task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
value |
|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Runge-Kutta_method | Runge-Kutta method | Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This equation has an exact solution:
... | #Wren | Wren | import "/fmt" for Fmt
var rungeKutta4 = Fn.new { |t0, tz, dt, y, yd|
var tn = t0
var yn = y.call(tn)
var z = ((tz - t0)/dt).truncate
for (i in 0..z) {
if (i % 10 == 0) {
var exact = y.call(tn)
var error = yn - exact
Fmt.print("$4.1f $10f $10f $9f", tn, yn... | Give a code snippet in #Wren
Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This equ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Quicksort | Sorting algorithms/Quicksort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Oz | Oz | declare
fun {QuickSort Xs}
case Xs of nil then nil
[] Pivot|Xr then
fun {IsSmaller X} X < Pivot end
Smaller Larger
in
{List.partition Xr IsSmaller ?Smaller ?Larger}
{Append {QuickSort Smaller} Pivot|{QuickSort Larger}}
end
end
in
{Show {QuickSort [3 1 4 1 5 9 2 6 5]}} | Give a code snippet in #Oz
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Padovan_sequence | Padovan sequence |
The Padovan sequence is similar to the Fibonacci sequence in several ways.
Some are given in the table below, and the referenced video shows some of the geometric
similarities.
Comment
Padovan
Fibonacci
Named after.
Richard Padovan
Leonardo of Pisa: Fibonacci
Recurrence initial values.... | #Delphi | Delphi |
program Padovan_sequence;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
Velthuis.BigDecimals,
Boost.Generics.Collection;
type
TpFn = TFunc<Integer, Integer>;
var
RecMemo: TDictionary<Integer, Integer>;
lSystemMemo: TDictionary<Integer, string>;
function pRec(n: Integer): Integer;
begin
if RecMemo.H... | Give a code snippet in #Delphi
The Padovan sequence is similar to the Fibonacci sequence in several ways.
Some are given in the table below, and the referenced video shows some of the geometric
similarities.
Comment
Padovan
Fibonacci
Named after.
Richard Padovan
Leonardo of Pisa: Fibonacci
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_numbers | Perfect numbers | Write a function which says whether a number is perfect.
A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself.
Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself).
Note: The faster Luca... | #M4 | M4 | define(`for',
`ifelse($#,0,``$0'',
`ifelse(eval($2<=$3),1,
`pushdef(`$1',$2)$4`'popdef(`$1')$0(`$1',incr($2),$3,`$4')')')')dnl
define(`ispart',
`ifelse(eval($2*$2<=$1),1,
`ifelse(eval($1%$2==0),1,
`ifelse(eval($2*$2==$1),1,
`ispart($1,incr($2),eval($3+$2))',
`ispart(... | Give a code snippet in #M4
Write a function which says whether a number is perfect.
A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself.
Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself).
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_length | String length | Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters.
F... | #sed | sed | # Change all characters to '|'.
s/./\|/g;
# Convert to digits
:convert
s/||||||||||/</g
s/<\([0-9]*\)$/<0\1/g
s/|||||||||/9/g;
s/|||||||||/9/g; s/||||||||/8/g; s/|||||||/7/g; s/||||||/6/g;
s/|||||/5/g; s/||||/4/g; s/|||/3/g; s/||/2/g; s/|/1/g;
s/</|/g
t convert
s/^$/0/ | Give a code snippet in #sed
Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme contai... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Forest_fire | Forest fire |
This page uses content from Wikipedia. The original article was at Forest-fire model. 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)
Task
Implement the Drossel and Schwabl definition of the fores... | #6502_Assembly | 6502 Assembly | ORG $4357
; SYS 17239 or CALL 17239
EMPTY2 = $00
TREE2 = $44
FIRE2 = $99
; common available zero page
GBASL = $26
GBASH = $27
SEED2 = $28
SEED0 = $29
SEED1 = $2A
H2 = $2B
V2 = $2C
PLOTC = $2D
COLOR = $2E
PAGE = $2F
TOPL = $30
TOPH = $31
MIDL = $32
MIDH = $33
BTML = $34
BTMH = $35
PLOTL = $36
PLOTH = $37
la... | Give a code snippet in #6502_Assembly
This page uses content from Wikipedia. The original article was at Forest-fire model. 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)
Task
Implement the Dros... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bernoulli_numbers | Bernoulli numbers | Bernoulli numbers are used in some series expansions of several functions (trigonometric, hyperbolic, gamma, etc.), and are extremely important in number theory and analysis.
Note that there are two definitions of Bernoulli numbers; this task will be using the modern usage (as per The National Institute of S... | #Frink | Frink | BernoulliNumber[n] :=
{
a = new array
for m = 0 to n
{
a@m = 1/(m+1)
for j = m to 1 step -1
a@(j-1) = j * (a@(j-1) - a@j)
}
return a@0
}
result = new array
for n=0 to 60
{
b = BernoulliNumber[n]
if b != 0
{
[num,den] = numeratorDenominator[b]
result.push[[n, ... | Give a code snippet in #Frink
Bernoulli numbers are used in some series expansions of several functions (trigonometric, hyperbolic, gamma, etc.), and are extremely important in number theory and analysis.
Note that there are two definitions of Bernoulli numbers; this task will be using the modern usage (as pe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Non-decimal_radices/Input | Non-decimal radices/Input | It is common to have a string containing a number written in some format, with the most common ones being decimal, hexadecimal, octal and binary. Such strings are found in many places (user interfaces, configuration files, XML data, network protocols, etc.)
This task requires parsing of such a string (which may be ass... | #E | E | ? __makeInt("200", 16)
# value: 512
? __makeInt("200", 10)
# value: 200 | Give a code snippet in #E
It is common to have a string containing a number written in some format, with the most common ones being decimal, hexadecimal, octal and binary. Such strings are found in many places (user interfaces, configuration files, XML data, network protocols, etc.)
This task requires parsing of such... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brilliant_numbers | Brilliant numbers | Brilliant numbers are a subset of semiprime numbers. Specifically, they are numbers that are the product of exactly two prime numbers that both have the same number of digits when expressed in base 10.
Brilliant numbers are useful in cryptography and when testing prime factoring algorithms.
E.G.
3 × 3 (9) is a bri... | #Haskell | Haskell | import Control.Monad (join)
import Data.Bifunctor (bimap)
import Data.List (intercalate, transpose)
import Data.List.Split (chunksOf, splitWhen)
import Data.Numbers.Primes (primeFactors)
import Text.Printf (printf)
-------------------- BRILLIANT NUMBERS -------------------
isBrilliant :: (Integral a, Show a) => a -... | Give a code snippet in #Haskell
Brilliant numbers are a subset of semiprime numbers. Specifically, they are numbers that are the product of exactly two prime numbers that both have the same number of digits when expressed in base 10.
Brilliant numbers are useful in cryptography and when testing prime factoring algori... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mian-Chowla_sequence | Mian-Chowla sequence | The Mian–Chowla sequence is an integer sequence defined recursively.
Mian–Chowla is an infinite instance of a Sidon sequence, and belongs to the class known as B₂ sequences.
The sequence starts with:
a1 = 1
then for n > 1, an is the smallest positive integer such that every pairwise sum
ai + aj
is distinct, fo... | #Phix | Phix | function mian_chowla(integer n)
sequence mc = {1},
is = {false,true}
integer len_is = 2, s
for i=2 to n do
sequence isx = {}
integer j = mc[i-1]+1
mc = append(mc,j)
while true do
for k=1 to length(mc) do
s = mc[k] + j
if s<=len... | Give a code snippet in #Phix
The Mian–Chowla sequence is an integer sequence defined recursively.
Mian–Chowla is an infinite instance of a Sidon sequence, and belongs to the class known as B₂ sequences.
The sequence starts with:
a1 = 1
then for n > 1, an is the smallest positive integer such that every pairwise... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Equilibrium_index | Equilibrium index | An equilibrium index of a sequence is an index into the sequence such that the sum of elements at lower indices is equal to the sum of elements at higher indices.
For example, in a sequence
A
{\displaystyle A}
:
A
0
=
−
7
{\displaystyle A_{0}=-7}
A
1
=
1
{\displaystyle A_{1}=1}
... | #Elixir | Elixir | defmodule Equilibrium do
def index(list) do
last = length(list)
Enum.filter(0..last-1, fn i ->
Enum.sum(Enum.slice(list, 0, i)) == Enum.sum(Enum.slice(list, i+1..last))
end)
end
end | Give a code snippet in #Elixir
An equilibrium index of a sequence is an index into the sequence such that the sum of elements at lower indices is equal to the sum of elements at higher indices.
For example, in a sequence
A
{\displaystyle A}
:
A
0
=
−
7
{\displaystyle A_{0}=-7}
A
1
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #Clojure | Clojure | (import '(java.util Scanner))
(def scan (Scanner. *in*))
(def s (.nextLine scan))
(def n (.nextInt scan)) | Give a code snippet in #Clojure
User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| christopher/rosetta-code | |
http://rosettacode.org/wiki/String_interpolation_(included) | String interpolation (included) |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Perl | Perl | $extra = "little";
print "Mary had a $extra lamb.\n";
printf "Mary had a %s lamb.\n", $extra; | Give a code snippet in #Perl
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tic-tac-toe | Tic-tac-toe |
Task
Play a game of tic-tac-toe.
Ensure that legal moves are played and that a winning position is notified.
Tic-tac-toe is also known as:
naughts and crosses
tic tac toe
tick tack toe
three in a row
tres en rayo and
Xs and Os
See also
MathWorld™, Tic-Tac-Toe game.
Wikipedi... | #FreeBASIC | FreeBASIC |
'About 400 lines of code, but it is a graphical (GUI ish) i.e. mouse driven.
'I have made provision for the player to beat the computer now and then.
Type box
As long x,y
As long wide,high,index
Dim As ulong colour
As String caption
Declare Sub show
Declare Sub NewCapti... | Give a code snippet in #FreeBASIC
Task
Play a game of tic-tac-toe.
Ensure that legal moves are played and that a winning position is notified.
Tic-tac-toe is also known as:
naughts and crosses
tic tac toe
tick tack toe
three in a row
tres en rayo and
Xs and Os
See also
MathWo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rosetta_Code/Rank_languages_by_popularity | Rosetta Code/Rank languages by popularity | Rosetta Code/Rank languages by popularity
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Sort the most popular computer programming languages based in number of members in Rosetta Code categories.
Sample output on 01 juin 2022 at 14:13 +02
Rank: 1 (1,... | #ALGOL_68 | ALGOL 68 | PROC good page = (REF STRING page) BOOL:
IF grep in string("^HTTP/[0-9.]* 200", page, NIL, NIL) = 0
THEN TRUE
ELSE IF INT start, end;
grep in string("^HTTP/[0-9.]* [0-9]+ [a-zA-Z ]*", page,
start, end) = 0
THEN print (page[start : end])
ELSE ... | Give a code snippet in #ALGOL_68
Rosetta Code/Rank languages by popularity
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Sort the most popular computer programming languages based in number of members in Rosetta Code categories.
Sample output on 01 ju... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conjugate_transpose | Conjugate transpose | Suppose that a matrix
M
{\displaystyle M}
contains complex numbers. Then the conjugate transpose of
M
{\displaystyle M}
is a matrix
M
H
{\displaystyle M^{H}}
containing the complex conjugates of the matrix transposition of
M
{\displaystyle M}
.
(
M
H
)
j
i
=
M
i
j
... | #C | C | /* Uses C99 specified complex.h, complex datatype has to be defined and operation provided if used on non-C99 compilers */
#include<stdlib.h>
#include<stdio.h>
#include<complex.h>
typedef struct
{
int rows, cols;
complex **z;
} matrix;
matrix
transpose (matrix a)
{
int i, j;
matrix b;
b.rows = a.cols;... | Give a code snippet in #C
Suppose that a matrix
M
{\displaystyle M}
contains complex numbers. Then the conjugate transpose of
M
{\displaystyle M}
is a matrix
M
H
{\displaystyle M^{H}}
containing the complex conjugates of the matrix transposition of
M
{\displaystyle M}
.
(
M
H... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Interactive_programming_(repl) | Interactive programming (repl) | Many language implementations come with an interactive mode.
This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a command mode, a read-eval-print loop (REPL), or a shell.
Task
Show how to start this... | #M2000_Interpreter | M2000 Interpreter | >edit f$()
| Give a code snippet in #M2000_Interpreter
Many language implementations come with an interactive mode.
This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a command mode, a read-eval-print loop (REPL), ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tokenize_a_string | Tokenize a string | Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks related to string operations:
Me... | #Cowgol | Cowgol | include "cowgol.coh";
include "strings.coh";
# Tokenize a string. Note: the string is modified in place.
sub tokenize(sep: uint8, str: [uint8], out: [[uint8]]): (length: intptr) is
length := 0;
loop
[out] := str;
out := @next out;
length := length + 1;
while [str] != 0 and [str... | Give a code snippet in #Cowgol
Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutation_test | Permutation test | Permutation test
You are encouraged to solve this task according to the task description, using any language you may know.
A new medical treatment was tested on a population of
n
+
m
{\displaystyle n+m}
volunteers, with each volunteer randomly assigned either to a group of
n
{\displaystyle n}
treatment... | #M2000_Interpreter | M2000 Interpreter |
Module Checkit {
Global data(), treat=0
data()=(85, 88, 75, 66, 25, 29, 83, 39, 97,68, 41, 10, 49, 16, 65, 32, 92, 28, 98)
Function pick(at, remain, accu) {
If remain Else =If(accu>treat->1,0):Exit
=pick(at-1,remain-1,accu+data(at-1))+If(at>remain->pick(at-1, remain, accu),0)... | Give a code snippet in #M2000_Interpreter
Permutation test
You are encouraged to solve this task according to the task description, using any language you may know.
A new medical treatment was tested on a population of
n
+
m
{\displaystyle n+m}
volunteers, with each volunteer randomly assigned either to a gro... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cheryl%27s_birthday | Cheryl's birthday | Albert and Bernard just became friends with Cheryl, and they want to know when her birthday is.
Cheryl gave them a list of ten possible dates:
May 15, May 16, May 19
June 17, June 18
July 14, July 16
August 14, August 15, August 17
Cheryl then tells Albert the month of birth, ... | #Racket | Racket | #lang racket
(define ((is x #:key [key identity]) y) (equal? (key x) (key y)))
(define albert first)
(define bernard second)
(define (((unique who) chs) date) (= 1 (count (is date #:key who) chs)))
(define (((unique-fix who-fix who) chs) date)
(ormap (conjoin (is date #:key who-fix) ((unique who) chs)) chs))
... | Give a code snippet in #Racket
Albert and Bernard just became friends with Cheryl, and they want to know when her birthday is.
Cheryl gave them a list of ten possible dates:
May 15, May 16, May 19
June 17, June 18
July 14, July 16
August 14, August 15, August 17
Cheryl then tells... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #Wart | Wart | def (rot13 s)
(as string
(map rot13
(as list s)))
Alphabet <- "abcdefghijklmnopqrstuvwxyz"
def (rot13 c) :case (and string?.c len.c=1)
if ("a" <= c <= "z")
let idx (pos c Alphabet)
Alphabet (idx+13 % 26)
("A" <= c <= "Z")
(downcase.c -> rot13 -> upcase)
:else
... | Give a code snippet in #Wart
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Command-line_arguments | Command-line arguments | Command-line arguments is part of Short Circuit's Console Program Basics selection.
Scripted main
See also Program name.
For parsing command line arguments intelligently, see Parsing command-line arguments.
Example command line:
myprogram -c "alpha beta" -h "gamma"
| #Elena | Elena | import system'routines;
import extensions;
public program()
{
program_arguments.forEvery:(int i)
{ console.printLine("Argument ",i," is ",program_arguments[i]) }
} | Give a code snippet in #Elena
Command-line arguments is part of Short Circuit's Console Program Basics selection.
Scripted main
See also Program name.
For parsing command line arguments intelligently, see Parsing command-line arguments.
Example command line:
myprogram -c "alpha beta" -h "gamma"
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Van_Eck_sequence | Van Eck sequence | The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured previously.
Example
Using ... | #Wren | Wren | var max = 1000
var a = List.filled(max, 0)
var seen = {}
for (n in 0...max-1) {
var m = seen[a[n]]
if (m != null) a[n+1] = n - m
seen[a[n]] = n
}
System.print("The first ten terms of the Van Eck sequence are:")
System.print(a[0...10])
System.print("\nTerms 991 to 1000 of the sequence are:")
System.print(a[9... | Give a code snippet in #Wren
The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/XML/DOM_serialization | XML/DOM serialization | Create a simple DOM and having it serialize to:
<?xml version="1.0" ?>
<root>
<element>
Some text here
</element>
</root>
| #Bracmat | Bracmat | ( ("?"."xml version=\"1.0\" ")
\n
(root.,"\n " (element.,"
Some text here
") \n)
: ?xml
& out$(toML$!xml)
); | Give a code snippet in #Bracmat
Create a simple DOM and having it serialize to:
<?xml version="1.0" ?>
<root>
<element>
Some text here
</element>
</root>
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For_with_a_specified_step | Loops/For with a specified step |
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop b... | #Tcl | Tcl | for {set i 2} {$i <= 8} {incr i 2} {
puts -nonewline "$i, "
}
puts "enough with the cheering already!" | Give a code snippet in #Tcl
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Incre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Numbers_with_equal_rises_and_falls | Numbers with equal rises and falls | When a number is written in base 10, adjacent digits may "rise" or "fall" as the number is read (usually from left to right).
Definition
Given the decimal digits of the number are written as a series d:
A rise is an index i such that d(i) < d(i+1)
A fall is an index i such that ... | #jq | jq | def risesEqualsFalls:
. as $n
| if . < 10 then true
else {rises: 0, falls: 0, prev: -1, n: $n}
| until (.n <= 0;
(.n % 10 ) as $d
| if .prev >= 0
then if $d < .prev then .rises += 1
elif $d > .prev then .falls += 1
else .
end
else .
end
... | Give a code snippet in #jq
When a number is written in base 10, adjacent digits may "rise" or "fall" as the number is read (usually from left to right).
Definition
Given the decimal digits of the number are written as a series d:
A rise is an index i such that d(i) < d(i+1)
A fall is... | christopher/rosetta-code | |
http://rosettacode.org/wiki/I_before_E_except_after_C | I before E except after C | The phrase "I before E, except after C" is a
widely known mnemonic which is supposed to help when spelling English words.
Task
Using the word list from http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
check if the two sub-clauses of the phrase are plausible individually:
"I before E when not pre... | #R | R | words = tolower(readLines("http://wiki.puzzlers.org/pub/wordlists/unixdict.txt"))
ie.npc = sum(grepl("(?<!c)ie", words, perl = T))
ei.npc = sum(grepl("(?<!c)ei", words, perl = T))
ie.pc = sum(grepl("cie", words, fixed = T))
ei.pc = sum(grepl("cei", words, fixed = T))
p1 = ie.npc > 2 * ei.npc
p2 = ei.pc > 2 * ie.pc
... | Give a code snippet in #R
The phrase "I before E, except after C" is a
widely known mnemonic which is supposed to help when spelling English words.
Task
Using the word list from http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
check if the two sub-clauses of the phrase are plausible individually:
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conway%27s_Game_of_Life | Conway's Game of Life | The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, in an m-by-m (or m×m) sq... | #Racket | Racket |
#lang racket
(require 2htdp/image 2htdp/universe)
;;;
;;; Grid object
;;;
(define (make-empty-grid m n)
(build-vector m (lambda (y) (make-vector n 0))))
(define rows vector-length)
(define (cols grid)
(vector-length (vector-ref grid 0)))
(define (make-grid m n living-cells)
(let loop ([grid (make-empt... | Give a code snippet in #Racket
The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Verhoeff_algorithm | Verhoeff algorithm | Description
The Verhoeff algorithm is a checksum formula for error detection developed by the Dutch mathematician Jacobus Verhoeff and first published in 1969. It was the first decimal check digit algorithm which detects all single-digit errors, and all transposition errors involving two adjacent digits, which was at t... | #J | J | cyc=: | +/~@i. NB. cyclic group, order y
ac=: |(+-/~@i.) NB. anticyclic group, order y
a2n=: (+#)@ NB. add 2^n
di=: (cyc,.cyc a2n),((ac a2n),.ac)
D=: di 5
INV=: ,I.0=D
P=: {&(C.1 5 8 9 4 2 7 0;3 6)^:(i.8) i.10
verhoeff=: {{
c=. 0
for_N. |.10 #.inv y do.
c=. D{~<c,P{~<(8|N_index),N
end.
}}
trace... | Give a code snippet in #J
Description
The Verhoeff algorithm is a checksum formula for error detection developed by the Dutch mathematician Jacobus Verhoeff and first published in 1969. It was the first decimal check digit algorithm which detects all single-digit errors, and all transposition errors involving two adja... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Graphical | Hello world/Graphical |
Task
Display the string Goodbye, World! on a GUI object (alert box, plain window, text area, etc.).
Related task
Hello world/Text
| #Panoramic | Panoramic | print "Goodbye, World!"
'Prints in the upper left corner of the window.
| Give a code snippet in #Panoramic
Task
Display the string Goodbye, World! on a GUI object (alert box, plain window, text area, etc.).
Related task
Hello world/Text
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric | Determine if a string is numeric | Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
Array length
String length
Cop... | #ALGOL_W | ALGOL W | begin
% determnines whether the string contains an integer, real or imaginary %
% number. Returns true if it does, false otherwise %
logical procedure isNumeric( string(32) value text ) ;
begin
logical ok;
% the "number" cannot be blank ... | Give a code snippet in #ALGOL_W
Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/The_Name_Game | The Name Game | Write a program that accepts a name as input and outputs the lyrics to the Shirley Ellis song "The Name Game".
The regular verse
Unless your name begins with a vowel (A, E, I, O, U), 'B', 'F' or 'M' you don't have to care about special rules.
The verse for the name 'Gary' would be like this:
Gary, Gary, bo-bary... | #J | J |
T=:TEMPLATE=: noun define
(X), (X), bo-b(Y)
Banana-fana fo-f(Y)
Fee-fi-mo-m(Y)
(X)!
)
nameGame=: monad define
X=. y
Y=. tolower }.^:('aeiouAEIOU' -.@:e.~ {.) y
heady=. tolower {. y
t=. TEMPLATE -. '()'
'ix iy'=. I. 'XY' =/ t
tbox=. ;/ t
match=. heady = (<: iy){::"0 _ tbox
remove =. match # iy
s... | Give a code snippet in #J
Write a program that accepts a name as input and outputs the lyrics to the Shirley Ellis song "The Name Game".
The regular verse
Unless your name begins with a vowel (A, E, I, O, U), 'B', 'F' or 'M' you don't have to care about special rules.
The verse for the name 'Gary' would be like th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exponentiation_operator | Exponentiation operator | Most programming languages have a built-in implementation of exponentiation.
Task
Re-implement integer exponentiation for both intint and floatint as both a procedure, and an operator (if your language supports operator definition).
If the language supports operator (or procedure) overloading, then an ov... | #EchoLisp | EchoLisp |
;; this exponentiation function handles integer, rational or float x.
;; n is a positive or negative integer.
(define (** x n) (cond
((zero? n) 1)
((< n 0) (/ (** x (- n)))) ;; x**-n = 1 / x**n
((= n 1) x)
((= n 0) 1)
((odd? n) (* x (** x (1- n)))) ;; x**(2p+1) = x * x**2p
(else (let ((m... | Give a code snippet in #EchoLisp
Most programming languages have a built-in implementation of exponentiation.
Task
Re-implement integer exponentiation for both intint and floatint as both a procedure, and an operator (if your language supports operator definition).
If the language supports operator (or ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Least_common_multiple | Least common multiple | Least common multiple
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Compute the least common multiple (LCM) of two integers.
Given m and n, the least common multiple is the smallest positive integer that has both m and n as factor... | #BASIC256 | BASIC256 | function mcm (m, n)
if m = 0 or n = 0 then return 0
if m < n then
t = m : m = n : n = t
end if
cont = 0
do
cont += 1
until (m * cont) mod n = 0
return m * cont
end function
print "lcm( 12, 18) = "; mcm( 12, -18)
print "lcm( 15, 12) = "; mcm( 15, 12)
print "lcm(-10, -14) = "; mcm(-10, -14)
print "lcm( ... | Give a code snippet in #BASIC256
Least common multiple
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Compute the least common multiple (LCM) of two integers.
Given m and n, the least common multiple is the smallest positive integer that ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Elliptic_curve_arithmetic | Elliptic curve arithmetic | Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In a nutshell, an elliptic curve is a... | #PicoLisp | PicoLisp | (scl 16)
(load "@lib/math.l")
(setq *B 7)
(de from_y (Y)
(let
(A (* 1.0 (- (* Y Y) *B))
B (pow (abs A) (*/ 1.0 1.0 3.0)) )
(list
(if (gt0 A) B (- B))
(* Y 1.0) ) ) )
(de prn (P)
(if (is_zero P)
"Zero"
(pack
(round (car P) 3)
" "
(round ... | Give a code snippet in #PicoLisp
Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Babbage_problem | Babbage problem |
Charles Babbage, looking ahead to the sorts of problems his Analytical Engine would be able to solve, gave this example:
What is the smallest positive integer whose square ends in the digits 269,696?
— Babbage, letter to Lord Bowden, 1837; see Hollingdale and Tootill, Electronic Computers, second edition, 1970, p.... | #Ada | Ada | -- The program is written in the programming language Ada. The name "Ada"
-- has been chosen in honour of your friend,
-- Augusta Ada King-Noel, Countess of Lovelace (née Byron).
--
-- This is an program to search for the smallest integer X, such that
-- (X*X) mod 1_000_000 = 269_696.
--
-- In the Ada language,... | Give a code snippet in #Ada
Charles Babbage, looking ahead to the sorts of problems his Analytical Engine would be able to solve, gave this example:
What is the smallest positive integer whose square ends in the digits 269,696?
— Babbage, letter to Lord Bowden, 1837; see Hollingdale and Tootill, Electronic Comput... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Idiomatically_determine_all_the_characters_that_can_be_used_for_symbols | Idiomatically determine all the characters that can be used for symbols | Idiomatically determine all the characters that can be used for symbols.
The word symbols is meant things like names of variables, procedures (i.e., named fragments of programs, functions, subroutines, routines), statement labels, events or conditions, and in general, anything a computer programmer can choose to name, ... | #XPL0 | XPL0 | char C, C1;
[Text(0, "First character set: ");
for C:= 0 to 255 do
if C>=^A then if C<=^Z ! C=^_ then
ChOut(0, C);
CrLf(0);
Text(0, "Next characters set: ");
for C:= 0 to 255 do
[if C>=^a & C<=^z then C1:= C & $DF \to uppercase
else C1:= C;
case of
... | Give a code snippet in #XPL0
Idiomatically determine all the characters that can be used for symbols.
The word symbols is meant things like names of variables, procedures (i.e., named fragments of programs, functions, subroutines, routines), statement labels, events or conditions, and in general, anything a computer p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Increment_loop_index_within_loop_body | Loops/Increment loop index within loop body | Sometimes, one may need (or want) a loop which
its iterator (the index
variable) is modified within the
loop body in addition to the normal incrementation by the (do) loop structure index.
Goal
Demonstrate the best way to accomplish this.
Task
Write a loop which:
starts the index (variable... | #Ring | Ring |
# Project : Loops/Increment loop index within loop body
load "stdlib.ring"
i = 42
n = 0
while n < 42
if isprime(i)
n = n + 1
see "n = " + n + " " + i + nl
i = i + i - 1
ok
i = i + 1
end
| Give a code snippet in #Ring
Sometimes, one may need (or want) a loop which
its iterator (the index
variable) is modified within the
loop body in addition to the normal incrementation by the (do) loop structure index.
Goal
Demonstrate the best way to accomplish this.
Task
Write a loop which:
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_size | File size | Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| #PowerShell | PowerShell | Get-ChildItem input.txt | Select-Object Name,Length
Get-ChildItem \input.txt | Select-Object Name,Length | Give a code snippet in #PowerShell
Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Tau_number | Tau number | A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau function
| #Action.21 | Action! | CARD FUNC DivisorCount(CARD n)
CARD result,p,count
result=1
WHILE (n&1)=0
DO
result==+1
n=n RSH 1
OD
p=3
WHILE p*p<=n
DO
count=1
WHILE n MOD p=0
DO
count==+1
n==/p
OD
result==*count
p==+2
OD
IF n>1 THEN
result==*2
FI
RETURN (result)
PROC Main... | Give a code snippet in #Action.21
A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau func... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tau_number | Tau number | A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau function
| #Modula-2 | Modula-2 | MODULE TauNumbers;
FROM InOut IMPORT WriteCard, WriteLn;
CONST
MaxNum = 1100; (* enough to generate 100 Tau numbers *)
NumTau = 100; (* how many Tau numbers to generate *)
VAR DivCount: ARRAY [1..MaxNum] OF CARDINAL;
seen, n: CARDINAL;
(* Find the amount of divisors for each number beforehand *)
PRO... | Give a code snippet in #Modula-2
A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau funct... | christopher/rosetta-code | |
http://rosettacode.org/wiki/21_game | 21 game | 21 game
You are encouraged to solve this task according to the task description, using any language you may know.
21 is a two player game, the game is played by choosing
a number (1, 2, or 3) to be added to the running total.
The game is won by the player whose chosen number causes the running total
to reach exactly ... | #Scala | Scala |
object Game21 {
import scala.collection.mutable.ListBuffer
import scala.util.Random
val N = 21 // the same game would also work for N other than 21...
val RND = new Random() // singular random number generator; add a seed number, if you want reproducibility
/** tuple: name and a play function: (rest... | Give a code snippet in #Scala
21 game
You are encouraged to solve this task according to the task description, using any language you may know.
21 is a two player game, the game is played by choosing
a number (1, 2, or 3) to be added to the running total.
The game is won by the player whose chosen number causes the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n)... | #D | D | void main() /*@safe*/ {
import std.stdio, std.algorithm, std.range;
static immutable properDivs = (in uint n) pure nothrow @safe /*@nogc*/ =>
iota(1, (n + 1) / 2 + 1).filter!(x => n % x == 0 && n != x);
enum Class { deficient, perfect, abundant }
static Class classify(in uint n) pure nothr... | Give a code snippet in #D
These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (O... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Image_noise | Image noise | Generate a random black and white 320x240 image continuously,
showing FPS (frames per second).
A sample image
| #JavaScript | JavaScript | <body>
<canvas id='c'></canvas>
<script>
var canvas = document.getElementById('c');
var ctx = canvas.getContext('2d');
var w = canvas.width = 320;
var h = canvas.height = 240;
var t1 = new Date().getTime();
var frame_count = 0;
ctx.font = 'normal 400 24px/2 Unknown Font, sans-serif';
var img = ctx.createImageData(w... | Give a code snippet in #JavaScript
Generate a random black and white 320x240 image continuously,
showing FPS (frames per second).
A sample image
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Monads/List_monad | Monads/List monad | A Monad is a combination of a data-type with two helper functions written for that type.
The data-type can be of any kind which can contain values of some other type – common examples are lists, records, sum-types, even functions or IO streams. The two special functions, mathematically known as eta and mu, but usually... | #Nim | Nim | import math,sequtils,sugar,strformat
func root(x:float):seq[float] = @[sqrt(x),-sqrt(x)]
func asin(x:float):seq[float] = @[arcsin(x),arcsin(x)+TAU,arcsin(x)-TAU]
func format(x:float):seq[string] = @[&"{x:.2f}"]
#'bind' is a nim keyword, how about an infix operator instead
#our bind is the standard map+cat
func `-->`[... | Give a code snippet in #Nim
A Monad is a combination of a data-type with two helper functions written for that type.
The data-type can be of any kind which can contain values of some other type – common examples are lists, records, sum-types, even functions or IO streams. The two special functions, mathematically kno... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Heapsort | Sorting algorithms/Heapsort |
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
... | #EchoLisp | EchoLisp |
(lib 'heap)
(define (heap-sort list)
(define heap (make-heap < )) ;; make a min heap
(list->heap list heap)
(while (not (heap-empty? heap))
(push 'stack (heap-pop heap)))
(stack->list 'stack))
(define L (shuffle (iota 15)))
→ (9 4 0 12 8 3 10 7 11 2 5 6 14 13 1)
(heap-sort L)
→ ... | Give a code snippet in #EchoLisp
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Test_a_function | Test a function |
Task
Using a well-known testing-specific library/module/suite for your language, write some tests for your language's entry in Palindrome.
If your language does not have a testing specific library well known to the language's community then state this or omit the language.
| #Arturo | Arturo | palindrome?: function [s][
s = reverse s
]
tests: [
[true? palindrome? "aba"]
[false? palindrome? "ab" ]
]
loop tests => ensure | Give a code snippet in #Arturo
Task
Using a well-known testing-specific library/module/suite for your language, write some tests for your language's entry in Palindrome.
If your language does not have a testing specific library well known to the language's community then state this or omit the language.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Keyboard_macros | Keyboard macros | Show how to link user defined methods to user defined keys.
An example of this is the facility provided by emacs for key bindings.
These key bindings may be application-specific or system-wide; state which you have done.
| #AutoHotkey | AutoHotkey | Loop, 200 ; loop 200 times while not paused
{
TrayTip, counting, %A_Index% press alt-p to pause
Sleep, 1000
}
!p:: ; links alt-p key combination to the method pauseme() (system wide)
pauseMe()
Return
!r:: ; links alt-r key combination to the method resume() (system wide)
resume()
Return
pauseMe()
{
... | Give a code snippet in #AutoHotkey
Show how to link user defined methods to user defined keys.
An example of this is the facility provided by emacs for key bindings.
These key bindings may be application-specific or system-wide; state which you have done.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/String_length | String length | Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters.
F... | #Vala | Vala |
string s = "Hello, world!";
int characterLength = s.length;
| Give a code snippet in #Vala
Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme conta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #SPL | SPL | #.clear() | Give a code snippet in #SPL
Task
Clear the terminal window.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Equilibrium_index | Equilibrium index | An equilibrium index of a sequence is an index into the sequence such that the sum of elements at lower indices is equal to the sum of elements at higher indices.
For example, in a sequence
A
{\displaystyle A}
:
A
0
=
−
7
{\displaystyle A_{0}=-7}
A
1
=
1
{\displaystyle A_{1}=1}
... | #K | K | f:{&{(+/y# x)=+/(y+1)_x}[x]'!#x}
f -7 1 5 2 -4 3 0
3 6
f 2 4 6
!0
f 2 9 2
,1
f 1 -1 1 -1 1 -1 1
0 1 2 3 4 5 6 | Give a code snippet in #K
An equilibrium index of a sequence is an index into the sequence such that the sum of elements at lower indices is equal to the sum of elements at higher indices.
For example, in a sequence
A
{\displaystyle A}
:
A
0
=
−
7
{\displaystyle A_{0}=-7}
A
1
=
1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Phrase_reversals | Phrase reversals | Task
Given a string of space separated words containing the following phrase:
rosetta code phrase reversal
Reverse the characters of the string.
Reverse the characters of each individual word in the string, maintaining original word order within the string.
Reverse the order of each word of the string, maintaini... | #Perl | Perl | use feature 'say';
my $s = "rosetta code phrase reversal";
say "0. Input : ", $s;
say "1. String reversed : ", scalar reverse $s;
say "2. Each word reversed : ", join " ", reverse split / /, reverse $s;
say "3. Word-order reversed : ", join " ", reverse split / /,$s;
# Or, using a regex:
say "2. ... | Give a code snippet in #Perl
Task
Given a string of space separated words containing the following phrase:
rosetta code phrase reversal
Reverse the characters of the string.
Reverse the characters of each individual word in the string, maintaining original word order within the string.
Reverse the order of each... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Display_an_extended_character | Terminal control/Display an extended character | Task
Display an extended (non ASCII) character onto the terminal.
Specifically, display a £ (GBP currency sign).
| #zkl | zkl | "\u00a3 \Ua3;".println() //-->£ £ | Give a code snippet in #zkl
Task
Display an extended (non ASCII) character onto the terminal.
Specifically, display a £ (GBP currency sign).
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Circles_of_given_radius_through_two_points | Circles of given radius through two points |
Given two points on a plane and a radius, usually two circles of given radius can be drawn through the points.
Exceptions
r==0.0 should be treated as never describing circles (except in the case where the points are coincident).
If the points are coincident then an infinite number of circles with the point on thei... | #Stata | Stata | real matrix centers(real colvector a, real colvector b, real scalar r) {
real matrix rot
real scalar d, u, v
d = norm(b-a)
if (r == 0 | d == 0) {
if (r == 0 & d == 0) {
return((a,a))
} else {
return(J(2, 2, .))
}
} else if (d <= 2*r) {
u = d/(2*r)
v = sqrt(1-u^2)
rot = u,-v\v,u
return((rot*(b-a... | Give a code snippet in #Stata
Given two points on a plane and a radius, usually two circles of given radius can be drawn through the points.
Exceptions
r==0.0 should be treated as never describing circles (except in the case where the points are coincident).
If the points are coincident then an infinite number of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Largest_int_from_concatenated_ints | Largest int from concatenated ints | Task
Given a set of positive integers, write a function to order the integers in such a way that the concatenation of the numbers forms the largest possible integer and return this integer.
Use the following two sets of integers as tests and show your program output here.
{1, 34, 3, 98, 9, 76, 45, 4}
{54,... | #Scala | Scala | object LIFCI extends App {
def lifci(list: List[Long]) = list.permutations.map(_.mkString).max
println(lifci(List(1, 34, 3, 98, 9, 76, 45, 4)))
println(lifci(List(54, 546, 548, 60)))
} | Give a code snippet in #Scala
Task
Given a set of positive integers, write a function to order the integers in such a way that the concatenation of the numbers forms the largest possible integer and return this integer.
Use the following two sets of integers as tests and show your program output here.
{1, 3... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Forward_difference | Forward difference | Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer elem... | #Ring | Ring |
# Project : Forward difference
s = [90, 47, 58, 29, 22, 32, 55, 5, 55, 73]
for p = 1 to 9
s = fwddiff(s)
showarray(s)
next
func fwddiff(s)
for j=1 to len(s)-1
s[j] = s[j+1]-s[j]
next
n = len(s)
del(s, n)
return s
func showarray(vect)
see... | Give a code snippet in #Ring
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Unicode_strings | Unicode strings | As the world gets smaller each day, internationalization becomes more and more important. For handling multiple languages, Unicode is your best friend.
It is a very capable tool, but also quite complex compared to older single- and double-byte character encodings.
How well prepared is your programming language for ... | #ALGOL_68 | ALGOL 68 | #!/usr/local/bin/a68g --script #
# -*- coding: utf-8 -*- #
# UNICHAR/UNICODE must be printed using REPR to convert to UTF8 #
MODE UNICHAR = STRUCT(BITS #31# bits); # assuming bits width >=31 #
MODE UNICODE = FLEX[0]UNICHAR;
OP INITUNICHAR = (BITS bits)UNICHAR: (UNICHAR out; bits OF out := #ABS# bits; out);
OP INI... | Give a code snippet in #ALGOL_68
As the world gets smaller each day, internationalization becomes more and more important. For handling multiple languages, Unicode is your best friend.
It is a very capable tool, but also quite complex compared to older single- and double-byte character encodings.
How well prepared... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Square_but_not_cube | Square but not cube | Task
Show the first 30 positive integers which are squares but not cubes of such integers.
Optionally, show also the first 3 positive integers which are both squares and cubes, and mark them as such.
| #Swift | Swift | var s = 1, c = 1, cube = 1, n = 0
while n < 30 {
let square = s * s
while cube < square {
c += 1
cube = c * c * c
}
if cube == square {
print("\(square) is a square and a cube.")
} else {
print(square)
n += 1
}
s += 1
} | Give a code snippet in #Swift
Task
Show the first 30 positive integers which are squares but not cubes of such integers.
Optionally, show also the first 3 positive integers which are both squares and cubes, and mark them as such.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_totient_numbers | Perfect totient numbers | Generate and show here, the first twenty Perfect totient numbers.
Related task
Totient function
Also see
the OEIS entry for perfect totient numbers.
mrob list of the first 54
| #Phix | Phix | with javascript_semantics
function totient(integer n)
integer tot = n, i = 2
while i*i<=n do
if mod(n,i)=0 then
while true do
n /= i
if mod(n,i)!=0 then exit end if
end while
tot -= tot/i
end if
i += iff(i=2?1:2)
end... | Give a code snippet in #Phix
Generate and show here, the first twenty Perfect totient numbers.
Related task
Totient function
Also see
the OEIS entry for perfect totient numbers.
mrob list of the first 54
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Superpermutation_minimisation | Superpermutation minimisation | A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to use the first two characters 'AB'... | #J | J | approxmin=:3 :0
seqs=. y{~(A.&i.~ !)#y
r=.{.seqs
seqs=.}.seqs
while.#seqs do.
for_n. i.-#y do.
tail=. (-n){. r
b=. tail -:"1 n{."1 seqs
if. 1 e.b do.
j=. b i.1
r=. r, n}.j{seqs
seqs=. (<<<j) { seqs
break.
end.
end.
end.
r
) | Give a code snippet in #J
A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to use th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_comparison | Integer comparison |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #RPG | RPG |
h dftactgrp(*no)
d pi
d integer1 10i 0
d integer2 10i 0
d message s 50a
if integer1 < integer2;
message = 'Integer 1 is less than integer 2';
endif;
if integer1 > integer2;
... | Give a code snippet in #RPG
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Co... | christopher/rosetta-code | |
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 ... | #NASM | NASM | %define a "%define "
%define b "db "
%define c "%deftok "
%define d "a, 97, 32, 34, a, 34, 10, a, 98, 32, 34, b, 34, 10, a, 99, 32, 34, c, 34, 10, a, 100, 32, 34, d, 34, 10, c, 101, 32, 100, 10, b, 101, 10"
%deftok e d
db e | Give a code snippet in #NASM
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
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Text_processing/Max_licenses_in_use | Text processing/Max licenses in use | A company currently pays a fixed sum for the use of a particular licensed software package. In determining if it has a good deal it decides to calculate its maximum use of the software from its license management log file.
Assume the software's licensing daemon faithfully records a checkout event when a copy of the ... | #HicEst | HicEst | CHARACTER Licenses="Licenses.txt"
REAL :: counts(1), Top10(10)
OPEN(FIle=Licenses, fmt='8x,A3,3x,A19,Nb ,', LENgth=lines)
ALLOCATE(counts, lines)
counts(1) = 1
DO line = 2, lines
counts(line) = counts(line-1) + 1 - 2*(Licenses(line,1)=='IN')
ENDDO
SORT(Vector=counts, Descending=1, Index=Top10)
DO i = 1, LEN(... | Give a code snippet in #HicEst
A company currently pays a fixed sum for the use of a particular licensed software package. In determining if it has a good deal it decides to calculate its maximum use of the software from its license management log file.
Assume the software's licensing daemon faithfully records a ch... | christopher/rosetta-code | |
http://rosettacode.org/wiki/First-class_functions | First-class functions | A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other functions
Use functions as retu... | #E | E | def sin(x) { return x.sin() }
def cos(x) { return x.cos() }
def asin(x) { return x.asin() }
def acos(x) { return x.acos() }
def cube(x) { return x ** 3 }
def curt(x) { return x ** (1/3) }
def forward := [sin, cos, cube]
def reverse := [asin, acos, curt] | Give a code snippet in #E
A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other funct... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Word_frequency | Word frequency | Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define what a letter is.
Undersc... | #REXX | REXX | /*REXX pgm displays top 10 words in a file (includes foreign letters), case is ignored.*/
parse arg fID top . /*obtain optional arguments from the CL*/
if fID=='' | fID=="," then fID= 'les_mes.txt' /*None specified? Then use the default.*/
if top=='' | top=="," then top= 10 ... | Give a code snippet in #REXX
Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define wha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hostname | Hostname | Task
Find the name of the host on which the routine is running.
| #Liberty_BASIC | Liberty BASIC | lpBuffer$=Space$(128) + Chr$(0)
struct SIZE,sz As Long
SIZE.sz.struct=Len(lpBuffer$)
calldll #kernel32, "GetComputerNameA",lpBuffer$ as ptr, SIZE as struct, result as Long
CurrentComputerName$=Trim$(Left$(lpBuffer$, SIZE.sz.struct))
print CurrentComputerName$ | Give a code snippet in #Liberty_BASIC
Task
Find the name of the host on which the routine is running.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Real_constants_and_functions | Real constants and functions | Task
Show how to use the following math constants and functions in your language (if not available, note it):
e (base of the natural logarithm)
π
{\displaystyle \pi }
square root
logarithm (any base allowed)
exponential (ex )
absolute value (a.k.a. "magnitude")
floor (largest ... | #Scala | Scala | object RealConstantsFunctions extends App{
println(math.E) // e
println(math.Pi) // pi
println(math.sqrt(2.0)) // square root
println(math.log(math.E)) // log to base e
println(math.log10(10.0)) // log to base 10
println(math.exp(1.0)) // exponential
p... | Give a code snippet in #Scala
Task
Show how to use the following math constants and functions in your language (if not available, note it):
e (base of the natural logarithm)
π
{\displaystyle \pi }
square root
logarithm (any base allowed)
exponential (ex )
absolute value (a.k.a. "m... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Polyspiral | Polyspiral | A Polyspiral is a spiral made of multiple line segments, whereby each segment is larger (or smaller) than the previous one by a given amount. Each segment also changes direction at a given angle.
Task
Animate a series of polyspirals, by drawing a complete spiral then incrementing the angle, and (after clearing the b... | #Ceylon | Ceylon | import javafx.application {
Application
}
import javafx.stage {
Stage
}
import javafx.animation {
AnimationTimer
}
import ceylon.numeric.float {
remainder,
cos,
sin,
toRadians
}
import javafx.scene.layout {
BorderPane
}
import javafx.scene.canvas {
Canvas
}
import javafx.scene {
... | Give a code snippet in #Ceylon
A Polyspiral is a spiral made of multiple line segments, whereby each segment is larger (or smaller) than the previous one by a given amount. Each segment also changes direction at a given angle.
Task
Animate a series of polyspirals, by drawing a complete spiral then incrementing the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations | Combinations | Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
0 3 4
1 2 3
1 2 4
1 3 4
2 3 4
... | #ERRE | ERRE |
PROGRAM COMBINATIONS
CONST M_MAX=3,N_MAX=5
DIM COMBINATION[M_MAX],STACK[100,1]
PROCEDURE GENERATE(M)
LOCAL I
IF (M>M_MAX) THEN
FOR I=1 TO M_MAX DO
PRINT(COMBINATION[I];" ";)
END FOR
PRINT
ELSE
FOR N=1 TO N_MAX DO
IF ((M=1) OR (N>COMBINATION[M-1])) THEN
COMBINATION[M]=... | Give a code snippet in #ERRE
Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_squares | Sum of squares | Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| #TUSCRIPT | TUSCRIPT |
$$ MODE TUSCRIPT
array="3'1'4'1'5'9",sum=0
LOOP a=array
sum=sum+(a*a)
ENDLOOP
PRINT sum
| Give a code snippet in #TUSCRIPT
Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Color_quantization | Color quantization | full color
Example: Gimp 16 color
Color quantization is the process of reducing number of colors used in an image while trying to maintain the visual appearance of the original image. In general, it is a form of cluster analysis, if each RGB color value is considered as a coordinate triple in the 3D colorspace. There... | #Julia | Julia |
const execstring =`convert Quantum_frog.png -dither None -colors 16 Quantum_frog_new.png`
run(execstring)
| Give a code snippet in #Julia
full color
Example: Gimp 16 color
Color quantization is the process of reducing number of colors used in an image while trying to maintain the visual appearance of the original image. In general, it is a form of cluster analysis, if each RGB color value is considered as a coordinate tri... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_HQ9%2B | Execute HQ9+ | Task
Implement a HQ9+ interpreter or compiler.
| #J | J | bob =: ": , ' bottle' , (1 = ]) }. 's of beer'"_
bobw=: bob , ' on the wall'"_
beer=: bobw , ', ' , bob , '; take one down and pass it around, ' , bobw@<: | Give a code snippet in #J
Task
Implement a HQ9+ interpreter or compiler.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Counting_sort | Sorting algorithms/Counting sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Perl | Perl | #! /usr/bin/perl
use strict;
sub counting_sort
{
my ($a, $min, $max) = @_;
my @cnt = (0) x ($max - $min + 1);
$cnt[$_ - $min]++ foreach @$a;
my $i = $min;
@$a = map {($i++) x $_} @cnt;
} | Give a code snippet in #Perl
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pick_random_element | Pick random element | Demonstrate how to pick a random element from a list.
| #ALGOL_68 | ALGOL 68 | # pick a random element from an array of strings #
OP PICKRANDOM = ( []STRING list )STRING:
BEGIN
INT number of elements = ( UPB list - LWB list ) + 1;
INT random element =
ENTIER ( next random * ( number of elements ) );
list[ LWB list + random element ]
END; # PICKRANDOM #
# can define a... | Give a code snippet in #ALGOL_68
Demonstrate how to pick a random element from a list.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sierpinski_carpet | Sierpinski carpet | Task
Produce a graphical or ASCII-art representation of a Sierpinski carpet of order N.
For example, the Sierpinski carpet of order 3 should look like this:
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # ## # # ## # # #
### ###### ... | #F.23 | F# | open System
let blank x = new String(' ', String.length x)
let nextCarpet carpet =
List.map (fun x -> x + x + x) carpet @
List.map (fun x -> x + (blank x) + x) carpet @
List.map (fun x -> x + x + x) carpet
let rec sierpinskiCarpet n =
let rec aux n carpet =
if n = 0 then carpet
else aux ... | Give a code snippet in #F.23
Task
Produce a graphical or ASCII-art representation of a Sierpinski carpet of order N.
For example, the Sierpinski carpet of order 3 should look like this:
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # ## ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_unity | Roots of unity | The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| #Arturo | Arturo | rect: function [r,phi][
to :complex @[ r * cos phi, r * sin phi ]
]
roots: function [n][
map 0..dec n 'k -> rect 1.0 2 * k * pi / n
]
loop 2..10 'nr ->
print [pad to :string nr 3 "=>" join.with:", " to [:string] .format:".3f" roots nr] | Give a code snippet in #Arturo
The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Mandelbrot_set | Mandelbrot set | Mandelbrot set
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw the Mandelbrot set.
Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
| #FOCAL | FOCAL | 1.1 S I1=-1.2; S I2=1.2; S R1=-2; S R2=.5
1.2 S MIT=30
1.3 F Y=1,24; D 2
1.4 Q
2.1 T !
2.2 F X=1,70; D 3
3.1 S R=X*(R2-R1)/70+R1
3.2 S I=Y*(I2-I1)/24+I1
3.3 S C1=R; S C2=I
3.4 F T=1,MIT; D 4
4.1 S C3=C1
4.2 S C1=C1*C1 - C2*C2
4.3 S C2=C3*C2 + C2*C3
4.4 S C1=C1+R
4.5 S C2=C2+I
4.6 I (-FABS(C1)+2)5.1
4.7 I (-FABS(C... | Give a code snippet in #FOCAL
Mandelbrot set
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw the Mandelbrot set.
Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Happy_numbers | Happy numbers | From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not inclu... | #Scheme | Scheme | (define (number->list num)
(do ((num num (quotient num 10))
(lst '() (cons (remainder num 10) lst)))
((zero? num) lst)))
(define (happy? num)
(let loop ((num num) (seen '()))
(cond ((= num 1) #t)
((memv num seen) #f)
(else (loop (apply + (map (lambda (x) (* x x)) (number->list n... | Give a code snippet in #Scheme
From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly... | christopher/rosetta-code | |
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.
| #Jsish | Jsish | /* Read by line, in Jsish */
var f = new Channel('read-by-line.jsi');
var line;
while (line = f.gets()) puts(line);
f.close(); | Give a code snippet in #Jsish
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.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Array_length | Array length | Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I befo... | #Haskell | Haskell | -- [[Char]] -> Int
length ["apple", "orange"] | Give a code snippet in #Haskell
Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter fre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Chaocipher | Chaocipher | Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
... | #Tailspin | Tailspin |
templates chaocipher&{left:,right:,decode:}
templates permute
def ctshift: [ $@chaocipher.ct($..last)..., $@chaocipher.ct(1..$-1)...];
def p1: $ mod 26 + 1;
def ptshift: [ $@chaocipher.pt($p1..last)..., $@chaocipher.pt(1..$p1-1)...];
..|@chaocipher: { ct: [ $ctshift(1), $ctshift(3..14)..., $ctshift(... | Give a code snippet in #Tailspin
Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Index_finite_lists_of_positive_integers | Index finite lists of positive integers | It is known that the set of finite lists of positive integers is countable.
This means that there exists a subset of natural integers which can be mapped to the set of finite lists of positive integers.
Task
Implement such a mapping:
write a function rank which assigns an integer to any finite, arbi... | #Tcl | Tcl | package require Tcl 8.6
proc rank {integers} {
join [lmap i $integers {format %llo $i}] 8
}
proc unrank {codedValue} {
lmap i [split $codedValue 8] {scan $i %llo}
} | Give a code snippet in #Tcl
It is known that the set of finite lists of positive integers is countable.
This means that there exists a subset of natural integers which can be mapped to the set of finite lists of positive integers.
Task
Implement such a mapping:
write a function rank which assigns a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
... | #gnuplot | gnuplot | A (m, n) = m == 0 ? n + 1 : n == 0 ? A (m - 1, 1) : A (m - 1, A (m, n - 1))
print A (0, 4)
print A (1, 4)
print A (2, 4)
print A (3, 4) | Give a code snippet in #gnuplot
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/A%2BB | A+B | A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separated by space(s):
(
−
1000
≤... | #Perl | Perl | my ($a,$b) = split(' ', scalar(<STDIN>));
print "$a $b " . ($a + $b) . "\n"; | Give a code snippet in #Perl
A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separated... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring/Top_and_tail | Substring/Top and tail | The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
If the program uses UTF-8 or UTF... | #XPL0 | XPL0 | include c:\cxpl\stdlib;
char S, P;
[S:= "Smiles";
Text(0, S+1); \first character removed
CrLf(0);
P:= S + StrLen(S) - 2; \point to last character in string
P(0):= P(0) ! $80; \set the MSb on the last character
Text(0, S); \last character removed
CrLf(0);
Text(0, S+1); \first and la... | Give a code snippet in #XPL0
The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
If... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable_size/Get | Variable size/Get | Demonstrate how to get the size of a variable.
See also: Host introspection
| #Common_Lisp | Common Lisp | (let ((a (cons 1 2))
(b (make-array 10))
(c "a string"))
(list (hcl:find-object-size a)
(hcl:find-object-size b)
(hcl:find-object-size c))) | Give a code snippet in #Common_Lisp
Demonstrate how to get the size of a variable.
See also: Host introspection
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Stack | Stack |
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.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is accessed through its top.
The ba... | #Pike | Pike |
object s = ADT.Stack();
s->push("a");
s->push("b");
write("top: %O, pop1: %O, pop2: %O\n",
s->top(), s->pop(), s->pop());
s->reset(); // Empty the stack
| Give a code snippet in #Pike
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.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is acc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Statistics/Basic | Statistics/Basic | Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldots ,n\,\!}
, the mean is
x
¯... | #Julia | Julia | using Printf
function hist(numbers)
maxwidth = 50
h = fill(0, 10)
for n in numbers
h[ceil(Int, 10n)] += 1
end
mx = maximum(h)
for (n, i) in enumerate(h)
@printf("%3.1f: %s\n", n / 10, "+" ^ floor(Int, i / mx * maxwidth))
end
end
for i in 1:6
n = rand(10 ^ i)
print... | Give a code snippet in #Julia
Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldots ,n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pick_random_element | Pick random element | Demonstrate how to pick a random element from a list.
| #Lasso | Lasso | local(
my array = array('one', 'two', 3)
)
#myarray -> get(integer_random(#myarray -> size, 1)) | Give a code snippet in #Lasso
Demonstrate how to pick a random element from a list.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Show_the_epoch | Show the epoch | Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind the scenes by the implementers), b... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols nobinary
import java.text.DateFormat
edate = Date(0)
zulu = DateFormat.getDateTimeInstance()
zulu.setTimeZone(TimeZone.getTimeZone('UTC'))
say zulu.format(edate)
return
| Give a code snippet in #NetRexx
Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_composition | Function composition | Task
Create a function, compose, whose two arguments f and g, are both functions with one argument.
The result of compose is to be a function of one argument, (lets call the argument x), which works like applying function f to the result of applying function g to x.
Example
compose... | #Objective-C | Objective-C | #include <Foundation/Foundation.h>
typedef id (^Function)(id);
// a commodity for "encapsulating" double f(double)
typedef double (*func_t)(double);
Function encapsulate(func_t f) {
return ^(id x) { return @(f([x doubleValue])); };
}
Function compose(Function a, Function b) {
return ^(id x) { return a(b(x)); ... | Give a code snippet in #Objective-C
Task
Create a function, compose, whose two arguments f and g, are both functions with one argument.
The result of compose is to be a function of one argument, (lets call the argument x), which works like applying function f to the result of applying function ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hailstone_sequence | Hailstone sequence | The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
The (unproven) Collatz conje... | #TXR | TXR | @(do (defun hailstone (n)
(cons n
(gen (not (eq n 1))
(set n (if (evenp n)
(trunc n 2)
(+ (* 3 n) 1)))))))
@(next :list @(mapcar* (fun tostring) (hailstone 27)))
27
82
41
124
@(skip)
8
4
2
1
@(eof)
@(do (let ((max 0) maxi)
... | Give a code snippet in #TXR
The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Long_year | Long year | Most years have 52 weeks, some have 53, according to ISO8601.
Task
Write a function which determines if a given year is long (53 weeks) or not, and demonstrate it.
| #C.2B.2B | C++ | // Reference:
// https://en.wikipedia.org/wiki/ISO_week_date#Weeks_per_year
#include <iostream>
inline int p(int year) {
return (year + (year/4) - (year/100) + (year/400)) % 7;
}
bool is_long_year(int year) {
return p(year) == 4 || p(year - 1) == 3;
}
void print_long_years(int from, int to) {
for (i... | Give a code snippet in #C.2B.2B
Most years have 52 weeks, some have 53, according to ISO8601.
Task
Write a function which determines if a given year is long (53 weeks) or not, and demonstrate it.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Abundant_odd_numbers | Abundant odd numbers | An Abundant number is a number n for which the sum of divisors σ(n) > 2n,
or, equivalently, the sum of proper divisors (or aliquot sum) s(n) > n.
E.G.
12 is abundant, it has the proper divisors 1,2,3,4 & 6 which sum to 16 ( > 12 or n);
or alternately, has the sigma sum of ... | #R | R | # Abundant Odd Numbers
find_div_sum <- function(x){
# Finds sigma: the sum of the divisors (not including the number itself) of an odd number
if (x < 16) return(0)
root <- sqrt(x)
vec <- as.vector(1)
for (i in seq.int(3, root - 1, by = 2)){
if(x %% i == 0){
vec <- c(vec, i, x/i)
}
}
if (ro... | Give a code snippet in #R
An Abundant number is a number n for which the sum of divisors σ(n) > 2n,
or, equivalently, the sum of proper divisors (or aliquot sum) s(n) > n.
E.G.
12 is abundant, it has the proper divisors 1,2,3,4 & 6 which sum to 16 ( > 12 or n);
or alternate... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Text | Hello world/Text | Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
| #Lua | Lua | print "Hello world!" | Give a code snippet in #Lua
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Largest_int_from_concatenated_ints | Largest int from concatenated ints | Task
Given a set of positive integers, write a function to order the integers in such a way that the concatenation of the numbers forms the largest possible integer and return this integer.
Use the following two sets of integers as tests and show your program output here.
{1, 34, 3, 98, 9, 76, 45, 4}
{54,... | #Icon_and_Unicon | Icon and Unicon | import Collections # For the Heap (dense priority queue) class
procedure main(a)
write(lici(a))
end
procedure lici(a)
every (result := "") ||:= Heap(a,,cmp).gen()
return result
end
procedure cmp(a,b)
return (a||b) > (b||a)
end | Give a code snippet in #Icon_and_Unicon
Task
Given a set of positive integers, write a function to order the integers in such a way that the concatenation of the numbers forms the largest possible integer and return this integer.
Use the following two sets of integers as tests and show your program output here.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Currying | Currying |
This page uses content from Wikipedia. The original article was at Currying. 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)
Task
Create a simple demonstrative example of Currying in a specific la... | #Factor | Factor | IN: scratchpad 2 [ 3 + ] curry
--- Data stack:
[ 2 3 + ]
IN: scratchpad call
--- Data stack:
5 | Give a code snippet in #Factor
This page uses content from Wikipedia. The original article was at Currying. 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)
Task
Create a simple demonstrative exam... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_length | String length | Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters.
F... | #Seed7 | Seed7 | length("Hello, world!") | Give a code snippet in #Seed7
Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme cont... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Department_numbers | Department numbers | There is a highly organized city that has decided to assign a number to each of their departments:
police department
sanitation department
fire department
Each department can have a number between 1 and 7 (inclusive).
The three department numbers are to be unique (different from each other) and mu... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | Select[Permutations[Range[7], {3}], Total[#] == 12 && EvenQ[First[#]] &] | Give a code snippet in #Mathematica.2FWolfram_Language
There is a highly organized city that has decided to assign a number to each of their departments:
police department
sanitation department
fire department
Each department can have a number between 1 and 7 (inclusive).
The three department num... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Kernighans_large_earthquake_problem | Kernighans large earthquake problem | Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example lines from the file would be lines li... | #C | C | #include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main() {
FILE *fp;
char *line = NULL;
size_t len = 0;
ssize_t read;
char *lw, *lt;
fp = fopen("data.txt", "r");
if (fp == NULL) {
printf("Unable to open file\n");
exit(1);
}
printf("Those earthquakes wit... | Give a code snippet in #C
Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example lines from... | christopher/rosetta-code |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.