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/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #REXX | REXX | /*REXX pgm generates 1,000 normally distributed numbers: mean=1, standard deviation=½.*/
numeric digits 20 /*the default decimal digit precision=9*/
parse arg n seed . /*allow specification of N and the seed*/
if n=='' | n=="," then n=1000 ... |
http://rosettacode.org/wiki/Read_a_configuration_file | Read a configuration file | The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a semicolon are ignored by the application
# pr... | #Ruby | Ruby | fullname = favouritefruit = ""
needspeeling = seedsremoved = false
otherfamily = []
IO.foreach("config.file") do |line|
line.chomp!
key, value = line.split(nil, 2)
case key
when /^([#;]|$)/; # ignore line
when "FULLNAME"; fullname = value
when "FAVOURITEFRUIT"; favouritefruit = value
when "NEEDSPEELING"... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Python | Python | def rangeexpand(txt):
lst = []
for r in txt.split(','):
if '-' in r[1:]:
r0, r1 = r[1:].split('-', 1)
lst += range(int(r[0] + r0), int(r1) + 1)
else:
lst.append(int(r))
return lst
print(rangeexpand('-6,-3--1,3-5,7-11,14,15,17-20')) |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #REXX | REXX | /*REXX program reads and displays (with a count) a file, one line at a time. */
parse arg fID . /*obtain optional argument from the CL.*/
if fID=='' then exit 8 /*Was no fileID specified? Then quit. */
say center(' displaying file: ' fID" ", 79, '═'... |
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
... | #Rust | Rust | let mut buffer = b"abcdef".to_vec();
buffer.reverse();
assert_eq!(buffer, b"fedcba"); |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #Icon_and_Unicon | Icon and Unicon |
# Use a record to hold a Queue, using a list as the concrete implementation
record Queue(items)
procedure make_queue ()
return Queue ([])
end
procedure queue_push (queue, item)
put (queue.items, item)
end
# if the queue is empty, this will 'fail' and return nothing
procedure queue_pop (queue)
return pop (... |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #Lua | Lua | Quaternion = {}
function Quaternion.new( a, b, c, d )
local q = { a = a or 1, b = b or 0, c = c or 0, d = d or 0 }
local metatab = {}
setmetatable( q, metatab )
metatab.__add = Quaternion.add
metatab.__sub = Quaternion.sub
metatab.__unm = Quaternion.unm
metatab.__mul = Quaternion.mul
... |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #E | E | " =~ x; println(E.toQuote(x),x)" =~ x; println(E.toQuote(x),x) |
http://rosettacode.org/wiki/Quickselect_algorithm | Quickselect algorithm |
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
... | #Standard_ML | Standard ML | fun quickselect (_, _, []) = raise Fail "empty"
| quickselect (k, cmp, x :: xs) = let
val (ys, zs) = List.partition (fn y => cmp (y, x) = LESS) xs
val l = length ys
in
if k < l then
quickselect (k, cmp, ys)
else if k > l then
quickselect (k-l-1, cmp, zs)
... |
http://rosettacode.org/wiki/Quickselect_algorithm | Quickselect algorithm |
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
... | #Swift | Swift | func select<T where T : Comparable>(var elements: [T], n: Int) -> T {
var r = indices(elements)
while true {
let pivotIndex = partition(&elements, r)
if n == pivotIndex {
return elements[pivotIndex]
} else if n < pivotIndex {
r.endIndex = pivotIndex
} else {
r.startIndex = pivotInd... |
http://rosettacode.org/wiki/Range_extraction | Range extraction | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #MiniScript | MiniScript | extractRange = function(ints)
result = []
idx = 0
while idx < ints.len
runLen = 1
while idx+runLen < ints.len and ints[idx+runLen] == ints[idx] + runLen
runLen = runLen + 1
end while
if runLen > 2 then
result.push ints[idx] + "-" + ints[idx+runLen-1]
... |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Ring | Ring |
for i = 1 to 10
see random(i) + nl
next i
|
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Ruby | Ruby | Array.new(1000) { 1 + Math.sqrt(-2 * Math.log(rand)) * Math.cos(2 * Math::PI * rand) } |
http://rosettacode.org/wiki/Read_a_configuration_file | Read a configuration file | The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a semicolon are ignored by the application
# pr... | #Run_BASIC | Run BASIC | dim param$(6)
dim paramVal$(6)
param$(1) = "fullname"
param$(2) = "favouritefruit"
param$(3) = "needspeeling"
param$(4) = "seedsremoved"
param$(5) = "otherfamily"
for i = 1 to 6
paramVal$(i) = "false"
next i
open DefaultDir$ + "\public\a.txt" for binary as #f
while not(eof(#f))
line input #f, a$
a$ = trim$(a$)
if... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #R | R |
rangeExpand <- function(text) {
lst <- gsub("(\\d)-", "\\1:", unlist(strsplit(text, ",")))
unlist(sapply(lst, function (x) eval(parse(text=x))), use.names=FALSE)
}
rangeExpand("-6,-3--1,3-5,7-11,14,15,17-20")
[1] -6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20
|
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Ring | Ring |
fp = fopen("C:\Ring\ReadMe.txt","r")
r = ""
while isstring(r)
r = fgetc(fp)
if r = char(10) see nl
else see r ok
end
fclose(fp)
|
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Ruby | Ruby | IO.foreach "foobar.txt" do |line|
# Do something with line.
puts line
end |
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
... | #S-lang | S-lang | variable sa = "Hello, World", aa = Char_Type[strlen(sa)+1];
init_char_array(aa, sa);
array_reverse(aa);
% print(aa);
% Unfortunately, strjoin() only joins strings, so we map char()
% [sadly named: actually converts char into single-length string]
% onto the array:
print( strjoin(array_map(String_Type, &char, aa), "... |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #J | J | queue_fifo_=: ''
pop_fifo_=: verb define
r=. {. ::] queue
queue=: }.queue
r
)
push_fifo_=: verb define
queue=: queue,y
y
)
isEmpty_fifo_=: verb define
0=#queue
) |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #M2000_Interpreter | M2000 Interpreter |
Module CheckIt {
class Quaternion {
\\ by default are double
a,b,c,d
Property ToString$ {
Value {
link parent a,b,c, d to a,b,c,d
value$=format$("{0} + {1}i + {2}j + {3}k",a,b,c,d)
}
... |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #Elixir | Elixir | a = <<"a = ~p~n:io.fwrite(a,[a])~n">>
:io.fwrite(a,[a]) |
http://rosettacode.org/wiki/Quickselect_algorithm | Quickselect algorithm |
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
... | #Tcl | Tcl | # Swap the values at two indices of a list
proc swap {list i j} {
upvar 1 $list l
set tmp [lindex $l $i]
lset l $i [lindex $l $j]
lset l $j $tmp
}
proc quickselect {vector k {left 0} {right ""}} {
set last [expr {[llength $vector] - 1}]
if {$right eq ""} {
set right $last
}
# Sanity a... |
http://rosettacode.org/wiki/Range_extraction | Range extraction | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #MUMPS | MUMPS | RANGCONT(X) ;Integer range contraction
NEW Y,I,CONT,NOTFIRST,CURR,PREV,NEXT,SEQ SET Y="",SEQ=0,PREV="",CONT=0
FOR I=1:1:$LENGTH(X,",") DO
.SET NOTFIRST=$LENGTH(Y),CURR=$PIECE(X,",",I),NEXT=$PIECE(X,",",I+1)
.FOR Q:$EXTRACT(CURR)'=" " S CURR=$EXTRACT(CURR,2,$LENGTH(CURR)) ;clean up leading spaces
.S SEQ=((CURR-1... |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Run_BASIC | Run BASIC | dim a(1000)
pi = 22/7
for i = 1 to 1000
a( i) = 1 + .5 * (sqr(-2 * log(rnd(0))) * cos(2 * pi * rnd(0)))
next i |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Rust | Rust | extern crate rand;
use rand::distributions::{Normal, IndependentSample};
fn main() {
let mut rands = [0.0; 1000];
let normal = Normal::new(1.0, 0.5);
let mut rng = rand::thread_rng();
for num in rands.iter_mut() {
*num = normal.ind_sample(&mut rng);
}
} |
http://rosettacode.org/wiki/Read_a_configuration_file | Read a configuration file | The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a semicolon are ignored by the application
# pr... | #Rust | Rust | use std::fs::File;
use std::io::BufRead;
use std::io::BufReader;
use std::iter::FromIterator;
use std::path::Path;
fn main() {
let path = String::from("file.conf");
let cfg = config_from_file(path);
println!("{:?}", cfg);
}
fn config_from_file(path: String) -> Config {
let path = Path::new(&path);
... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Racket | Racket |
#lang racket
(define (range-expand s)
(append*
(for/list ([r (regexp-split "," s)])
(match (regexp-match* "(-?[0-9]+)-(-?[0-9]+)" r
#:match-select cdr)
[(list (list f t))
(range (string->number f) (+ (string->number t) 1))]
[(list)
(list (str... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Raku | Raku | sub range-expand (Str $range-description) {
my token number { '-'? \d+ }
my token range { (<&number>) '-' (<&number>) }
$range-description
.split(',')
.map({ .match(&range) ?? $0..$1 !! +$_ })
.flat
}
say range-expand('-6,-3--1,3-5,7-11,14,15,17-20').join(', '); |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Run_BASIC | Run BASIC | open DefaultDir$ + "\public\filetest.txt" for input as #f
while not(eof(#f))
line input #f, a$
print a$
wend
close #f
|
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Rust | Rust | use std::io::{BufReader,BufRead};
use std::fs::File;
fn main() {
let file = File::open("file.txt").unwrap();
for line in BufReader::new(file).lines() {
println!("{}", line.unwrap());
}
} |
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
... | #SAS | SAS | data _null_;
length a b $11;
a="I am Legend";
b=reverse(a);
put a;
put b;
run; |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #Java | Java | public class Queue<E>{
Node<E> head = null, tail = null;
static class Node<E>{
E value;
Node<E> next;
Node(E value, Node<E> next){
this.value= value;
this.next= next;
}
}
public Queue(){
}
public void enqueue(E value){ //standard ... |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #Maple | Maple |
with(ArrayTools);
module Quaternion()
option object;
local real := 0;
local i := 0;
local j := 0;
local k := 0;
export getReal::static := proc(self::Quaternion, $)
return self:-real;
end proc;
export getI::static := proc(self::Quaternion, $)
return self:-i;
end proc;
export getJ::static := proc(... |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #Erlang | Erlang | PROGRAM QUINE
BEGIN
READ(D$,Y$)
LOOP
READ(X$)
EXIT IF LEN(X$)<1
PRINT(X$)
END LOOP
RESTORE
LOOP
READ(X$)
EXIT IF LEN(X$)<1
PRINT(D$;CHR$(34);X$;CHR$(34);CHR$(41))
END LOOP
PRINT(D$;CHR$(34);CHR$(34);CHR$(41))
PRINT(Y$)
DATA("DATA(")
DATA("END PROGRAM")
DATA("PROGRAM QUINE")
DATA("BEGIN")
DATA("R... |
http://rosettacode.org/wiki/Quickselect_algorithm | Quickselect algorithm |
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
... | #VBA | VBA | Dim s As Variant
Private Function quick_select(ByRef s As Variant, k As Integer) As Integer
Dim left As Integer, right As Integer, pos As Integer
Dim pivotValue As Integer, tmp As Integer
left = 1: right = UBound(s)
Do While left < right
pivotValue = s(k)
tmp = s(k)
s(k) = s(righ... |
http://rosettacode.org/wiki/Range_extraction | Range extraction | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #NetRexx | NetRexx | /*NetRexx program to test range extraction. ***************************
* 07.08.2012 Walter Pachl derived from my Rexx Version
* Changes: line continuation in aaa assignment changed
* 1e99 -> 999999999
* Do -> Loop
* words(aaa) -> aaa.words()
* word(aaa,i) -> aaa.word(i)
************... |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #SAS | SAS |
/* Generate 1000 random numbers with mean 1 and standard deviation 0.5.
SAS version 9.2 was used to create this code.*/
data norm1000;
call streaminit(123456);
/* Set the starting point, so we can replicate results.
If you want different results each time, comment the above line. */
do i=1 to 1000;
... |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Sather | Sather | class MAIN is
main is
a:ARRAY{FLTD} := #(1000);
i:INT;
RND::seed(2010);
loop i := 1.upto!(1000) - 1;
a[i] := 1.0d + 0.5d * RND::standard_normal;
end;
-- testing the distribution
mean ::= a.reduce(bind(_.plus(_))) / a.size.fltd;
#OUT + "mean " + mean + "\n";
a.map(bind(_.m... |
http://rosettacode.org/wiki/Read_a_configuration_file | Read a configuration file | The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a semicolon are ignored by the application
# pr... | #Scala | Scala | val conf = scala.io.Source.fromFile("config.file").
getLines.
toList.
filter(_.trim.size > 0).
filterNot("#;" contains _(0)).
map(_ split(" ", 2) toList).
map(_ :+ "true" take 2).
map {
s:List[String] => (s(0).toLowerCase, s(1).split(",").map(_.trim).toList)
}.toMap |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Raven | Raven | define get_num use $lst
# "-22" split by "-" is [ "", "22" ] so check if
# first list item is "" -> a negative number
$lst 0 get "" = if
# negative number
#
# convert str to integer and multiply by -1
-1 $lst 1 get 0 prefer *
$lst shift $lst shift drop drop
else
... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #REXX | REXX | /*REXX program expands an ordered list of integers into an expanded list. */
old= '-6,-3--1, 3-5, 7-11, 14,15,17-20'; a=translate(old,,',')
new= /*translate [↑] commas (,) ───► blanks*/
do until a==''; parse var a X a /*obtain th... |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Scala | Scala | import scala.io._
Source.fromFile("foobar.txt").getLines.foreach(println) |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Scheme | Scheme | ; Commented line below should be uncommented to use read-line with Guile
;(use-modules (ice-9 rdelim))
(define file (open-input-file "input.txt"))
(do ((line (read-line file) (read-line file))) ((eof-object? line))
(display line)
(newline)) |
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
... | #Sather | Sather | class MAIN is
main is
s ::= "asdf";
reversed ::= s.reverse;
-- current implementation does not handle multibyte encodings correctly
end;
end; |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #JavaScript | JavaScript | var fifo = [];
fifo.push(42); // Enqueue.
fifo.push(43);
var x = fifo.shift(); // Dequeue.
alert(x); // 42 |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | <<Quaternions`
q=Quaternion[1,2,3,4]
q1=Quaternion[2,3,4,5]
q2=Quaternion[3,4,5,6]
r=7
->Quaternion[1,2,3,4]
->Quaternion[2,3,4,5]
->Quaternion[3,4,5,6]
->7
Abs[q]
->√30
-q
->Quaternion[-1,-2,-3,-4]
Conjugate[q]
->Quaternion[1,-2,-3,-4]
r+q
->Quaternion[8,2,3,4]
q+r
->Quaternion[8,2,3,4]
q1+q2
->Quaternion[5,7,9,11]
... |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #ERRE | ERRE | PROGRAM QUINE
BEGIN
READ(D$,Y$)
LOOP
READ(X$)
EXIT IF LEN(X$)<1
PRINT(X$)
END LOOP
RESTORE
LOOP
READ(X$)
EXIT IF LEN(X$)<1
PRINT(D$;CHR$(34);X$;CHR$(34);CHR$(41))
END LOOP
PRINT(D$;CHR$(34);CHR$(34);CHR$(41))
PRINT(Y$)
DATA("DATA(")
DATA("END PROGRAM")
DATA("PROGRAM QUINE")
DATA("BEGIN")
DATA("R... |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #Euphoria | Euphoria | constant p="constant p=%s%s%s printf(1,p,{34,p,34})" printf(1,p,{34,p,34}) |
http://rosettacode.org/wiki/Quickselect_algorithm | Quickselect algorithm |
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
... | #Wren | Wren | import "/sort" for Find
var a = [9, 8, 7, 6, 5, 0, 1, 2, 3, 4]
for (k in 0..9) {
System.write(Find.quick(a, k))
if (k < 9) System.write(", ")
}
System.print() |
http://rosettacode.org/wiki/Range_extraction | Range extraction | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Nim | Nim | import parseutils, re, strutils, sequtils
proc extractRange(input: string): string =
var list = input.replace(re"\s+").split(',').map(parseInt)
var ranges: seq[string]
var i = 0
while i < list.len:
var first = list[i] # first element in the current range
var offset = i
while True: # skip ahead to ... |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Scala | Scala | List.fill(1000)(1.0 + 0.5 * scala.util.Random.nextGaussian) |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Scheme | Scheme | ; linear congruential generator given in C99 section 7.20.2.1
(define ((c-rand seed)) (set! seed (remainder (+ (* 1103515245 seed) 12345) 2147483648)) (quotient seed 65536))
; uniform real numbers in open interval (0, 1)
(define (unif-rand seed) (let ((r (c-rand seed))) (lambda () (/ (+ (r) 1) 32769.0))))
; Box-Mul... |
http://rosettacode.org/wiki/Read_a_configuration_file | Read a configuration file | The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a semicolon are ignored by the application
# pr... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "scanfile.s7i";
var string: fullname is "";
var string: favouritefruit is "";
var boolean: needspeeling is FALSE;
var boolean: seedsremoved is FALSE;
var array string: otherfamily is 0 times "";
const proc: main is func
local
var file: configFile is STD_NULL;
var stri... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Ring | Ring |
# Project : Range expansion
int = "-6,-3--1,3-5,7-11,14,15,17-20"
int = str2list(substr(int, ",", nl))
newint = []
for n=1 to len(int)
nrint = substr(int[n], "-")
nrint2 = substr(int[n], "--")
if nrint2 > 0
temp1 = left(int[n], nrint2 -1)
temp2 = right(int[n], len(int[n]) - nrint2)
... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Ruby | Ruby | def range_expand(rng)
rng.split(',').flat_map do |part|
if part =~ /^(-?\d+)-(-?\d+)$/
($1.to_i .. $2.to_i).to_a
else
Integer(part)
end
end
end
p range_expand('-6,-3--1,3-5,7-11,14,15,17-20') |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Sed | Sed | #!/bin/sed -f
p
|
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Seed7 | Seed7 | $ include "seed7_05.s7i";
const proc: main is func
local
var file: aFile is STD_NULL;
var string: line is "";
begin
aFile := open("input.txt", "r");
while hasNext(aFile) do
readln(aFile, line);
writeln("LINE: " <& line);
end while;
end func; |
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
... | #Scala | Scala | "asdf".reverse |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #jq | jq | # An empty queue:
def fifo: [];
def push(e): [e] + .;
def pop: [.[0], .[1:]];
def pop_or_error: if length == 0 then error("pop_or_error") else pop end;
def empty: length == 0; |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #Julia | Julia |
struct Queue{T}
a::Array{T,1}
end
Queue() = Queue(Any[])
Queue(a::DataType) = Queue(a[])
Queue(a) = Queue(typeof(a)[])
Base.isempty(q::Queue) = isempty(q.a)
function Base.pop!(q::Queue{T}) where {T}
!isempty(q) || error("queue must be non-empty")
pop!(q.a)
end
function Base.push!(q::Queue{T}, x::T... |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #Mercury | Mercury | :- module quaternion.
:- interface.
:- import_module float.
:- type quaternion
---> q( w :: float,
i :: float,
j :: float,
k :: float ).
% conversion
:- func r(float) = quaternion is det.
% operations
:- func norm(quaternion) = float is det.
:... |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #F.23 | F# | let s = "let s = {0}{1}{0} in System.Console.WriteLine(s, char 34, s);;" in System.Console.WriteLine(s, char 34, s);; |
http://rosettacode.org/wiki/Quickselect_algorithm | Quickselect algorithm |
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
... | #zkl | zkl | fcn qselect(list,nth){ // in place quick select
fcn(list,left,right,nth){
if (left==right) return(list[left]);
pivotIndex:=(left+right)/2; // or median of first,middle,last
// partition
pivot:=list[pivotIndex];
list.swap(pivotIndex,right); // move pivot to end
pivotIndex := lef... |
http://rosettacode.org/wiki/Range_extraction | Range extraction | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Oberon-2 | Oberon-2 |
MODULE RangeExtraction;
IMPORT Out;
PROCEDURE Range(s: ARRAY OF INTEGER);
VAR
i,j: INTEGER;
PROCEDURE Emit(sep: CHAR);
BEGIN
IF i > 2 THEN
Out.Int(s[j],3);Out.Char('-');Out.Int(s[j + i - 1],3);Out.Char(sep);
INC(j,i)
ELSE
Out.Int(s[j],3);Out.Char(sep);
INC(j)
END;
END Emit;
BEGIN
j := 0;i... |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "float.s7i";
include "math.s7i";
const func float: frand is func # Uniform distribution, (0..1]
result
var float: frand is 0.0;
begin
repeat
frand := rand(0.0, 1.0);
until frand <> 0.0;
end func;
const func float: randomNormal is # Normal distribution,... |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Sidef | Sidef | var arr = 1000.of { 1 + (0.5 * sqrt(-2 * 1.rand.log) * cos(Num.tau * 1.rand)) }
arr.each { .say } |
http://rosettacode.org/wiki/Read_a_configuration_file | Read a configuration file | The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a semicolon are ignored by the application
# pr... | #SenseTalk | SenseTalk |
// read the configuration file and get a list of just the interesting lines
set lines to each line of file "config.txt" where char 1 of each isn't in ("#", ";", "")
set the listFormat's quotes to quote -- be sure to quote values for evaluating
repeat with each configLine in lines
put word 1 of configLine into va... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Run_BASIC | Run BASIC | PRINT rangeExpand$("-6,-3--1,3-5,7-11,14,15,17-20")
end
function rangeExpand$(range$)
[loop]
i = INSTR(range$, "-", i+1)
IF i THEN
j = i
WHILE MID$(range$,j-1,1) <> "," AND j <> 1
j = j - 1
wend
IF i > j then
IF MID$(range$,j,i-j) <> str$(i-j)+" " THEN
t$ = ""
FOR k = VAL(MID$(range$,j)) T... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Rust | Rust | use std::str::FromStr;
// Precondition: range doesn't contain multibyte UTF-8 characters
fn range_expand(range : &str) -> Vec<i32> {
range.split(',').flat_map(|item| {
match i32::from_str(item) {
Ok(n) => n..n+1,
_ => {
let dashpos=
match item.rfi... |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #SenseTalk | SenseTalk | repeat with each line of file "input.txt"
put it
end repeat
|
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Sidef | Sidef | File(__FILE__).open_r.each { |line|
print line
} |
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
... | #Scheme | Scheme | (define (string-reverse s)
(list->string (reverse (string->list s)))) |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #Klingphix | Klingphix | { include ..\Utilitys.tlhy }
"..\Utilitys.tlhy" load
:push! { l i -- l&i }
0 put
;
:empty? { l -- flag }
len not { len 0 equal }
;
:pop! { l -- l-1 }
empty? (
["Empty"]
[pop swap]
) if
;
( ) { empty queue }
1 push! 2 push! 3 push!
pop! ? pop! ? pop! ? pop! ?
"End ... |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #Nim | Nim | import math, tables
type Quaternion* = object
a, b, c, d: float
func initQuaternion*(a, b, c, d = 0.0): Quaternion =
Quaternion(a: a, b: b, c: c, d: d)
func `-`*(q: Quaternion): Quaternion =
initQuaternion(-q.a, -q.b, -q.c, -q.d)
func `+`*(q: Quaternion; r: float): Quaternion =
initQuaternion(q.a + r, q... |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #Factor | Factor | "%s [ 34 1string dup surround ] keep printf" [ 34 1string dup surround ] keep printf |
http://rosettacode.org/wiki/Range_extraction | Range extraction | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Objeck | Objeck | class IdentityMatrix {
function : Main(args : String[]) ~ Nil {
Compress2Range("-6, -3, -2, -1, 0, 1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20")->PrintLine();
Compress2Range("0, 1, 2, 4, 6, 7, 8, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 38... |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Standard_ML | Standard ML | val seed = 0w42;
val gen = Rand.mkRandom seed;
fun random_gaussian () =
1.0 + Math.sqrt (~2.0 * Math.ln (Rand.norm (gen ()))) * Math.cos (2.0 * Math.pi * Rand.norm (gen ()));
val a = List.tabulate (1000, fn _ => random_gaussian ()); |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Stata | Stata | clear all
set obs 1000
gen x=rnormal(1,0.5) |
http://rosettacode.org/wiki/Read_a_configuration_file | Read a configuration file | The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a semicolon are ignored by the application
# pr... | #Sidef | Sidef | var fullname = (var favouritefruit = "");
var needspeeling = (var seedsremoved = false);
var otherfamily = [];
ARGF.each { |line|
var(key, value) = line.strip.split(/\h+/, 2)...;
given(key) {
when (nil) { }
when (/^([#;]|\h*$)/) { }
when ("FULLNAME") { fullname =... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #S-lang | S-lang | variable r_expres = "-6,-3--1,3-5,7-11,14,15,17-20", s, r_expan = {}, dpos, i;
foreach s (strchop(r_expres, ',', 0))
{
% S-Lang built-in RE's are fairly limited, and have a quirk:
% grouping is done with \\( and \\), not ( and )
% [PCRE and Oniguruma RE's are available via standard libraries]
if (string_mat... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Scala | Scala | def rangex(str: String): Seq[Int] =
str split "," flatMap { (s) =>
val r = """(-?\d+)(?:-(-?\d+))?""".r
val r(a,b) = s
if (b == null) Seq(a.toInt) else a.toInt to b.toInt
} |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Smalltalk | Smalltalk |
(StandardFileStream oldFileNamed: 'test.txt') contents lines do: [ :each | Transcript show: each. ]
|
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #SNOBOL4 | SNOBOL4 | input(.infile,20,"readfrom.txt") :f(end)
rdloop output = infile :s(rdloop)
end |
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
... | #Scratch | Scratch | #!/bin/sed -f
/../! b
# Reverse a line. Begin embedding the line between two newlines
s/^.*$/\
&\
/
# Move first character at the end. The regexp matches until
# there are zero or one characters between the markers
tx
:x
s/\(\n.\)\(.*\)\(.\n\)/\3\2\1/
tx
# Remove the newline markers
s/\n//g |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #Kotlin | Kotlin | // version 1.1.2
import java.util.LinkedList
class Queue<E> {
private val data = LinkedList<E>()
val size get() = data.size
val empty get() = size == 0
fun push(element: E) = data.add(element)
fun pop(): E {
if (empty) throw RuntimeException("Can't pop elements from an empty queu... |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #OCaml | OCaml |
type quaternion = {a: float; b: float; c: float; d: float}
let norm q = sqrt (q.a**2.0 +.
q.b**2.0 +.
q.c**2.0 +.
q.d**2.0 )
let floatneg r = ~-. r (* readability *)
let negative q =
{a = floatneg q.a;
b = floatneg q.b;
c = floatneg q.c;
d = ... |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #FALSE | FALSE | ["'[,34,$!34,'],!"]'[,34,$!34,'],! |
http://rosettacode.org/wiki/Range_extraction | Range extraction | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Objective-C | Objective-C | #import <Foundation/Foundation.h>
NSString *extractRanges(NSArray *nums) {
NSMutableIndexSet *indexSet = [[NSMutableIndexSet alloc] init];
for (NSNumber *n in nums) {
if ([n integerValue] < 0)
@throw [NSException exceptionWithName:NSInvalidArgumentException reason:@"negative number not supported" userIn... |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Tcl | Tcl | package require Tcl 8.5
variable ::pi [expr acos(0)]
proc ::tcl::mathfunc::nrand {} {
expr {sqrt(-2*log(rand())) * cos(2*$::pi*rand())}
}
set mean 1.0
set stddev 0.5
for {set i 0} {$i < 1000} {incr i} {
lappend result [expr {$mean + $stddev*nrand()}]
} |
http://rosettacode.org/wiki/Read_a_configuration_file | Read a configuration file | The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a semicolon are ignored by the application
# pr... | #Smalltalk | Smalltalk | dict := Dictionary new.
configFile asFilename readingLinesDo:[:line |
(line isEmpty or:[ line startsWithAnyOf:#('#' ';') ]) ifFalse:[
s := line readStream.
(s skipSeparators; atEnd) ifFalse:[
|optionName values|
optionName := s upToSeparator.
values := (s upToEnd ... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Scheme | Scheme | (define split
(lambda (str char skip count)
(let ((len (string-length str)))
(let loop ((index skip)
(last-index 0)
(result '()))
(if (= index len)
(reverse (cons (substring str last-index) result))
(if (eq? char (string-ref str index))
... |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Sparkling | Sparkling | let f = fopen("foo.txt", "r");
if f != nil {
var line;
while (line = fgetline(f)) != nil {
print(line);
}
fclose(f);
} |
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
... | #Sed | Sed | #!/bin/sed -f
/../! b
# Reverse a line. Begin embedding the line between two newlines
s/^.*$/\
&\
/
# Move first character at the end. The regexp matches until
# there are zero or one characters between the markers
tx
:x
s/\(\n.\)\(.*\)\(.\n\)/\3\2\1/
tx
# Remove the newline markers
s/\n//g |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #LabVIEW | LabVIEW | define myqueue => type {
data store = list
public onCreate(...) => {
if(void != #rest) => {
with item in #rest do .`store`->insert(#item)
}
}
public push(value) => .`store`->insertLast(#value)
public pop => {
handle => {
.`store`->removefirst
... |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #Octave | Octave | pkg install -forge quaternion |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #Fish | Fish | 00000000000000000000++++++++++++++++++ v
2[$:{:@]$g:0=?v >o:4a*=?!v~1+:3=?;0ao>
>~" "^ >1+ ^ |
http://rosettacode.org/wiki/Range_extraction | Range extraction | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #OCaml | OCaml | let range_extract = function
| [] -> []
| x::xs ->
let f (i,j,ret) k =
if k = succ j then (i,k,ret) else (k,k,(i,j)::ret) in
let (m,n,ret) = List.fold_left f (x,x,[]) xs in
List.rev ((m,n)::ret)
let string_of_range rng =
let str (a,b) =
if a = b then string_of_int a
else Printf.sprintf... |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #TI-83_BASIC | TI-83 BASIC | randNorm(1,.5)
|
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #TorqueScript | TorqueScript | for (%i = 0; %i < 1000; %i++)
%list[%i] = 1 + mSqrt(-2 * mLog(getRandom())) * mCos(2 * $pi * getRandom()); |
http://rosettacode.org/wiki/Read_a_configuration_file | Read a configuration file | The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a semicolon are ignored by the application
# pr... | #Tcl | Tcl | proc readConfig {filename {defaults {}}} {
global cfg
# Read the file in
set f [open $filename]
set contents [read $f]
close $f
# Set up the defaults, if supplied
foreach {var defaultValue} $defaults {
set cfg($var) $defaultValue
}
# Parse the file's contents
foreach line [split... |
Subsets and Splits
Rosetta Code COBOL Python Hard Tasks
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Rosetta Code Task Comparisons
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SQL Code Examples from Training Data
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SQL Code Examples from Training Data
Retrieves raw SQL code examples for the SQL language, which is basic filtering that shows what data looks like but doesn't provide meaningful analysis or patterns.
Select Specific Languages Codes
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