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 |
|---|---|---|---|---|---|
http://rosettacode.org/wiki/Reduced_row_echelon_form | Reduced row echelon form | Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenient
(for most languages, this wil... | #C.2B.2B | C++ | #include <algorithm> // for std::swap
#include <cstddef>
#include <cassert>
// Matrix traits: This describes how a matrix is accessed. By
// externalizing this information into a traits class, the same code
// can be used both with native arrays and matrix classes. To use the
// default implementation of the traits c... |
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 ... | #C.23 | C# | using System;
class Program {
static void Main(string[] args) {
Console.WriteLine(Math.E); //E
Console.WriteLine(Math.PI); //PI
Console.WriteLine(Math.Sqrt(10)); //Square Root
Console.WriteLine(Math.Log(10)); // Logarithm
Console.WriteLine(Math.Log10(10)); // Base 1... |
http://rosettacode.org/wiki/Remove_lines_from_a_file | Remove lines from a file | Task
Remove a specific line or a number of lines from a file.
This should be implemented as a routine that takes three parameters (filename, starting line, and the number of lines to be removed).
For the purpose of this task, line numbers and the number of lines start at one, so to remove the first two lines from th... | #Go | Go | package main
import (
"bytes"
"errors"
"fmt"
"io/ioutil"
"os"
)
func main() {
if err := removeLines("foobar.txt", 1, 2); err != nil {
fmt.Println(err)
}
}
func removeLines(fn string, start, n int) (err error) {
if start < 1 {
return errors.New("invalid request. lin... |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #Crystal | Crystal | content = File.read("input.txt")
puts content |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #D | D | import std.file: read, readText;
void main() {
// To read a whole file into a dynamic array of unsigned bytes:
auto data = cast(ubyte[])read("unixdict.txt");
// To read a whole file into a validated UTF-8 string:
string txt = readText("unixdict.txt");
} |
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... | #jq | jq | def is_rep_string:
# if self is a rep-string then return [n, prefix]
# where n is the number of full occurrences of prefix
def _check(prefix; n; sofar):
length as $length
| if length <= (sofar|length) then [n, prefix]
else (sofar+prefix) as $sofar
| if startswith($sofar) then _check(prefix; n... |
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... | #Julia | Julia | function repstring(r::AbstractString)
n = length(r)
replst = String[]
for m in 1:n÷2
s = r[1:chr2ind(r, m)]
if (s ^ cld(n, m))[1:chr2ind(r, n)] != r continue end
push!(replst, s)
end
return replst
end
tests = ["1001110011", "1110111011", "0010010010", "1010101010", "1111111... |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #Kotlin | Kotlin | // version 1.0.6
fun main(args: Array<String>) {
val s1 = "I am the original string"
val r1 = Regex("^.*string$")
if (s1.matches(r1)) println("`$s1` matches `$r1`")
val r2 = Regex("original")
val s3 = "replacement"
val s2 = s1.replace(r2, s3)
if (s2 != s1) println("`$s2` replaces `$r2` wit... |
http://rosettacode.org/wiki/Reverse_a_string | Reverse a string | Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
... | #Brat | Brat | p "olleh".reverse #Prints "hello" |
http://rosettacode.org/wiki/Repeat | Repeat | Task
Write a procedure which accepts as arguments another procedure and a positive integer.
The latter procedure is executed a number of times equal to the accepted integer.
| #PureBasic | PureBasic | Prototype.i fun(x.i)
Procedure.i quark(z.i)
Debug "Quark "+Str(z) : ProcedureReturn z-1
EndProcedure
Procedure rep(q.fun,n.i)
Repeat : n=q(n) : Until n=0
EndProcedure
rep(@quark(),3) |
http://rosettacode.org/wiki/Repeat | Repeat | Task
Write a procedure which accepts as arguments another procedure and a positive integer.
The latter procedure is executed a number of times equal to the accepted integer.
| #Python | Python | #!/usr/bin/python
def repeat(f,n):
for i in range(n):
f();
def procedure():
print("Example");
repeat(procedure,3); #prints "Example" (without quotes) three times, separated by newlines. |
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... | #MAXScript | MAXScript | -- Here
renameFile "input.txt" "output.txt"
-- Root
renameFile "/input.txt" "/output.txt" |
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... | #Mercury | Mercury | :- module rename_file.
:- interface.
:- import_module io.
:- pred main(io::di, io::uo) is det.
:- implementation.
:- import_module dir.
main(!IO) :-
rename_file("input.txt", "output.txt", !IO),
rename_file("docs", "mydocs", !IO),
rename_file("/input.txt", "/output.txt", !IO),
rename_file("/docs"... |
http://rosettacode.org/wiki/Reverse_words_in_a_string | Reverse words in a string | Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spaces (formally, white-space); t... | #Logo | Logo | do.until [
make "line readlist
print reverse :line
] [word? :line]
bye |
http://rosettacode.org/wiki/Reverse_words_in_a_string | Reverse words in a string | Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spaces (formally, white-space); t... | #Lua | Lua |
local lines = {}
for line in (s .. "\n"):gmatch("(.-)\n") do
local this = {}
for word in line:gmatch("%S+") do
table.insert(this, 1, word)
end
lines[#lines + 1] = table.concat(this, " ")
end
print(table.concat(lines, "\n"))
|
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #Rust | Rust | fn rot13(string: &str) -> String {
string.chars().map(|c| {
match c {
'a'..='m' | 'A'..='M' => ((c as u8) + 13) as char,
'n'..='z' | 'N'..='Z' => ((c as u8) - 13) as char,
_ => c
}
}).collect()
}
fn main () {
assert_eq!(rot13("abc"), "nop");
} |
http://rosettacode.org/wiki/Roman_numerals/Encode | Roman numerals/Encode | Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a value of zero.
In Roman numeral... | #REXX | REXX | roman: procedure
arg number
/* handle only 1 to 3999, else return ? */
if number >= 4000 | number <= 0 then return "?"
romans = " M CM D CD C XC L XL X IX V IV I"
arabic = "1000 900 500 400 100 90 50 40 10 9 5 4 1"
result = ""
do i = 1 to words(romans)
do while number >= word(arabic,i)
r... |
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... | #True_BASIC | True BASIC | FUNCTION romtodec(roman$)
LET num = 0
LET prenum = 0
FOR i = LEN(roman$) TO 1 STEP -1
LET x$ = (roman$)[i:i+1-1]
LET n = 0
IF x$ = "M" THEN LET n = 1000
IF x$ = "D" THEN LET n = 500
IF x$ = "C" THEN LET n = 100
IF x$ = "L" THEN LET n = 50
IF x$ = "X" T... |
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... | #Elena | Elena | import system'routines;
import extensions;
import extensions'text;
public program()
{
var s := new Range(0, 5).selectBy:(x => "ha").summarize(new StringWriter())
} |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #MATLAB_.2F_Octave | MATLAB / Octave | function [a,b,c]=foo(d)
a = 1-d;
b = 2+d;
c = a+b;
end;
[x,y,z] = foo(5) |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #Maxima | Maxima | f(a, b) := [a * b, a + b]$
[u, v]: f(5, 6);
[30, 11] |
http://rosettacode.org/wiki/Remove_duplicate_elements | Remove duplicate elements |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Common_Lisp | Common Lisp | (remove-duplicates '(1 3 2 9 1 2 3 8 8 1 0 2))
> (9 3 8 1 0 2) |
http://rosettacode.org/wiki/Recaman%27s_sequence | Recaman's sequence | The Recamán's sequence generates Natural numbers.
Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated.
If the conditions don't hold then a(n) = a(n-1) + n.
Task
Generate and show here the... | #JavaScript | JavaScript | (() => {
const main = () => {
console.log(
'First 15 Recaman:\n' +
recamanUpto(i => 15 === i)
);
console.log(
'\n\nFirst duplicated Recaman:\n' +
last(recamanUpto(
(_, set, rs) => set.size !== rs.length
))
... |
http://rosettacode.org/wiki/Reduced_row_echelon_form | Reduced row echelon form | Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenient
(for most languages, this wil... | #Common_Lisp | Common Lisp | (defun convert-to-row-echelon-form (matrix)
(let* ((dimensions (array-dimensions matrix))
(row-count (first dimensions))
(column-count (second dimensions))
(lead 0))
(labels ((find-pivot (start lead)
(let ((i start))
(loop
:while (zerop (aref matrix i lead))
:do (progn
(incf i)... |
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 ... | #C.2B.2B | C++ | #include <iostream>
#include <cmath>
#ifdef M_E
static double euler_e = M_E;
#else
static double euler_e = std::exp(1); // standard fallback
#endif
#ifdef M_PI
static double pi = M_PI;
#else
static double pi = std::acos(-1);
#endif
int main()
{
std::cout << "e = " << euler_e
<< "\npi = " << pi
... |
http://rosettacode.org/wiki/Remove_lines_from_a_file | Remove lines from a file | Task
Remove a specific line or a number of lines from a file.
This should be implemented as a routine that takes three parameters (filename, starting line, and the number of lines to be removed).
For the purpose of this task, line numbers and the number of lines start at one, so to remove the first two lines from th... | #Groovy | Groovy | static def removeLines(String filename, int startingLine, int lineCount) {
def sourceFile = new File(filename).getAbsoluteFile()
def outputFile = File.createTempFile("remove", ".tmp", sourceFile.getParentFile())
outputFile.withPrintWriter { outputWriter ->
sourceFile.eachLine { line, lineNumber ->... |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #Delphi | Delphi | program ReadAll;
{$APPTYPE CONSOLE}
uses Classes;
var
i: Integer;
lList: TStringList;
begin
lList := TStringList.Create;
try
lList.LoadFromFile('c:\input.txt');
// Write everything at once
Writeln(lList.Text);
// Write one line at a time
for i := 0 to lList.Count - 1 do
Writeln(l... |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #D.C3.A9j.C3.A0_Vu | Déjà Vu | local :filecontents !decode!utf-8 !read "file.txt" |
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... | #Kotlin | Kotlin | // version 1.0.6
fun repString(s: String): MutableList<String> {
val reps = mutableListOf<String>()
if (s.length < 2) return reps
for (c in s) if (c != '0' && c != '1') throw IllegalArgumentException("Not a binary string")
for (len in 1..s.length / 2) {
val t = s.take(len)
val n = s.le... |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #langur | langur | if matching(re/abc/, "somestring") { ... } |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #Lasso | Lasso | local(mytext = 'My name is: Stone, Rosetta
My name is: Hippo, Campus
')
local(regexp = regexp(
-find = `(?m)^My name is: (.*?), (.*?)$`,
-input = #mytext,
-replace = `Hello! I am $2 $1`,
-ignorecase
))
while(#regexp -> find) => {^
#regexp -> groupcount > 1 ? (#regexp -> matchString(2) -> trim&) + '<br />... |
http://rosettacode.org/wiki/Reverse_a_string | Reverse a string | Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
... | #Burlesque | Burlesque |
"Hello, world!"<-
|
http://rosettacode.org/wiki/Repeat | Repeat | Task
Write a procedure which accepts as arguments another procedure and a positive integer.
The latter procedure is executed a number of times equal to the accepted integer.
| #Quackery | Quackery | [ stack ] is times.start ( --> s )
protect times.start
[ stack ] is times.count ( --> s )
protect times.count
[ stack ] is times.action ( --> s )
protect times.action
[ ]'[ times.action put
dup times.start put
[ ... |
http://rosettacode.org/wiki/Rename_a_file | Rename a file | Task
Rename:
a file called input.txt into output.txt and
a directory called docs into mydocs.
This should be done twice:
once "here", i.e. in the current working directory and once in the filesystem root.
It can be assumed that the user has the rights to do so.
(In unix-type s... | #MUMPS | MUMPS | ;Local
S X=$ZF(-1,"rename input.txt output.txt")
S X=$ZF(-1,"rename docs.dir mydocs.dir")
;Root of current device
S X=$ZF(-1,"rename [000000]input.txt [000000]output.txt")
S X=$ZF(-1,"rename [000000]docs.dir [000000]mydocs.dir") |
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... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols binary
runSample(arg)
return
-- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
method isFileRenamed(oldFile, newFile) public static returns boolean
fo = File(oldFile)
fn = File(newFile)
fRenamed = fo.renameTo(fn... |
http://rosettacode.org/wiki/Reverse_words_in_a_string | Reverse words in a string | Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spaces (formally, white-space); t... | #Maple | Maple | while (true) do
input := readline("input.txt"):
if input = 0 then break: fi:
input := StringTools:-Trim(input): # remove leading/trailing space
input := StringTools:-Join(ListTools:-Reverse(StringTools:-Split(input, " "))," "):
printf("%s\n", input):
od: |
http://rosettacode.org/wiki/Reverse_words_in_a_string | Reverse words in a string | Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spaces (formally, white-space); t... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | poem = "---------- Ice and Fire ------------
fire, in end will world the say Some
ice. in say Some
desire of tasted I've what From
fire. favor who those with hold I
... elided paragraph last ...
Frost Robert -----------------------";
lines = StringSplit[poem, "\n"];
wordArray = Stri... |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #S-BASIC | S-BASIC |
comment
Return the rot13 transformation of s, preserving case and
passing non-alphabetic characters without change
end
function rot13(s = string) = string
var i, k = integer
var ch = char
var normal, rotated = string
normal = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
rotated = "NOPQRSTUV... |
http://rosettacode.org/wiki/Roman_numerals/Encode | Roman numerals/Encode | Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a value of zero.
In Roman numeral... | #Ring | Ring |
arabic = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1]
roman = ["M", "CM", "D", "CD", "C" ,"XC", "L", "XL" ,"X", "IX", "V", "IV", "I"]
see "2009 = " + toRoman(2009) + nl
see "1666 = " + toRoman(1666) + nl
see "3888 = " + toRoman(3888) + nl
func toRoman val
result = ""
for i = 1 to 13
... |
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... | #TUSCRIPT | TUSCRIPT | $$ MODE TUSCRIPT
LOOP roman_number="MCMXC'MMVIII'MDCLXVI"
arab_number=DECODE (roman_number,ROMAN)
PRINT "Roman number ",roman_number," equals ", arab_number
ENDLOOP |
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... | #Elixir | Elixir |
String.duplicate("ha", 5)
|
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... | #Emacs_Lisp | Emacs Lisp | (apply 'concat (make-list 5 "ha")) |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #Mercury | Mercury | :- module addsub.
:- interface.
:- import_module io.
:- pred main(io::di, io::uo) is det.
:- implementation.
:- import_module int, list, string.
main(!IO) :-
command_line_arguments(Args, !IO),
filter_map(to_int, Args, CleanArgs),
(length(CleanArgs, 2) ->
X = det_index1(CleanArgs,1),
Y ... |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #min | min | (over over / '* dip) :muldiv |
http://rosettacode.org/wiki/Remove_duplicate_elements | Remove duplicate elements |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Crystal | Crystal | ary = [1, 1, 2, 2, "a", [1, 2, 3], [1, 2, 3], "a"]
p ary.uniq |
http://rosettacode.org/wiki/Recaman%27s_sequence | Recaman's sequence | The Recamán's sequence generates Natural numbers.
Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated.
If the conditions don't hold then a(n) = a(n-1) + n.
Task
Generate and show here the... | #jq | jq |
# Let R[n] be the Recaman sequence, n >= 0, so R[0]=0.
# Input: a number, $required, specifying the required range of integers, [1 .. $required]
# to be covered by R[0] ... R[.n]
# $capture: the number of elements of the sequence to retain.
# Output: an object as described below.
# Note that .a|length will be ... |
http://rosettacode.org/wiki/Recaman%27s_sequence | Recaman's sequence | The Recamán's sequence generates Natural numbers.
Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated.
If the conditions don't hold then a(n) = a(n-1) + n.
Task
Generate and show here the... | #Julia | Julia | function recaman()
a = Vector{Int}([0])
used = Dict{Int, Bool}(0 => true)
used1000 = Set(0)
founddup = false
termcount = 1
while length(used1000) <= 1000
nextterm = a[termcount] - termcount
if nextterm < 1 || haskey(used, nextterm)
nextterm += termcount + termcount
... |
http://rosettacode.org/wiki/Reduced_row_echelon_form | Reduced row echelon form | Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenient
(for most languages, this wil... | #D | D | import std.stdio, std.algorithm, std.array, std.conv;
void toReducedRowEchelonForm(T)(T[][] M) pure nothrow @nogc {
if (M.empty)
return;
immutable nrows = M.length;
immutable ncols = M[0].length;
size_t lead;
foreach (immutable r; 0 .. nrows) {
if (ncols <= lead)
retu... |
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 ... | #Chef | Chef | (Math/E); //e
(Math/PI); //pi
(Math/sqrt x); //square root--cube root also available (cbrt)
(Math/log x); //natural logarithm--log base 10 also available (log10)
(Math/exp x); //exponential
(Math/abs x); //absolute value
(Math/floor x); //floor
(Math/ceil x); //ceiling
(Math/pow x y); //power |
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 ... | #Clojure | Clojure | (Math/E); //e
(Math/PI); //pi
(Math/sqrt x); //square root--cube root also available (cbrt)
(Math/log x); //natural logarithm--log base 10 also available (log10)
(Math/exp x); //exponential
(Math/abs x); //absolute value
(Math/floor x); //floor
(Math/ceil x); //ceiling
(Math/pow x y); //power |
http://rosettacode.org/wiki/Remove_lines_from_a_file | Remove lines from a file | Task
Remove a specific line or a number of lines from a file.
This should be implemented as a routine that takes three parameters (filename, starting line, and the number of lines to be removed).
For the purpose of this task, line numbers and the number of lines start at one, so to remove the first two lines from th... | #Haskell | Haskell | import System.Environment (getArgs)
main = getArgs >>= (\[a, b, c] ->
do contents <- fmap lines $ readFile a
let b1 = read b :: Int
c1 = read c :: Int
putStr $ unlines $ concat [take (b1 - 1) contents, drop c1 $ drop b1 contents]
) |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #E | E | <file:foo.txt>.getText() |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #Elixir | Elixir |
defmodule FileReader do
# Read in the file
def read(path) do
case File.read(path) do
{:ok, body} ->
IO.inspect body
{:error,reason} ->
:file.format_error(reason)
end
end
# Open the file path, then read in the file
def bit_read(path) do
case File.open(path) do
... |
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... | #LFE | LFE |
(defun get-reps (text)
(lists:filtermap
(lambda (x)
(case (get-rep text (lists:split x text))
('() 'false)
(x `#(true ,x))))
(lists:seq 1 (div (length text) 2))))
(defun get-rep
((text `#(,head ,tail))
(case (string:str text tail)
(1 head)
(_ '()))))
|
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #Lua | Lua | test = "My name is Lua."
pattern = ".*name is (%a*).*"
if test:match(pattern) then
print("Name found.")
end
sub, num_matches = test:gsub(pattern, "Hello, %1!")
print(sub) |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #M2000_Interpreter | M2000 Interpreter |
Module CheckIt {
declare global ObjRegEx "VBscript.RegExp"
Function RegEx.Replace$(from$, what$) {
Method ObjRegEx, "Replace", from$, what$ as response$
=response$
}
Function RegEx.Test(what$) {
Method ObjRegEx, "Test", what$ as response
=respons... |
http://rosettacode.org/wiki/Reverse_a_string | Reverse a string | Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
... | #C | C | #include <stdio.h>
#include <stdlib.h>
#include <locale.h>
#include <wchar.h>
const char *sa = "abcdef";
const char *su = "as⃝df̅"; /* Should be in your native locale encoding. Mine is UTF-8 */
int is_comb(wchar_t c)
{
if (c >= 0x300 && c <= 0x36f) return 1;
if (c >= 0x1dc0 && c <= 0x1dff) return 1;
if (c >= 0x2... |
http://rosettacode.org/wiki/Repeat | Repeat | Task
Write a procedure which accepts as arguments another procedure and a positive integer.
The latter procedure is executed a number of times equal to the accepted integer.
| #R | R |
f1 <- function(...){print("coucou")}
f2 <-function(f,n){
lapply(seq_len(n),eval(f))
}
f2(f1,4)
|
http://rosettacode.org/wiki/Repeat | Repeat | Task
Write a procedure which accepts as arguments another procedure and a positive integer.
The latter procedure is executed a number of times equal to the accepted integer.
| #Racket | Racket | #lang racket/base
(define (repeat f n) ; the for loop is idiomatic of (although not exclusive to) racket
(for ((_ n)) (f)))
(define (repeat2 f n) ; This is a bit more "functional programmingy"
(when (positive? n) (f) (repeat2 f (sub1 n))))
(display "...")
(repeat (λ () (display " and over")) 5)
(display "...")
... |
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... | #NewLISP | NewLISP | (rename-file "./input.txt" "./output.txt")
(rename-file "./docs" "./mydocs")
(rename-file "/input.txt" "/output.txt")
(rename-file "/docs" "/mydocs") |
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... | #Nim | Nim | import os
moveFile("input.txt", "output.txt")
moveFile("docs", "mydocs")
moveFile(DirSep & "input.txt", DirSep & "output.txt")
moveFile(DirSep & "docs", DirSep & "mydocs") |
http://rosettacode.org/wiki/Reverse_words_in_a_string | Reverse words in a string | Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spaces (formally, white-space); t... | #MATLAB_.2F_Octave | MATLAB / Octave | function testReverseWords
testStr = {'---------- Ice and Fire ------------' ; ...
'' ; ...
'fire, in end will world the say Some' ; ...
'ice. in say Some' ; ...
'desire of tasted I''ve what From' ... |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #S-lang | S-lang | variable old = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
variable new = "NOPQRSTUVWXYZABCDEFGHIJKLMnopqrstuvwxyzabcdefghijklm";
define rot13(s) {
s = strtrans(s, old, new);
return s;
}
define rot13_stream(s) {
variable ln;
while (-1 != fgets(&ln, s))
fputs(rot13(ln), stdout);
}
if (__arg... |
http://rosettacode.org/wiki/Roman_numerals/Encode | Roman numerals/Encode | Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a value of zero.
In Roman numeral... | #Ruby | Ruby | Symbols = { 1=>'I', 5=>'V', 10=>'X', 50=>'L', 100=>'C', 500=>'D', 1000=>'M' }
Subtractors = [ [1000, 100], [500, 100], [100, 10], [50, 10], [10, 1], [5, 1], [1, 0] ]
def roman(num)
return Symbols[num] if Symbols.has_key?(num)
Subtractors.each do |cutPoint, subtractor|
return roman(cutPoint) + roman(num - cu... |
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... | #UNIX_Shell | UNIX Shell |
#!/bin/bash
roman_to_dec() {
local rnum=$1
local n=0
local prev=0
for ((i=${#rnum}-1;i>=0;i--))
do
case "${rnum:$i:1}" in
M) a=1000 ;;
D) a=500 ;;
C) a=100 ;;
L) a=50 ;;
X) a=10 ;;
V) a=5 ;;
I) a=1 ;;
esac
if [[ $a -lt $prev ]]
then
let n-=a
... |
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... | #Erlang | Erlang | repeat(X,N) ->
lists:flatten(lists:duplicate(N,X)). |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #Nemerle | Nemerle | using System;
using System.Console;
using Nemerle.Assertions;
module MultReturn
{
MinMax[T] (ls : list[T]) : T * T
where T : IComparable
requires ls.Length > 0 otherwise throw ArgumentException("An empty list has no extreme values.")
{
def greaterOf(a, b) { if (a.CompareTo(b) > 0) a else b... |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols nobinary
-- =============================================================================
class RReturnMultipleVals public
properties constant
L = 'L'
R = 'R'
K_lipsum = 'Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do ... |
http://rosettacode.org/wiki/Remove_duplicate_elements | Remove duplicate elements |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #D | D | void main() {
import std.stdio, std.algorithm;
[1, 3, 2, 9, 1, 2, 3, 8, 8, 1, 0, 2]
.sort()
.uniq
.writeln;
} |
http://rosettacode.org/wiki/Recaman%27s_sequence | Recaman's sequence | The Recamán's sequence generates Natural numbers.
Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated.
If the conditions don't hold then a(n) = a(n-1) + n.
Task
Generate and show here the... | #Kotlin | Kotlin | // Version 1.2.60
fun main(args: Array<String>) {
val a = mutableListOf(0)
val used = mutableSetOf(0)
val used1000 = mutableSetOf(0)
var foundDup = false
var n = 1
while (n <= 15 || !foundDup || used1000.size < 1001) {
var next = a[n - 1] - n
if (next < 1 || used.contains(next)... |
http://rosettacode.org/wiki/Reduced_row_echelon_form | Reduced row echelon form | Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenient
(for most languages, this wil... | #Euphoria | Euphoria | function ToReducedRowEchelonForm(sequence M)
integer lead,rowCount,columnCount,i
sequence temp
lead = 1
rowCount = length(M)
columnCount = length(M[1])
for r = 1 to rowCount do
if columnCount <= lead then
exit
end if
i = r
while M[i][lead] = 0 do
... |
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 ... | #COBOL | COBOL | E *> e
PI *> Pi
SQRT(n) *> Sqaure root
LOG(n) *> Natural logarithm
LOG10(n) *> Logarithm (base 10)
EXP(n) *> e to the nth power
ABS(n) *> Absolute value
INTEGER(n) *> While not a proper floor function, it is implemented in the same way.
*> There is no ceiling function. However, it coul... |
http://rosettacode.org/wiki/Remove_lines_from_a_file | Remove lines from a file | Task
Remove a specific line or a number of lines from a file.
This should be implemented as a routine that takes three parameters (filename, starting line, and the number of lines to be removed).
For the purpose of this task, line numbers and the number of lines start at one, so to remove the first two lines from th... | #Icon_and_Unicon | Icon and Unicon | procedure main() # remove lines
removelines("foo.bar",3,2) | stop("Failed to remove lines.")
end
procedure removelines(fn,start,skip)
f := open(fn,"r") | fail # open to read
every put(F := [],|read(f)) # file to list
close(f)
if *F < start-1+skip then fail
every F[... |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #Emacs_Lisp | Emacs Lisp | (setq my-variable (with-temp-buffer
(insert-file-contents "foo.txt")
(buffer-string))) |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #Erlang | Erlang | {ok, B} = file:read_file("myfile.txt"). |
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... | #Maple | Maple | repstr? := proc( s :: string )
local per := StringTools:-Period( s );
if 2 * per <= length( s ) then
true, s[ 1 .. per ]
else
false, ""
end if
end proc: |
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... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | RepStringQ[strin_String]:=StringCases[strin,StartOfString~~Repeated[x__,{2,\[Infinity]}]~~y___~~EndOfString/;StringMatchQ[x,StartOfString~~y~~___]:>x, Overlaps -> All] |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #M4 | M4 | regexp(`GNUs not Unix', `\<[a-z]\w+')
regexp(`GNUs not Unix', `\<[a-z]\(\w+\)', `a \& b \1 c') |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #Maple | Maple | #Examples from Maple Help
StringTools:-RegMatch("^ab+bc$", "abbbbc");
StringTools:-RegMatch("^ab+bc$", "abbbbcx");
StringTools:-RegSub("a([bc]*)(c*d)", "abcd", "&-\\1-\\2");
StringTools:-RegSub("(.*)c(anad[ai])(.*)", "Maple is canadian", "\\1C\\2\\3"); |
http://rosettacode.org/wiki/Reverse_a_string | Reverse a string | Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
... | #C.23 | C# | static string ReverseString(string input)
{
char[] inputChars = input.ToCharArray();
Array.Reverse(inputChars);
return new string(inputChars);
} |
http://rosettacode.org/wiki/Repeat | Repeat | Task
Write a procedure which accepts as arguments another procedure and a positive integer.
The latter procedure is executed a number of times equal to the accepted integer.
| #Raku | Raku | sub repeat (&f, $n) { f() xx $n };
sub example { say rand }
repeat(&example, 3); |
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... | #Objeck | Objeck |
use IO;
bundle Default {
class FileExample {
function : Main(args : String[]) ~ Nil {
File->Rename("input.txt", "output.txt");
File->Rename("docs", "mydocs");
File->Rename("/input.txt", "/output.txt");
File->Rename("/docs", "/mydocs");
}
}
}
|
http://rosettacode.org/wiki/Reverse_words_in_a_string | Reverse words in a string | Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spaces (formally, white-space); t... | #MAXScript | MAXScript |
-- MAXScript : Reverse words in a string : N.H. 2019
--
(
text = stringstream "---------- Ice and Fire ------------\n\nfire, in end will world the say Some\nice. in say Some\ndesire of tasted I've what From\nfire. favor who those with hold I\n\n... elided paragraph last ...\n\nFrost Robert -----------------------\n"
... |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #Scala | Scala | scala> def rot13(s: String) = s map {
| case c if 'a' <= c.toLower && c.toLower <= 'm' => c + 13 toChar
| case c if 'n' <= c.toLower && c.toLower <= 'z' => c - 13 toChar
| case c => c
| }
rot13: (s: String)String
scala> rot13("7 Cities of Gold.")
res61: String = 7 Pvgvrf bs Tbyq.
scala> ro... |
http://rosettacode.org/wiki/Roman_numerals/Encode | Roman numerals/Encode | Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a value of zero.
In Roman numeral... | #Run_BASIC | Run BASIC | [loop]
input "Input value:";val$
print roman$(val$)
goto [loop]
' ------------------------------
' Roman numerals
' ------------------------------
FUNCTION roman$(val$)
a2r$ = "M:1000,CM:900,D:500,CD:400,C:100,XC:90,L:50,XL:40,X:10,IX:9,V:5,IV:4,I:1"
v = val(val$)
for i = 1 to 13
r$ = word$(a2r$,i,",")
a = val... |
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... | #VBA | VBA |
Option Explicit
Sub Main_Romans_Decode()
Dim Arr(), i&
Arr = Array("III", "XXX", "CCC", "MMM", "VII", "LXVI", "CL", "MCC", "IV", "IX", "XC", "ICM", "DCCCXCIX", "CMI", "CIM", "MDCLXVI", "MCMXC", "MMXVII")
For i = 0 To UBound(Arr)
Debug.Print Arr(i) & " >>> " & lngConvert(CStr(Arr(i)))
Next
En... |
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... | #ERRE | ERRE |
PROCEDURE REPEAT_STRING(S$,N%->REP$)
LOCAL I%
REP$=""
FOR I%=1 TO N% DO
REP$=REP$+S$
END FOR
END PROCEDURE
|
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #Nim | Nim | proc addsub(x, y: int): (int, int) =
(x + y, x - y)
var (a, b) = addsub(12, 15) |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #Objeck | Objeck | class Program {
function : Main(args : String[]) ~ Nil {
a := IntHolder->New(3); b := IntHolder->New(7);
Addon(a,b);
a->Get()->PrintLine(); b->Get()->PrintLine();
}
function : Addon(a : IntHolder, b : IntHolder) ~ Nil {
a->Set(a->Get() + 2); b->Set(b->Get() + 13);
}
} |
http://rosettacode.org/wiki/Remove_duplicate_elements | Remove duplicate elements |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Delphi | Delphi | program RemoveDuplicateElements;
{$APPTYPE CONSOLE}
uses Generics.Collections;
var
i: Integer;
lIntegerList: TList<Integer>;
const
INT_ARRAY: array[1..7] of Integer = (1, 2, 2, 3, 4, 5, 5);
begin
lIntegerList := TList<Integer>.Create;
try
for i in INT_ARRAY do
if not lIntegerList.Contains(i) then
... |
http://rosettacode.org/wiki/Recaman%27s_sequence | Recaman's sequence | The Recamán's sequence generates Natural numbers.
Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated.
If the conditions don't hold then a(n) = a(n-1) + n.
Task
Generate and show here the... | #Lua | Lua | local a = {[0]=0}
local used = {[0]=true}
local used1000 = {[0]=true}
local foundDup = false
local n = 1
while n<=15 or not foundDup or #used1000<1001 do
local nxt = a[n - 1] - n
if nxt<1 or used[nxt] ~= nil then
nxt = nxt + 2 * n
end
local alreadyUsed = used[nxt] ~= nil
table.insert(a, nx... |
http://rosettacode.org/wiki/Reduced_row_echelon_form | Reduced row echelon form | Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenient
(for most languages, this wil... | #Factor | Factor | USE: math.matrices.elimination
{ { 1 2 -1 -4 } { 2 3 -1 -11 } { -2 0 -3 22 } } solution . |
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 ... | #Common_Lisp | Common Lisp |
(exp 1) ; e (Euler's number)
pi ; pi constant
(sqrt x) ; square root: works for negative reals and complex
(log x) ; natural logarithm: works for negative reals and complex
(log x 10) ; logarithm base 10
(exp x) ; exponential
(abs x) ; absolute value: result exact if input exact: (abs -1/... |
http://rosettacode.org/wiki/Remove_lines_from_a_file | Remove lines from a file | Task
Remove a specific line or a number of lines from a file.
This should be implemented as a routine that takes three parameters (filename, starting line, and the number of lines to be removed).
For the purpose of this task, line numbers and the number of lines start at one, so to remove the first two lines from th... | #J | J | removeLines=: 4 :0
'count start'=. x
file=. boxxopen y
lines=. <;.2 fread file
(;lines {~ <<< (start-1)+i.count) fwrite file
) |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #Euphoria | Euphoria |
function load_file(sequence filename)
integer fn,c
sequence data
fn = open(filename,"r") -- "r" for text files, "rb" for binary files
if (fn = -1) then return {} end if -- failed to open the file
data = {} -- init to empty sequence
c = getc(fn) -- prime the char buffer
while (c != -1) do -- ... |
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... | #Modula-2 | Modula-2 | MODULE RepStrings;
FROM InOut IMPORT Write, WriteString, WriteLn, WriteCard;
FROM Strings IMPORT Copy, Length;
(* Find the length of the longest rep-string given a string.
If there is no rep-string, the result is 0. *)
PROCEDURE repLength(s: ARRAY OF CHAR): CARDINAL;
VAR strlen, replen, i, j: CARDINAL;
... |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | StringCases["I am a string with the number 18374 in me",RegularExpression["[0-9]+"]]
StringReplace["I am a string",RegularExpression["I\\sam"] -> "I'm"] |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #MAXScript | MAXScript |
samples = #("Some string 123","Example text 123","string",\
"ThisString Will Not Match","A123,333,string","123451")
samples2 = #("I am a string","Me too.")
regex = dotnetobject "System.Text.RegularExpressions.Regex" ".*\bstring*"
regex2 = dotnetobject "System.Text.RegularExpressions.Regex" "\ba\b"
clearliste... |
http://rosettacode.org/wiki/Reverse_a_string | Reverse a string | Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
... | #C.2B.2B | C++ | #include <iostream>
#include <string>
#include <algorithm>
int main()
{
std::string s;
std::getline(std::cin, s);
std::reverse(s.begin(), s.end()); // modifies s
std::cout << s << std::endl;
return 0;
} |
http://rosettacode.org/wiki/Repeat | Repeat | Task
Write a procedure which accepts as arguments another procedure and a positive integer.
The latter procedure is executed a number of times equal to the accepted integer.
| #Red | Red | Red[]
myrepeat: function [fn n] [loop n [do fn]]
myrepeat [print "hello"] 3 |
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