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/Dinesman%27s_multiple-dwelling_problem | Dinesman's multiple-dwelling problem | Task
Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below.
Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of... | #UTFool | UTFool |
···
http://rosettacode.org/wiki/Dinesman's_multiple-dwelling_problem
···
import java.util.HashSet
■ Dinesman
§ static
houses⦂ HashSet⟨String⟩°
▶ main
• args⦂ String[]
· Baker, Cooper, Fletcher, Miller, and Smith …
build *StringBuilder°, *StringBuilder "BCFMS"
∀ house ∈ houses⦂ St... | Give a code snippet in #UTFool
Task
Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below.
Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_common_divisor | Greatest common divisor | Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greatest common measure.
Related tas... | #Maple | Maple | igcd( a, b ) | Give a code snippet in #Maple
Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greatest... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Temperature_conversion | Temperature conversion | There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 kelvin.
0 kelvin is absolute z... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols
numeric digits 20
runSample(arg)
return
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/*
+ Kelvin Celsius Fahrenheit Rankine Delisle Newton Réaumur ... | Give a code snippet in #NetRexx
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation | Horner's rule for polynomial evaluation | A fast scheme for evaluating a polynomial such as:
−
19
+
7
x
−
4
x
2
+
6
x
3
{\displaystyle -19+7x-4x^{2}+6x^{3}\,}
when
x
=
3
{\displaystyle x=3\;}
.
is to arrange the computation as follows:
(
(
(
(
0
)
x
+
6
)
x
+
(
−
4
)
)
x
+
7
)
x
+
(
−
19
)
{\displaystyle ((((0)x+6)x+(-4))x... | #Tcl | Tcl | package require Tcl 8.5
proc horner {coeffs x} {
set y 0
foreach c [lreverse $coeffs] {
set y [expr { $y*$x+$c }]
}
return $y
} | Give a code snippet in #Tcl
A fast scheme for evaluating a polynomial such as:
−
19
+
7
x
−
4
x
2
+
6
x
3
{\displaystyle -19+7x-4x^{2}+6x^{3}\,}
when
x
=
3
{\displaystyle x=3\;}
.
is to arrange the computation as follows:
(
(
(
(
0
)
x
+
6
)
x
+
(
−
4
)
)
x
+
7
)
x
+
(
−
19
)
{\di... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hostname | Hostname | Task
Find the name of the host on which the routine is running.
| #R | R | Sys.info()[["nodename"]] | Give a code snippet in #R
Task
Find the name of the host on which the routine is running.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Straddling_checkerboard | Straddling checkerboard | Task
Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a series of decimal digits.
Num... | #Haskell | Haskell | import Data.Char
import Data.Map
charToInt :: Char -> Int
charToInt c = ord c - ord '0'
-- Given a string, decode a single character from the string.
-- Return the decoded char and the remaining undecoded string.
decodeChar :: String -> (Char,String)
decodeChar ('7':'9':r:rs) = (r,rs)
decodeChar ('7':r:rs) = ("... | Give a code snippet in #Haskell
Task
Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Integer | Arithmetic/Integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #bc | bc | define f(a, b) {
"add: "; a + b
"sub: "; a - b
"mul: "; a * b
"div: "; a / b /* truncates toward zero */
"mod: "; a % b /* same sign as first operand */
"pow: "; a ^ b
} | Give a code snippet in #bc
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Con... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newline_omission | Hello world/Newline omission | Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standard error
Hello world/Text
| #Icon_and_Unicon | Icon and Unicon | procedure main()
writes("Goodbye, World!")
end | Give a code snippet in #Icon_and_Unicon
Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello w... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Recursively | Walk a directory/Recursively | Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk a directory/Non-recursively ... | #Prolog_2 | Prolog | % submitted by Aykayayciti (Earl Lamont Montgomery)
% altered from fsaenzperez April 2019
% (swi-prolog.discourse-group)
test_run :-
proc_dir('C:\\vvvv\\vvvv_beta_39_x64').
proc_dir(Directory) :-
format('Directory: ~w~n',[Directory]),
directory_files(Directory,Files),!, %cut inserted
proc_file... | Give a code snippet in #Prolog_2
Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
W... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compound_data_type | Compound data type |
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.
Task
Create a compound data type:
Point(x,y)
A compound data type is one that holds multiple independent values.
Related task
Enumeration
S... | #MATLAB_.2F_Octave | MATLAB / Octave | point.x=3;
point.y=4; | Give a code snippet in #MATLAB_.2F_Octave
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.
Task
Create a compound data type:
Point(x,y)
A compound data type is one that holds multiple independent ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newline_omission | Hello world/Newline omission | Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standard error
Hello world/Text
| #Swift | Swift | print("Goodbye, World!", terminator: "") | Give a code snippet in #Swift
Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Stand... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_input/output | File input/output | File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file into a variable
how to write ... | #Wren | Wren | import "io" for File
var contents = File.read("input.txt")
File.create("output.txt") {|file|
file.writeBytes(contents)
} | Give a code snippet in #Wren
File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file in... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Extend_your_language | Extend your language | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Some programming languages allow you to extend the language. While this can be done to a certain degree in most languages (e.g. by using macros), other langua... | #E | E | pragma.enable("lambda-args") # The feature is still experimental syntax
def makeIf2Control(evalFn, tf, ft, ff) {
return def if2Control {
to only1__control_0(tf) { return makeIf2Control(evalFn, tf, ft, ff) }
to only2__control_0(ft) { return makeIf2Control(evalFn, tf, ft, ff) }
to else__control_0 (ff) { r... | Give a code snippet in #E
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Some programming languages allow you to extend the language. While this can be done to a certain degree in most languages (e.g. by ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_a_quadratic_function | Roots of a quadratic function | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Write a program to find the roots of a quadratic equation, i.e., solve the equation
a
x
2
+
b
x
+
c
=
0
{\displaystyle ax^{2}+bx+c=0}
.
Your program must correctly handle n... | #Ruby | Ruby | require 'cmath'
def quadratic(a, b, c)
sqrt_discriminant = CMath.sqrt(b**2 - 4*a*c)
[(-b + sqrt_discriminant) / (2.0*a), (-b - sqrt_discriminant) / (2.0*a)]
end
p quadratic(3, 4, 4/3.0) # [-2/3]
p quadratic(3, 2, -1) # [1/3, -1]
p quadratic(3, 2, 1) # [(-1/3 + sqrt(2/9)i), (-1/3 - sqrt(2/9)i)]
p quadr... | Give a code snippet in #Ruby
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Write a program to find the roots of a quadratic equation, i.e., solve the equation
a
x
2
+
b
x
+
c
=
0
{\displaystyle ax^{2}+bx+c=0}
.
Your p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Bubble_sort | Sorting algorithms/Bubble 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
... | #X86_Assembly | X86 Assembly | .model tiny
.code
.486
org 100h
start: mov si, offset array
mov ax, 40 ;length of array (not including $)
call bsort
mov dx, si ;point to array
mov ah, 09h ;display it as a string
int 21h
... | Give a code snippet in #X86_Assembly
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 |
Q... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #Java | Java |
import java.util.LinkedList;
public class DoublyLinkedList {
public static void main(String[] args) {
LinkedList<String> list = new LinkedList<String>();
list.addFirst("Add First");
list.addLast("Add Last 1");
list.addLast("Add Last 2");
list.addLast("Add Last 1");
... | Give a code snippet in #Java
Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Gauss-Jordan_matrix_inversion | Gauss-Jordan matrix inversion | Task
Invert matrix A using Gauss-Jordan method.
A being an n × n matrix.
| #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | a = N@{{1, 7, 5, 0}, {5, 8, 6, 9}, {2, 1, 6, 4}, {8, 1, 2, 4}};
elimmat = RowReduce[Join[a, IdentityMatrix[Length[a]], 2]];
inv = elimmat[[All, -Length[a] ;;]] | Give a code snippet in #Mathematica_.2F_Wolfram_Language
Task
Invert matrix A using Gauss-Jordan method.
A being an n × n matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Password_generator | Password generator | Create a password generation program which will generate passwords containing random ASCII characters from the following groups:
lower-case letters: a ──► z
upper-case letters: A ──► Z
digits: 0 ──► 9
other printable characters: !"#$%&'()*+,-./:;<=>?@[]^_{|}~
(the above ch... | #R | R |
passwords <- function(nl = 8, npw = 1, help = FALSE) {
if (help) return("gives npw passwords with nl characters each")
if (nl < 4) nl <- 4
spch <- c("!", "\"", "#", "$", "%", "&", "'", "(", ")", "*", "+", ",", "-", ".", "/", ":", ";", "<", "=", ">", "?", "@", "[", "]", "^", "_", "{", "|", "}", "~")
for(i in 1... | Give a code snippet in #R
Create a password generation program which will generate passwords containing random ASCII characters from the following groups:
lower-case letters: a ──► z
upper-case letters: A ──► Z
digits: 0 ──► 9
other printable characters: !"#$%&'()*+,-./:;<=... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #Logo | Logo | to fib :n [:a 0] [:b 1]
if :n < 1 [output :a]
output (fib :n-1 :b :a+:b)
end | Give a code snippet in #Logo
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Primality_by_Wilson%27s_theorem | Primality by Wilson's theorem | Task
Write a boolean function that tells whether a given integer is prime using Wilson's theorem.
By Wilson's theorem, a number p is prime if and only if p divides (p - 1)! + 1.
Remember that 1 and all non-positive integers are not prime.
See also
Cut-the-knot: Wilson's theorem.
Wikipedia: Wilson's theorem
| #Python | Python | from math import factorial
def is_wprime(n):
return n == 2 or (
n > 1
and n % 2 != 0
and (factorial(n - 1) + 1) % n == 0
)
if __name__ == '__main__':
c = int(input('Enter upper limit: '))
print(f'Primes under {c}:')
print([n for n in range(c) if is_wprime(n)]) | Give a code snippet in #Python
Task
Write a boolean function that tells whether a given integer is prime using Wilson's theorem.
By Wilson's theorem, a number p is prime if and only if p divides (p - 1)! + 1.
Remember that 1 and all non-positive integers are not prime.
See also
Cut-the-knot: Wilson's theorem.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Descending_primes | Descending primes | Generate and show all primes with strictly descending decimal digits.
See also
OEIS:A052014 - Primes with distinct digits in descending order
Related
Ascending primes
| #J | J | extend=: {{ y;y,L:0(1+each i.1-{:y)}}
($~ q:@$)(#~ 1 p: ])10#.&>([:~.@;extend each)^:# >:i.9
2 3 31 43 41 431 421 5 53 541 521 5431 61 653 643 641 631 6521 6421 7 73 71 761 751 743 7643 7621 7541 7321
76543 76541 76421 75431 764321 83 ... | Give a code snippet in #J
Generate and show all primes with strictly descending decimal digits.
See also
OEIS:A052014 - Primes with distinct digits in descending order
Related
Ascending primes
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Self_numbers | Self numbers | A number n is a self number if there is no number g such that g + the sum of g's digits = n. So 18 is not a self number because 9+9=18, 43 is not a self number because 35+5+3=43.
The task is:
Display the first 50 self numbers;
I believe that the 100000000th self number is 1022727208. You should either confirm or d... | #Java | Java | public class SelfNumbers {
private static final int MC = 103 * 1000 * 10000 + 11 * 9 + 1;
private static final boolean[] SV = new boolean[MC + 1];
private static void sieve() {
int[] dS = new int[10_000];
for (int a = 9, i = 9999; a >= 0; a--) {
for (int b = 9; b >= 0; b--) {
... | Give a code snippet in #Java
A number n is a self number if there is no number g such that g + the sum of g's digits = n. So 18 is not a self number because 9+9=18, 43 is not a self number because 35+5+3=43.
The task is:
Display the first 50 self numbers;
I believe that the 100000000th self number is 1022727208. ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Ringing_the_terminal_bell | Terminal control/Ringing the terminal bell |
Task
Make the terminal running the program ring its "bell".
On modern terminal emulators, this may be done by playing some other sound which might or might not be configurable, or by flashing the title bar or inverting the colors of the screen, but was classically a physical bell within the terminal. It is usua... | #PureBasic | PureBasic | Print(#BEL$) | Give a code snippet in #PureBasic
Task
Make the terminal running the program ring its "bell".
On modern terminal emulators, this may be done by playing some other sound which might or might not be configurable, or by flashing the title bar or inverting the colors of the screen, but was classically a physical bel... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calculating_the_value_of_e | Calculating the value of e | Task
Calculate the value of e.
(e is also known as Euler's number and Napier's constant.)
See details: Calculating the value of e
| #Common_Lisp | Common Lisp | (ql:quickload :computable-reals :silent t)
(use-package :computable-reals)
(defparameter *iterations* 1000)
(let ((e 1) (f 1))
(loop for i from 1 to *iterations* doing
(setq f (* f i))
(setq e (+ e (/ 1 f))))
(format t "After ~a iterations, e = " *iterations*)
(print-r e 2570)) | Give a code snippet in #Common_Lisp
Task
Calculate the value of e.
(e is also known as Euler's number and Napier's constant.)
See details: Calculating the value of e
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Reduced_row_echelon_form | Reduced row echelon form | Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenient
(for most languages, this wil... | #Sage | Sage | sage: m = matrix(ZZ, [[1,2,-1,-4],[2,3,-1,-11],[-2,0,-3,22]])
sage: m.rref() ... | Give a code snippet in #Sage
Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenient... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Executable_library | Executable library | The general idea behind an executable library is to create a library
that when used as a library does one thing;
but has the ability to be run directly via command line.
Thus the API comes with a CLI in the very same source code file.
Task detail
Create a library/module/dll/shared object/... for a programming langua... | #Ada | Ada | package Parameter is
X: Natural := 0;
Y: Natural;
end Parameter; | Give a code snippet in #Ada
The general idea behind an executable library is to create a library
that when used as a library does one thing;
but has the ability to be run directly via command line.
Thus the API comes with a CLI in the very same source code file.
Task detail
Create a library/module/dll/shared object... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_case | String case | Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not reversable.
Show any additional... | #Racket | Racket | #lang racket
(define example "alphaBETA")
(string-upcase example)
;"ALPHABETA"
(string-downcase example)
;"alphabeta"
(string-titlecase example)
;"Alphabeta" | Give a code snippet in #Racket
Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Gaussian_elimination | Gaussian elimination | Task
Solve Ax=b using Gaussian elimination then backwards substitution.
A being an n by n matrix.
Also, x and b are n by 1 vectors.
To improve accuracy, please use partial pivoting and scaling.
See also
the Wikipedia entry: Gaussian elimination
| #Rust | Rust |
// using a Vec<f32> might be a better idea
// for now, let us create a fixed size array
// of size:
const SIZE: usize = 6;
pub fn eliminate(mut system: [[f32; SIZE+1]; SIZE]) -> Option<Vec<f32>> {
// produce the row reduced echelon form
//
// for every row...
for i in 0..SIZE-1 {
// for ever... | Give a code snippet in #Rust
Task
Solve Ax=b using Gaussian elimination then backwards substitution.
A being an n by n matrix.
Also, x and b are n by 1 vectors.
To improve accuracy, please use partial pivoting and scaling.
See also
the Wikipedia entry: Gaussian elimination
| christopher/rosetta-code | |
http://rosettacode.org/wiki/String_case | String case | Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not reversable.
Show any additional... | #Ring | Ring |
aString = "WELCOME TO THE ring programming language"
see lower(aString) + nl
see upper(aString) + nl
| Give a code snippet in #Ring
Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not re... | 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... | #Brat | Brat | hailstone = { num |
sequence = [num]
while { num != 1 }
{ true? num % 2 == 0
{ num = num / 2 }
{ num = num * 3 + 1 }
sequence << num
}
sequence
}
#Check sequence for 27
seq = hailstone 27
true? (seq[0,3] == [27 82 41 124] && seq[-1, -4] == [8 4 2 1])
{ p "Sequence for 27 is correct... | Give a code snippet in #Brat
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/Multiple_distinct_objects | Multiple distinct objects | Create a sequence (array, list, whatever) consisting of n distinct, initialized items of the same type. n should be determined at runtime.
By distinct we mean that if they are mutable, changes to one do not affect all others; if there is an appropriate equality operator they are considered unequal; etc. The code need ... | #Racket | Racket |
#lang racket
;; a list of 10 references to the same vector
(make-list 10 (make-vector 10 0))
;; a list of 10 distinct vectors
(build-list 10 (λ (n) (make-vector 10 0)))
| Give a code snippet in #Racket
Create a sequence (array, list, whatever) consisting of n distinct, initialized items of the same type. n should be determined at runtime.
By distinct we mean that if they are mutable, changes to one do not affect all others; if there is an appropriate equality operator they are conside... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Vector | Vector | Task
Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented.
The Vector may be initialized in any reasonable way.
Start and end points, and direction
Angular coefficient and value (length)
The four operations to... | #Modula-2 | Modula-2 | MODULE Vector;
FROM FormatString IMPORT FormatString;
FROM RealStr IMPORT RealToStr;
FROM Terminal IMPORT WriteString,WriteLn,ReadChar;
TYPE Vector =
RECORD
x,y : REAL;
END;
PROCEDURE Add(a,b : Vector) : Vector;
BEGIN
RETURN Vector{a.x+b.x, a.y+b.y}
END Add;
PROCEDURE Sub(a,b : Vector) : Vecto... | Give a code snippet in #Modula-2
Task
Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented.
The Vector may be initialized in any reasonable way.
Start and end points, and direction
Angular coefficient and value... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/While | Loops/While | Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For... | #MAXScript | MAXScript | a = 1024
while a > 0 do
(
print a
a /= 2
) | Give a code snippet in #MAXScript
Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Dow... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Old_Russian_measure_of_length | Old Russian measure of length | Task
Write a program to perform a conversion of the old Russian measures of length to the metric system (and vice versa).
It is an example of a linear transformation of several variables.
The program should accept a single value in a selected unit of measurement, and convert and return it to the other units:
... | #Delphi | Delphi |
program Old_Russian_measure_of_length;
{$APPTYPE CONSOLE}
uses
System.SysUtils;
const
units: array[0..12] of string = ('tochka', 'liniya', 'dyuim', 'vershok',
'piad', 'fut', 'arshin', 'sazhen', 'versta', 'milia', 'centimeter', 'meter',
'kilometer');
convs: array[0..12] of double = (0.0254, 0.254, ... | Give a code snippet in #Delphi
Task
Write a program to perform a conversion of the old Russian measures of length to the metric system (and vice versa).
It is an example of a linear transformation of several variables.
The program should accept a single value in a selected unit of measurement, and convert and... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fixed_length_records | Fixed length records | Fixed length read/write
Before terminals, computers commonly used punch card readers or paper tape input.
A common format before these devices were superseded by terminal technology was based on the Hollerith code, Hollerith code.
These input devices handled 80 columns per card and had a limited character set, encod... | #Rust | Rust | use std::fs::File;
use std::io::prelude::*;
use std::io::{BufReader, BufWriter};
fn reverse_file(
input_filename: &str,
output_filename: &str,
record_len: usize,
) -> std::io::Result<()> {
let mut input = BufReader::new(File::open(input_filename)?);
let mut output = BufWriter::new(File::create(out... | Give a code snippet in #Rust
Fixed length read/write
Before terminals, computers commonly used punch card readers or paper tape input.
A common format before these devices were superseded by terminal technology was based on the Hollerith code, Hollerith code.
These input devices handled 80 columns per card and had ... | 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.
| #Objeck | Objeck |
use IO;
...
File("input.txt")->Size()->PrintLine();
File("c:\input.txt")->Size()->PrintLine();
| Give a code snippet in #Objeck
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/Filter | Filter | Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| #Lang5 | Lang5 | : filter over swap execute select ;
10 iota "2 % not" filter . "\n" .
# [ 0 2 4 6 8 ] | Give a code snippet in #Lang5
Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_a_two-dimensional_array_at_runtime | Create a two-dimensional array at runtime |
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.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numbers, and which can be accessed ... | #Swift | Swift | import Foundation
print("Enter the dimensions of the array seperated by a space (width height): ")
let fileHandle = NSFileHandle.fileHandleWithStandardInput()
let dims = NSString(data: fileHandle.availableData, encoding: NSUTF8StringEncoding)?.componentsSeparatedByString(" ")
if let dims = dims where dims.count =... | Give a code snippet in #Swift
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.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numb... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hough_transform | Hough transform | Task
Implement the Hough transform, which is used as part of feature extraction with digital images.
It is a tool that makes it far easier to identify straight lines in the source image, whatever their orientation.
The transform maps each point in the target image,
(
ρ
,
θ
)
{\displaystyle (\rho ,\theta )}
, ... | #MATLAB | MATLAB | import lenientops, math
import grayscale_image
const White = 255
func houghTransform*(img: GrayImage; hx = 460; hy = 360): GrayImage =
assert not img.isNil
assert hx > 0 and hy > 0
assert (hy and 1) == 0, "hy argument must be even"
result = newGrayImage(hx, hy)
result.fill(White)
let rMax = hypot(im... | Give a code snippet in #MATLAB
Task
Implement the Hough transform, which is used as part of feature extraction with digital images.
It is a tool that makes it far easier to identify straight lines in the source image, whatever their orientation.
The transform maps each point in the target image,
(
ρ
,
θ
)
{\d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Evolutionary_algorithm | Evolutionary algorithm | Starting with:
The target string: "METHINKS IT IS LIKE A WEASEL".
An array of random characters chosen from the set of upper-case letters together with the space, and of the same length as the target string. (Call it the parent).
A fitness function that computes the ‘closeness’ of its argument to the target string.... | #vbscript | vbscript |
'This is the string we want to "evolve" to. Any string of any length will
'do as long as it consists only of upper case letters and spaces.
Target = "METHINKS IT IS LIKE A WEASEL"
'This is the pool of letters that will be selected at random for a mutation
letters = " ABCDEFGHIJKLMNOPQRSTUVWXYZ"
'A mutation r... | Give a code snippet in #vbscript
Starting with:
The target string: "METHINKS IT IS LIKE A WEASEL".
An array of random characters chosen from the set of upper-case letters together with the space, and of the same length as the target string. (Call it the parent).
A fitness function that computes the ‘closeness’ of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Object_serialization | Object serialization | Create a set of data types based upon inheritance. Each data type or class should have a print command that displays the contents of an instance of that class to standard output. Create instances of each class in your inheritance hierarchy and display them to standard output. Write each of the objects to a file named o... | #PicoLisp | PicoLisp | (class +Point)
# x y
(dm T (X Y)
(=: x (or X 0))
(=: y (or Y 0)) )
(dm print> ()
(prinl "Point " (: x) "," (: y)) )
(class +Circle +Point)
# r
(dm T (X Y R)
(super X Y)
(=: r (or R 0)) )
(dm print> ()
(prinl "Circle " (: x) "," (: y) "," (: r)) )
(setq
P (new '(+Point) 3 4)
C (new '(... | Give a code snippet in #PicoLisp
Create a set of data types based upon inheritance. Each data type or class should have a print command that displays the contents of an instance of that class to standard output. Create instances of each class in your inheritance hierarchy and display them to standard output. Write eac... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Yellowstone_sequence | Yellowstone sequence | The Yellowstone sequence, also called the Yellowstone permutation, is defined as:
For n <= 3,
a(n) = n
For n >= 4,
a(n) = the smallest number not already in sequence such that a(n) is relatively prime to a(n-1) and
is not relatively prime to a(n-2).
The sequence is a permutation of the natural n... | #Action.21 | Action! | BYTE FUNC Gcd(BYTE a,b)
BYTE tmp
IF a<b THEN
tmp=a a=b b=tmp
FI
WHILE b#0
DO
tmp=a MOD b
a=b b=tmp
OD
RETURN (a)
BYTE FUNC Contains(BYTE ARRAY a BYTE len,value)
BYTE i
FOR i=0 TO len-1
DO
IF a(i)=value THEN
RETURN (1)
FI
OD
RETURN (0)
PROC Generate(BYTE ARRAY seq ... | Give a code snippet in #Action.21
The Yellowstone sequence, also called the Yellowstone permutation, is defined as:
For n <= 3,
a(n) = n
For n >= 4,
a(n) = the smallest number not already in sequence such that a(n) is relatively prime to a(n-1) and
is not relatively prime to a(n-2).
The sequenc... | christopher/rosetta-code | |
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... | #ActionScript | ActionScript | PROC ℒ next random = (REF ℒ INT a)ℒ REAL: ( a :=
¢ the next pseudo-random ℒ integral value after 'a' from a
uniformly distributed sequence on the interval [ℒ 0,ℒ maxint] ¢;
¢ the real value corresponding to 'a' according to some mapping of
integral values [ℒ 0, ℒ max int] into real values [ℒ 0, ℒ 1)
i.e. such th... | Give a code snippet in #ActionScript
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 a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jewels_and_stones | Jewels and stones | Jewels and stones
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a function which takes two string parameters: 'stones' and 'jewels' and returns an integer.
Both strings can contain any number of upper or lower case letters. However, in the case ... | #Raku | Raku | sub count-jewels ( Str $j, Str $s --> Int ) {
my %counts_of_all = $s.comb.Bag;
my @jewel_list = $j.comb.unique;
return %counts_of_all ∩ @jewel_list.Bag ?? %counts_of_all{ @jewel_list }.sum !! 0;
}
say count-jewels 'aA' , 'aAAbbbb';
say count-jewels 'z' , 'ZZ'; | Give a code snippet in #Raku
Jewels and stones
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a function which takes two string parameters: 'stones' and 'jewels' and returns an integer.
Both strings can contain any number of upper or lower case ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Shell_sort | Sorting algorithms/Shell 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
... | #MATLAB_.2F_Octave | MATLAB / Octave | function list = shellSort(list)
N = numel(list);
increment = round(N/2);
while increment > 0
for i = (increment+1:N)
temp = list(i);
j = i;
while (j >= increment+1) && (list(j-increment) > temp)
list(j) = list(j-increment);
j ... | Give a code snippet in #MATLAB_.2F_Octave
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 sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Remove_duplicate_elements | Remove duplicate elements |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #AppleScript | AppleScript | unique({1, 2, 3, "a", "b", "c", 2, 3, 4, "b", "c", "d"})
on unique(x)
set R to {}
repeat with i in x
if i is not in R then set end of R to i's contents
end repeat
return R
end unique | Give a code snippet in #AppleScript
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 |
Qu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Program_termination | Program termination |
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers/destructors, run-on-exit hooks... | #Forth | Forth | debug @
if QUIT \ quit back to the interpreter
else BYE \ exit forth environment completely (e.g. end of a Forth shell script)
then | Give a code snippet in #Forth
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence_of_non-squares | Sequence of non-squares | Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 in the OEIS database.
| #Ol | Ol |
(import (lib math))
(print
; sequence for 1 .. 22
(map (lambda (n)
(+ n (floor (+ 1/2 (exact (sqrt n))))))
(iota 22 1)))
; ==> (2 3 5 6 7 8 10 11 12 13 14 15 17 18 19 20 21 22 23 24 26 27)
(print
; filter out non squares
(filter
(lambda (x)
(let ((s (floor (exact (sqrt x)... | Give a code snippet in #Ol
Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_append | String append |
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 |... | #Avail | Avail | str : string := "99 bottles of ";
str ++= "beer";
Print: str; | Give a code snippet in #Avail
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
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Attractive_numbers | Attractive numbers | A number is an attractive number if the number of its prime factors (whether distinct or not) is also prime.
Example
The number 20, whose prime decomposition is 2 × 2 × 5, is an attractive number because the number of its prime factors (3) is also prime.
Task
Show sequence items up to 120.... | #D | D | import std.stdio;
enum MAX = 120;
bool isPrime(int n) {
if (n < 2) return false;
if (n % 2 == 0) return n == 2;
if (n % 3 == 0) return n == 3;
int d = 5;
while (d * d <= n) {
if (n % d == 0) return false;
d += 2;
if (n % d == 0) return false;
d += 4;
}
ret... | Give a code snippet in #D
A number is an attractive number if the number of its prime factors (whether distinct or not) is also prime.
Example
The number 20, whose prime decomposition is 2 × 2 × 5, is an attractive number because the number of its prime factors (3) is also prime.
Task
Show ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pascal%27s_triangle | Pascal's triangle | Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either 1 or the sum of the two elemen... | #Clojure | Clojure | (defn pascal [n]
(let [newrow (fn newrow [lst ret]
(if lst
(recur (rest lst)
(conj ret (+ (first lst) (or (second lst) 0))))
ret))
genrow (fn genrow [n lst]
(when (< 0 n)
(do ... | Give a code snippet in #Clojure
Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is eith... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #F.23 | F# |
let mutable nm=uint64(1)
let mutable dm=uint64(1)
let mutable a=uint64(1)
printf "1, "
for i = 2 to 15 do
nm<-uint64(1)
dm<-uint64(1)
for k = 2 to i do
nm <-uint64( uint64(nm) * (uint64(i)+uint64(k)))
dm <-uint64( uint64(dm) * uint64(k))
let a = uint64(uint64(nm)/uint64(dm))
prin... | Give a code snippet in #F.23
Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that gener... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Read_a_PPM_file | Bitmap/Read a PPM file | Using the data storage type defined on this page for raster images, read an image from a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
Task: Use write ppm file solution and grayscale image solution with this one in order to convert a color image to grayscale one.
| #Forth | Forth | : read-ppm { fid -- bmp }
pad dup 80 fid read-line throw 0= abort" Partial line"
s" P6" compare abort" Only P6 supported."
pad dup 80 fid read-line throw 0= abort" Partial line"
0. 2swap >number
1 /string \ skip space
0. 2swap >number
2drop drop nip ( w h )
bitmap { bmp }
pad dup 80 fid read-line ... | Give a code snippet in #Forth
Using the data storage type defined on this page for raster images, read an image from a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
Task: Use write ppm file solution and grayscale image solution with this one in order to convert a color image to graysc... | 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
... | #AppleScript | AppleScript | -- quickSort :: (Ord a) => [a] -> [a]
on quickSort(xs)
if length of xs > 1 then
set {h, t} to uncons(xs)
-- lessOrEqual :: a -> Bool
script lessOrEqual
on |λ|(x)
x ≤ h
end |λ|
end script
set {less, more} to partition(lessOrEqual, t)... | Give a code snippet in #AppleScript
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 |
Qu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Respond_to_an_unknown_method_call | Respond to an unknown method call | Task
Demonstrate how to make the object respond (sensibly/usefully) to an invocation of a method on it that it does not support through its class definitions.
Note that this is not the same as just invoking a defined method whose name is given dynamically; the method named at the point of invocation must not be defin... | #PHP | PHP | <?php
class Example {
function foo() {
echo "this is foo\n";
}
function bar() {
echo "this is bar\n";
}
function __call($name, $args) {
echo "tried to handle unknown method $name\n";
if ($args)
echo "it had arguments: ", implode(', ', $args), "\n";
}
}
$example = new Example();
$ex... | Give a code snippet in #PHP
Task
Demonstrate how to make the object respond (sensibly/usefully) to an invocation of a method on it that it does not support through its class definitions.
Note that this is not the same as just invoking a defined method whose name is given dynamically; the method named at the point of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters | Determine if a string has all the same characters | Task
Given a character string (which may be empty, or have a length of zero characters):
create a function/procedure/routine to:
determine if all the characters in the string are the same
indicate if or which character is different from the previous character
display each string and its length (as the... | #Scala | Scala | import scala.collection.immutable.ListMap
object StringAllSameCharacters {
/**Transform an input String into an HashMap of its characters and its first occurrence index*/
def countChar( s : String) : Map[Char, Int] = {
val mapChar = s.toSeq.groupBy(identity).map{ case (a,b) => a->s.indexOf(a) }
val orde... | Give a code snippet in #Scala
Task
Given a character string (which may be empty, or have a length of zero characters):
create a function/procedure/routine to:
determine if all the characters in the string are the same
indicate if or which character is different from the previous character
display each ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dining_philosophers | Dining philosophers | The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra.
Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a rou... | #AutoHotkey | AutoHotkey | #Persistent
SetWorkingDir, %A_ScriptDir%
FileDelete, output.txt
EnoughForks := 2 ; required forks to begin eating
Fork1 := Fork2 := Fork3 := Fork4 := Fork5 := 1 ; fork supply per philosopher
SetTimer, AristotleWaitForLeftFork
SetTimer, KantWaitForLeftFork
SetTimer, SpinozaWaitForLeftFork
SetTimer, MarxWaitForLeftFork
S... | Give a code snippet in #AutoHotkey
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra.
Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Show_ASCII_table | Show ASCII table | Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
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 before E except after C
Bioin... | #zkl | zkl | const width=9;
println(" ",[0..width].pump(String,"%4d".fmt));
[30..127].pump("".println,T(Void.Read,width,False), // don't fail on short lines
fcn(a,b,c){
String("%3d: ".fmt(a),
vm.arglist.pump(String,"toChar", // parameters (ints) to list to text
T("replace","\x1e",""),T("replace","\x1f",... | Give a code snippet in #zkl
Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
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 b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hostname | Hostname | Task
Find the name of the host on which the routine is running.
| #Harbour | Harbour | ? NetName() | Give a code snippet in #Harbour
Task
Find the name of the host on which the routine is running.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Idiomatically_determine_all_the_lowercase_and_uppercase_letters | Idiomatically determine all the lowercase and uppercase letters |
Idiomatically determine all the lowercase and uppercase letters (of the Latin [English] alphabet) being used currently by a computer programming language.
The method should find the letters regardless of the hardware architecture that is being used (ASCII, EBCDIC, or other).
Task requirements
Display the set of... | #Lua | Lua | function ASCIIstring (pattern)
local matchString, ch = ""
for charNum = 0, 255 do
ch = string.char(charNum)
if string.match(ch, pattern) then
matchString = matchString .. ch
end
end
return matchString
end
print(ASCIIstring("%l"))
print(ASCIIstring("%u"))
| Give a code snippet in #Lua
Idiomatically determine all the lowercase and uppercase letters (of the Latin [English] alphabet) being used currently by a computer programming language.
The method should find the letters regardless of the hardware architecture that is being used (ASCII, EBCDIC, or other).
Task re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #Scilab | Scilab | if condition1 then instructions1
[elseif condition2 then instructions2]
....
[else instructionse]
end
| Give a code snippet in #Scilab
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Barnsley_fern | Barnsley fern |
A Barnsley fern is a fractal named after British mathematician Michael Barnsley and can be created using an iterated function system (IFS).
Task
Create this fractal fern, using the following transformations:
ƒ1 (chosen 1% of the time)
xn + 1 = 0
yn + 1 = 0.16 yn
ƒ2 (chosen 85% of the time)
... | #Action.21 | Action! | INCLUDE "H6:REALMATH.ACT"
BYTE CH=$02FC,COLOR1=$02C5,COLOR2=$02C6
REAL r0,r4,r15,r16,r20,r22,r23,r24,r26,r28,r44,r85,r160
PROC Init()
ValR("0",r0)
ValR("0.04",r4)
ValR("0.15",r16)
ValR("0.16",r16)
ValR("0.2",r20)
ValR("0.22",r22)
ValR("0.23",r23)
ValR("0.24",r24)
ValR("0.26",r26)
ValR("0.28",r28... | Give a code snippet in #Action.21
A Barnsley fern is a fractal named after British mathematician Michael Barnsley and can be created using an iterated function system (IFS).
Task
Create this fractal fern, using the following transformations:
ƒ1 (chosen 1% of the time)
xn + 1 = 0
yn + 1 = 0.16 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Padovan_n-step_number_sequences | Padovan n-step number sequences | As the Fibonacci sequence expands to the Fibonacci n-step number sequences; We similarly expand the Padovan sequence to form these Padovan n-step number sequences.
The Fibonacci-like sequences can be defined like this:
For n == 2:
start: 1, 1
Recurrence: R(n, x) = R(n, x-1) + R(n, x-2); for n ==... | #ALGOL_68 | ALGOL 68 | BEGIN # show some valuies of the Padovan n-step number sequences #
# returns an array with the elements set to the elements of #
# the Padovan sequences from 2 to max s & elements 1 to max e #
# max s must be >= 2 #
PROC padovan sequences = ( INT max s, max e ... | Give a code snippet in #ALGOL_68
As the Fibonacci sequence expands to the Fibonacci n-step number sequences; We similarly expand the Padovan sequence to form these Padovan n-step number sequences.
The Fibonacci-like sequences can be defined like this:
For n == 2:
start: 1, 1
Recurrence: R(n, x)... | christopher/rosetta-code | |
http://rosettacode.org/wiki/RPG_attributes_generator | RPG attributes generator | RPG = Role Playing Game.
You're running a tabletop RPG, and your players are creating characters.
Each character has six core attributes: strength, dexterity, constitution, intelligence, wisdom, and charisma.
One way of generating values for these attributes is to roll four, 6-sided dice (d6) and sum the three... | #REXX | REXX | /* REXX
Generates 4 random, whole values between 1 and 6.
Saves the sum of the 3 largest values.
Generates a total of 6 values this way.
Displays the total, and all 6 values once finished.
*/
Do try=1 By 1
ge15=0
sum=0
ol=''
Do i=1 To 6
rl=''
Do j=1 To 4
rl=rl (random(5)+1)
End
rl=wordso... | Give a code snippet in #REXX
RPG = Role Playing Game.
You're running a tabletop RPG, and your players are creating characters.
Each character has six core attributes: strength, dexterity, constitution, intelligence, wisdom, and charisma.
One way of generating values for these attributes is to roll four, 6-sid... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hamming_numbers | Hamming numbers | Hamming numbers are numbers of the form
H = 2i × 3j × 5k
where
i, j, k ≥ 0
Hamming numbers are also known as ugly numbers and also 5-smooth numbers (numbers whose prime divisors are less or equal to 5).
Task
Generate the sequence of Hamming numbers, in increasing order. In ... | #ALGOL_68 | ALGOL 68 | PR precision=100 PR
MODE SERIES = FLEX [1 : 0] UNT, # Initially, no elements #
UNT = LONG LONG INT; # A 100-digit unsigned integer #
PROC hamming number = (INT n) UNT: # The n-th Hamming number #
CASE n
IN 1, 2, 3, 4, 5, 6, 8, 9, 10, 12 # First 10 in a table #
OUT # Additional operators #
... | Give a code snippet in #ALGOL_68
Hamming numbers are numbers of the form
H = 2i × 3j × 5k
where
i, j, k ≥ 0
Hamming numbers are also known as ugly numbers and also 5-smooth numbers (numbers whose prime divisors are less or equal to 5).
Task
Generate the sequence of Hamming n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Safe_addition | Safe addition | Implementation of interval arithmetic and more generally fuzzy number arithmetic require operations that yield safe upper and lower bounds of the exact result.
For example, for an addition, it is the operations +↑ and +↓ defined as: a +↓ b ≤ a + b ≤ a +↑ b.
Additionally it is desired that the widt... | #D | D | import std.traits;
auto safeAdd(T)(T a, T b)
if (isFloatingPoint!T) {
import std.math; // nexDown, nextUp
import std.typecons; // tuple
return tuple!("d", "u")(nextDown(a+b), nextUp(a+b));
}
import std.stdio;
void main() {
auto a = 1.2;
auto b = 0.03;
auto r = safeAdd(a, b);
writefln... | Give a code snippet in #D
Implementation of interval arithmetic and more generally fuzzy number arithmetic require operations that yield safe upper and lower bounds of the exact result.
For example, for an addition, it is the operations +↑ and +↓ defined as: a +↓ b ≤ a + b ≤ a +↑ b.
Additionally ... | 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)... | #Frink | Frink |
d = new dict
for n = 1 to 20000
{
s = sum[allFactors[n, true, false, true], 0]
rel = s <=> n
d.increment[rel, 1]
}
println["Deficient: " + d@(-1)]
println["Perfect: " + d@0]
println["Abundant: " + d@1]
| Give a code snippet in #Frink
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Echo_server | Echo server | Create a network service that sits on TCP port 12321, which accepts connections on that port, and which echoes complete lines (using a carriage-return/line-feed sequence as line separator) back to clients. No error handling is required. For the purposes of testing, it is only necessary to support connections from local... | #Raku | Raku | my $socket = IO::Socket::INET.new:
:localhost<localhost>,
:localport<12321>,
:listen;
while $socket.accept -> $conn {
say "Accepted connection";
start {
while $conn.recv -> $stuff {
say "Echoing $stuff";
$conn.print($stuff);
}
$conn.close;
}
} | Give a code snippet in #Raku
Create a network service that sits on TCP port 12321, which accepts connections on that port, and which echoes complete lines (using a carriage-return/line-feed sequence as line separator) back to clients. No error handling is required. For the purposes of testing, it is only necessary to ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Delegates | Delegates | A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern.
Objects ... | #zkl | zkl | class Thingable{ var thing; }
class Delegator{
var delegate;
fcn operation{
if (delegate) delegate.thing;
else "default implementation"
}
}
class Delegate(Thingable){ thing = "delegate implementation" } | Give a code snippet in #zkl
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cistercian_numerals | Cistercian numerals | Cistercian numerals were used across Europe by Cistercian monks during the Late Medieval Period as an alternative to Roman numerals. They were used to represent base 10 integers from 0 to 9999.
How they work
All Cistercian numerals begin with a vertical line segment, which by itself represents the number 0. Then, glyp... | #J | J | main'jc.svg'[load'jc.ijs'
open browser to /tmp/jc.svg
| Give a code snippet in #J
Cistercian numerals were used across Europe by Cistercian monks during the Late Medieval Period as an alternative to Roman numerals. They were used to represent base 10 integers from 0 to 9999.
How they work
All Cistercian numerals begin with a vertical line segment, which by itself represen... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Polynomial_long_division | Polynomial long division |
This page uses content from Wikipedia. The original article was at Polynomial long division. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In algebra, polynomial long division is an algorithm for d... | #Clojure | Clojure | (defn grevlex [term1 term2]
(let [grade1 (reduce +' term1)
grade2 (reduce +' term2)
comp (- grade2 grade1)] ;; total degree
(if (not= 0 comp)
comp
(loop [term1 term1
term2 term2]
(if (empty? term1)
0
(let [grade1 (last term1)
gra... | Give a code snippet in #Clojure
This page uses content from Wikipedia. The original article was at Polynomial long division. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In algebra, polynomial lo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Gray_code | Gray code | Gray code
Karnaugh maps
Create functions to encode a number to and decode a number from Gray code.
Display the normal binary representations, Gray code representations, and decoded Gray code values for all 5-bit binary numbers (0-31 inclusive, leading 0's not necessary).
There are many possible Gray codes. The follow... | #Factor | Factor | USING: math.ranges locals ;
IN: rosetta-gray
: gray-encode ( n -- n' ) dup -1 shift bitxor ;
:: gray-decode ( n! -- n' )
n :> p!
[ n -1 shift dup n! 0 = not ] [
p n bitxor p!
] while
p ;
: main ( -- )
-1 32 [a,b] [ dup [ >bin ] [ gray-encode ] bi [ >bin ] [ gray-decode ] bi 4array . ] each ;... | Give a code snippet in #Factor
Gray code
Karnaugh maps
Create functions to encode a number to and decode a number from Gray code.
Display the normal binary representations, Gray code representations, and decoded Gray code values for all 5-bit binary numbers (0-31 inclusive, leading 0's not necessary).
There are many... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Collections | Collections | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Collections are abstractions to represent sets of values.
In statically-typed languages, the values are typically of a common data type.
Task
Create a collection, and add a fe... | #PARI.2FGP | PARI/GP | v = vector(0);
v = [];
cv = vectorv(0);
cv = []~;
m = matrix(1,1);
s = Set(v);
l = List(v);
vs = vectorsmall(0);
M = Map() | Give a code snippet in #PARI.2FGP
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Collections are abstractions to represent sets of values.
In statically-typed languages, the values are typically of a common data type.
Task... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Metronome | Metronome |
The task is to implement a metronome.
The metronome should be capable of producing high and low audio beats, accompanied by a visual beat indicator, and the beat pattern and tempo should be configurable.
For the purpose of this task, it is acceptable to play sound files for production of the beat notes, and an ext... | #Scala | Scala | def metronome(bpm: Int, bpb: Int, maxBeats: Int = Int.MaxValue) {
val delay = 60000L / bpm
var beats = 0
do {
Thread.sleep(delay)
if (beats % bpb == 0) print("\nTICK ")
else print("tick ")
beats+=1
}
while (beats < maxBeats)
println()
}
metronome(120, 4, 20) // limit to 20 | Give a code snippet in #Scala
The task is to implement a metronome.
The metronome should be capable of producing high and low audio beats, accompanied by a visual beat indicator, and the beat pattern and tempo should be configurable.
For the purpose of this task, it is acceptable to play sound files for productio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Caesar_cipher | Caesar cipher |
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A).
So key 2 encrypts "HI" to... | #OCaml | OCaml | let islower c =
c >= 'a' && c <= 'z'
let isupper c =
c >= 'A' && c <= 'Z'
let rot x str =
let upchars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
and lowchars = "abcdefghijklmnopqrstuvwxyz" in
let rec decal x =
if x < 0 then decal (x + 26) else x
in
let x = (decal x) mod 26 in
let decal_up = x - (int_of_char... | Give a code snippet in #OCaml
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to... | 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.... | #C | C | #include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
/* Generate (and memoize) the Padovan sequence using
* the recurrence relationship */
int pRec(int n) {
static int *memo = NULL;
static size_t curSize = 0;
/* grow memoization array when necessary and fill with zeroes */
i... | Give a code snippet in #C
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/First_class_environments | First class environments | According to Wikipedia, "In computing, a first-class object ... is an entity that can be constructed at run-time, passed as a parameter, returned from a subroutine, or assigned into a variable".
Often this term is used in the context of "first class functions". In an analogous way, a programming language may support "... | #jq | jq | { "value": <HAILSTONE>, "count": <COUNT> }
| Give a code snippet in #jq
According to Wikipedia, "In computing, a first-class object ... is an entity that can be constructed at run-time, passed as a parameter, returned from a subroutine, or assigned into a variable".
Often this term is used in the context of "first class functions". In an analogous way, a progra... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zumkeller_numbers | Zumkeller numbers | Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the divisors are partitioned, only that ... | #Python | Python | from sympy import divisors
from sympy.combinatorics.subsets import Subset
def isZumkeller(n):
d = divisors(n)
s = sum(d)
if not s % 2 and max(d) <= s/2:
for x in range(1, 2**len(d)):
if sum(Subset.unrank_binary(x, d).subset) == s/2:
return True
return False
... | Give a code snippet in #Python
Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the divi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Convert_seconds_to_compound_duration | Convert seconds to compound duration | Task
Write a function or program which:
takes a positive integer representing a duration in seconds as input (e.g., 100), and
returns a string which shows the same duration decomposed into:
weeks,
days,
hours,
minutes, and
seconds.
This is detailed below (e.g., "2 hr, 59 sec").
Demonstrat... | #Clojure | Clojure | (require '[clojure.string :as string])
(def seconds-in-minute 60)
(def seconds-in-hour (* 60 seconds-in-minute))
(def seconds-in-day (* 24 seconds-in-hour))
(def seconds-in-week (* 7 seconds-in-day))
(defn seconds->duration [seconds]
(let [weeks ((juxt quot rem) seconds seconds-in-week)
wk (first w... | Give a code snippet in #Clojure
Task
Write a function or program which:
takes a positive integer representing a duration in seconds as input (e.g., 100), and
returns a string which shows the same duration decomposed into:
weeks,
days,
hours,
minutes, and
seconds.
This is detailed below (e.g... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Comments | Comments | Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| #Chapel | Chapel | // single line
/* multi
line */ | Give a code snippet in #Chapel
Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_definition | Function definition | A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are ... | #Fexl | Fexl | \multiply=(\x\y * x y) | Give a code snippet in #Fexl
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Classes | Classes | In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of the class.
A class of types itself, a... | #Processing | Processing | class ProgrammingLanguage
{
// instance variable:
private String name;
// constructor (let's use it to give the instance variable a value):
public ProgrammingLanguage(String name)
{
this.name = name;
// note use of "this" to distinguish the instance variable from the argument
}
// a met... | Give a code snippet in #Processing
In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Long_multiplication | Long multiplication | Task
Explicitly implement long multiplication.
This is one possible approach to arbitrary-precision integer algebra.
For output, display the result of 264 * 264.
Optionally, verify your result against builtin arbitrary precision support.
The decimal representation of 264 is:
18,446,744,073,709,551,61... | #Haskell | Haskell | import Data.List (transpose, inits)
import Data.Char (digitToInt)
longmult :: Integer -> Integer -> Integer
longmult x y = foldl1 ((+) . (10 *)) (polymul (digits x) (digits y))
polymul :: [Integer] -> [Integer] -> [Integer]
polymul xs ys =
sum <$>
transpose
(zipWith
(<>)
(inits $ repeat 0)
... | Give a code snippet in #Haskell
Task
Explicitly implement long multiplication.
This is one possible approach to arbitrary-precision integer algebra.
For output, display the result of 264 * 264.
Optionally, verify your result against builtin arbitrary precision support.
The decimal representation of 264 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Levenshtein_distance | Levenshtein distance |
This page uses content from Wikipedia. The original article was at Levenshtein distance. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In information theory and computer science, the Levenshtein ... | #Iterative | Iterative | levenshtein(S,T) = Dist =>
M = 1+S.length,
N = 1+T.length,
D = new_array(M,N),
foreach(I in 1..M)
D[I,1] := I-1
end,
foreach(J in 1..N)
D[1,J] := J-1
end,
foreach(J in 2..N, I in 2..M)
if S[I-1] == T[J-1] then
D[I,J] := D[I-1,J-1] % no operation required
else
... | Give a code snippet in #Iterative
This page uses content from Wikipedia. The original article was at Levenshtein distance. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In information theory and... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Pythagorean_means | Averages/Pythagorean means | Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldots ,x_{n})}
for this set of p... | #VBScript | VBScript |
Function arithmetic_mean(arr)
sum = 0
For i = 0 To UBound(arr)
sum = sum + arr(i)
Next
arithmetic_mean = sum / (UBound(arr)+1)
End Function
Function geometric_mean(arr)
product = 1
For i = 0 To UBound(arr)
product = product * arr(i)
Next
geometric_mean = product ^ (1/(UBound(arr)+1))
End Function
Func... | Give a code snippet in #VBScript
Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Penney%27s_game | Penney's game | Penney's game is a game where two players bet on being the first to see a particular sequence of heads or tails in consecutive tosses of a fair coin.
It is common to agree on a sequence length of three then one player will openly choose a sequence, for example:
Heads, Tails, Heads, or HTH for short.
The other pla... | #BASIC | BASIC |
global jugador, computador, secuencia
jugador = "" : computador = ""
function SecuenciaJugador(secuencia)
do
valido = TRUE
print chr(10) + "Ingresa una secuencia de 3 opciones, cada una de ellas H o T:";
input " > ", secuencia
secuencia = upper(secuencia)
if length(secuencia) <> 3 then valido = FALSE
i... | Give a code snippet in #BASIC
Penney's game is a game where two players bet on being the first to see a particular sequence of heads or tails in consecutive tosses of a fair coin.
It is common to agree on a sequence length of three then one player will openly choose a sequence, for example:
Heads, Tails, Heads, o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Extreme_floating_point_values | Extreme floating point values | The IEEE floating point specification defines certain 'extreme' floating point values such as minus zero, -0.0, a value distinct from plus zero; not a number, NaN; and plus and minus infinity.
The task is to use expressions involving other 'normal' floating point values in your language to calculate these, (and maybe ... | #PicoLisp | PicoLisp | (load "@lib/math.l")
: (exp 1000.0) # Too large for IEEE floats
-> T
: (+ 1 2 NIL 3) # NaN propagates
-> NIL | Give a code snippet in #PicoLisp
The IEEE floating point specification defines certain 'extreme' floating point values such as minus zero, -0.0, a value distinct from plus zero; not a number, NaN; and plus and minus infinity.
The task is to use expressions involving other 'normal' floating point values in your langua... | 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 ... | #Ada | Ada | with Ada.Text_Io;
with Ada.Integer_Text_Io;
procedure Equal_Rise_Fall is
use Ada.Text_Io;
function Has_Equal_Rise_Fall (Value : Natural) return Boolean is
Rises : Natural := 0;
Falls : Natural := 0;
Image : constant String := Natural'Image (Value);
Last : Character := Image (Image'Fir... | Give a code snippet in #Ada
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 i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Almost_prime | Almost prime | A k-Almost-prime is a natural number
n
{\displaystyle n}
that is the product of
k
{\displaystyle k}
(possibly identical) primes.
Example
1-almost-primes, where
k
=
1
{\displaystyle k=1}
, are the prime numbers themselves.
2-almost-primes, where
k
=
2
{\displaystyl... | #Arturo | Arturo | almostPrime: function [k, listLen][
result: new []
test: 2
c: 0
while [c < listLen][
i: 2
m: 0
n: test
while [i =< n][
if? zero? n % i [
n: n / i
m: m + 1
]
else -> i: i + 1
]
if m = k... | Give a code snippet in #Arturo
A k-Almost-prime is a natural number
n
{\displaystyle n}
that is the product of
k
{\displaystyle k}
(possibly identical) primes.
Example
1-almost-primes, where
k
=
1
{\displaystyle k=1}
, are the prime numbers themselves.
2-almost-primes, w... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, gi... | #ActionScript | ActionScript |
package
{
public class ZigZagMatrix extends Array
{
private var height:uint;
private var width:uint;
public var mtx:Array = [];
public function ZigZagMatrix(size:uint)
{
this.height = size;
this.width = size;
this.mtx = [];
for (var i:uint... | Give a code snippet in #ActionScript
Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Shell_sort | Sorting algorithms/Shell 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
... | #Pascal | Pascal | Const
MaxN = 100; { number of elements (my example is 100) }
Type
TArray = Array [0..MaxN] of Integer;
Procedure ShellSort ( var A : TArray; N : Integer );
Var
i, j, step, tmp : Integer;
Begin
step:=N div 2; // step:=step shr 1
While step>0 Do Begin
For i:=step to N Do Begin
tmp:=A[i];
j:=i... | Give a code snippet in #Pascal
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 s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Prime_triangle | Prime triangle | You will require a function f which when given an integer S will return a list of the arrangements of the integers 1 to S such that g1=1 gS=S and generally for n=1 to n=S-1 gn+gn+1 is prime. S=1 is undefined. For S=2 to S=20 print f(S) to form a triangle. Then again for S=2 to S=20 print the number of possible arrangem... | #Rust | Rust | fn is_prime(n: u32) -> bool {
assert!(n < 64);
((1u64 << n) & 0x28208a20a08a28ac) != 0
}
fn prime_triangle_row(a: &mut [u32]) -> bool {
if a.len() == 2 {
return is_prime(a[0] + a[1]);
}
for i in (1..a.len() - 1).step_by(2) {
if is_prime(a[0] + a[i]) {
a.swap(i, 1);
... | Give a code snippet in #Rust
You will require a function f which when given an integer S will return a list of the arrangements of the integers 1 to S such that g1=1 gS=S and generally for n=1 to n=S-1 gn+gn+1 is prime. S=1 is undefined. For S=2 to S=20 print f(S) to form a triangle. Then again for S=2 to S=20 print t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/100_prisoners | 100 prisoners |
The Problem
100 prisoners are individually numbered 1 to 100
A room having a cupboard of 100 opaque drawers numbered 1 to 100, that cannot be seen from outside.
Cards numbered 1 to 100 are placed randomly, one to a drawer, and the drawers all closed; at the start.
Prisoners start outside the room
They can decid... | #Sather | Sather | class MAIN is
shuffle (a: ARRAY{INT}) is
ARR_PERMUTE_ALG{INT, ARRAY{INT}}::shuffle(a);
end;
try_random (n: INT, drawers: ARRAY{INT}, tries: INT): BOOL is
my_tries ::= drawers.inds; shuffle(my_tries);
loop tries.times!;
if drawers[my_tries.elt!] = n then return true; end;
end;... | Give a code snippet in #Sather
The Problem
100 prisoners are individually numbered 1 to 100
A room having a cupboard of 100 opaque drawers numbered 1 to 100, that cannot be seen from outside.
Cards numbered 1 to 100 are placed randomly, one to a drawer, and the drawers all closed; at the start.
Prisoners start ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pragmatic_directives | Pragmatic directives | Pragmatic directives cause the language to operate in a specific manner, allowing support for operational variances within the program code (possibly by the loading of specific or alternative modules).
Task
List any pragmatic directives supported by the language, and demonstrate how to activate and deactivate... | #Wren | Wren | /* windows.wren */
class Windows {
static message { "Using Windows" }
static lineSeparator { "\\r\\n" }
} | Give a code snippet in #Wren
Pragmatic directives cause the language to operate in a specific manner, allowing support for operational variances within the program code (possibly by the loading of specific or alternative modules).
Task
List any pragmatic directives supported by the language, and demonstrate ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Order_two_numerical_lists | Order two numerical lists | sorting
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
She... | #AutoHotkey | AutoHotkey | List1 := [1,2,1,3,2]
List2 := [1,2,0,4,4,0,0,0]
MsgBox % order(List1, List2)
order(L1, L2){
return L1.MaxIndex() < L2.MaxIndex()
} | Give a code snippet in #AutoHotkey
sorting
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 so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zebra_puzzle | Zebra puzzle | Zebra puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
The Zebra puzzle, a.k.a. Einstein's Riddle,
is a logic puzzle which is to be solved programmatically.
It has several variants, one of them this:
There are five houses.
The English man lives ... | #Nial | Nial |
remove is op x xs {filter (not (x =)) xs}
append_map is transformer func op seq { \
reduce (op x xs { (func x) link xs}) (seq append []) }
permutations is op seq { \
if empty seq then [[]] else \
(append_map \
(op head {each (op tail {head hitch tail}) \
(permutations (remove he... | Give a code snippet in #Nial
Zebra puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
The Zebra puzzle, a.k.a. Einstein's Riddle,
is a logic puzzle which is to be solved programmatically.
It has several variants, one of them this:
There are five hou... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mutual_recursion | Mutual recursion | Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n
)
=
n
−
M
(
F
(
n
−
1
)
)
,
... | #JavaScript | JavaScript | function f(num) {
return (num === 0) ? 1 : num - m(f(num - 1));
}
function m(num) {
return (num === 0) ? 0 : num - f(m(num - 1));
}
function range(m, n) {
return Array.apply(null, Array(n - m + 1)).map(
function (x, i) { return m + i; }
);
}
var a = range(0, 19);
//return a new array of the results an... | Give a code snippet in #JavaScript
Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Repeat_a_string | Repeat a string | Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").
Other tasks re... | #Scala | Scala | "ha" * 5 // ==> "hahahahaha" | Give a code snippet in #Scala
Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers | Luhn test of credit card numbers | The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order of the digits in the number.
Tak... | #IS-BASIC | IS-BASIC | 100 PROGRAM "CredCard.bas"
110 DO
120 PRINT :PRINT "Credit card number:":INPUT PROMPT ">":CCN$
130 IF CCN$="" THEN EXIT DO
140 IF LUHN(TRIM$(CCN$)) THEN
150 PRINT "Card number is valid."
160 ELSE
170 SET #102:INK 3:PRINT "Card number is invalid.":SET #102:INK 1
180 END IF
190 LOOP
200 DEF LUHN(CCN$)
2... | Give a code snippet in #IS-BASIC
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Iteration | Associative array/Iteration | Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked ... | #AWK | AWK | BEGIN {
a["hello"] = 1
a["world"] = 2
a["!"] = 3
# iterate over keys, undefined order
for(key in a) {
print key, a[key]
}
} | Give a code snippet in #AWK
Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Compo... | christopher/rosetta-code |
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