OISC).
It is named after its only instruction, which is SUbtract and Branch if Less than or EQual to zero.
Task
Your task is to create an interpreter which emulates a SUBLEQ machine.
The machine's memory consists of an array of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_block_comments | Strip block comments | A block comment begins with a beginning delimiter and ends with a ending delimiter, including the delimiters. These delimiters are often multi-character sequences.
Task
Strip block comments from program text (of a programming language much like classic C).
Your demos should at least handle simple, non-ne... | #Ksh | Ksh |
#!/bin/ksh
# Strip block comments
# # Variables:
#
bd=${1:-'/*'}
ed=${2:-'*/'}
testcase='/**
* Some comments
* longer comments here that we can parse.
*
* Rahoo
*/
function subroutine() {
a = /* inline comment */ b + c ;
}
/*/ <-- tricky comments */
/**
* Another comment.
*/
function something()... | Give a code snippet in #Ksh
A block comment begins with a beginning delimiter and ends with a ending delimiter, including the delimiters. These delimiters are often multi-character sequences.
Task
Strip block comments from program text (of a programming language much like classic C).
Your demos should a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations_with_repetitions | Combinations with repetitions | The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of those sets is chosen from
S... | #Python | Python | >>> from itertools import combinations_with_replacement
>>> n, k = 'iced jam plain'.split(), 2
>>> list(combinations_with_replacement(n,k))
[('iced', 'iced'), ('iced', 'jam'), ('iced', 'plain'), ('jam', 'jam'), ('jam', 'plain'), ('plain', 'plain')]
>>> # Extra credit
>>> len(list(combinations_with_replacement(range(10)... | Give a code snippet in #Python
The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Median | Averages/Median | Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.
There are several approaches ... | #Vlang | Vlang | fn main() {
println(median([3, 1, 4, 1])) // prints 2
println(median([3, 1, 4, 1, 5])) // prints 3
}
fn median(aa []int) int {
mut a := aa.clone()
a.sort()
half := a.len / 2
mut m := a[half]
if a.len%2 == 0 {
m = (m + a[half-1]) / 2
}
return m
} | Give a code snippet in #Vlang
Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/While | Loops/While | Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For... | #Sather | Sather | class MAIN is
main is
i ::= 1024;
loop while!(i > 0);
#OUT + i + "\n";
i := i / 2;
end;
end;
end; | Give a code snippet in #Sather
Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downwa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Harmonic_series | Harmonic series |
This page uses content from Wikipedia. The original article was at Harmonic number. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In mathematics, the n-th harmonic number is the sum of the recipr... | #R | R | HofN <- function(n) sum(1/seq_len(n)) #Task 1
H <- sapply(1:100000, HofN)
print(H[1:20]) #Task 2
print(sapply(1:10, function(x) which.max(H > x))) #Task 3 and stretch | Give a code snippet in #R
This page uses content from Wikipedia. The original article was at Harmonic number. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In mathematics, the n-th harmonic numb... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Almost_prime | Almost prime | A k-Almost-prime is a natural number
n
{\displaystyle n}
that is the product of
k
{\displaystyle k}
(possibly identical) primes.
Example
1-almost-primes, where
k
=
1
{\displaystyle k=1}
, are the prime numbers themselves.
2-almost-primes, where
k
=
2
{\displaystyl... | #MAD | MAD | NORMAL MODE IS INTEGER
INTERNAL FUNCTION(NN,KK)
ENTRY TO KPRIME.
F = 0
N = NN
THROUGH SCAN, FOR P=2, 1, F.GE.KK .OR. P*P.G.N
DIV WHENEVER N.E.N/P*P
N = N/P
F = F+1
TRANSFER TO DIV
... | Give a code snippet in #MAD
A k-Almost-prime is a natural number
n
{\displaystyle n}
that is the product of
k
{\displaystyle k}
(possibly identical) primes.
Example
1-almost-primes, where
k
=
1
{\displaystyle k=1}
, are the prime numbers themselves.
2-almost-primes, wher... | christopher/rosetta-code | |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Racket | Racket |
#lang racket
(require net/dns)
(dns-get-address "8.8.8.8" "www.kame.net")
| Give a code snippet in #Racket
DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Reflection/Get_source | Reflection/Get source | Task
The goal is to get the source code or file path and line number where a programming object (e.g. module, class, function, method) is defined.
| #Wren | Wren | import "os" for Platform, Process
import "io" for File
import "/pattern" for Pattern
var getSourceLines = Fn.new {
var fileName = Process.allArguments[1]
var text = File.read(fileName)
var sep = Platform.isWindows ? "\r\n" : "\n"
return [fileName, text.split(sep)]
}
var res = getSourceLines.call()
v... | Give a code snippet in #Wren
Task
The goal is to get the source code or file path and line number where a programming object (e.g. module, class, function, method) is defined.
| christopher/rosetta-code |
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