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/Write_language_name_in_3D_ASCII | Write language name in 3D ASCII | Task
Write/display a language's name in 3D ASCII.
(We can leave the definition of "3D ASCII" fuzzy,
so long as the result is interesting or amusing,
not a cheap hack to satisfy the task.)
Related tasks
draw a sphere
draw a cuboid
draw a rotating cube
draw a Deathstar
| #Ruby | Ruby | text = <<EOS
#### #
# # #
# # #
#### # # ### # #
# # # # # # # #
# # # # # # #
# # ### ### #
#
#
EOS
def banner3D_1(text, shift=-1)
txt = text.each_line.map{|line| line.gsub('#','__/').gsub(' ',' ')}
offset = Array.new(txt.size){|i... | Give a code snippet in #Ruby
Task
Write/display a language's name in 3D ASCII.
(We can leave the definition of "3D ASCII" fuzzy,
so long as the result is interesting or amusing,
not a cheap hack to satisfy the task.)
Related tasks
draw a sphere
draw a cuboid
draw a rotating cube
draw a Deathstar
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping | Sutherland-Hodgman polygon clipping | The Sutherland-Hodgman clipping algorithm finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”).
It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a... | #C | C | #include <stdio.h>
#include <stdlib.h>
#include <math.h>
typedef struct { double x, y; } vec_t, *vec;
inline double dot(vec a, vec b)
{
return a->x * b->x + a->y * b->y;
}
inline double cross(vec a, vec b)
{
return a->x * b->y - a->y * b->x;
}
inline vec vsub(vec a, vec b, vec res)
{
res->x = a->x - b->x;
r... | Give a code snippet in #C
The Sutherland-Hodgman clipping algorithm finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”).
It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displaye... | christopher/rosetta-code | |
http://rosettacode.org/wiki/XML/Input | XML/Input | Given the following XML fragment, extract the list of student names using whatever means desired. If the only viable method is to use XPath, refer the reader to the task XML and XPath.
<Students>
<Student Name="April" Gender="F" DateOfBirth="1989-01-02" />
<Student Name="Bob" Gender="M" DateOfBirth="1990-03-04" /... | #Bracmat | Bracmat | ( :?names
& ( get$("students.xml",X,ML)
: ?
( ( Student
. (? (Name.?name) ?,)
| ? (Name.?name) ?
)
& !names !name:?names
& ~
)
?
| !names
)
) | Give a code snippet in #Bracmat
Given the following XML fragment, extract the list of student names using whatever means desired. If the only viable method is to use XPath, refer the reader to the task XML and XPath.
<Students>
<Student Name="April" Gender="F" DateOfBirth="1989-01-02" />
<Student Name="Bob" Gende... | 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... | #J | J | NB. Create a "Point" class
coclass'Point'
NB. Define its constructor
create =: 3 : 0
'X Y' =: y
)
NB. Instantiate an instance (i.e. an object)
cocurrent 'base'
P =: 10 20 conew 'Point'
NB. Interrogate its members
X__P
10
Y__P
20 | Give a code snippet in #J
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.
Relat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Write_a_PPM_file | Bitmap/Write a PPM file | Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| #Go | Go | package raster
import (
"fmt"
"io"
"os"
)
// WriteTo outputs 8-bit P6 PPM format to an io.Writer.
func (b *Bitmap) WritePpmTo(w io.Writer) (err error) {
// magic number
if _, err = fmt.Fprintln(w, "P6"); err != nil {
return
}
// comments
for _, c := range b.Comments {
... | Give a code snippet in #Go
Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/FizzBuzz | FizzBuzz | Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuzz (instead of the number)
... | #Lambdatalk | Lambdatalk |
1. direct:
{S.map
{lambda {:i}
{if {= {% :i 15} 0}
then fizzbuzz
else {if {= {% :i 3} 0}
then fizz
else {if {= {% :i 5} 0}
then buzz
else :i}}}}
{S.serie 1 100}}
-> 1 2 fizz 4 buzz fizz 7 8 fizz buzz 11 fizz 13 14 fizzbuzz 16 17 fizz 19 buzz fizz 22 23 fizz buzz 26 fizz 28 29 fizzbuzz 31... | Give a code snippet in #Lambdatalk
Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print Fiz... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Top_rank_per_group | Top rank per group | Task
Find the top N salaries in each department, where N is provided as a parameter.
Use this data as a formatted internal data structure (adapt it to your language-native idioms, rather than parse at runtime), or identify your external data source:
Employee Name,Employee ID,Salary,Department
Tyler Bennett... | #XPL0 | XPL0 | proc Sort(Array, Field, Size); \Sort Array in descending order by Field
int Array, Field, Size, I, J, T;
[for J:= Size-1 downto 0 do
for I:= 0 to J-1 do
if Array(I,Field) < Array(I+1,Field) then
[T:= Array(I); Array(I):= Array(I+1); Array(I+1):= T];
];
int Data, I, I0, Dept, N, Cnt;
[Data:... | Give a code snippet in #XPL0
Task
Find the top N salaries in each department, where N is provided as a parameter.
Use this data as a formatted internal data structure (adapt it to your language-native idioms, rather than parse at runtime), or identify your external data source:
Employee Name,Employee ID,S... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Standard_error | Hello world/Standard error | Hello world/Standard error is part of Short Circuit's Console Program Basics selection.
A common practice in computing is to send error messages
to a different output stream than normal text console messages.
The normal messages print to what is called "standard output" or "standard out".
The error messages print to ... | #Avail | Avail | Error: "Goodbye, World!"; | Give a code snippet in #Avail
Hello world/Standard error is part of Short Circuit's Console Program Basics selection.
A common practice in computing is to send error messages
to a different output stream than normal text console messages.
The normal messages print to what is called "standard output" or "standard out"... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Vogel%27s_approximation_method | Vogel's approximation method | Vogel's Approximation Method (VAM) is a technique for finding a good initial feasible solution to an allocation problem.
The powers that be have identified 5 tasks that need to be solved urgently. Being imaginative chaps, they have called them “A”, “B”, “C”, “D”, and “E”. They estimate that:
A will require 30 hours ... | #Tcl | Tcl | package require Tcl 8.6
# A sort that works by sorting by an auxiliary key computed by a lambda term
proc sortByFunction {list lambda} {
lmap k [lsort -index 1 [lmap k $list {
list $k [uplevel 1 [list apply $lambda $k]]
}]] {lindex $k 0}
}
# A simple way to pick a “best” item from a list
proc minimax {list... | Give a code snippet in #Tcl
Vogel's Approximation Method (VAM) is a technique for finding a good initial feasible solution to an allocation problem.
The powers that be have identified 5 tasks that need to be solved urgently. Being imaginative chaps, they have called them “A”, “B”, “C”, “D”, and “E”. They estimate tha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_join | Hash join | An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash join" algorithm, and demonstrate tha... | #TXR | TXR | (defvar age-name '((27 Jonah)
(18 Alan)
(28 Glory)
(18 Popeye)
(28 Alan)))
(defvar nemesis-name '((Jonah Whales)
(Jonah Spiders)
(Alan Ghosts)
(Alan Zombies)
... | Give a code snippet in #TXR
An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash join" a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third... | #AmigaE | AmigaE | PROC main()
DEF t[100]: ARRAY,
pass, door
FOR door := 0 TO 99 DO t[door] := FALSE
FOR pass := 0 TO 99
door := pass
WHILE door <= 99
t[door] := Not(t[door])
door := door + pass + 1
ENDWHILE
ENDFOR
FOR door := 0 TO 99 DO WriteF('\d is \s\n', door+1,
... | Give a code snippet in #AmigaE
There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, .... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Statistics/Basic | Statistics/Basic | Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldots ,n\,\!}
, the mean is
x
¯... | #Stata | Stata | . clear all
. set obs 100000
number of observations (_N) was 0, now 100,000
. gen x=runiform()
. summarize x
Variable | Obs Mean Std. Dev. Min Max
-------------+---------------------------------------------------------
x | 100,000 .4991874 .2885253 1.18e-06 .9... | Give a code snippet in #Stata
Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldots ,n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Element_definition | Doubly-linked list/Element definition | Task
Define the data structure for a doubly-linked list element.
The element should include a data member to hold its value and pointers to both the next element in the list and the previous element in the list.
The pointers should be mutable.
See also
Array
Associative array: Creation, Iteration
Collections
... | #OCaml | OCaml | type 'a dlink = {
mutable data: 'a;
mutable next: 'a dlink option;
mutable prev: 'a dlink option;
}
let dlink_of_list li =
let f prev_dlink x =
let dlink = {
data = x;
prev = None;
next = prev_dlink }
in
begin match prev_dlink with
| None -> ()
| Some prev_dlink ->
... | Give a code snippet in #OCaml
Task
Define the data structure for a doubly-linked list element.
The element should include a data member to hold its value and pointers to both the next element in the list and the previous element in the list.
The pointers should be mutable.
See also
Array
Associative array: Cr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Run-length_encoding | Run-length encoding | Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a function to reverse the compression... | #Run_BASIC | Run BASIC | string$ = "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW"
beg = 1
i = 1
[loop]
s$ = mid$(string$,beg,1)
while mid$(string$,i,1) = s$
i = i + 1
wend
press$ = press$ ; i-beg;s$
beg = i
if i < len(string$) then goto [loop]
print "Compressed:";press$
beg = 1
i = 1
[expand]
while mid$(press$... | Give a code snippet in #Run_BASIC
Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Closest-pair_problem | Closest-pair problem |
This page uses content from Wikipedia. The original article was at Closest pair of points problem. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Provide a function to find the closest two p... | #Elixir | Elixir | defmodule Closest_pair do
# brute-force algorithm:
def bruteForce([p0,p1|_] = points), do: bf_loop(points, {distance(p0, p1), {p0, p1}})
defp bf_loop([_], acc), do: acc
defp bf_loop([h|t], acc), do: bf_loop(t, bf_loop(h, t, acc))
defp bf_loop(_, [], acc), do: acc
defp bf_loop(p0, [p1|t], {minD, minP}) d... | Give a code snippet in #Elixir
This page uses content from Wikipedia. The original article was at Closest pair of points problem. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Provide a fu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Faulhaber%27s_formula | Faulhaber's formula | In mathematics, Faulhaber's formula, named after Johann Faulhaber, expresses the sum of the p-th powers of the first n positive integers as a (p + 1)th-degree polynomial function of n, the coefficients involving Bernoulli numbers.
Task
Generate the first 10 closed-form expressions, starting with p = 0.
R... | #Maxima | Maxima | sum1(p):=sum(stirling2(p,k)*pochhammer(n-k+1,k+1)/(k+1),k,0,p)$
sum2(p):=sum((-1)^j*binomial(p+1,j)*bern(j)*n^(p-j+1),j,0,p)/(p+1)$
makelist(expand(sum1(p)-sum2(p)),p,1,10);
[0,0,0,0,0,0,0,0,0,0]
for p from 0 thru 9 do print(expand(sum2(p))); | Give a code snippet in #Maxima
In mathematics, Faulhaber's formula, named after Johann Faulhaber, expresses the sum of the p-th powers of the first n positive integers as a (p + 1)th-degree polynomial function of n, the coefficients involving Bernoulli numbers.
Task
Generate the first 10 closed-form expres... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_and_product_of_an_array | Sum and product of an array | Task
Compute the sum and product of an array of integers.
| #AutoHotkey | AutoHotkey | numbers = 1,2,3,4,5
product := 1
loop, parse, numbers, `,
{
sum += A_LoopField
product *= A_LoopField
}
msgbox, sum = %sum%`nproduct = %product% | Give a code snippet in #AutoHotkey
Task
Compute the sum and product of an array of integers.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Roman_numerals/Decode | Roman numerals/Decode | Task
Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer.
You don't need to validate the form of the Roman numeral.
Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately,
starting with the leftmost decima... | #Jsish | Jsish | prompt$ jsish -e 'require("Roman"); puts(Roman.fromRoman("MDCLXVI"));'
1666 | Give a code snippet in #Jsish
Task
Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer.
You don't need to validate the form of the Roman numeral.
Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately,
st... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Foreach | Loops/Foreach | Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for... | #Nanoquery | Nanoquery | for item in collection
println item
end | Give a code snippet in #Nanoquery
Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
L... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Comma_quibbling | Comma quibbling | Comma quibbling is a task originally set by Eric Lippert in his blog.
Task
Write a function to generate a string output which is the concatenation of input words from a list/sequence where:
An input of no words produces the output string of just the two brace characters "{}".
An input of just one word, e.g. ["AB... | #Oberon-2 | Oberon-2 |
MODULE CommaQuibbling;
IMPORT
NPCT:Args,
Strings,
Out;
VAR
str: ARRAY 256 OF CHAR;
PROCEDURE Do(VAR s: ARRAY OF CHAR);
VAR
aux: ARRAY 128 OF CHAR;
i,params: LONGINT;
BEGIN
params := Args.Number() - 1;
CASE params OF
0:
COPY("{}",s)
|1:
Args.At(1,aux);
... | Give a code snippet in #Oberon-2
Comma quibbling is a task originally set by Eric Lippert in his blog.
Task
Write a function to generate a string output which is the concatenation of input words from a list/sequence where:
An input of no words produces the output string of just the two brace characters "{}".
An... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Downward_for | Loops/Downward for | Task
Write a for loop which writes a countdown from 10 to 0.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop body... | #M2000_Interpreter | M2000 Interpreter |
For i=1 to 10 step 2 : Print i : Next i
| Give a code snippet in #M2000_Interpreter
Task
Write a for loop which writes a countdown from 10 to 0.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
... | 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... | #XPL0 | XPL0 | include c:\cxpl\codes; \intrinsic 'code' declarations
int I;
[RanSeed(12345); \set random number generator seed to 12345
for I:= 1 to 5 do
[IntOut(0, Ran(1_000_000)); CrLf(0)];
] | Give a code snippet in #XPL0
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_squares | Sum of squares | Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "float.s7i";
const array float: list1 is [] (3.0, 1.0, 4.0, 1.0, 5.0, 9.0);
const array float: list2 is 0 times 0.0;
const func float: squaredSum (in array float: floatList) is func
result
var float: sum is 0.0;
local
var float: number is 0.0;
begin
for number r... | Give a code snippet in #Seed7
Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Draw_a_sphere | Draw a sphere | Task
Draw a sphere.
The sphere can be represented graphically, or in ASCII art, depending on the language capabilities.
Either static or rotational projection is acceptable for this task.
Related tasks
draw a cuboid
draw a rotating cube
write language name in 3D ASCII
draw a Deathstar
| #jq | jq | def svg:
"<svg width='100%' height='100%' version='1.1'
xmlns='http://www.w3.org/2000/svg'
xmlns:xlink='http://www.w3.org/1999/xlink'>" ;
# A radial gradient to make a circle look like a sphere.
# "colors" should be [startColor, intermediateColor, endColor]
# or null for ["white", "teal", "black"]
def sphe... | Give a code snippet in #jq
Task
Draw a sphere.
The sphere can be represented graphically, or in ASCII art, depending on the language capabilities.
Either static or rotational projection is acceptable for this task.
Related tasks
draw a cuboid
draw a rotating cube
write language name in 3D ASCII
draw a Death... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Text_processing/1 | Text processing/1 | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another pr... | #REXX | REXX | /*REXX program to process instrument data from a data file. */
numeric digits 20 /*allow for bigger (precision) numbers.*/
ifid='READINGS.TXT' /*the name of the input file. */
ofid='READINGS.OUT' /* " " " " output " ... | Give a code snippet in #REXX
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Often data is produced by one program, in the wrong format for later use by another program or person. ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Amb | Amb | Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton").
The Amb operator takes a v... | #Common_Lisp | Common Lisp | (define-condition amb-failure () ()
(:report "No amb alternative succeeded."))
(defun invoke-ambiguously (function thunks)
"Call function with successive values produced by successive
functions in thunks until some invocation of function does not signal
an amb-failure."
(do ((thunks thunks (rest thunks)))
... | Give a code snippet in #Common_Lisp
Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite aut... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_and_product_puzzle | Sum and product puzzle | Task[edit]
Solve the "Impossible Puzzle":
X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in th... | #Nim | Nim | import sequtils, sets, sugar, tables
var
xycandidates = toSeq(2..98)
sums = collect(initHashSet, for s in 5..100: {s}) # Set of possible sums.
factors: Table[int, seq[(int, int)]] # Mapping product -> list of factors.
# Build the factor mapping.
for i in 0..<xycandidates.high:
let x = xycan... | Give a code snippet in #Nim
Task[edit]
Solve the "Impossible Puzzle":
X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P k... | 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.... | #Smalltalk | Smalltalk | String subclass: Mutant [
<shape: #character>
Target := Mutant from: 'METHINKS IT IS LIKE A WEASEL'.
Letters := ' ABCDEFGHIJKLMNOPQRSTUVWXYZ'.
Mutant class >> run: c rate: p
["Run Evolutionary algorighm, using c copies and mutate rate p."
| pool parent |
parent := self newRan... | Give a code snippet in #Smalltalk
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/Brace_expansion | Brace expansion | Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified.
Task[edit]
W... | #Visual_Basic_.NET | Visual Basic .NET | Module Module1
Function GetGroup(s As String, depth As Integer) As Tuple(Of List(Of String), String)
Dim out As New List(Of String)
Dim comma = False
While Not String.IsNullOrEmpty(s)
Dim gs = GetItem(s, depth)
Dim g = gs.Item1
s = gs.Item2
I... | Give a code snippet in #Visual_Basic_.NET
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enabl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if ... | #Julia | Julia |
using AnsiColor
function showbasecolors()
for color in keys(Base.text_colors)
print_with_color(color, " ", string(color), " ")
end
println()
end
function showansicolors()
for fore in keys(AnsiColor.COLORS)
print(@sprintf("%15s ", fore))
for back in keys(AnsiColor.COLORS)
... | Give a code snippet in #Julia
Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to ... | 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... | #Zig | Zig | const std = @import("std");
pub fn main() !void {
const stdout_wr = std.io.getStdOut().writer();
const string = "alphaBETA";
var lower: [string.len]u8 = undefined;
var upper: [string.len]u8 = undefined;
for (string) |char, i| {
lower[i] = std.ascii.toLower(char);
upper[i] = std.asc... | Give a code snippet in #Zig
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 rev... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Square_but_not_cube | Square but not cube | Task
Show the first 30 positive integers which are squares but not cubes of such integers.
Optionally, show also the first 3 positive integers which are both squares and cubes, and mark them as such.
| #BASIC | BASIC | 10 DEFINT C,S,Q,R,N: C=1: S=1: Q=1: R=1: N=1
20 IF N>30 THEN END
30 S=Q*Q
40 IF S>C THEN R=R+1: C=R*R*R: GOTO 40
50 IF S<C THEN N=N+1: PRINT S;
60 Q=Q+1
70 GOTO 20 | Give a code snippet in #BASIC
Task
Show the first 30 positive integers which are squares but not cubes of such integers.
Optionally, show also the first 3 positive integers which are both squares and cubes, and mark them as such.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_comparison | Integer comparison |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols nobinary
numL = 0
numR = 0
loop label running forever
say 'Provide two integers [or anything else to stop]:'
parse ask numL numR .
if \numL.datatype('w') | \numR.datatype('w') then leave running
if numL < numR then say numL 'is less than' num... | Give a code snippet in #NetRexx
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 Operation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Selection_sort | Sorting algorithms/Selection 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
... | #BBC_BASIC | BBC BASIC | DEF PROC_SelectionSort(Size%)
FOR I% = 1 TO Size%-1
lowest% = I%
FOR J% = (I% + 1) TO Size%
IF data%(J%) < data%(lowest%) lowest% = J%
NEXT J%
IF I%<>lowest% SWAP data%(I%),data%(lowest%)
NEXT I%
ENDPROC | Give a code snippet in #BBC_BASIC
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 |
Quic... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #Icon_and_Unicon | Icon and Unicon | procedure main()
s := "A simple string"
p := "string$" # regular expression
s ? write(image(s),if ReFind(p) then " matches " else " doesn't match ",image(p))
s[j := ReFind(p,s):ReMatch(p,s,j)] := "replacement"
write(image(s))
end
link regexp # link to IPL regexp | Give a code snippet in #Icon_and_Unicon
Task
match a string against a regular expression
substitute part of a string using a regular expression
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_an_integer_array | Sort an integer array |
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
... | #Stata | Stata | . clear
. matrix a=(2,9,4,7,5,3,6,1,8)'
. qui svmat a
. sort a
. list
+----+
| a1 |
|----|
1. | 1 |
2. | 2 |
3. | 3 |
4. | 4 |
5. | 5 |
|----|
6. | 6 |
7. | 7 |
8. | 8 |
9. | 9 |
+----+ | Give a code snippet in #Stata
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 so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fractran | Fractran | FRACTRAN is a Turing-complete esoteric programming language invented by the mathematician John Horton Conway.
A FRACTRAN program is an ordered list of positive fractions
P
=
(
f
1
,
f
2
,
…
,
f
m
)
{\displaystyle P=(f_{1},f_{2},\ldots ,f_{m})}
, together with an initial positive integer input
n
... | #Prolog | Prolog |
load(Program, Fractions) :-
re_split("[ ]+", Program, Split), odd_items(Split, TextualFractions),
maplist(convert_frac, TextualFractions, Fractions).
odd_items(L, L) :- L = [_], !. % remove the even elements from a list.
odd_items([X,_|L], [X|R]) :- odd_items(L, R).
convert_frac(Text, Frac) :-
re_mat... | Give a code snippet in #Prolog
FRACTRAN is a Turing-complete esoteric programming language invented by the mathematician John Horton Conway.
A FRACTRAN program is an ordered list of positive fractions
P
=
(
f
1
,
f
2
,
…
,
f
m
)
{\displaystyle P=(f_{1},f_{2},\ldots ,f_{m})}
, together with an initi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Grayscale_image | Grayscale image | Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
To get luminance of a color u... | #Ada | Ada | type Grayscale_Image is array (Positive range <>, Positive range <>) of Luminance; | Give a code snippet in #Ada
Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
... | #Ioke | Ioke | ackermann = method(m,n,
cond(
m zero?, n succ,
n zero?, ackermann(m pred, 1),
ackermann(m pred, ackermann(m, n pred)))
) | Give a code snippet in #Ioke
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Runge-Kutta_method | Runge-Kutta method | Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This equation has an exact solution:
... | #ALGOL_W | ALGOL W | begin
real procedure rk4 ( real procedure f ; real value y, x, dx ) ;
begin % Fourth-order Runge-Kutta method %
real dy1, dy2, dy3, dy4;
dy1 := dx * f(x, y);
dy2 := dx * f(x + dx / 2.0, y + dy1 / 2.0);
dy3 := dx * f(x + dx / 2.0, y + dy2 / 2.0);
dy4 := dx * f(x + dx, y + dy3)... | Give a code snippet in #ALGOL_W
Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parameterized_SQL_statement | Parameterized SQL statement | SQL injection
Using a SQL update statement like this one (spacing is optional):
UPDATE players
SET name = 'Smith, Steve', score = 42, active = TRUE
WHERE jerseyNum = 99
Non-parameterized SQL is the GoTo statement of database programming. Don't do it, and make sure your coworkers don't either. | #Nim | Nim | import db_sqlite
let db = open(":memory:", "", "", "")
# Setup
db.exec(sql"CREATE TABLE players (name, score, active, jerseyNum)")
db.exec(sql"INSERT INTO players VALUES (?, ?, ?, ?)", "name", 0, "false", 99)
# Update the row.
db.exec(sql"UPDATE players SET name=?, score=?, active=? WHERE jerseyNum=?",
"S... | Give a code snippet in #Nim
SQL injection
Using a SQL update statement like this one (spacing is optional):
UPDATE players
SET name = 'Smith, Steve', score = 42, active = TRUE
WHERE jerseyNum = 99
Non-parameterized SQL is the GoTo statement of database programming. Don't do it, and make sure your coworkers don'... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Character_codes | Character codes |
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out... | #AArch64_Assembly | AArch64 Assembly |
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program character64.s */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeConstantesAR... | Give a code snippet in #AArch64_Assembly
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unic... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library | Call a function in a shared library | Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign language function where the focus is c... | #Julia | Julia |
#this example works on Windows
ccall( (:GetDoubleClickTime, "User32"), stdcall,
Uint, (), )
ccall( (:clock, "libc"), Int32, ()) | Give a code snippet in #Julia
Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign languag... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm | Trabb Pardo–Knuth algorithm | The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of... | #EchoLisp | EchoLisp |
(define (trabb-fun n)
(+ (* 5 n n n) (sqrt(abs n))))
(define (check-trabb n)
(if (number? n)
(if (<= (trabb-fun n) 400)
(printf "🌱 f(%d) = %d" n (trabb-fun n))
(printf "❌ f(%d) = %d" n (trabb-fun n)))
(error "not a number" n)))
(define (trabb (numlist null))
(while (< (length numlist) 11)
(set! num... | Give a code snippet in #EchoLisp
The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 195... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Do-while | Loops/Do-while | Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loo... | #Sidef | Sidef | var value = 0;
do {
say ++value;
} while (value % 6); | Give a code snippet in #Sidef
Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/D... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_length | String length | Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters.
F... | #Delphi | Delphi | "Hello World".Length() | Give a code snippet in #Delphi
Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme con... | 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... | #Ursa | Ursa | stop | Give a code snippet in #Ursa
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/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #Liberty_BASIC | Liberty BASIC | nomainwin
mainwin 50 20
WindowHeight =620
WindowWidth =690
open "Graphics library" for graphics as #a
#a, "trapclose [quit]"
#a "down"
Turn$ ="R"
Pace =100
s = 16
[again]
print Turn$
#a "cls ; home ; north ; down ; fill black"
for i =1 to len( Turn$)... | Give a code snippet in #Liberty_BASIC
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon fol... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the f... | #AppleScript | AppleScript | on fibonacci(n) -- "Anonymous recursion" task.
-- For the sake of the task, a needlessly anonymous local script object containing a needlessly recursive handler.
-- The script could easily (and ideally should) be assigned to a local variable.
script
property one : 1
property sequence : {}
... | Give a code snippet in #AppleScript
While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic_evaluation | Arithmetic evaluation | Create a program which parses and evaluates arithmetic expressions.
Requirements
An abstract-syntax tree (AST) for the expression must be created from parsing the input.
The AST must be used in evaluation, also, so the input may not be directly evaluated (e.g. by calling eval or a similar language feature.)
The ... | #Common_Lisp | Common Lisp | (defun tokenize-stream (stream)
(labels ((whitespace-p (char)
(find char #(#\space #\newline #\return #\tab)))
(consume-whitespace ()
(loop while (whitespace-p (peek-char nil stream nil #\a))
do (read-char stream)))
(read-integer ()
(loop... | Give a code snippet in #Common_Lisp
Create a program which parses and evaluates arithmetic expressions.
Requirements
An abstract-syntax tree (AST) for the expression must be created from parsing the input.
The AST must be used in evaluation, also, so the input may not be directly evaluated (e.g. by calling eval o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Null_object | Null object |
Null (or nil) is the computer science concept of an undefined or unbound object.
Some languages have an explicit way to access the null object, and some don't.
Some languages distinguish the null object from undefined values, and some don't.
Task
Show how to access null in your language by checking to see if an ob... | #Neko | Neko | /**
<doc>
<p>Neko uses <i>null</i> for undefined variables,
and also as a programmer accessible value.</p>
<p>The <i>null</i> value can be treated as a boolean value with the
builtin $istrue, and tests as false.</p>
</doc>
*/
var n = null
if n == null $print("n is null\n")
if $not($istrue(n)) $print("and test... | Give a code snippet in #Neko
Null (or nil) is the computer science concept of an undefined or unbound object.
Some languages have an explicit way to access the null object, and some don't.
Some languages distinguish the null object from undefined values, and some don't.
Task
Show how to access null in your langua... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #Oz | Oz | declare
fun {RotChar C}
if C >= &A andthen C =< &Z then &A + (C - &A + 13) mod 26
elseif C >= &a andthen C =< &z then &a + (C - &a + 13) mod 26
else C
end
end
fun {Rot13 S}
{Map S RotChar}
end
in
{System.showInfo {Rot13 "NOWHERE Abjurer 42"}}
{System.showInfo {Rot13 {Rot13 "NO... | Give a code snippet in #Oz
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 en... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Julia_set | Julia set |
Task
Generate and draw a Julia set.
Related tasks
Mandelbrot Set
| #BASIC | BASIC | escala = 1 / 81
zeroX = 160
zeroY = 100
maxiter = 32
CR = -.798
CI = .1618
SCREEN 13
FOR x = 0 TO 2 * zeroX - 1
FOR y = 0 TO 2 * zeroY - 1
zreal = (x - zeroX) * escala
zimag = (zeroY - y) * escala
FOR iter = 1 TO maxiter
BR = CR + zreal * zreal - zimag * zimag
zim... | Give a code snippet in #BASIC
Task
Generate and draw a Julia set.
Related tasks
Mandelbrot Set
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_specific_line_from_a_file | Read a specific line from a file | Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store it in a variable or in memory (fo... | #ALGOL_68 | ALGOL 68 | # reads the line with number "number" (counting from 1) #
# from the file named "file name" and returns the text of the #
# in "line". If an error occurs, the result is FALSE and a #
# message is returned in "err". If no error occurs, TRUE is #
# returned #
... | Give a code snippet in #ALGOL_68
Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calendar | Calendar | Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 display with accented characters). Target fo... | #WYLBUR | WYLBUR | Any Year Calendar
--------------------
S M T W T F S
| Give a code snippet in #WYLBUR
Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 display with... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Arithmetic_mean | Averages/Arithmetic mean | Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin... | #XPL0 | XPL0 | code CrLf=9;
code real RlOut=48;
func real Mean(A, N);
real A; int N;
real S; int I;
[if N=0 then return 0.0;
S:= 0.0;
for I:= 0 to N-1 do
S:= S+A(I);
return S/float(N);
]; \Mean
real Test;
[Test:= [1.0, 2.0, 5.0, -5.0, 9.5, 3.14159];
RlOut(0, Mean(Test, 6)); CrLf(0);
] | Give a code snippet in #XPL0
Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an estab... | 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... | #Phix | Phix | with javascript_semantics
sequence collection = {}
collection = append(collection,"one")
collection = prepend(collection,2)
? collection -- {2,"one"}
| Give a code snippet in #Phix
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
Cre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Longest_common_subsequence | Longest common subsequence | Introduction
Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string.
The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings.
Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be strings drawn from an alphabet Σ of ... | #Julia | Julia | longest(a::String, b::String) = length(a) ≥ length(b) ? a : b
"""
julia> lcsrecursive("thisisatest", "testing123testing")
"tsitest"
"""
# Recursive
function lcsrecursive(xstr::String, ystr::String)
if length(xstr) == 0 || length(ystr) == 0
return ""
end
x, xs, y, ys = xstr[1], xstr[2:end], ystr[... | Give a code snippet in #Julia
Introduction
Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string.
The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings.
Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be strin... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_sentence_type | Determine sentence type | Use these sentences:
"hi there, how are you today? I'd like to present to you the washing machine 9001. You have been nominated to win one of these! Just make sure you don't break it."
Task
Search for the last used punctuation in a sentence, and determine its type according to its punctuation.
Output one of these le... | #Wren | Wren | var sentenceType = Fn.new { |s|
if (s.count == 0) return ""
var types = []
for (c in s) {
if (c == "?") {
types.add("Q")
} else if (c == "!") {
types.add("E")
} else if (c == ".") {
types.add("S")
}
}
if (!"?!.".contains(s[-1])) typ... | Give a code snippet in #Wren
Use these sentences:
"hi there, how are you today? I'd like to present to you the washing machine 9001. You have been nominated to win one of these! Just make sure you don't break it."
Task
Search for the last used punctuation in a sentence, and determine its type according to its punctu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Church_numerals | Church numerals | Task
In the Church encoding of natural numbers, the number N is encoded by a function that applies its first argument N times to its second argument.
Church zero always returns the identity function, regardless of its first argument. In other words, the first argument is not applied to the second argument at all.
C... | #Raku | Raku | constant $zero = sub (Code $f) {
sub ( $x) { $x }}
constant $succ = sub (Code $n) {
sub (Code $f) {
sub ( $x) { $f($n($f)($x)) }}}
constant $add = sub (Code $n) {
sub (Code $m) {
sub (Code $f) {
s... | Give a code snippet in #Raku
Task
In the Church encoding of natural numbers, the number N is encoded by a function that applies its first argument N times to its second argument.
Church zero always returns the identity function, regardless of its first argument. In other words, the first argument is not applied to ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available,... | #Tern | Tern | let list = [1, 22, 3, 24, 35, 6];
for(i in list) {
println(i);
}
| Give a code snippet in #Tern
This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrie... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Law_of_cosines_-_triples | Law of cosines - triples | The Law of cosines states that for an angle γ, (gamma) of any triangle, if the sides adjacent to the angle are A and B and the side opposite is C; then the lengths of the sides are related by this formula:
A2 + B2 - 2ABcos(γ) = C2
Specific angles
For an angle of of 90º this becomes the more familiar ... | #AWK | AWK |
# syntax: GAWK -f LAW_OF_COSINES_-_TRIPLES.AWK
# converted from C
BEGIN {
description[1] = "90 degrees, a*a + b*b = c*c"
description[2] = "60 degrees, a*a + b*b - a*b = c*c"
description[3] = "120 degrees, a*a + b*b + a*b = c*c"
split("0,1,-1",coeff,",")
main(13,1,0)
main(1000,0,1) # 10,000 tak... | Give a code snippet in #AWK
The Law of cosines states that for an angle γ, (gamma) of any triangle, if the sides adjacent to the angle are A and B and the side opposite is C; then the lengths of the sides are related by this formula:
A2 + B2 - 2ABcos(γ) = C2
Specific angles
For an angle of of 90º th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conway%27s_Game_of_Life | Conway's Game of Life | The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, in an m-by-m (or m×m) sq... | #Retro | Retro | :w/l [ $. eq? [ #0 ] [ #1 ] choose , ] s:for-each ;
'World d:create
'.................... w/l
'.................... w/l
'.................... w/l
'..ooo............... w/l
'....o............... w/l
'...o................ w/l
'.................... w/l
'.................... w/l
'.................... w/... | Give a code snippet in #Retro
The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_digits_of_an_integer | Sum digits of an integer | Task
Take a Natural Number in a given base and return the sum of its digits:
110 sums to 1
123410 sums to 10
fe16 sums to 29
f0e16 sums to 29
| #Go | Go | // File digit.go
package digit
import (
"math/big"
"strconv"
)
func SumString(n string, base int) (int, error) {
i, ok := new(big.Int).SetString(n, base)
if !ok {
return 0, strconv.ErrSyntax
}
if i.Sign() < 0 {
return 0, strconv.ErrRange
}
if i.BitLen() <= 64 {
return Sum(i.Uint64(), base), nil
}
... | Give a code snippet in #Go
Task
Take a Natural Number in a given base and return the sum of its digits:
110 sums to 1
123410 sums to 10
fe16 sums to 29
f0e16 sums to 29
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Main_step_of_GOST_28147-89 | Main step of GOST 28147-89 | GOST 28147-89 is a standard symmetric encryption based on a Feistel network.
The structure of the algorithm consists of three levels:
encryption modes - simple replacement, application range, imposing a range of feedback and authentication code generation;
cycles - 32-З, 32-Р and 16-З, is a repetition of the ... | #Nim | Nim | import sequtils, strutils
const
K1 = [byte 4, 10, 9, 2, 13, 8, 0, 14, 6, 11, 1, 12, 7, 15, 5, 3]
K2 = [byte 14, 11, 4, 12, 6, 13, 15, 10, 2, 3, 8, 1, 0, 7, 5, 9]
K3 = [byte 5, 8, 1, 13, 10, 3, 4, 2, 14, 15, 12, 7, 6, 0, 9, 11]
K4 = [byte 7, 13, 10, 1, 0, 8, 9, 15, 14, 4, 6... | Give a code snippet in #Nim
GOST 28147-89 is a standard symmetric encryption based on a Feistel network.
The structure of the algorithm consists of three levels:
encryption modes - simple replacement, application range, imposing a range of feedback and authentication code generation;
cycles - 32-З, 32-Р and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Duffinian_numbers | Duffinian numbers | A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian numbers are very common.
It is not u... | #Julia | Julia | using Primes
function σ(n)
f = [one(n)]
for (p,e) in factor(n)
f = reduce(vcat, [f*p^j for j in 1:e], init=f)
end
return sum(f)
end
isDuffinian(n) = !isprime(n) && gcd(n, σ(n)) == 1
function testDuffinians()
println("First 50 Duffinian numbers:")
foreach(p -> print(rpad(p[2], 4), p... | Give a code snippet in #Julia
A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian number... | christopher/rosetta-code | |
http://rosettacode.org/wiki/FizzBuzz | FizzBuzz | Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuzz (instead of the number)
... | #Cowgol | Cowgol | include "cowgol.coh";
var i: uint8 := 1;
while i <= 100 loop
if i % 15 == 0 then
print("FizzBuzz");
elseif i % 5 == 0 then
print("Buzz");
elseif i % 3 == 0 then
print("Fizz");
else
print_i8(i);
end if;
print_nl();
i := i + 1;
end loop; | Give a code snippet in #Cowgol
Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuz... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Merge_and_aggregate_datasets | Merge and aggregate datasets | Merge and aggregate datasets
Task
Merge and aggregate two datasets as provided in .csv files into a new resulting dataset.
Use the appropriate methods and data structures depending on the programming language.
Use the most common libraries only when built-in functionality is not sufficient.
Note
Either lo... | #Julia | Julia | using CSV, DataFrames, Statistics
# load data from csv files
#df_patients = CSV.read("patients.csv", DataFrame)
#df_visits = CSV.read("visits.csv", DataFrame)
# create DataFrames from text that is hard coded, so use IOBuffer(String) as input
str_patients = IOBuffer("""PATIENT_ID,LASTNAME
1001,Hopper
4004,Wirth
3003... | Give a code snippet in #Julia
Merge and aggregate datasets
Task
Merge and aggregate two datasets as provided in .csv files into a new resulting dataset.
Use the appropriate methods and data structures depending on the programming language.
Use the most common libraries only when built-in functionality is not... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Prime_decomposition | Prime decomposition | The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the prime decomposition of a given ... | #Nim | Nim | import math, sequtils, strformat, strutils, times
proc getStep(n: int64): int64 {.inline.} =
result = 1 + n shl 2 - n shr 1 shl 1
proc primeFac(n: int64): seq[int64] =
var maxq = int64(sqrt(float(n)))
var d = 1
var q: int64 = 2 + (n and 1) # Start with 2 or 3 according to oddity.
while q <= maxq and n %... | Give a code snippet in #Nim
The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the pr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitcoin/public_point_to_address | Bitcoin/public point to address | Bitcoin uses a specific encoding format to encode the digest of an elliptic curve public point into a short ASCII string. The purpose of this task is to perform such a conversion.
The encoding steps are:
take the X and Y coordinates of the given public point, and concatenate them in order to have a 64 byte-longed st... | #C | C | #include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <openssl/sha.h>
#include <openssl/ripemd.h>
#define COIN_VER 0
const char *coin_err;
typedef unsigned char byte;
int is_hex(const char *s) {
int i;
for (i = 0; i < 64; i++)
if (!isxdigit(s[i])) return 0;
return 1;
}
void str_to_byte(const c... | Give a code snippet in #C
Bitcoin uses a specific encoding format to encode the digest of an elliptic curve public point into a short ASCII string. The purpose of this task is to perform such a conversion.
The encoding steps are:
take the X and Y coordinates of the given public point, and concatenate them in order ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greyscale_bars/Display | Greyscale bars/Display | The task is to display a series of vertical greyscale bars (contrast bars) with a sufficient number of bars to span the entire width of the display.
For the top quarter of the display, the left hand bar should be black, and we then incrementally step through six shades of grey until we have a white bar on the right ha... | #Amazing_Hopper | Amazing Hopper |
#include <flow.h>
#include <flow-term.h>
#define SPACE(_T_,_N_) REPLICATE( " ", {_T_}DIV-INTO(_N_) )
DEF-MAIN(argv,argc)
CLR-SCR
GOSUB( Print Grey Scale )
END
RUTINES
DEF-FUN( Print Grey Scale )
SET( nrcolors, 8 )
SET( direction, 1 )
MSET( quarter, color )
LOCATE( 0, 0 )
FOR( LT?( quarter, ... | Give a code snippet in #Amazing_Hopper
The task is to display a series of vertical greyscale bars (contrast bars) with a sufficient number of bars to span the entire width of the display.
For the top quarter of the display, the left hand bar should be black, and we then incrementally step through six shades of grey u... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_palindromic_numbers_in_both_binary_and_ternary_bases | Find palindromic numbers in both binary and ternary bases | Find palindromic numbers in both binary and ternary bases
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find and show (in decimal) the first six numbers (non-negative integers) that are palindromes in both:
base 2
base 3
Display 0 ... | #Tcl | Tcl | proc format_%t {n} {
while {$n} {
append r [expr {$n % 3}]
set n [expr {$n / 3}]
}
if {![info exists r]} {set r 0}
string reverse $r
} | Give a code snippet in #Tcl
Find palindromic numbers in both binary and ternary bases
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find and show (in decimal) the first six numbers (non-negative integers) that are palindromes in both:
base ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_using_a_custom_comparator | Sort using a custom comparator |
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
... | #Raku | Raku | my @strings = <Here are some sample strings to be sorted>;
put @strings.sort:{.chars, .lc};
put sort -> $x { $x.chars, $x.lc }, @strings; | Give a code snippet in #Raku
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Apply_a_callback_to_an_array | Apply a callback to an array | Task
Take a combined set of elements and apply a function to each element.
| #Klingphix | Klingphix | include ..\Utilitys.tlhy
( 1 2 3 4 ) [dup *] map
pstack
" " input | Give a code snippet in #Klingphix
Task
Take a combined set of elements and apply a function to each element.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/ABC_problem | ABC problem | ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet is guaranteed amongst all sid... | #M2000_Interpreter | M2000 Interpreter |
Module ABC {
can_make_word("A")
can_make_word("BaRk")
can_make_word("BOOK")
can_make_word("TREAT")
can_make_word("CommoN")
can_make_word("SQUAD")
Gosub can_make_word("CONFUSE") ' we can use Gosub before
Sub can_make_word(c$)
local b$=ucase$(c$)
... | Give a code snippet in #M2000_Interpreter
ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A comp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_length | String length | Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters.
F... | #PL.2FSQL | PL/SQL | DECLARE
string VARCHAR2(50) := 'Hello, world!';
stringlength NUMBER;
BEGIN
stringlength := LENGTHB(string);
END; | Give a code snippet in #PL.2FSQL
Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For_with_a_specified_step | Loops/For with a specified step |
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop b... | #EchoLisp | EchoLisp |
(for ((i (in-range 0 15 2))) (write i))
0 2 4 6 8 10 12 14
(for ((q (in-range 0 15 14/8))) (write q))
0 7/4 7/2 21/4 7 35/4 21/2 49/4 14
(for ((x (in-range 0 15 PI))) (write x))
0 3.141592653589793 6.283185307179586 9.42477796076938 12.566370614359172
| Give a code snippet in #EchoLisp
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/... | christopher/rosetta-code | |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial ... | #Raku | Raku | constant expansions = [1], [1,-1], -> @prior { [|@prior,0 Z- 0,|@prior] } ... *;
sub polyprime($p where 2..*) { so expansions[$p].[1 ..^ */2].all %% $p }
# Showing the expansions:
say ' p: (x-1)ᵖ';
say '-----------';
sub super ($n) {
$n.trans: '0123456789'
=> '⁰¹²³⁴⁵⁶⁷⁸⁹';
}
for ^13 -> $d {
... | Give a code snippet in #Raku
The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SOAP | SOAP | In this task, the goal is to create a SOAP client which accesses functions defined at http://example.com/soap/wsdl, and calls the functions soapFunc( ) and anotherSoapFunc( ).
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified... | #Ruby | Ruby | require 'soap/wsdlDriver'
wsdl = SOAP::WSDLDriverFactory.new("http://example.com/soap/wsdl")
soap = wsdl.create_rpc_driver
response1 = soap.soapFunc(:elementName => "value")
puts response1.soapFuncReturn
response2 = soap.anotherSoapFunc(:aNumber => 42)
puts response2.anotherSoapFuncReturn | Give a code snippet in #Ruby
In this task, the goal is to create a SOAP client which accesses functions defined at http://example.com/soap/wsdl, and calls the functions soapFunc( ) and anotherSoapFunc( ).
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect onc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Amb | Amb | Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton").
The Amb operator takes a v... | #Rust | Rust | use std::ops::Add;
struct Amb<'a> {
list: Vec<Vec<&'a str>>,
}
fn main() {
let amb = Amb {
list: vec![
vec!["the", "that", "a"],
vec!["frog", "elephant", "thing"],
vec!["walked", "treaded", "grows"],
vec!["slowly", "quickly"],
],
};
match a... | Give a code snippet in #Rust
Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Langton%27s_ant | Langton's ant | Langton's ant is a cellular automaton that models an ant sitting on a plane of cells, all of which are white initially, the ant facing in one of four directions.
Each cell can either be black or white.
The ant moves according to the color of the cell it is currently sitting in, with the following rules:
If the ce... | #BBC_BASIC | BBC BASIC |
REM Implementation of Langton's ant for Rosetta Code
fieldsize%=100
REM Being pedantic, this will actually result in a field of 101 square,
REM since arrays start at 0, and my implementation allows them to use it
DIM field&(fieldsize%,fieldsize%) : REM variables with an & suffix are by... | Give a code snippet in #BBC_BASIC
Langton's ant is a cellular automaton that models an ant sitting on a plane of cells, all of which are white initially, the ant facing in one of four directions.
Each cell can either be black or white.
The ant moves according to the color of the cell it is currently sitting in, with... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #Racket | Racket |
#lang scribble/manual
(require (for-label "sandwiches.rkt"))
@defproc[(make-sandwich [ingredients (listof ingredient?)])
sandwich?]{
Returns a sandwich given the right ingredients.
}
| Give a code snippet in #Racket
See also
Related task: Comments
Related task: Here_document
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Partial_function_application | Partial function application | Partial function application is the ability to take a function of many
parameters and apply arguments to some of the parameters to create a new
function that needs only the application of the remaining arguments to
produce the equivalent of applying all arguments to the original function.
E.g:
Given values v1, v2
... | #Scala | Scala | def fs[X](f:X=>X)(s:Seq[X]) = s map f
def f1(x:Int) = x * 2
def f2(x:Int) = x * x
def fsf[X](f:X=>X) = fs(f) _
val fsf1 = fsf(f1) // or without the fsf intermediary: val fsf1 = fs(f1) _
val fsf2 = fsf(f2) // or without the fsf intermediary: val fsf2 = fs(f2) _
assert(fsf1(List(0,1,2,3)) == List(0,2,4,6))
assert(fsf... | Give a code snippet in #Scala
Partial function application is the ability to take a function of many
parameters and apply arguments to some of the parameters to create a new
function that needs only the application of the remaining arguments to
produce the equivalent of applying all arguments to the original functio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Entropy | Entropy | Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary), the Shannon entropy of X in bit... | #Swift | Swift | import Foundation
func entropy(of x: String) -> Double {
return x
.reduce(into: [String: Int](), {cur, char in
cur[String(char), default: 0] += 1
})
.values
.map({i in Double(i) / Double(x.count) } as (Int) -> Double)
.map({p in -p * log2(p) } as (Double) -> Double)
.reduce(0.0, +)
}
... | Give a code snippet in #Swift
Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary), ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Partial_function_application | Partial function application | Partial function application is the ability to take a function of many
parameters and apply arguments to some of the parameters to create a new
function that needs only the application of the remaining arguments to
produce the equivalent of applying all arguments to the original function.
E.g:
Given values v1, v2
... | #Java | Java | import java.util.Arrays;
public class PartialApplication {
interface IntegerFunction {
int call(int arg);
}
// Original method fs(f, s).
static int[] fs(IntegerFunction f, int[] s) {
int[] r = new int[s.length];
for (int i = 0; i < s.length; i++)
r[i] = f.call(s[i]);
return r;
}
interface Seque... | Give a code snippet in #Java
Partial function application is the ability to take a function of many
parameters and apply arguments to some of the parameters to create a new
function that needs only the application of the remaining arguments to
produce the equivalent of applying all arguments to the original function... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bulls_and_cows | Bulls and cows | Bulls and Cows
Task
Create a four digit random number from the digits 1 to 9, without duplication.
The program should:
ask for guesses to this number
reject guesses that are malformed
print the score for the guess
The score is computed as:
The player wins if the guess is the same as the random... | #J | J | require 'misc'
plural=: conjunction define
(":m),' ',n,'s'#~1~:m
)
bullcow=:monad define
number=. 1+4?9
whilst. -.guess-:number do.
guess=. 0 "."0 prompt 'Guess my number: '
if. (4~:#guess)+.(4~:#~.guess)+.0 e.guess e.1+i.9 do.
if. 0=#guess do.
smoutput 'Giving up.'
return.
... | Give a code snippet in #J
Bulls and Cows
Task
Create a four digit random number from the digits 1 to 9, without duplication.
The program should:
ask for guesses to this number
reject guesses that are malformed
print the score for the guess
The score is computed as:
The player wins if the gues... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring | Substring |
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 |... | #Raven | Raven | define println use $s
$s print "\n" print
"0123456789" as $str
$str 3 2 extract println # at 4th pos get 2 chars
$str 8 4 extract println # at 9th pos get 4 chars (when only 1 char available)
$str 3 $str length extract println # at 4th pos get all chars to end of str
$str 3 0x7FFFFFFF extr... | Give a code snippet in #Raven
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/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
... | #Clay | Clay | ackermann(m, n) {
if(m == 0)
return n + 1;
if(n == 0)
return ackermann(m - 1, 1);
return ackermann(m - 1, ackermann(m, n - 1));
} | Give a code snippet in #Clay
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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.... | #Swift | Swift | import Foundation
class PadovanRecurrence: Sequence, IteratorProtocol {
private var p = [1, 1, 1]
private var n = 0
func next() -> Int? {
let pn = n < 3 ? p[n] : p[0] + p[1]
p[0] = p[1]
p[1] = p[2]
p[2] = pn
n += 1
return pn
}
}
class PadovanFloor: S... | Give a code snippet in #Swift
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/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #AArch64_Assembly | AArch64 Assembly | .text
.global _start
_start:
mov x0, #0
mov x8, #93
svc #0 | Give a code snippet in #AArch64_Assembly
Task
Create the simplest possible program that is still considered "correct."
| 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.)
| #zkl | zkl | x=1; // comment ala C++
x=2; # ala scripts
/* ala C, these comments are parsed (also ala C) */
/* can /* be */ nested */
#if 0
also ala C (and parsed)
#endif
#<<<#
"here" comment, unparsed
#<<<# | Give a code snippet in #zkl
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/JortSort | JortSort |
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
... | #Ring | Ring |
aList = [4,2,3,1]
see jortSort(aList) + nl
func jortSort array
originalArray = array
array = sort(array)
for i= 1 to len(originalArray)
if originalArray[i] != array[i] return false ok
next
return true
| Give a code snippet in #Ring
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Proper_divisors | Proper divisors | The proper divisors of a positive integer N are those numbers, other than N itself, that divide N without remainder.
For N > 1 they will always include 1, but for N == 1 there are no proper divisors.
Examples
The proper divisors of 6 are 1, 2, and 3.
The proper divisors of 100 are 1, 2, 4, 5... | #PicoLisp | PicoLisp | # Generate all proper divisors.
(de propdiv (N)
(head -1 (filter
'((X) (=0 (% N X)))
(range 1 N) )) )
# Obtaining the values from 1 to 10 inclusive.
(mapcar propdiv (range 1 10))
# Output:
# (NIL (1) (1) (1 2) (1) (1 2 3) (1) (1 2 4) (1 3) (1 2 5)) | Give a code snippet in #PicoLisp
The proper divisors of a positive integer N are those numbers, other than N itself, that divide N without remainder.
For N > 1 they will always include 1, but for N == 1 there are no proper divisors.
Examples
The proper divisors of 6 are 1, 2, and 3.
The proper di... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Chinese_remainder_theorem | Chinese remainder theorem | Suppose
n
1
{\displaystyle n_{1}}
,
n
2
{\displaystyle n_{2}}
,
…
{\displaystyle \ldots }
,
n
k
{\displaystyle n_{k}}
are positive integers that are pairwise co-prime.
Then, for any given sequence of integers
a
1
{\displaystyle a_{1}}
,
a
2
... | #EasyLang | EasyLang | func mul_inv a b . x1 .
b0 = b
x1 = 1
if b <> 1
while a > 1
q = a div b
t = b
b = a mod b
a = t
t = x0
x0 = x1 - q * x0
x1 = t
.
if x1 < 0
x1 += b0
.
.
.
func remainder . n[] a[] r .
prod = 1
sum = 0
for i range len n[]
prod *= n[i]
.
... | Give a code snippet in #EasyLang
Suppose
n
1
{\displaystyle n_{1}}
,
n
2
{\displaystyle n_{2}}
,
…
{\displaystyle \ldots }
,
n
k
{\displaystyle n_{k}}
are positive integers that are pairwise co-prime.
Then, for any given sequence of integers
a
1
{\displ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix | Sum of elements below main diagonal of matrix | Task
Find and display the sum of elements that are below the main diagonal of a matrix.
The matrix should be a square matrix.
─── Matrix to be used: ───
[[1,3,7,8,10],
[2,4,16,14,4],
[3,1,9,18,11],
[12,14,17,18,20],
[7,1,3,9,5]]
| #Perl | Perl | #!/usr/bin/perl
use strict;
use warnings;
use List::Util qw( sum );
my $matrix =
[[1,3,7,8,10],
[2,4,16,14,4],
[3,1,9,18,11],
[12,14,17,18,20],
[7,1,3,9,5]];
my $lowersum = sum map @{ $matrix->[$_] }[0 .. $_ - 1], 1 .. $#$matrix;
print "lower sum = $lowersum\n"; | Give a code snippet in #Perl
Task
Find and display the sum of elements that are below the main diagonal of a matrix.
The matrix should be a square matrix.
─── Matrix to be used: ───
[[1,3,7,8,10],
[2,4,16,14,4],
[3,1,9,18,11],
[12,14,17,18,20],
[7,1,3,9,5]]
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mode | Averages/Mode | Task[edit]
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), if possible. If it is not appropriat... | #Elixir | Elixir | defmodule Average do
def mode(list) do
gb = Enum.group_by(list, &(&1))
max = Enum.map(gb, fn {_,val} -> length(val) end) |> Enum.max
for {key,val} <- gb, length(val)==max, do: key
end
end
lists = [[3,1,4,1,5,9,2,6,5,3,5,8,9],
[1, 2, "qwe", "asd", 1, 2, "qwe", "asd", 2, "qwe"]]
Enum.each(lists... | Give a code snippet in #Elixir
Task[edit]
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), if p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sieve_of_Eratosthenes | Sieve of Eratosthenes | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algorithm, with the only allowed... | #XPL0 | XPL0 | include c:\cxpl\codes; \intrinsic 'code' declarations
int Size, Prime, I, Kill;
char Flag;
[Size:= IntIn(0);
Flag:= Reserve(Size+1);
for I:= 2 to Size do Flag(I):= true;
for I:= 2 to Size do
if Flag(I) then \found a prime
[Prime:= I;
IntOut(0, Prime); CrLf(0);
... | Give a code snippet in #XPL0
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes al... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Do-while | Loops/Do-while | Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loo... | #Phix | Phix | integer x = 0
while 1 do
x += 1
?x
if mod(x,6)=0 then exit end if
end while
| Give a code snippet in #Phix
Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Do... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar tricker... | #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Sub main()
Print "Hello from main!"
End Sub
main
Sleep | Give a code snippet in #FreeBASIC
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languag... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/Continuous | Knapsack problem/Continuous |
A thief burgles a butcher's shop, where he can select from some items.
The thief knows the weights and prices of each items. Because he has a knapsack with 15 kg maximal capacity, he wants to select the items such that he would have his profit maximized. He may cut the items; the item has a reduced price after... | #GNU_APL | GNU APL | ⍝ Data
Items←'beef' 'pork' 'ham' 'greaves' 'flitch' 'brawn' 'welt' 'salami' 'sausage'
Weights←3.8 5.4 3.6 2.4 4 2.5 3.7 3 5.9
Prices←36 43 90 45 30 56 67 95 98
⍝ Solution
Order←⍒Worth←Prices÷Weights ⍝ 'Worth' is each item value for 1 kg.
diff←{¯1↓(⍵,0)-0,⍵} ⍝ 'diff' betw... | Give a code snippet in #GNU_APL
A thief burgles a butcher's shop, where he can select from some items.
The thief knows the weights and prices of each items. Because he has a knapsack with 15 kg maximal capacity, he wants to select the items such that he would have his profit maximized. He may cut the items; t... | christopher/rosetta-code |
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