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/Ramanujan%27s_constant | Ramanujan's constant | Calculate Ramanujan's constant (as described on the OEIS site) with at least
32 digits of precision, by the method of your choice. Optionally, if using the 𝑒**(π*√x) approach,
show that when evaluated with the last four Heegner numbers
the result is almost an integer.
| #Python | Python | from mpmath import mp
heegner = [19,43,67,163]
mp.dps = 50
x = mp.exp(mp.pi*mp.sqrt(163))
print("calculated Ramanujan's constant: {}".format(x))
print("Heegner numbers yielding 'almost' integers:")
for i in heegner:
print(" for {}: {} ~ {} error: {}".format(str(i),mp.exp(mp.pi*mp.sqrt(i)),round(mp.exp(mp.pi*mp.sqrt... |
http://rosettacode.org/wiki/Ramanujan%27s_constant | Ramanujan's constant | Calculate Ramanujan's constant (as described on the OEIS site) with at least
32 digits of precision, by the method of your choice. Optionally, if using the 𝑒**(π*√x) approach,
show that when evaluated with the last four Heegner numbers
the result is almost an integer.
| #Raku | Raku | use Rat::Precise;
# set the degree of precision for calculations
constant D = 54;
constant d = 15;
# two versions of exponentiation where base and exponent are both FatRat
multi infix:<**> (FatRat $base, FatRat $exp where * >= 1 --> FatRat) {
2 R** $base**($exp/2);
}
multi infix:<**> (FatRat $base, FatRat $ex... |
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... | #C.23 | C# | using System;
using System.Collections.Generic;
using System.Linq;
class RangeExtraction
{
static void Main()
{
const string testString = "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, 39";
var result = String.Join("... |
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
| #Eiffel | Eiffel |
class
APPLICATION
inherit
ARGUMENTS
create
make
feature {NONE} -- Initialization
l_time: TIME
l_seed: INTEGER
math:DOUBLE_MATH
rnd:RANDOM
Size:INTEGER
once
Result:= 1000
end
make
-- Run application.
local
ergebnis:ARRAY[DOUBLE]
tavg: DOUBLE
x: INTEGER
tmp: DOUBLE
text : S... |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #Fortran | Fortran |
program rosetta_random
implicit none
integer, parameter :: rdp = kind(1.d0)
real(rdp) :: num
integer, allocatable :: seed(:)
integer :: un,n, istat
call random_seed(size = n)
allocate(seed(n))
! Seed with the OS random number generator
open(newunit=un, file="/dev/urandom", access="str... |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #Free_Pascal | Free Pascal |
program RandomNumbers;
// Program to demonstrate the Random and Randomize functions.
var
RandomInteger: integer;
RandomFloat: double;
begin
Randomize; // generate a new sequence every time the program is run
RandomFloat := Random(); // 0 <= RandomFloat < 1
Writeln('Random float between 0 and 1: ', Ran... |
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... | #Fantom | Fantom |
class Main
{
// remove the given key and an optional '=' from start of line
Str removeKey (Str key, Str line)
{
remainder := line[key.size..-1].trim
if (remainder.startsWith("="))
{
remainder = remainder.replace("=", "").trim
}
return remainder
}
Void main ()
{
// define th... |
http://rosettacode.org/wiki/Rare_numbers | Rare numbers | Definitions and restrictions
Rare numbers are positive integers n where:
n is expressed in base ten
r is the reverse of n (decimal digits)
n must be non-palindromic (n ≠ r)
(n+r) is the sum
(n-r) is the difference and must be positive
the sum and the ... | #Phix | Phix | with javascript_semantics
function revn(atom n, integer nd)
atom r = 0
for i=1 to nd do
r = r*10+remainder(n,10)
n = floor(n/10)
end for
return r
end function
integer nd = 2, count = 0
atom lim = 99, n = 9, t0 = time()
while true do
n += 1
atom r = revn(n,nd)
if r<n then
... |
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... | #COBOL | COBOL | >>SOURCE FREE
IDENTIFICATION DIVISION.
PROGRAM-ID. expand-range.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 comma-pos PIC 99 COMP VALUE 1.
01 dash-pos PIC 99 COMP.
01 end-num PIC S9(3).
01 Max-Part-Len C... |
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.
| #CoffeeScript | CoffeeScript |
# This module shows two ways to read a file line-by-line in node.js.
fs = require 'fs'
# First, let's keep things simple, and do things synchronously. This
# approach is well-suited for simple scripts.
do ->
fn = "read_file.coffee"
for line in fs.readFileSync(fn).toString().split '\n'
console.log line
co... |
http://rosettacode.org/wiki/Ranking_methods | Ranking methods |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | data = Transpose@{{44, 42, 42, 41, 41, 41, 39}, {"Solomon", "Jason",
"Errol", "Garry", "Bernard", "Barry", "Stephen"}};
rank[data_, type_] :=
Module[{t = Transpose@{Sort@data, Range[Length@data, 1, -1]}},
Switch[type,
"standard", data/.Rule@@@First/@SplitBy[t, First],
"modified", data/.Rule@@@Last/@Spl... |
http://rosettacode.org/wiki/Range_consolidation | Range consolidation | Define a range of numbers R, with bounds b0 and b1 covering all numbers between and including both bounds.
That range can be shown as:
[b0, b1]
or equally as:
[b1, b0]
Given two ranges, the act of consolidation between them compares the two ranges:
If one range covers all of the other then t... | #Racket | Racket | #lang racket
;; Racket's max and min allow inexact numbers to contaminate exact numbers
;; Use argmax and argmin instead, as they don't have this problem
(define (max . xs) (argmax identity xs))
(define (min . xs) (argmin identity xs))
;; a bag is a list of disjoint intervals
(define ((irrelevant? x y) item) (o... |
http://rosettacode.org/wiki/Range_consolidation | Range consolidation | Define a range of numbers R, with bounds b0 and b1 covering all numbers between and including both bounds.
That range can be shown as:
[b0, b1]
or equally as:
[b1, b0]
Given two ranges, the act of consolidation between them compares the two ranges:
If one range covers all of the other then t... | #Raku | Raku | # Union
sub infix:<∪> (Range $a, Range $b) { Range.new($a.min,max($a.max,$b.max)) }
# Intersection
sub infix:<∩> (Range $a, Range $b) { so $a.max >= $b.min }
multi consolidate() { () }
multi consolidate($this is copy, **@those) {
gather {
for consolidate |@those -> $that {
if $this ∩ $that... |
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
... | #OpenEdge.2FProgress | OpenEdge/Progress | FUNCTION reverseString RETURNS CHARACTER (
INPUT i_c AS CHARACTER
):
DEFINE VARIABLE cresult AS CHARACTER NO-UNDO.
DEFINE VARIABLE ii AS INTEGER NO-UNDO.
DO ii = LENGTH( i_c ) TO 1 BY -1:
cresult = cresult + SUBSTRING( i_c, ii, 1 ).
END.
RETURN cresult.
END FUNCTION.
MESSAGE r... |
http://rosettacode.org/wiki/Random_number_generator_(device) | Random number generator (device) | Task
If your system has a means to generate random numbers involving not only a software algorithm (like the /dev/urandom devices in Unix), then:
show how to obtain a random 32-bit number from that mechanism.
Related task
Random_number_generator_(included)
| #Lasso | Lasso | file(`/dev/urandom`)->readSomeBytes(4)->export32bits |
http://rosettacode.org/wiki/Random_number_generator_(device) | Random number generator (device) | Task
If your system has a means to generate random numbers involving not only a software algorithm (like the /dev/urandom devices in Unix), then:
show how to obtain a random 32-bit number from that mechanism.
Related task
Random_number_generator_(included)
| #M2000_Interpreter | M2000 Interpreter |
Module checkit {
Declare random1 lib "advapi32.SystemFunction036" {long lpbuffer, long length}
Buffer Clear Alfa as long*2
Print Eval(Alfa,0)
Print Eval(Alfa,1)
call void random1(alfa(0), 8)
Print Eval(Alfa,0)
Print Eval(Alfa,1)
}
checkit
|
http://rosettacode.org/wiki/Random_number_generator_(device) | Random number generator (device) | Task
If your system has a means to generate random numbers involving not only a software algorithm (like the /dev/urandom devices in Unix), then:
show how to obtain a random 32-bit number from that mechanism.
Related task
Random_number_generator_(included)
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | rand32[] := RandomInteger[{-2^31, 2^31 - 1}] |
http://rosettacode.org/wiki/Random_Latin_squares | Random Latin squares | A Latin square of size n is an arrangement of n symbols in an n-by-n square in such a way that each row and column has each symbol appearing exactly once.
A randomised Latin square generates random configurations of the symbols for any given n.
Example n=4 randomised Latin square
0 2 3 1
2 1 0 3
3 0 1 2
1 3 2 0
Task... | #Haskell | Haskell | import Data.List (permutations, (\\))
latinSquare :: Eq a => [a] -> [a] -> [[a]]
latinSquare [] [] = []
latinSquare c r
| head r /= head c = []
| otherwise = reverse <$> foldl addRow firstRow perms
where
-- permutations grouped by the first element
perms =
tail $
fmap
(fmap . (:)... |
http://rosettacode.org/wiki/Ray-casting_algorithm | Ray-casting algorithm |
This page uses content from Wikipedia. The original article was at Point_in_polygon. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Given a point and a polygon, check if the point is inside or out... | #PicoLisp | PicoLisp | (scl 4)
(de intersects (Px Py Ax Ay Bx By)
(when (> Ay By)
(xchg 'Ax 'Bx)
(xchg 'Ay 'By) )
(when (or (= Py Ay) (= Py By))
(inc 'Py) )
(and
(>= Py Ay)
(>= By Py)
(>= (max Ax Bx) Px)
(or
(> (min Ax Bx) Px)
(= Ax Px)
(and
(<> Ax Bx... |
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... | #11l | 11l | T FIFO
[Int] contents
F push(item)
.contents.append(item)
F pop()
R .contents.pop(0)
F empty()
R .contents.empty
V f = FIFO()
f.push(3)
f.push(2)
f.push(1)
L !f.empty()
print(f.pop()) |
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 ... | #ACL2 | ACL2 | (defun print-quine (quine)
(cw quine quine))
(print-quine
"(defun print-quine (quine)
(cw quine quine))
(print-quine ~x0)~%") |
http://rosettacode.org/wiki/Queue/Usage | Queue/Usage |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Create a queue data structure and demonstrate its operations.
(For implementations of queues, see the FIFO task.)
Ope... | #AppleScript | AppleScript | on push(StackRef, value)
set StackRef's contents to {value} & StackRef's contents
return StackRef
end push
on pop(StackRef)
set R to missing value
if StackRef's contents ≠ {} then
set R to StackRef's contents's item 1
set StackRef's contents to {} & rest of StackRef's contents
end ... |
http://rosettacode.org/wiki/Read_a_specific_line_from_a_file | Read a specific line from a file | Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store it in a variable or in memory (fo... | #Python | Python | with open('xxx.txt') as f:
for i, line in enumerate(f):
if i == 6:
break
else:
print('Not 7 lines in file')
line = None |
http://rosettacode.org/wiki/Read_a_specific_line_from_a_file | Read a specific line from a file | Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store it in a variable or in memory (fo... | #R | R | > seven <- scan('hw.txt', '', skip = 6, nlines = 1, sep = '\n') # too short
Read 0 items
> seven <- scan('Incoming/quotes.txt', '', skip = 6, nlines = 1, sep = '\n')
Read 1 item
|
http://rosettacode.org/wiki/Quoting_constructs | Quoting constructs | Pretty much every programming language has some form of quoting construct to allow embedding of data in a program, be it literal strings, numeric data or some combination thereof.
Show examples of the quoting constructs in your language. Explain where they would likely be used, what their primary use is, what limitati... | #zkl | zkl | #<<<
text:=
"
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
... | #ATS | ATS | (*------------------------------------------------------------------*)
(*
For linear linked lists, using a random pivot:
* stable three-way "separation" (a variant of quickselect)
* quickselect
* stable quicksort
Also a couple of routines for splitting lists according to a
predicate.
Linear ... |
http://rosettacode.org/wiki/Ramer-Douglas-Peucker_line_simplification | Ramer-Douglas-Peucker line simplification | Ramer-Douglas-Peucker line simplification
You are encouraged to solve this task according to the task description, using any language you may know.
The Ramer–Douglas–Peucker algorithm is a line simplification algorithm for reducing the number of points used to define its shape.
Task
Using the Ramer–Douglas–P... | #JavaScript | JavaScript | /**
* @typedef {{
* x: (!number),
* y: (!number)
* }}
*/
let pointType;
/**
* @param {!Array<pointType>} l
* @param {number} eps
*/
const RDP = (l, eps) => {
const last = l.length - 1;
const p1 = l[0];
const p2 = l[last];
const x21 = p2.x - p1.x;
const y21 = p2.y - p1.y;
const [dMax, x] = ... |
http://rosettacode.org/wiki/Ramanujan%27s_constant | Ramanujan's constant | Calculate Ramanujan's constant (as described on the OEIS site) with at least
32 digits of precision, by the method of your choice. Optionally, if using the 𝑒**(π*√x) approach,
show that when evaluated with the last four Heegner numbers
the result is almost an integer.
| #REXX | REXX | /*REXX pgm displays Ramanujan's constant to at least 100 decimal digits of precision. */
d= min( length(pi()), length(e()) ) - length(.) /*calculate max #decimal digs supported*/
parse arg digs sDigs . 1 . . $ /*obtain optional arguments from the CL*/
if digs=='' | digs=="," then digs= d ... |
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... | #C.2B.2B | C++ |
#include <iostream>
#include <iterator>
#include <cstddef>
template<typename InIter>
void extract_ranges(InIter begin, InIter end, std::ostream& os)
{
if (begin == end)
return;
int current = *begin++;
os << current;
int count = 1;
while (begin != end)
{
int next = *begin++;
if (next == ... |
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
| #Elena | Elena | import extensions;
import extensions'math;
randomNormal()
{
^ cos(2 * Pi_value * randomGenerator.nextReal())
* sqrt(-2 * ln(randomGenerator.nextReal()))
}
public program()
{
real[] a := new real[](1000);
real tAvg := 0;
for (int x := 0, x < a.Length, x += 1)
{
a... |
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
| #Elixir | Elixir | defmodule Random do
def normal(mean, sd) do
{a, b} = {:rand.uniform, :rand.uniform}
mean + sd * (:math.sqrt(-2 * :math.log(a)) * :math.cos(2 * :math.pi * b))
end
end
std_dev = fn (list) ->
mean = Enum.sum(list) / length(list)
sd = Enum.reduce(list, 0, fn x,acc -> acc + (x-mean)*(... |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #FreeBASIC | FreeBASIC | randomInteger = rnd(expr)
|
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #FutureBasic | FutureBasic | randomInteger = rnd(expr)
|
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #GAP | GAP | # Creating a random source
rs := RandomSource(IsMersenneTwister);
# Generate a random number between 1 and 10
Random(rs, 1, 10);
# Same with default random source
Random(1, 10); |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #Go | Go | setrand(3)
random(6)+1
\\ chosen by fair dice roll.
\\ guaranteed to the random. |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #Golfscript | Golfscript | setrand(3)
random(6)+1
\\ chosen by fair dice roll.
\\ guaranteed to the random. |
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... | #Forth | Forth | \ declare the configuration variables in the FORTH app
FORTH DEFINITIONS
32 CONSTANT $SIZE
VARIABLE FULLNAME $SIZE ALLOT
VARIABLE FAVOURITEFRUIT $SIZE ALLOT
VARIABLE NEEDSPEELING
VARIABLE SEEDSREMOVED
VARIABLE OTHERFAMILY(1) $SIZE ALLOT
VARIABLE OTHERFAMILY(2) $SIZE ALLOT
: -leading ( addr len -- addr' len... |
http://rosettacode.org/wiki/Rare_numbers | Rare numbers | Definitions and restrictions
Rare numbers are positive integers n where:
n is expressed in base ten
r is the reverse of n (decimal digits)
n must be non-palindromic (n ≠ r)
(n+r) is the sum
(n-r) is the difference and must be positive
the sum and the ... | #Python | Python |
# rare.py
# find rare numbers
# by kHz
from math import floor, sqrt
from datetime import datetime
def main():
start = datetime.now()
for i in xrange(1, 10 ** 11):
if rare(i):
print "found a rare:", i
end = datetime.now()
print "time elapsed:", end - start
def is_square(n):
s = floor(sqrt(n + 0.5))
re... |
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... | #Common_Lisp | Common Lisp | (defun expand-ranges (string)
(loop
with prevnum = nil
for idx = 0 then (1+ nextidx)
for (number nextidx) = (multiple-value-list
(parse-integer string
:start idx :junk-allowed t))
append (cond
(prevnum
... |
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.
| #Common_Lisp | Common Lisp | (with-open-file (input "file.txt")
(loop for line = (read-line input nil)
while line do (format t "~a~%" line))) |
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.
| #D | D | void main() {
import std.stdio;
foreach (line; "read_a_file_line_by_line.d".File.byLine)
line.writeln;
} |
http://rosettacode.org/wiki/Ranking_methods | Ranking methods |
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
... | #Modula-2 | Modula-2 | MODULE RankingMethods;
FROM FormatString IMPORT FormatString;
FROM RealStr IMPORT RealToFixed;
FROM Terminal IMPORT WriteString,WriteLn,ReadChar;
PROCEDURE WriteCard(c : CARDINAL);
VAR buf : ARRAY[0..15] OF CHAR;
BEGIN
FormatString("%c", buf, c);
WriteString(buf)
END WriteCard;
TYPE Entry = RECORD
name ... |
http://rosettacode.org/wiki/Range_consolidation | Range consolidation | Define a range of numbers R, with bounds b0 and b1 covering all numbers between and including both bounds.
That range can be shown as:
[b0, b1]
or equally as:
[b1, b0]
Given two ranges, the act of consolidation between them compares the two ranges:
If one range covers all of the other then t... | #REXX | REXX | /*REXX program performs range consolidation (they can be [equal] ascending/descending). */
#.= /*define the default for range sets. */
parse arg #.1 /*obtain optional arguments from the CL*/
if #.1='' then do ... |
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
... | #OxygenBasic | OxygenBasic |
'8 BIT CHARACTERS
string s="qwertyuiop"
sys a,b,i,j,le=len s
'
for i=1 to le
j=le-i+1
if j<=i then exit for
a=asc s,i
b=asc s,j
mid s,j,chr a
mid s,i,chr b
next
'
print s
'16 BIT CHARACTERS
wstring s="qwertyuiop"
sys a,b,i,j,le=len s
'
for i=1 to le
j=le-i+1
if j<=i then exit for
a=unic s,... |
http://rosettacode.org/wiki/Random_number_generator_(device) | Random number generator (device) | Task
If your system has a means to generate random numbers involving not only a software algorithm (like the /dev/urandom devices in Unix), then:
show how to obtain a random 32-bit number from that mechanism.
Related task
Random_number_generator_(included)
| #Mercury | Mercury | :- module random_number_device.
:- interface.
:- import_module io.
:- pred main(io::di, io::uo) is det.
:- implementation.
:- import_module maybe, random, random.system_rng, require.
main(!IO) :-
open_system_rng(MaybeRNG, !IO),
(
MaybeRNG = ok(RNG),
random.generate_uint32(RNG, U32, !IO),
i... |
http://rosettacode.org/wiki/Random_number_generator_(device) | Random number generator (device) | Task
If your system has a means to generate random numbers involving not only a software algorithm (like the /dev/urandom devices in Unix), then:
show how to obtain a random 32-bit number from that mechanism.
Related task
Random_number_generator_(included)
| #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref savelog symbols binary
import java.math.BigInteger
randomDevNameFile = File
randomDevNameList = ['/dev/random', '/dev/urandom'] -- list of random data source devices
randomDevIStream = InputStream
do
loop dn = 0 to randomDevNameList.length - 1
random... |
http://rosettacode.org/wiki/Random_Latin_squares | Random Latin squares | A Latin square of size n is an arrangement of n symbols in an n-by-n square in such a way that each row and column has each symbol appearing exactly once.
A randomised Latin square generates random configurations of the symbols for any given n.
Example n=4 randomised Latin square
0 2 3 1
2 1 0 3
3 0 1 2
1 3 2 0
Task... | #J | J | rls=: 3 : 0
s=. ?~ y NB. "deal" y unique integers from 0 to y
for_ijk. i.<:y do.
NB. deal a new row. subtract it from all previous rows
NB. if you get a 0, some column has a matching integer, deal again
whilst. 0 = */ */ s -"1 r do.
r=. ?~ y
end.
s=. s ,,: r NB. "lamin... |
http://rosettacode.org/wiki/Random_Latin_squares | Random Latin squares | A Latin square of size n is an arrangement of n symbols in an n-by-n square in such a way that each row and column has each symbol appearing exactly once.
A randomised Latin square generates random configurations of the symbols for any given n.
Example n=4 randomised Latin square
0 2 3 1
2 1 0 3
3 0 1 2
1 3 2 0
Task... | #Java | Java | import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;
public class RandomLatinSquares {
private static void printSquare(List<List<Integer>> latin) {
for (List<Integer> row : latin) {
Iterator<Integer> it = row.iter... |
http://rosettacode.org/wiki/Ray-casting_algorithm | Ray-casting algorithm |
This page uses content from Wikipedia. The original article was at Point_in_polygon. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Given a point and a polygon, check if the point is inside or out... | #PureBasic | PureBasic | Structure point_f
x.f
y.f
EndStructure
Procedure inpoly(*p.point_f, List poly.point_f())
Protected.point_f new, old, lp, rp
Protected inside
If ListSize(poly()) < 3: ProcedureReturn 0: EndIf
LastElement(poly()): old = poly()
ForEach poly()
;find leftmost endpoint 'lp' and the rightmost endpoint 'rp' ... |
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... | #AArch64_Assembly | AArch64 Assembly |
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program defqueue64.s */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeConstantesARM... |
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 ... | #Ada | Ada | integer f;
text s, t;
f = 36;
s = "integer f;
text s, t;
f = 36;
s = \"\";
o_text(cut(s, 0, f));
o_text(cut(s, 0, f - 1));
o_etext(cut(s, f - 1, 2));
o_text(cut(s, f + 1, 8888 - f));
o_text(cut(s, f, 8888 - f));
";
o_text(cut(s, 0, f));
o_text(cut(s, 0, f - 1));
o_etext(cut(s, f - 1, 2));
o_text(cut(s, f + 1, 8... |
http://rosettacode.org/wiki/Queue/Usage | Queue/Usage |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Create a queue data structure and demonstrate its operations.
(For implementations of queues, see the FIFO task.)
Ope... | #Astro | Astro | let my_queue = Queue()
my_queue.push!('foo')
my_queue.push!('bar')
my_queue.push!('baz')
print my_queue.pop!() # 'foo'
print my_queue.pop!() # 'bar'
print my_queue.pop!() # 'baz' |
http://rosettacode.org/wiki/Queue/Usage | Queue/Usage |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Create a queue data structure and demonstrate its operations.
(For implementations of queues, see the FIFO task.)
Ope... | #AutoHotkey | AutoHotkey | push("qu", 2), push("qu", 44), push("qu", "xyz") ; TEST
MsgBox % "Len = " len("qu") ; Number of entries
While !empty("qu") ; Repeat until queue is not empty
MsgBox % pop("qu") ; Print popped values (2, 44, xyz)
MsgBox Error = %ErrorLevel% ; ErrorLevel = 0: OK
MsgBox % pop("qu") ; Empty
Msg... |
http://rosettacode.org/wiki/Read_a_specific_line_from_a_file | Read a specific line from a file | Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store it in a variable or in memory (fo... | #Racket | Racket |
#lang racket
;; simple, but reads the whole file
(define s1 (list-ref (file->lines "some-file") 6))
;; more efficient: read and discard n-1 lines
(define s2
(call-with-input-file "some-file"
(λ(i) (for/last ([line (in-lines i)] [n 7]) line))))
|
http://rosettacode.org/wiki/Read_a_specific_line_from_a_file | Read a specific line from a file | Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store it in a variable or in memory (fo... | #Raku | Raku | say lines[6] // die "Short file"; |
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
... | #AutoHotkey | AutoHotkey | MyList := [9, 8, 7, 6, 5, 0, 1, 2, 3, 4]
Loop, 10
Out .= Select(MyList, 1, MyList.MaxIndex(), A_Index) (A_Index = MyList.MaxIndex() ? "" : ", ")
MsgBox, % Out
return
Partition(List, Left, Right, PivotIndex) {
PivotValue := List[PivotIndex]
, Swap(List, pivotIndex, Right)
, StoreIndex := Left
, i := Left - 1
Loo... |
http://rosettacode.org/wiki/Ramer-Douglas-Peucker_line_simplification | Ramer-Douglas-Peucker line simplification | Ramer-Douglas-Peucker line simplification
You are encouraged to solve this task according to the task description, using any language you may know.
The Ramer–Douglas–Peucker algorithm is a line simplification algorithm for reducing the number of points used to define its shape.
Task
Using the Ramer–Douglas–P... | #Julia | Julia | const Point = Vector{Float64}
function perpdist(pt::Point, lnstart::Point, lnend::Point)
d = normalize!(lnend .- lnstart)
pv = pt .- lnstart
# Get dot product (project pv onto normalized direction)
pvdot = dot(d, pv)
# Scale line direction vector
ds = pvdot .* d
# Subtract this from pv
... |
http://rosettacode.org/wiki/Ramanujan%27s_constant | Ramanujan's constant | Calculate Ramanujan's constant (as described on the OEIS site) with at least
32 digits of precision, by the method of your choice. Optionally, if using the 𝑒**(π*√x) approach,
show that when evaluated with the last four Heegner numbers
the result is almost an integer.
| #Ruby | Ruby | require "bigdecimal/math"
include BigMath
e, pi = E(200), PI(200)
[19, 43, 67, 163].each do |x|
puts "#{x}: #{(e ** (pi * BigMath.sqrt(BigDecimal(x), 200))).round(100).to_s("F")}"
end
|
http://rosettacode.org/wiki/Ramanujan%27s_constant | Ramanujan's constant | Calculate Ramanujan's constant (as described on the OEIS site) with at least
32 digits of precision, by the method of your choice. Optionally, if using the 𝑒**(π*√x) approach,
show that when evaluated with the last four Heegner numbers
the result is almost an integer.
| #Sidef | Sidef | func ramanujan_const(x, decimals=32) {
local Num!PREC = *"#{4*round((Num.pi*√x)/log(10) + decimals + 1)}"
exp(Num.pi * √x) -> round(-decimals).to_s
}
var decimals = 100
printf("Ramanujan's constant to #{decimals} decimals:\n%s\n\n",
ramanujan_const(163, decimals))
say "Heegner numbers yielding 'almost'... |
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... | #Ceylon | Ceylon | shared void run() {
value numbers = [
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, 39
];
function asRangeFormattedString<Value>([Value*] values)
given Value satisfies Enumerable<Value> {
value builder = StringBuilde... |
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
| #Erlang | Erlang |
mean(Values) ->
mean(tl(Values), hd(Values), 1).
mean([], Acc, Length) ->
Acc / Length;
mean(Values, Acc, Length) ->
mean(tl(Values), hd(Values)+Acc, Length+1).
variance(Values) ->
Mean = mean(Values),
variance(Values, Mean, 0) / length(Values).
variance([], _, Acc) ->
Acc;
variance(Valu... |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #Groovy | Groovy | setrand(3)
random(6)+1
\\ chosen by fair dice roll.
\\ guaranteed to the random. |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #Haskell | Haskell | setrand(3)
random(6)+1
\\ chosen by fair dice roll.
\\ guaranteed to the random. |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #Icon_and_Unicon | Icon and Unicon | setrand(3)
random(6)+1
\\ chosen by fair dice roll.
\\ guaranteed to the random. |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #Inform_7 | Inform 7 | setrand(3)
random(6)+1
\\ chosen by fair dice roll.
\\ guaranteed to the random. |
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... | #Fortran | Fortran |
program readconfig
implicit none
integer, parameter :: strlen = 100
logical :: needspeeling = .false., seedsremoved =.false.
character(len=strlen) :: favouritefruit = "", fullname = "", fst, snd
character(len=strlen), allocatable :: otherfamily(:), tmp(:)
character(len=1000) :: line
i... |
http://rosettacode.org/wiki/Rare_numbers | Rare numbers | Definitions and restrictions
Rare numbers are positive integers n where:
n is expressed in base ten
r is the reverse of n (decimal digits)
n must be non-palindromic (n ≠ r)
(n+r) is the sum
(n-r) is the difference and must be positive
the sum and the ... | #Quackery | Quackery | [ dup 1
[ 2dup > while
+ 1 >>
2dup / again ]
drop nip ] is sqrt ( n --> n )
[ dup sqrt 2 ** = not ] is !square ( n --> b )
[ number$ reverse
$->n drop ] is revnumber ( n --> n )
[ 0 swap
[ base share /mod
rot + swap
... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Cowgol | Cowgol | include "cowgol.coh";
# Callback interface
interface RangeCb(n: int32);
# This will call `cb' for each number in the range, in ascending order.
# It will return NULL on success, or the location of an error if
# there is one.
sub Expand(ranges: [uint8], cb: RangeCb): (err: [uint8]) is
err := 0 as [uint8];
l... |
http://rosettacode.org/wiki/Range_expansion | Range expansion | A format for expressing an ordered list of integers is to use a comma separated list of either
individual integers
Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
The range s... | #Crystal | Crystal | def range_expand(range)
range.split(',').flat_map do |part|
match = /^(-?\d+)-(-?\d+)$/.match(part)
if match
(match[1].to_i .. match[2].to_i).to_a
else
part.to_i
end
end
end
puts 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.
| #DBL | DBL | ;
; Read a file line by line for DBL version 4
;
RECORD
LINE, A100
PROC
;-----------------------------------------------
OPEN (1,I,"FILE.TXT") [ERR=NOFIL]
DO FOREVER
BEGIN
READS (1,LINE,EOF) [ERR=EREAD]
END
EOF, CLOSE 3
GOTO CLO... |
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.
| #DCL | DCL | $ open input input.txt
$ loop:
$ read /end_of_file = done input line
$ goto loop
$ done:
$ close input |
http://rosettacode.org/wiki/Ranking_methods | Ranking methods |
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
... | #Nim | Nim | import algorithm, sequtils, stats, tables
type
Record = tuple[score: int; name: string] # Input data.
Groups = OrderedTable[int, seq[string]] # Maps score to list of names.
Rank = tuple[rank: int; name: string; score: int] # Result.
FractRank = tuple[rank: float; nam... |
http://rosettacode.org/wiki/Range_consolidation | Range consolidation | Define a range of numbers R, with bounds b0 and b1 covering all numbers between and including both bounds.
That range can be shown as:
[b0, b1]
or equally as:
[b1, b0]
Given two ranges, the act of consolidation between them compares the two ranges:
If one range covers all of the other then t... | #Rust | Rust | use std::fmt::{Display, Formatter};
// We could use std::ops::RangeInclusive, but we would have to extend it to
// normalize self (not much trouble) and it would not have to handle pretty
// printing for it explicitly. So, let's make rather an own type.
#[derive(Clone, Debug, PartialEq, PartialOrd)]
pub struct Clos... |
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
... | #OxygenBasic_x86_Assembler | OxygenBasic x86 Assembler |
string s="qwertyuiop"
sys p=strptr s, le=len s
mov esi,p
mov edi,esi
add edi,le
dec edi
(
cmp esi,edi
jge exit
mov al,[esi]
mov ah,[edi]
mov [esi],ah
mov [edi],al
inc esi
dec edi
repeat
)
print s
|
http://rosettacode.org/wiki/Random_number_generator_(device) | Random number generator (device) | Task
If your system has a means to generate random numbers involving not only a software algorithm (like the /dev/urandom devices in Unix), then:
show how to obtain a random 32-bit number from that mechanism.
Related task
Random_number_generator_(included)
| #Nim | Nim | var f = open("/dev/urandom")
var r: int32
discard f.readBuffer(addr r, 4)
close(f)
echo r |
http://rosettacode.org/wiki/Random_number_generator_(device) | Random number generator (device) | Task
If your system has a means to generate random numbers involving not only a software algorithm (like the /dev/urandom devices in Unix), then:
show how to obtain a random 32-bit number from that mechanism.
Related task
Random_number_generator_(included)
| #OCaml | OCaml | let input_rand_int ic =
let i1 = int_of_char (input_char ic)
and i2 = int_of_char (input_char ic)
and i3 = int_of_char (input_char ic)
and i4 = int_of_char (input_char ic) in
i1 lor (i2 lsl 8) lor (i3 lsl 16) lor (i4 lsl 24)
let () =
let ic = open_in "/dev/urandom" in
let ri31 = input_rand_int ic in
c... |
http://rosettacode.org/wiki/Random_number_generator_(device) | Random number generator (device) | Task
If your system has a means to generate random numbers involving not only a software algorithm (like the /dev/urandom devices in Unix), then:
show how to obtain a random 32-bit number from that mechanism.
Related task
Random_number_generator_(included)
| #PARI.2FGP | PARI/GP | rnd(n=10)=extern("cat /dev/urandom|tr -dc '[:digit:]'|fold -w"n"|head -1") |
http://rosettacode.org/wiki/Random_Latin_squares | Random Latin squares | A Latin square of size n is an arrangement of n symbols in an n-by-n square in such a way that each row and column has each symbol appearing exactly once.
A randomised Latin square generates random configurations of the symbols for any given n.
Example n=4 randomised Latin square
0 2 3 1
2 1 0 3
3 0 1 2
1 3 2 0
Task... | #JavaScript | JavaScript |
class Latin {
constructor(size = 3) {
this.size = size;
this.mst = [...Array(this.size)].map((v, i) => i + 1);
this.square = Array(this.size).fill(0).map(() => Array(this.size).fill(0));
if (this.create(0, 0)) {
console.table(this.square);
}
}
create(c, r) {
const d = [...this.... |
http://rosettacode.org/wiki/Ray-casting_algorithm | Ray-casting algorithm |
This page uses content from Wikipedia. The original article was at Point_in_polygon. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Given a point and a polygon, check if the point is inside or out... | #Python | Python | from collections import namedtuple
from pprint import pprint as pp
import sys
Pt = namedtuple('Pt', 'x, y') # Point
Edge = namedtuple('Edge', 'a, b') # Polygon edge from a to b
Poly = namedtuple('Poly', 'name, edges') # Polygon
_eps = 0.00001
_huge = sys.float_info.max
_tiny = sys.float_i... |
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... | #ACL2 | ACL2 | (defun enqueue (x xs)
(cons x xs))
(defun dequeue (xs)
(declare (xargs :guard (and (consp xs)
(true-listp xs))))
(if (or (endp xs) (endp (rest xs)))
(mv (first xs) nil)
(mv-let (x ys)
(dequeue (rest xs))
(mv x (cons (first xs) ys)))))
(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 ... | #Aime | Aime | integer f;
text s, t;
f = 36;
s = "integer f;
text s, t;
f = 36;
s = \"\";
o_text(cut(s, 0, f));
o_text(cut(s, 0, f - 1));
o_etext(cut(s, f - 1, 2));
o_text(cut(s, f + 1, 8888 - f));
o_text(cut(s, f, 8888 - f));
";
o_text(cut(s, 0, f));
o_text(cut(s, 0, f - 1));
o_etext(cut(s, f - 1, 2));
o_text(cut(s, f + 1, 8... |
http://rosettacode.org/wiki/Queue/Usage | Queue/Usage |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Create a queue data structure and demonstrate its operations.
(For implementations of queues, see the FIFO task.)
Ope... | #AWK | AWK | function deque(arr) {
arr["start"] = 0
arr["end"] = 0
}
function dequelen(arr) {
return arr["end"] - arr["start"]
}
function empty(arr) {
return dequelen(arr) == 0
}
function push(arr, elem) {
arr[++arr["end"]] = elem
}
function pop(arr) {
if (empty(arr)) {
return
}
retur... |
http://rosettacode.org/wiki/Read_a_specific_line_from_a_file | Read a specific line from a file | Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store it in a variable or in memory (fo... | #REBOL | REBOL |
x: pick read/lines request-file/only 7
either x [print x] [print "No seventh line"]
|
http://rosettacode.org/wiki/Read_a_specific_line_from_a_file | Read a specific line from a file | Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store it in a variable or in memory (fo... | #Red | Red | >> x: pick read/lines %file.txt 7
case [
x = none [print "File has less than seven lines"]
(length? x) = 0 [print "Line 7 is empty"]
(length? x) > 0 [print append "Line seven = " 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
... | #C | C | #include <stdio.h>
#include <string.h>
int qselect(int *v, int len, int k)
{
# define SWAP(a, b) { tmp = v[a]; v[a] = v[b]; v[b] = tmp; }
int i, st, tmp;
for (st = i = 0; i < len - 1; i++) {
if (v[i] > v[len-1]) continue;
SWAP(i, st);
st++;
}
SWAP(len-1, st);
return k == st ?v[st]
:st > k ? qselec... |
http://rosettacode.org/wiki/Ramer-Douglas-Peucker_line_simplification | Ramer-Douglas-Peucker line simplification | Ramer-Douglas-Peucker line simplification
You are encouraged to solve this task according to the task description, using any language you may know.
The Ramer–Douglas–Peucker algorithm is a line simplification algorithm for reducing the number of points used to define its shape.
Task
Using the Ramer–Douglas–P... | #Kotlin | Kotlin | // version 1.1.0
typealias Point = Pair<Double, Double>
fun perpendicularDistance(pt: Point, lineStart: Point, lineEnd: Point): Double {
var dx = lineEnd.first - lineStart.first
var dy = lineEnd.second - lineStart.second
// Normalize
val mag = Math.hypot(dx, dy)
if (mag > 0.0) { dx /= mag; dy ... |
http://rosettacode.org/wiki/Ramanujan%27s_constant | Ramanujan's constant | Calculate Ramanujan's constant (as described on the OEIS site) with at least
32 digits of precision, by the method of your choice. Optionally, if using the 𝑒**(π*√x) approach,
show that when evaluated with the last four Heegner numbers
the result is almost an integer.
| #Wren | Wren | import "/big" for BigRat
import "/fmt" for Fmt
var pi = "3.1415926535897932384626433832795028841971693993751058209749445923078164"
var bigPi = BigRat.fromDecimal(pi)
var exp = Fn.new { |x, p|
var sum = x + 1
var prevTerm = x
var k = 2
var eps = BigRat.fromDecimal("0.5e-%(p)")
while (true) {
... |
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... | #Clojure | Clojure | (use '[flatland.useful.seq :only (partition-between)])
(defn nonconsecutive? [[x y]]
(not= (inc x) y))
(defn string-ranges [coll]
(let [left (first coll)
size (count coll)]
(cond
(> size 2) (str left "-" (last coll))
(= size 2) (str left "," (last coll))
:else (str left))))
(defn... |
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
| #ERRE | ERRE |
PROGRAM DISTRIBUTION
!
! for rosettacode.org
!
! formulas taken from TI-59 Master Library manual
CONST NUM_ITEM=1000
!VAR SUMX#,SUMX2#,R1#,R2#,Z#,I%
DIM A#[1000]
BEGIN
! seeds random number generator with system time
RANDOMIZE(TIMER)
PRINT(CHR$(12);) !CLS
SUMX#=0 SUMX2#=0
FOR I%=1 TO NUM... |
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
| #Euler_Math_Toolbox | Euler Math Toolbox |
>v=normal(1,1000)*0.5+1;
>mean(v), dev(v)
1.00291801071
0.498226876528
|
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #Io | Io | setrand(3)
random(6)+1
\\ chosen by fair dice roll.
\\ guaranteed to the random. |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #J | J | setrand(3)
random(6)+1
\\ chosen by fair dice roll.
\\ guaranteed to the random. |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #Java | Java | setrand(3)
random(6)+1
\\ chosen by fair dice roll.
\\ guaranteed to the random. |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #JavaScript | JavaScript | setrand(3)
random(6)+1
\\ chosen by fair dice roll.
\\ guaranteed to the random. |
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... | #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Sub split (s As Const String, sepList As Const String, result() As String)
If s = "" OrElse sepList = "" Then
Redim result(0)
result(0) = s
Return
End If
Dim As Integer i, j, count = 0, empty = 0, length
Dim As Integer position(Len(s) + 1)
position(0) = 0
For i = 0 To l... |
http://rosettacode.org/wiki/Rare_numbers | Rare numbers | Definitions and restrictions
Rare numbers are positive integers n where:
n is expressed in base ten
r is the reverse of n (decimal digits)
n must be non-palindromic (n ≠ r)
(n+r) is the sum
(n-r) is the difference and must be positive
the sum and the ... | #Raku | Raku | # 20220315 Raku programming solution
sub rare (\target where ( target > 0 and target ~~ Int )) {
my \digit = $ = 2;
my $count = 0;
my @numeric_digits = 0..9 Z, 0 xx *;
my @diffs1 = 0,1,4,5,6;
# all possible digits pairs to calculate potential diffs
my @pairs = 0..9 ... |
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... | #D | D | import std.stdio, std.regex, std.conv, std.range, std.algorithm;
enum rangeEx = (string s) /*pure*/ => s.matchAll(`(-?\d+)-?(-?\d+)?,?`)
.map!q{ a[1].to!int.iota(a[1 + !a[2].empty].to!int + 1) }.join;
void main() {
"-6,-3--1,3-5,7-11,14,15,17-20".rangeEx.writeln;
} |
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.
| #Delphi | Delphi |
procedure ReadFileByLine;
var
TextFile: text;
TextLine: String;
begin
Assign(TextFile, 'c:\test.txt');
Reset(TextFile);
while not Eof(TextFile) do
Readln(TextFile, TextLine);
CloseFile(TextFile);
end;
|
http://rosettacode.org/wiki/Ranking_methods | Ranking methods |
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
... | #PARI.2FGP | PARI/GP | standard(v)=v=vecsort(v,1,4); my(last=v[1][1]+1); for(i=1,#v, v[i][1]=if(v[i][1]<last,last=v[i][1]; i, v[i-1][1])); v;
modified(v)=v=vecsort(v,1,4); my(last=v[#v][1]-1); forstep(i=#v,1,-1, v[i][1]=if(v[i][1]>last,last=v[i][1]; i, v[i+1][1])); v;
dense(v)=v=vecsort(v,1,4); my(last=v[1][1]+1,rank); for(i=1,#v, v[i][1]=if... |
http://rosettacode.org/wiki/Range_consolidation | Range consolidation | Define a range of numbers R, with bounds b0 and b1 covering all numbers between and including both bounds.
That range can be shown as:
[b0, b1]
or equally as:
[b1, b0]
Given two ranges, the act of consolidation between them compares the two ranges:
If one range covers all of the other then t... | #Wren | Wren | class Span {
construct new(r) {
if (r.type != Range || !r.isInclusive) Fiber.abort("Argument must be an inclusive range.")
_low = r.from
_high = r.to
if (_low > _high) {
_low = r.to
_high = r.from
}
}
low { _low }
high { _high }
co... |
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