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/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #C.23 | C# | using System;
namespace C_Sharp_Console {
class example {
static void Main() {
string word;
int num;
Console.Write("Enter an integer: ");
num = Console.Read();
Console.Write("Enter a String: ");
word = Console.ReadLine();
... | Give a code snippet in #C.23
User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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. | #Tcl | Tcl | package require Tcl 8.6
# These next two lines are the only ones specific to SQLite
package require tdbc::sqlite3
set db [tdbc::sqlite3::connection new /path/to/database.sql]
# Use a helper procedure to make a scope
proc setPlayer {db jersey -> playerName playerScore playerActive} {
# Note that the '->' above i... | Give a code snippet in #Tcl
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/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:
... | #Kotlin | Kotlin | // version 1.1.2
typealias Y = (Double) -> Double
typealias Yd = (Double, Double) -> Double
fun rungeKutta4(t0: Double, tz: Double, dt: Double, y: Y, yd: Yd) {
var tn = t0
var yn = y(tn)
val z = ((tz - t0) / dt).toInt()
for (i in 0..z) {
if (i % 10 == 0) {
val exact = y(tn)
... | Give a code snippet in #Kotlin
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 e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Median | Averages/Median | Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.
There are several approaches ... | #COBOL | COBOL | FUNCTION MEDIAN(some-table (ALL)) | Give a code snippet in #COBOL
Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation | Permutations/Rank of a permutation | A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items.
For our purposes the ranking will assign integers
0..
(
n
!
−
1
)
{\displaystyle 0..(n!-1)}
to an ordering of all the permutations of the integers
0..
(
n
−
1
)
{\disp... | #Nim | Nim | func mrUnrank1(vec: var openArray[int]; rank, n: int) =
if n < 1: return
let q = rank div n
let r = rank mod n
swap vec[r], vec[n - 1]
vec.mrUnrank1(q, n - 1)
func mrRank1(vec, inv: var openArray[int]; n: int): int =
if n < 2: return 0
let s = vec[n - 1]
swap vec[n - 1], vec[inv[n - 1]]
swap inv[s],... | Give a code snippet in #Nim
A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items.
For our purposes the ranking will assign integers
0..
(
n
!
−
1
)
{\displaystyle 0..(n!-1)}
to an ordering of all the permutations of the intege... | 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)
... | #Sed | Sed | #n
# doesn't work if there's no input
# initialize counters (0 = empty) and value
s/.*/ 0/
: loop
# increment counters, set carry
s/^\(a*\) \(b*\) \([0-9][0-9]*\)/\1a \2b \3@/
# propagate carry
: carry
s/ @/ 1/
s/9@/@0/
s/8@/9/
s/7@/8/
s/6@/7/
s/5@/6/
s/4@/5/
s/3@/4/
s/2@/3/
s/1@/2/
s/0@/1/
/@/b carry
# save state
h
#... | Give a code snippet in #Sed
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
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 l... | #Comal | Comal | LOOP
PRINT "SPAM"
ENDLOOP | Give a code snippet in #Comal
Task
Print out SPAM followed by a newline in an infinite loop.
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
Loop... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_unity | Roots of unity | The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| #IDL | IDL | n = 5
print, exp( dcomplex( 0, 2*!dpi/n) ) ^ ( 1 + indgen(n) ) | Give a code snippet in #IDL
The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_HQ9%2B | Execute HQ9+ | Task
Implement a HQ9+ interpreter or compiler.
| #Fortran | Fortran | "bottle" // IF (B.NE.1) THEN "s" FI // " of beer" | Give a code snippet in #Fortran
Task
Implement a HQ9+ interpreter or compiler.
| 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... | #Eiffel | Eiffel |
class
APPLICATION
create
make
feature
make
-- Test of the feature comma_quibbling.
local
l: LINKED_LIST [STRING]
do
create l.make
io.put_string (comma_quibbling (l) + "%N")
l.extend ("ABC")
io.put_string (comma_quibbling (l) + "%N")
l.extend ("DEF")
io.put_string (comma_quibbling... | Give a code snippet in #Eiffel
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 i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Latin_Squares_in_reduced_form | Latin Squares in reduced form | A Latin Square is in its reduced form if the first row and first column contain items in their natural order. The order n is the number of items. For any given n there is a set of reduced Latin Squares whose size increases rapidly with n. g is a number which identifies a unique element within the set of reduced Latin S... | #Ruby | Ruby | def printSquare(a)
for row in a
print row, "\n"
end
print "\n"
end
def dList(n, start)
start = start - 1 # use 0 based indexing
a = Array.new(n) {|i| i}
a[0], a[start] = a[start], a[0]
a[1..] = a[1..].sort
first = a[1]
r = []
recurse = lambda {|last|
if last =... | Give a code snippet in #Ruby
A Latin Square is in its reduced form if the first row and first column contain items in their natural order. The order n is the number of items. For any given n there is a set of reduced Latin Squares whose size increases rapidly with n. g is a number which identifies a unique element wit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Semordnilap | Semordnilap | A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total number of unique semordnilap ... | #Liberty_BASIC | Liberty BASIC |
print "Loading dictionary."
open "unixdict.txt" for input as #1
while not(eof(#1))
line input #1, a$
dict$=dict$+" "+a$
wend
close #1
print "Dictionary loaded."
print "Seaching for semordnilaps."
semo$=" " 'string to hold words with semordnilaps
do
i=i+1
w$=word$(dict$,i)
p$=reverseString$(w... | Give a code snippet in #Liberty_BASIC
A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
... | #8th | 8th |
\
\ anagrams.8th
\ Rosetta Code - Anagrams problem
\ Using the word list at:
\ http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
\ find the sets of words that share the same characters
\ that contain the most words in them.
\
ns: anagrams
m:new var, anamap
a:new var, anaptr
0 var, analen
\ sort a string
... | Give a code snippet in #8th
When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abbreviations,_automatic | Abbreviations, automatic | The use of abbreviations (also sometimes called synonyms, nicknames, AKAs, or aliases) can be an
easy way to add flexibility when specifying or using commands, sub─commands, options, etc.
It would make a list of words easier to maintain (as words are added, changed, and/or deleted) if
the minimum abbrevia... | #Delphi | Delphi |
program Abbreviations_Automatic;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
System.Generics.Collections,
System.IOUtils;
function DistinctStrings(strs: TArray<string>): TArray<string>;
begin
var l := length(strs);
var _set := TDictionary<string, Boolean>.Create;
SetLength(result, 0);
for var str in ... | Give a code snippet in #Delphi
The use of abbreviations (also sometimes called synonyms, nicknames, AKAs, or aliases) can be an
easy way to add flexibility when specifying or using commands, sub─commands, options, etc.
It would make a list of words easier to maintain (as words are added, changed, and/or de... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Repeat_a_string | Repeat a string | Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").
Other tasks re... | #MUMPS | MUMPS | RPTSTR(S,N)
;Repeat a string S for N times
NEW I
FOR I=1:1:N WRITE S
KILL I
QUIT
RPTSTR1(S,N) ;Functionally equivalent, but denser to read
F I=1:1:N W S
Q
| Give a code snippet in #MUMPS
Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Search_a_list | Search a list | Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle that has multiple occurrences in ... | #11l | 11l | V haystack = [‘Zig’, ‘Zag’, ‘Wally’, ‘Ronald’, ‘Bush’, ‘Krusty’, ‘Charlie’, ‘Bush’, ‘Bozo’]
L(needle) (‘Washington’, ‘Bush’)
X.try
print(haystack.index(needle)‘ ’needle)
X.catch ValueError
print(needle‘ is not in haystack’) | Give a code snippet in #11l
Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle that... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Wilson_primes_of_order_n | Wilson primes of order n | Definition
A Wilson prime of order n is a prime number p such that p2 exactly divides:
(n − 1)! × (p − n)! − (− 1)n
If n is 1, the latter formula reduces to the more familiar: (p - n)! + 1 where the only known examples for p are 5, 13, and 563.
Task
Calculate and show on thi... | #Phix | Phix | with javascript_semantics
constant limit = 11000
include mpfr.e
mpz f = mpz_init()
sequence primes = get_primes_le(limit),
facts = mpz_inits(limit,1) -- (nb 0!==1!, same slot)
for i=2 to limit do mpz_mul_si(facts[i],facts[i-1],i) end for
integer sgn = 1
printf(1," n: Wilson primes\n")
printf(1,"--------------... | Give a code snippet in #Phix
Definition
A Wilson prime of order n is a prime number p such that p2 exactly divides:
(n − 1)! × (p − n)! − (− 1)n
If n is 1, the latter formula reduces to the more familiar: (p - n)! + 1 where the only known examples for p are 5, 13, and 563.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mean_time_of_day | Averages/Mean time of day | Task[edit]
A particular activity of bats occurs at these times of the day:
23:00:17, 23:40:20, 00:12:45, 00:17:19
Using the idea that there are twenty-four hours in a day,
which is analogous to there being 360 degrees in a circle,
map times of day to and from angles;
and using the ideas of Averages/Mean angle
compute ... | #PL.2FI | PL/I | *process source attributes xref;
avt: Proc options(main);
/*--------------------------------------------------------------------
* 25.06.2014 Walter Pachl taken from REXX
*-------------------------------------------------------------------*/
Dcl (addr,hbound,sin,cos,atan) Builtin;
Dcl sysprint Print;
Dcl times(4... | Give a code snippet in #PL.2FI
Task[edit]
A particular activity of bats occurs at these times of the day:
23:00:17, 23:40:20, 00:12:45, 00:17:19
Using the idea that there are twenty-four hours in a day,
which is analogous to there being 360 degrees in a circle,
map times of day to and from angles;
and using the ideas... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jump_anywhere | Jump anywhere | Imperative programs
conditional structures
loops
local jumps
This task is to demonstrate a local jump and a global jump and the various other types of jumps that the language supports.
For the purpose of this task, the jumps need not be used for a single purpose and you have the freedom to use these jumps for different... | #SSEM | SSEM | 10000000000000000000000000000000 0. 1 to CI
11001000000000000000000000000000 1. 19 | Give a code snippet in #SSEM
Imperative programs
conditional structures
loops
local jumps
This task is to demonstrate a local jump and a global jump and the various other types of jumps that the language supports.
For the purpose of this task, the jumps need not be used for a single purpose and you have the freedom to... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Super-d_numbers | Super-d numbers | A super-d number is a positive, decimal (base ten) integer n such that d × nd has at least d consecutive digits d where
2 ≤ d ≤ 9
For instance, 753 is a super-3 number because 3 × 7533 = 1280873331.
Super-d numbers are also shown on MathWorld™ as super-d or super-d.
Task
Write a... | #Go | Go | package main
import (
"fmt"
"math/big"
"strings"
"time"
)
func main() {
start := time.Now()
rd := []string{"22", "333", "4444", "55555", "666666", "7777777", "88888888", "999999999"}
one := big.NewInt(1)
nine := big.NewInt(9)
for i := big.NewInt(2); i.Cmp(nine) <= 0; i.Add(i, one... | Give a code snippet in #Go
A super-d number is a positive, decimal (base ten) integer n such that d × nd has at least d consecutive digits d where
2 ≤ d ≤ 9
For instance, 753 is a super-3 number because 3 × 7533 = 1280873331.
Super-d numbers are also shown on MathWorld™ as super-d or ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Monty_Hall_problem | Monty Hall problem |
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for the time being.
The game show hos... | #M2000_Interpreter | M2000 Interpreter |
Module CheckIt {
Enum Strat {Stay, Random, Switch}
total=10000
Print $("0.00")
player_win_stay=0
player_win_switch=0
player_win_random=0
For i=1 to total {
Dim doors(1 to 3)=False
doors(Random(1,3))=True
guess=Random(1,3)
Invent... | Give a code snippet in #M2000_Interpreter
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains cl... | 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... | #4DOS_Batch | 4DOS Batch |
@echo off
set doors=%@repeat[C,100]
do step = 1 to 100
do door = %step to 100 by %step
set doors=%@left[%@eval[%door-1],%doors]%@if[%@instr[%@eval[%door-1],1,%doors]==C,O,C]%@right[%@eval[100-%door],%doors]
enddo
enddo
| Give a code snippet in #4DOS_Batch
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, #... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bioinformatics/Sequence_mutation | Bioinformatics/Sequence mutation | Task
Given a string of characters A, C, G, and T representing a DNA sequence write a routine to mutate the sequence, (string) by:
Choosing a random base position in the sequence.
Mutate the sequence by doing one of either:
Swap the base at that position by changing it to one of A, C, G, or T. (which has a chance o... | #Racket | Racket | #lang racket
(define current-S-weight (make-parameter 1))
(define current-D-weight (make-parameter 1))
(define current-I-weight (make-parameter 1))
(define bases '(#\A #\C #\G #\T))
(define (fold-sequence seq kons #:finalise (finalise (λ x (apply values x))) . k0s)
(define (recur seq . ks)
(if (null? seq)
... | Give a code snippet in #Racket
Task
Given a string of characters A, C, G, and T representing a DNA sequence write a routine to mutate the sequence, (string) by:
Choosing a random base position in the sequence.
Mutate the sequence by doing one of either:
Swap the base at that position by changing it to one of A, C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_comments_from_a_string | Strip comments from a string | Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line.
Whitespace debacle: There is s... | #Applesoft_BASIC | Applesoft BASIC | 10 LET C$ = ";#"
20 S$(1)="APPLES, PEARS # AND BANANAS"
30 S$(2)="APPLES, PEARS ; AND BANANAS"
40 FOR Q = 1 TO 2
50 LET S$ = S$(Q)
60 GOSUB 100"STRIP COMMENTS
70 PRINT S$
80 NEXT Q
90 END
100 IF S$ = "" THEN RETURN
110 FOR I = 1 TO LEN(S$)
120 LET A$ = MID$(S$, I, 1)
130 FOR J = 1 TO LEN(C$)
140 ... | Give a code snippet in #Applesoft_BASIC
Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #Nim | Nim | import gintro/cairo
proc draw(ctx: Context; x, y, r: float) =
ctx.arc(x, y, r + 1, 1.571, 7.854)
ctx.setSource(0.0, 0.0, 0.0)
ctx.fill()
ctx.arcNegative(x, y - r / 2, r / 2, 1.571, 4.712)
ctx.arc(x, y + r / 2, r / 2, 1.571, 4.712)
ctx.arcNegative(x, y, r, 4.712, 1.571)
ctx.setSource(1.0, 1.0, 1.0)
ctx... | Give a code snippet in #Nim
One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Superellipse | Superellipse | A superellipse is a geometric figure defined as the set of all points (x, y) with
|
x
a
|
n
+
|
y
b
|
n
=
1
,
{\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,}
where n, a, and b are positive numbers.
Task
Draw a superellipse with n = 2.5, and a... | #JavaScript | JavaScript |
var n = 2.5, a = 200, b = 200, ctx;
function point( x, y ) {
ctx.fillRect( x, y, 1, 1);
}
function start() {
var can = document.createElement('canvas');
can.width = can.height = 600;
ctx = can.getContext( "2d" );
ctx.rect( 0, 0, can.width, can.height );
ctx.fillStyle = "#000000"; ctx.fill... | Give a code snippet in #JavaScript
A superellipse is a geometric figure defined as the set of all points (x, y) with
|
x
a
|
n
+
|
y
b
|
n
=
1
,
{\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,}
where n, a, and b are positive numbers.
Task
Dra... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Modular_exponentiation | Modular exponentiation | Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
235139930337346448646612254452369009474497523... | #C.2B.2B | C++ | #include <iostream>
#include <boost/multiprecision/cpp_int.hpp>
#include <boost/multiprecision/integer.hpp>
int main() {
using boost::multiprecision::cpp_int;
using boost::multiprecision::pow;
using boost::multiprecision::powm;
cpp_int a("298834816205857413691589142149881946632016331292695242379102307... | Give a code snippet in #C.2B.2B
Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
235139930337... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #Swift | Swift | import Cocoa
func fibonacci(n: Int) -> Int {
let square_root_of_5 = sqrt(5.0)
let p = (1 + square_root_of_5) / 2
let q = 1 / p
return Int((pow(p,CDouble(n)) + pow(q,CDouble(n))) / square_root_of_5 + 0.5)
}
for i in 1...30 {
println(fibonacci(i))
} | Give a code snippet in #Swift
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Thiele%27s_interpolation_formula | Thiele's interpolation formula |
This page uses content from Wikipedia. The original article was at Thiele's interpolation formula. 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)
Thiele's interpolation formula is an interpolation ... | #Swift | Swift | let N = 32
let N2 = N * (N - 1) / 2
let step = 0.05
var xval = [Double](repeating: 0, count: N)
var tsin = [Double](repeating: 0, count: N)
var tcos = [Double](repeating: 0, count: N)
var ttan = [Double](repeating: 0, count: N)
var rsin = [Double](repeating: .nan, count: N2)
var rcos = [Double](repeating: .nan, count... | Give a code snippet in #Swift
This page uses content from Wikipedia. The original article was at Thiele's interpolation formula. 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)
Thiele's interpolati... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Short-circuit_evaluation | Short-circuit evaluation | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable resources without side effects, an... | #11l | 11l | F a(v)
print(‘ ## Called function a(#.)’.format(v))
R v
F b(v)
print(‘ ## Called function b(#.)’.format(v))
R v
L(i) (0B, 1B)
L(j) (0B, 1B)
print("\nCalculating: x = a(i) and b(j)")
V x = a(i) & b(j)
print(‘Calculating: y = a(i) or b(j)’)
V y = a(i) | b(j) | Give a code snippet in #11l
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable resou... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Semordnilap | Semordnilap | A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total number of unique semordnilap ... | #Delphi | Delphi |
program Semordnilap;
{$APPTYPE CONSOLE}
{$R *.res}
uses
System.SysUtils,
System.Classes,
System.StrUtils,
System.Diagnostics;
function Sort(s: string): string;
var
c: Char;
i, j, aLength: Integer;
begin
aLength := s.Length;
if aLength = 0 then
exit('');
Result := s;
for i := 1 to a... | Give a code snippet in #Delphi
A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the tot... | 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 ... | #Elixir | Elixir | defmodule Palindromic do
import Integer, only: [is_odd: 1]
def number23 do
Stream.concat([0,1], Stream.unfold(1, &number23/1))
end
def number23(i) do
n3 = Integer.to_string(i,3)
n = (n3 <> "1" <> String.reverse(n3)) |> String.to_integer(3)
n2 = Integer.to_string(n,2)
if is_odd(String.lengt... | Give a code snippet in #Elixir
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:
ba... | 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... | #Haskell | Haskell | import qualified Data.Text as T
import Data.Time
import Data.Time.Calendar
import Data.Time.Calendar.WeekDate
import Data.List.Split (chunksOf)
import Data.List
data Day = Su | Mo | Tu | We | Th | Fr | Sa
deriving (Show, Eq, Ord, Enum)
data Month = January | February | March
| April | May ... | Give a code snippet in #Haskell
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 wit... | christopher/rosetta-code | |
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
| #Action.21 | Action! | BYTE ARRAY data = [
$00 $00 $00 $00 $4E $4E $4E $00 $00 $00 $00 $00 $00 $00 $00 $00 $4E $00 $00 $00 $00 $4E $00 $00 $00 $00 $00 $00 $00 $00 $00 $00 $00 $00 $00 $00 $4E $00 $00 $00
$00 $00 $00 $46 $47 $00 $00 $47 $00 $00 $00 $00 $00 $00 $00 $42 $47 $47 $00 $00 $42 $47 $47 $00 $00 $00 $00 $00 $00 $00 $00 $00 $00 $00... | Give a code snippet in #Action.21
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/Vector | Vector | Task
Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented.
The Vector may be initialized in any reasonable way.
Start and end points, and direction
Angular coefficient and value (length)
The four operations to... | #Factor | Factor | (scratchpad) USE: math.vectors
(scratchpad) { 1 2 } { 3 4 } v+
--- Data stack:
{ 4 6 } | Give a code snippet in #Factor
Task
Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented.
The Vector may be initialized in any reasonable way.
Start and end points, and direction
Angular coefficient and value (... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Magic_squares_of_odd_order | Magic squares of odd order | A magic square is an NxN square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column, and both long (main) diagonals are equal to the same sum (which is called the magic number or magic constant).
The numbers are usually (but not always) t... | #Elixir | Elixir | defmodule RC do
def odd_magic_square(n) when rem(n,2)==1 do
for i <- 0..n-1 do
for j <- 0..n-1, do: n * rem(i+j+1+div(n,2),n) + rem(i+2*j+2*n-5,n) + 1
end
end
def print_square(sq) do
width = List.flatten(sq) |> Enum.max |> to_char_list |> length
fmt = String.duplicate(" ~#{width}w", length... | Give a code snippet in #Elixir
A magic square is an NxN square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column, and both long (main) diagonals are equal to the same sum (which is called the magic number or magic constant).
The number... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Damm_algorithm | Damm algorithm | The Damm algorithm is a checksum algorithm which detects all single digit errors and adjacent transposition errors.
The algorithm is named after H. Michael Damm.
Task
Verify the checksum, stored as last digit of an input.
| #zkl | zkl | fcn damm(digits){ // digits is something that supports an iterator of integers
var [const] tbl=Data(0,Int, // 10x10 byte bucket
0, 3, 1, 7, 5, 9, 8, 6, 4, 2,
7, 0, 9, 2, 1, 5, 4, 8, 6, 3,
4, 2, 0, 6, 8, 7, 1, 3, 5, 9,
1, 7, 5, 0, 9, 8, 3, 4, 2, 6,
6, 1, 2, 3, 0, 4, 5, 9, 7, 8,
... | Give a code snippet in #zkl
The Damm algorithm is a checksum algorithm which detects all single digit errors and adjacent transposition errors.
The algorithm is named after H. Michael Damm.
Task
Verify the checksum, stored as last digit of an input.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Address_of_a_variable | Address of a variable |
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 |... | #X86_Assembly | X86 Assembly | movl my_variable, %eax | Give a code snippet in #X86_Assembly
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 Oper... | 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... | #Raku | Raku | sub bernoulli_number($n) {
return 1/2 if $n == 1;
return 0/1 if $n % 2;
my @A;
for 0..$n -> $m {
@A[$m] = 1 / ($m + 1);
for $m, $m-1 ... 1 -> $j {
@A[$j - 1] = $j * (@A[$j - 1] - @A[$j]);
}
}
return @A[0];
}
sub binomial($n, $k) {
$k == 0 || $n == ... | Give a code snippet in #Raku
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 expressi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reverse_a_string | Reverse a string | Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
... | #Pascal | Pascal | { the result array must be at least as large as the original array }
procedure reverse(s: array[min .. max: integer] of char, var result: array[min1 .. max1: integer] of char);
var
i, len: integer;
begin
len := max-min+1;
for i := 0 to len-1 do
result[min1 + len-1 - i] := s[min + i]
end; | Give a code snippet in #Pascal
Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empt... | 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
| #Elena | Elena | import system'routines;
import extensions;
SumOfSquares(list)
= list.selectBy:(x => x * x).summarize(new Integer());
public program()
{
console
.printLine(SumOfSquares(new int[]{4, 8, 15, 16, 23, 42}))
.printLine(SumOfSquares(new int[]{1, 2, 3, 4, 5}))
.printLine(SumOfSquares(Array.... | Give a code snippet in #Elena
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/Horizontal_sundial_calculations | Horizontal sundial calculations | Task
Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location.
For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit... | #Modula-2 | Modula-2 |
MODULE SunDial;
FROM STextIO IMPORT
WriteString, WriteLn, SkipLine;
FROM SRealIO IMPORT
ReadReal, WriteFixed, WriteFloat;
FROM SWholeIO IMPORT
WriteInt;
FROM RealMath IMPORT
sin, pi, arctan, tan;
VAR
Lat, Slat, Lng, Ref: REAL;
Hour: INTEGER;
HourAngle, HourLineAngle: REAL;
BEGIN
WriteString("Enter... | Give a code snippet in #Modula-2
Task
Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location.
For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Isl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Almkvist-Giullera_formula_for_pi | Almkvist-Giullera formula for pi | The Almkvist-Giullera formula for calculating 1/π2 is based on the Calabi-Yau
differential equations of order 4 and 5, which were originally used to describe certain manifolds
in string theory.
The formula is:
1/π2 = (25/3) ∑0∞ ((6n)! / (n!6))(532n2 + 126n + 9) / 10002n+1
This formula can be used to calcul... | #Python | Python | import mpmath as mp
with mp.workdps(72):
def integer_term(n):
p = 532 * n * n + 126 * n + 9
return (p * 2**5 * mp.factorial(6 * n)) / (3 * mp.factorial(n)**6)
def exponent_term(n):
return -(mp.mpf("6.0") * n + 3)
def nthterm(n):
return integer_term(n) * mp.mpf("10.0")... | Give a code snippet in #Python
The Almkvist-Giullera formula for calculating 1/π2 is based on the Calabi-Yau
differential equations of order 4 and 5, which were originally used to describe certain manifolds
in string theory.
The formula is:
1/π2 = (25/3) ∑0∞ ((6n)! / (n!6))(532n2 + 126n + 9) / 10002n+1
Th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/JSON | JSON | Load a JSON string into a data structure.
Also, create a new data structure and serialize it into JSON.
Use objects and arrays (as appropriate for your language)
and make sure your JSON is valid (https://jsonformatter.org).
| #Arturo | Arturo | print read.json {{ "foo": 1, "bar": [10, "apples"] }}
object: #[
name: "john"
surname: "doe"
address: #[
number: 10
street: "unknown"
country: "Spain"
]
married: false
]
print write.json ø object | Give a code snippet in #Arturo
Load a JSON string into a data structure.
Also, create a new data structure and serialize it into JSON.
Use objects and arrays (as appropriate for your language)
and make sure your JSON is valid (https://jsonformatter.org).
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Hunt_the_Wumpus | Hunt the Wumpus | 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.
Create a simple implementation of the classic textual game Hunt The Wumpus.
The rules are:
The game is set in a cave that consists ... | #FORTRAN | FORTRAN | Makefile
| Give a code snippet in #FORTRAN
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.
Create a simple implementation of the classic textual game Hunt The Wumpus.
The rules are:
The gam... | 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 |... | #Eiffel | Eiffel | class
APPLICATION
inherit
ARGUMENTS
create
make
feature {NONE} -- Initialization
make
local
i, j: INTEGER_32
do
io.read_integer_32
i := io.last_integer_32
io.read_integer_32
j := io.last_integer_32
if i < j then
print("first is less than second%N")
end
if i = j then
print... | Give a code snippet in #Eiffel
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/Towers_of_Hanoi | Towers of Hanoi | Task
Solve the Towers of Hanoi problem with recursion.
| #Dyalect | Dyalect | func hanoi(n, a, b, c) {
if n > 0 {
hanoi(n - 1, a, c, b)
print("Move disk from \(a) to \(c)")
hanoi(n - 1, b, a, c)
}
}
hanoi(4, "A", "B", "C") | Give a code snippet in #Dyalect
Task
Solve the Towers of Hanoi problem with recursion.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Nim_game | Nim game | Nim game
You are encouraged to solve this task according to the task description, using any language you may know.
Nim is a simple game where the second player ─── if they know the trick ─── will always win.
The game has only 3 rules:
start with 12 tokens
each player takes 1, 2, or 3 tokens in tur... | #AutoHotkey | AutoHotkey | Play:
tokens := 12
while tokens {
while !(D>0 && D<4)
InputBox, D, Nim Game, % "Tokens Remaining = " tokens
. "`nHow many tokens would you like to take?"
. "`nChoose 1, 2 or 3"
tokens -= D
MsgBox % "Computer Takes " 4-D
tokens -= 4-d, d:=0
}
MsgBox, 262212,,Computer Always Wins!`nWould you like to play again?... | Give a code snippet in #AutoHotkey
Nim game
You are encouraged to solve this task according to the task description, using any language you may know.
Nim is a simple game where the second player ─── if they know the trick ─── will always win.
The game has only 3 rules:
start with 12 tokens
each player t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substitution_cipher | Substitution cipher | Substitution Cipher Implementation - File Encryption/Decryption
Task
Encrypt a input/source file by replacing every upper/lower case alphabets of the source file with another predetermined upper/lower case alphabets or symbols and save it into another output/encrypted file and then again convert that output/encrypt... | #zkl | zkl | class SubstitutionCipher{
// 92 characters: " !"#$%&" ... "xyz{|}", doesn't include "~"
const KEY="]kYV}(!7P$n5_0i R:?jOWtF/=-pe'AD&@r6%ZXs\"v*N"
"[#wSl9zq2^+g;LoB`aGh{3.HIu4fbK)mU8|dMET><,Qc\\C1yxJ";
fcn encode(s){ s.apply(fcn(c){ try{ KEY[c.toAsc()-32] }catch{ c } }) }
fcn decode(s){ s.apply(... | Give a code snippet in #zkl
Substitution Cipher Implementation - File Encryption/Decryption
Task
Encrypt a input/source file by replacing every upper/lower case alphabets of the source file with another predetermined upper/lower case alphabets or symbols and save it into another output/encrypted file and then agai... | 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... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | Needs["NETLink`"];
externalFloor = DefineDLLFunction["floor", "msvcrt.dll", "double", { "double" }];
externalFloor[4.2]
-> 4. | Give a code snippet in #Mathematica.2FWolfram_Language
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calculating_the_value_of_e | Calculating the value of e | Task
Calculate the value of e.
(e is also known as Euler's number and Napier's constant.)
See details: Calculating the value of e
| #Free_Pascal | Free Pascal | ' version 02-07-2018
' compile with: fbc -s console
Dim As Double e , e1
Dim As ULongInt n = 1, n1 = 1
e = 1 / 1
While e <> e1
e1 = e
e += 1 / n
n1 += 1
n *= n1
Wend
Print "The value of e ="; e
' empty keyboard buffer
While InKey <> "" : Wend
Print : Print "hit any key to end program"
Sleep
En... | Give a code snippet in #Free_Pascal
Task
Calculate the value of e.
(e is also known as Euler's number and Napier's constant.)
See details: Calculating the value of e
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Leonardo_numbers | Leonardo numbers |
Leonardo numbers are also known as the Leonardo series.
The Leonardo numbers are a sequence of numbers defined by:
L(0) = 1 [1st equation]
L(1) = 1 [2nd equation]
L(n) = L(n-1) + L(n-2) + 1 ... | #Fortran | Fortran | SUBROUTINE LEONARDO(LAST,L0,L1,AF) !Show the first LAST values of the sequence.
INTEGER LAST !Limit to show.
INTEGER L0,L1 !Starting values.
INTEGER AF !The "Add factor" to deviate from Fibonacci numbers.
OPTIONAL AF !Indicate that this parameter may be omitted.
INTEGER EMBOLISM... | Give a code snippet in #Fortran
Leonardo numbers are also known as the Leonardo series.
The Leonardo numbers are a sequence of numbers defined by:
L(0) = 1 [1st equation]
L(1) = 1 [2nd equation]
L(n)... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Negative_base_numbers | Negative base numbers | Negative base numbers are an alternate way to encode numbers without the need for a minus sign. Various negative bases may be used including negadecimal (base -10), negabinary (-2) and negaternary (-3).[1][2]
Task
Encode the decimal number 10 as negabinary (expect 11110)
Encode the decimal number 146 as negaternary... | #C | C | #include <stdio.h>
const char DIGITS[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
const int DIGITS_LEN = 64;
void encodeNegativeBase(long n, long base, char *out) {
char *ptr = out;
if (base > -1 || base < -62) {
/* Bounds check*/
out = "";
return;
}
... | Give a code snippet in #C
Negative base numbers are an alternate way to encode numbers without the need for a minus sign. Various negative bases may be used including negadecimal (base -10), negabinary (-2) and negaternary (-3).[1][2]
Task
Encode the decimal number 10 as negabinary (expect 11110)
Encode the decima... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Filter | Filter | Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| #NewLISP | NewLISP | > (filter (fn (x) (= (% x 2) 0)) '(1 2 3 4 5 6 7 8 9 10))
(2 4 6 8 10)
| Give a code snippet in #NewLISP
Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutation_test | Permutation test | Permutation test
You are encouraged to solve this task according to the task description, using any language you may know.
A new medical treatment was tested on a population of
n
+
m
{\displaystyle n+m}
volunteers, with each volunteer randomly assigned either to a group of
n
{\displaystyle n}
treatment... | #Nim | Nim | import strformat
const data = [85, 88, 75, 66, 25,
29, 83, 39, 97, 68,
41, 10, 49, 16, 65,
32, 92, 28, 98]
func pick(at, remain, accu, treat: int): int =
if remain == 0:
return if accu > treat: 1 else: 0
return pick(at - 1, remain - 1, accu + data[at - 1], treat) + ... | Give a code snippet in #Nim
Permutation test
You are encouraged to solve this task according to the task description, using any language you may know.
A new medical treatment was tested on a population of
n
+
m
{\displaystyle n+m}
volunteers, with each volunteer randomly assigned either to a group of
n
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Nested_templated_data | Nested templated data | A template for data is an arbitrarily nested tree of integer indices.
Data payloads are given as a separate mapping, array or other simpler, flat,
association of indices to individual items of data, and are strings.
The idea is to create a data structure with the templates' nesting, and the
payload corresponding to e... | #Factor | Factor | USING: formatting kernel literals math sequences sequences.deep ;
IN: rosetta-code.nested-template-data
CONSTANT: payloads $[ 7 <iota> [ "Payload#%d" sprintf ] map ]
: insert-payloads ( template -- data-structure )
[ dup fixnum? [ payloads ?nth ] when ] deep-map ;
{ { { 1 2 }
{ 3 4 1 }
5 } }
{ { { 1... | Give a code snippet in #Factor
A template for data is an arbitrarily nested tree of integer indices.
Data payloads are given as a separate mapping, array or other simpler, flat,
association of indices to individual items of data, and are strings.
The idea is to create a data structure with the templates' nesting, an... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Nested | Loops/Nested | Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is met.
Specifically, this task als... | #zkl | zkl | const N=5;
var rows=(0).pump(N,List, (0).pump.fp(N,List,(1).random.fpM("1-",21)) );
try{
foreach r in (N){
foreach c in (N){
x:=rows[r][c]; x.print(",");
if (x==20) { println("Found it!"); throw(Exception.Generic); }
}
}
println("Not found");
}catch(Generic){} | Give a code snippet in #zkl
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is met.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Move-to-front_algorithm | Move-to-front algorithm | Given a symbol table of a zero-indexed array of all possible input symbols
this algorithm reversibly transforms a sequence
of input symbols into an array of output numbers (indices).
The transform in many cases acts to give frequently repeated input symbols
lower indices which is useful in some compression algorithms... | #Perl | Perl | use strict;
use warnings;
sub encode {
my ($str) = @_;
my $table = join '', 'a' .. 'z';
map {
$table =~ s/(.*?)$_/$_$1/ or die;
length($1);
} split //, $str;
}
sub decode {
my $table = join '', 'a' .. 'z';
join "", map {
$table =~ s/(.{$_})(.)/$2$1/ or die;
$2;
} @_;
}
for my $test ( qw(broood banana... | Give a code snippet in #Perl
Given a symbol table of a zero-indexed array of all possible input symbols
this algorithm reversibly transforms a sequence
of input symbols into an array of output numbers (indices).
The transform in many cases acts to give frequently repeated input symbols
lower indices which is useful ... | 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
... | #AWK | AWK | function 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))
}
BEGIN {
for(n=0; n < 7; n++) {
for(m=0; m < 4; m++) {
print "A(" m "," n ") = " ackermann(m,n)
}
}
} | Give a code snippet in #AWK
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Euler%27s_sum_of_powers_conjecture | Euler's sum of powers conjecture | There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth power,
except for the trivial case... | #ALGOL_68 | ALGOL 68 | # max number will be the highest integer we will consider #
INT max number = 250;
# Construct a table of the fifth powers of 1 : max number #
[ max number ]LONG INT fifth;
FOR i TO max number DO
LONG INT i2 = i * i;
fifth[ i ] := i2 * i2 * i
OD;
# find the first a, b, ... | Give a code snippet in #ALGOL_68
There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth powe... | 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
... | #ALGOL_68 | ALGOL 68 | # as the numbers required for finding the first 20 primes are quite large, #
# we use Algol 68G's LONG LONG INT with a precision of 100 digits #
PR precision 100 PR
# mode to hold fractions #
MODE FRACTION = STRUCT( INT numerator, INT denominator );
# define / between two INTs to yield a FRACTION #
OP / = ... | Give a code snippet in #ALGOL_68
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 ini... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Evaluate_binomial_coefficients | Evaluate binomial coefficients | This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2
)
…
(
n
−
k
+
1
)
k
(
k
−
1... | #ERRE | ERRE | PROGRAM BINOMIAL
!$DOUBLE
PROCEDURE BINOMIAL(N,K->BIN)
LOCAL R,D
R=1 D=N-K
IF D>K THEN K=D D=N-K END IF
WHILE N>K DO
R*=N
N-=1
WHILE D>1 AND (R-D*INT(R/D))=0 DO
R/=D
D-=1
END WHILE
END WHILE
BIN=R
END PROCEDURE
BEGIN
BINOM... | Give a code snippet in #ERRE
This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
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 l... | #blz | blz | while true
print("SPAM")
end | Give a code snippet in #blz
Task
Print out SPAM followed by a newline in an infinite loop.
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/Symmetric_difference | Symmetric difference | Task
Given two sets A and B, compute
(
A
∖
B
)
∪
(
B
∖
A
)
.
{\displaystyle (A\setminus B)\cup (B\setminus A).}
That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B.
In other words:
(
A
∪
B
)
∖
(
A
∩
B
)
{\displaystyle (A\cup B)\setminus (A... | #D.C3.A9j.C3.A0_Vu | Déjà Vu | set :setA set{ :John :Bob :Mary :Serena }
set :setB set{ :Jim :Mary :John :Bob }
symmetric-difference A B:
}
for a in keys A:
if not has B a:
a
for b in keys B:
if not has A b:
b
set{
!. symmetric-difference setA setB | Give a code snippet in #D.C3.A9j.C3.A0_Vu
Task
Given two sets A and B, compute
(
A
∖
B
)
∪
(
B
∖
A
)
.
{\displaystyle (A\setminus B)\cup (B\setminus A).}
That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B.
In other words:
(
A
∪
B
)
∖
(
A
∩... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Linear_congruential_generator | Linear congruential generator | The linear congruential generator is a very simple example of a random number generator.
All linear congruential generators use this formula:
r
n
+
1
=
a
×
r
n
+
c
(
mod
m
)
{\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}}
Where:
r
0
{\displaystyle r_{0}}
is a seed.
r
1
... | #Standard_ML | Standard ML | local
open Word32
in
fun bsdLcg (seed : int) : int =
toInt (andb (0w1103515245 * fromInt seed + 0w12345, 0wx7fffffff))
fun mscLcg (seed : word) : int * word =
let
val state = andb (0w214013 * seed + 0w2531011, 0wx7fffffff)
in
(toInt (>> (state, 0w16)), state)
end
end | Give a code snippet in #Standard_ML
The linear congruential generator is a very simple example of a random number generator.
All linear congruential generators use this formula:
r
n
+
1
=
a
×
r
n
+
c
(
mod
m
)
{\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}}
Where:
r
0
{\displays... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Singleton | Singleton | A Global Singleton is a class of which only one instance exists within a program.
Any attempt to use non-static members of the class involves performing operations on this one instance.
| #Icon_and_Unicon | Icon and Unicon | class Singleton
method print()
write("Hi there.")
end
initially
write("In constructor!")
Singleton := create |self
end
procedure main()
Singleton().print()
Singleton().print()
end | Give a code snippet in #Icon_and_Unicon
A Global Singleton is a class of which only one instance exists within a program.
Any attempt to use non-static members of the class involves performing operations on this one instance.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Draw_a_clock | Draw a clock | Task
Draw a clock.
More specific:
Draw a time keeping device. It can be a stopwatch, hourglass, sundial, a mouth counting "one thousand and one", anything. Only showing the seconds is required, e.g.: a watch with just a second hand will suffice. However, it must clearly change every second, and the change must cy... | #FunL | FunL | import concurrent.{scheduleAtFixedRate, scheduler}
val ROW = 10
val COL = 20
val digits = array( [
" __",
" / /",
"/__/ ",
" ",
" /",
" / ",
" __",
" __/",
"/__ ",
" __",
" __/",
" __/ ",
" ",
" /__/",
" / ",
" __",
" /__ ",
" __/ ",
" __",
" /__ ",... | Give a code snippet in #FunL
Task
Draw a clock.
More specific:
Draw a time keeping device. It can be a stopwatch, hourglass, sundial, a mouth counting "one thousand and one", anything. Only showing the seconds is required, e.g.: a watch with just a second hand will suffice. However, it must clearly change every ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Egyptian_fractions | Egyptian fractions | An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1 (unity) and a denominator that... | #D | D | import std.stdio, std.bigint, std.algorithm, std.range, std.conv, std.typecons,
arithmetic_rational: Rat = Rational;
Rat[] egyptian(Rat r) pure nothrow {
typeof(return) result;
if (r >= 1) {
if (r.denominator == 1)
return [r, Rat(0, 1)];
result = [Rat(r.numerator / r.denom... | Give a code snippet in #D
An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1 (unit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Word_frequency | Word frequency | Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define what a letter is.
Undersc... | #PicoLisp | PicoLisp | (setq *Delim " ^I^J^M-_.,\"'*[]?!&@#$%^\(\):;")
(setq *Skip (chop *Delim))
(de word+ NIL
(prog1
(lowc (till *Delim T))
(while (member (peek) *Skip) (char)) ) )
(off B)
(in "135-0.txt"
(until (eof)
(let W (word+)
(if (idx 'B W T) (inc (car @)) (set W 1)) ) ) )
(for L (head 10 (flip (... | Give a code snippet in #PicoLisp
Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bioinformatics/base_count | Bioinformatics/base count | Given this string representing ordered DNA bases:
CGTAAAAAATTACAACGTCCTTTGGCTATCTCTTAAACTCCTGCTAAATG
CTCGTGCTTTCCAATTATGTAAGCGTTCCGAGACGGGGTGGTCGATTCTG
AGGACAAAGGTCAAGATGGAGCGCATCGAACGCAATAAGGATCATTTGAT
GGGACGTTTCGTCGACAAAGTCTTGTTTCGAGAGTAACGGCTACCGTCTT
CGATTCTGCTTATAACACTATGTTCTTATGAAATGGATGTTCTGAGTTGG
TCAGTCCCAATGTG... | #PureBasic | PureBasic | dna$ = "CGTAAAAAATTACAACGTCCTTTGGCTATCTCTTAAACTCCTGCTAAATG" +
"CTCGTGCTTTCCAATTATGTAAGCGTTCCGAGACGGGGTGGTCGATTCTG" +
"AGGACAAAGGTCAAGATGGAGCGCATCGAACGCAATAAGGATCATTTGAT" +
"GGGACGTTTCGTCGACAAAGTCTTGTTTCGAGAGTAACGGCTACCGTCTT" +
"CGATTCTGCTTATAACACTATGTTCTTATGAAATGGATGTTCT... | Give a code snippet in #PureBasic
Given this string representing ordered DNA bases:
CGTAAAAAATTACAACGTCCTTTGGCTATCTCTTAAACTCCTGCTAAATG
CTCGTGCTTTCCAATTATGTAAGCGTTCCGAGACGGGGTGGTCGATTCTG
AGGACAAAGGTCAAGATGGAGCGCATCGAACGCAATAAGGATCATTTGAT
GGGACGTTTCGTCGACAAAGTCTTGTTTCGAGAGTAACGGCTACCGTCTT
CGATTCTGCTTATAACACTATGTTCTTATG... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Identity_matrix | Identity matrix | Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
0
1
⋯
0
⋮
⋮
⋮
⋱
... | #FunL | FunL | def identity( n ) = vector( n, n, \r, c -> if r == c then 1 else 0 )
println( identity(3) ) | Give a code snippet in #FunL
Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
0
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Harshad_or_Niven_series | Harshad or Niven series | The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task is to create a function/method/... | #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Function sumDigits(n As Integer) As Integer
If n < 0 Then Return 0
Dim sum As Integer
While n > 0
sum += n Mod 10
n \= 10
Wend
Return sum
End Function
Function isHarshad(n As Integer) As Boolean
Return n Mod sumDigits(n) = 0
End Function
Print "The first 20 Harshad or Niven n... | Give a code snippet in #FreeBASIC
The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Creation | Associative array/Creation | Task
The goal is to create an associative array (also known as a dictionary, map, or hash).
Related tasks:
Associative arrays/Iteration
Hash from two arrays
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element ins... | #Crystal | Crystal | hash1 = {"foo" => "bar"}
# hash literals that don't perfectly match the intended hash type must be given an explicit type specification
# the following would fail without `of String => String|Int32`
hash2 : Hash(String, String|Int32) = {"foo" => "bar"} of String => String|Int32 | Give a code snippet in #Crystal
Task
The goal is to create an associative array (also known as a dictionary, map, or hash).
Related tasks:
Associative arrays/Iteration
Hash from two arrays
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Extend_your_language | Extend your language | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Some programming languages allow you to extend the language. While this can be done to a certain degree in most languages (e.g. by using macros), other langua... | #Smalltalk | Smalltalk | or:condition2 ifBoth:bothBlk ifFirst:firstBlk ifSecond:scndBlk ifNone:noneBlk
"I know for sure, that I am true..."
^ condition2 ifTrue:bothBlk ifFalse:firstBlk | Give a code snippet in #Smalltalk
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Some programming languages allow you to extend the language. While this can be done to a certain degree in most languages (... | 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:
... | #C | C | #include <stdio.h>
#include <stdlib.h>
#include <math.h>
double rk4(double(*f)(double, double), double dx, double x, double y)
{
double k1 = dx * f(x, y),
k2 = dx * f(x + dx / 2, y + k1 / 2),
k3 = dx * f(x + dx / 2, y + k2 / 2),
k4 = dx * f(x + dx, y + k3);
return y + (k1 + 2 * k2 + 2 * k3 + k4) / 6;
}
doub... | Give a code snippet in #C
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 equati... | 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 ... | #Raku | Raku | my %costs =
:W{:16A, :16B, :13C, :22D, :17E},
:X{:14A, :14B, :13C, :19D, :15E},
:Y{:19A, :19B, :20C, :23D, :50E},
:Z{:50A, :12B, :50C, :15D, :11E};
my %demand = :30A, :20B, :70C, :30D, :60E;
my %supply = :50W, :60X, :50Y, :50Z;
my @cols = %demand.keys.sort;
my %res;
my %g = (|%supply.keys.map: ->... | Give a code snippet in #Raku
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 th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Deming%27s_Funnel | Deming's Funnel | W Edwards Deming was an American statistician and management guru who used physical demonstrations to illuminate his teachings. In one demonstration Deming repeatedly dropped marbles through a funnel at a target, marking where they landed, and observing the resulting pattern. He applied a sequence of "rules" to try to ... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | dxs = {-0.533, 0.27, 0.859, -0.043, -0.205, -0.127, -0.071, 0.275,
1.251, -0.231, -0.401, 0.269, 0.491, 0.951, 1.15, 0.001, -0.382,
0.161, 0.915, 2.08, -2.337, 0.034, -0.126, 0.014, 0.709,
0.129, -1.093, -0.483, -1.193, 0.02, -0.051, 0.047, -0.095, 0.695,
0.34, -0.182, 0.287, 0.213, -0.423, -0.021, -0.1... | Give a code snippet in #Mathematica.2FWolfram_Language
W Edwards Deming was an American statistician and management guru who used physical demonstrations to illuminate his teachings. In one demonstration Deming repeatedly dropped marbles through a funnel at a target, marking where they landed, and observing the result... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Barnsley_fern | Barnsley fern |
A Barnsley fern is a fractal named after British mathematician Michael Barnsley and can be created using an iterated function system (IFS).
Task
Create this fractal fern, using the following transformations:
ƒ1 (chosen 1% of the time)
xn + 1 = 0
yn + 1 = 0.16 yn
ƒ2 (chosen 85% of the time)
... | #R | R | ## pBarnsleyFern(fn, n, clr, ttl, psz=600): Plot Barnsley fern fractal.
## Where: fn - file name; n - number of dots; clr - color; ttl - plot title;
## psz - picture size.
## 7/27/16 aev
pBarnsleyFern <- function(fn, n, clr, ttl, psz=600) {
cat(" *** START:", date(), "n=", n, "clr=", clr, "psz=", psz, "\n");
cat(" ... | Give a code snippet in #R
A Barnsley fern is a fractal named after British mathematician Michael Barnsley and can be created using an iterated function system (IFS).
Task
Create this fractal fern, using the following transformations:
ƒ1 (chosen 1% of the time)
xn + 1 = 0
yn + 1 = 0.16 yn
ƒ2 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Naming_conventions | Naming conventions | Many languages have naming conventions regarding the identifiers used in the language, its libraries, and programs written in the language. Such conventions, which may be classified as de facto or de jure depending on how they are enforced,
often take the form of rules regarding prefixes, suffixes, and the use of upper... | #Rust | Rust | Dim dblDistance as Double | Give a code snippet in #Rust
Many languages have naming conventions regarding the identifiers used in the language, its libraries, and programs written in the language. Such conventions, which may be classified as de facto or de jure depending on how they are enforced,
often take the form of rules regarding prefixes, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Floyd-Warshall_algorithm | Floyd-Warshall algorithm | The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been checked for loops, parallel ... | #Tcl | Tcl | package require Tcl 8.5 ;# for {*} and [dict]
package require struct::graph
package require struct::graph::op
struct::graph g
set arclist {
a b
a p
b m
b c
c d
d e
e f
f q
f g
}
g node insert {*}$arclist
foreach {from to} $arclist {
set a [g arc insert $from $to]
... | Give a code snippet in #Tcl
The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Quicksort | Sorting algorithms/Quicksort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #D | D | import std.stdio : writefln, writeln;
import std.algorithm: filter;
import std.array;
T[] quickSort(T)(T[] xs) =>
xs.length == 0 ? [] :
xs[1 .. $].filter!(x => x< xs[0]).array.quickSort ~
xs[0 .. 1] ~
xs[1 .. $].filter!(x => x>=xs[0]).array.quickSort;
void main() =>
[4, 65, 2, -31, 0, 99, 2,... | Give a code snippet in #D
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fivenum | Fivenum | Many big data or scientific programs use boxplots to show distributions of data. In addition, sometimes saving large arrays for boxplots can be impractical and use extreme amounts of RAM. It can be useful to save large arrays as arrays with five numbers to save memory.
For example, the R programming language i... | #Scala | Scala | import java.util
object Fivenum extends App {
val xl = Array(
Array(15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0),
Array(36.0, 40.0, 7.0, 39.0, 41.0, 15.0),
Array(0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594, 0.73438555,
-0.03035726, 1.46675970, -0.74621349, -0.7... | Give a code snippet in #Scala
Many big data or scientific programs use boxplots to show distributions of data. In addition, sometimes saving large arrays for boxplots can be impractical and use extreme amounts of RAM. It can be useful to save large arrays as arrays with five numbers to save memory.
For example, t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Cursor_positioning | Terminal control/Cursor positioning |
Task
Move the cursor to column 3, row 6, and display the word "Hello" (without the quotes), so that the letter H is in column 3 on row 6.
| #Ada | Ada | with Ada.Text_IO;
procedure Cursor_Pos is
begin
Ada.Text_IO.Set_Line(6);
Ada.Text_IO.Set_Col(3);
Ada.Text_IO.Put("Hello");
end Cursor_Pos; | Give a code snippet in #Ada
Task
Move the cursor to column 3, row 6, and display the word "Hello" (without the quotes), so that the letter H is in column 3 on row 6.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #Mercury | Mercury | S = "", % assignment
( if S = "" then ... else ... ), % checking if a string is empty
( if not S = "" then ... else ... ), % checking if a string is not empty | Give a code snippet in #Mercury
Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
O... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Increment_loop_index_within_loop_body | Loops/Increment loop index within loop body | Sometimes, one may need (or want) a loop which
its iterator (the index
variable) is modified within the
loop body in addition to the normal incrementation by the (do) loop structure index.
Goal
Demonstrate the best way to accomplish this.
Task
Write a loop which:
starts the index (variable... | #ARM_Assembly | ARM Assembly |
/* ARM assembly Raspberry PI */
/* program loopinc96.s */
/************************************/
/* Constantes */
/************************************/
.equ STDOUT, 1 @ Linux output console
.equ EXIT, 1 @ Linux syscall
.equ WRITE, 4 @ Linux syscall
/**********************... | Give a code snippet in #ARM_Assembly
Sometimes, one may need (or want) a loop which
its iterator (the index
variable) is modified within the
loop body in addition to the normal incrementation by the (do) loop structure index.
Goal
Demonstrate the best way to accomplish this.
Task
Write a loop... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Call_a_function | Call a function | Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function with a variable number of arguments
C... | #Wren | Wren | var f1 = Fn.new { System.print("Function 'f1' with no arguments called.") }
var f2 = Fn.new { |a, b|
System.print("Function 'f2' with 2 arguments called and passed %(a) & %(b).")
}
var f3 = Fn.new { 42 } // function which returns a concrete value
f1.call() // statement context
f2.call(2, 3) ... | Give a code snippet in #Wren
Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function with a var... | 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... | #XPL0 | XPL0 | include c:\cxpl\codes; \intrinsic 'code' declarations
proc ClosestPair(P, N); \Show closest pair of points in array P
real P; int N;
real Dist2, MinDist2;
int I, J, SI, SJ;
[MinDist2:= 1e300;
for I:= 0 to N-2 do
[for J:= I+1 to N-1 do
[Dist2:= sq(P(I,0)-P(J,0)) + sq(P(I,1)-P(J,1));
... | Give a code snippet in #XPL0
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 func... | 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... | #Pascal | Pascal | program countto6(output);
var
i: integer;
begin
i := 0;
repeat
i := i + 1;
writeln(i)
until i mod 6 = 0
end. | Give a code snippet in #Pascal
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/... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_search | Binary search | A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret number, and will only tell the p... | #HicEst | HicEst | REAL :: n=10, array(n)
array = NINT( RAN(n) )
SORT(Vector=array, Sorted=array)
x = NINT( RAN(n) )
idx = binarySearch( array, x )
WRITE(ClipBoard) x, "has position ", idx, "in ", array
END
FUNCTION binarySearch(A, value)
REAL :: A(1), value
low = 1
high = LEN(A)
DO i = 1, high
I... | Give a code snippet in #HicEst
A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Man_or_boy_test | Man or boy test | Man or boy test
You are encouraged to solve this task according to the task description, using any language you may know.
Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguis... | #Forth | Forth | : A {: w^ k x1 x2 x3 xt: x4 xt: x5 | w^ B :} recursive
k @ 0<= IF x4 x5 f+ ELSE
B k x1 x2 x3 action-of x4 [{: B k x1 x2 x3 x4 :}L
-1 k +!
k @ B @ x1 x2 x3 x4 A ;] dup B !
execute THEN ;
10 [: 1e ;] [: -1e ;] 2dup swap [: 0e ;] A f. | Give a code snippet in #Forth
Man or boy test
You are encouraged to solve this task according to the task description, using any language you may know.
Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The ai... | christopher/rosetta-code | |
http://rosettacode.org/wiki/MD4 | MD4 | Find the MD4 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Code” (without quotes).
You may either call an MD4 library, or implement MD4 in your language.
MD4 is an obsolete hash function that computes a 128-bit message digest that sometimes appears in obsolete protocols.
RFC 1320 specifi... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "msgdigest.s7i";
const proc: main is func
begin
writeln(hex(md4("Rosetta Code")));
end func; | Give a code snippet in #Seed7
Find the MD4 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Code” (without quotes).
You may either call an MD4 library, or implement MD4 in your language.
MD4 is an obsolete hash function that computes a 128-bit message digest that sometimes appears in obsole... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zero_to_the_zero_power | Zero to the zero power | Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or 0^0 at compile time, ... | #Nial | Nial | 0 0.0 o outer power 0 0.0 o
+--+--+--+
| 1|1.| 1|
+--+--+--+
|1.|1.|1.|
+--+--+--+
| 1|1.| 1|
+--+--+--+ | Give a code snippet in #Nial
Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Visualize_a_tree | Visualize a tree | A tree structure (i.e. a rooted, connected acyclic graph) is often used in programming.
It's often helpful to visually examine such a structure.
There are many ways to represent trees to a reader, such as:
indented text (à la unix tree command)
nested HTML tables
hierarchical GUI widgets
2D or ... | #jq | jq | 0
├─ 1
├─ 2
└─ 3
| Give a code snippet in #jq
A tree structure (i.e. a rooted, connected acyclic graph) is often used in programming.
It's often helpful to visually examine such a structure.
There are many ways to represent trees to a reader, such as:
indented text (à la unix tree command)
nested HTML tables
hierarch... | 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 ... | #Raku | Raku | sub ev (Str $s --> Numeric) {
grammar expr {
token TOP { ^ <sum> $ }
token sum { <product> (('+' || '-') <product>)* }
token product { <factor> (('*' || '/') <factor>)* }
token factor { <unary_minus>? [ <parens> || <literal> ] }
token unary_minus { '-' }
token paren... | Give a code snippet in #Raku
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 sim... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Repeat_a_string | Repeat a string | Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").
Other tasks re... | #Befunge | Befunge | v> ">:#,_v
>29*+00p>~:"0"- #v_v $
v ^p0p00:-1g00< $ >
v p00&p0-1g00+4*65< >00g1-:00p#^_@ | Give a code snippet in #Befunge
Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #REXX | REXX | /*REXX program reads a specific line from a file (and displays the length and content).*/
parse arg FID n . /*obtain optional arguments from the CL*/
if FID=='' | FID=="," then FID= 'JUNK.TXT' /*not specified? Then use the default.*/
if n=='' | n=="," then n=7 ... | Give a code snippet in #REXX
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Longest_string_challenge | Longest string challenge | Background
This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through th... | #AutoHotkey | AutoHotkey | input =
(
a
bb
ccc
ddd
ee
f
ggg
)
longestLen := 0, buffer := ""
Loop Parse, input, `n
{
top := SubStr(buffer, 1, InStr(buffer, "`n"))
StringReplace, top, top, `n
If SubStr(A_LoopField, LongestLen) ; at least as long
buffer .= A_LoopField "`n"
If !SubStr(top, StrLen(A_LoopField)) ; longer
buffer ... | Give a code snippet in #AutoHotkey
Background
This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the ch... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Median | Averages/Median | Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.
There are several approaches ... | #Haskell | Haskell | import Data.List (partition)
nth :: Ord t => [t] -> Int -> t
nth (x:xs) n
| k == n = x
| k > n = nth ys n
| otherwise = nth zs $ n - k - 1
where
(ys, zs) = partition (< x) xs
k = length ys
medianMay :: (Fractional a, Ord a) => [a] -> Maybe a
medianMay xs
| n < 1 = Nothing
| even n = Just ((nth x... | Give a code snippet in #Haskell
Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle value... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Play_recorded_sounds | Play recorded sounds | Load at least two prerecorded sounds, and demonstrate as many of these features as you can:
playing them individually and simultaneously
stopping before the end of the sound
looping (preferably glitch-free)
setting the volume of each sound
stereo or 3D positional mixing
performing other actions when marked times... | #Go | Go | package main
import (
"log"
"os"
"os/exec"
)
func main() {
args := []string{
"-m", "-v", "0.75", "a.wav", "-v", "0.25", "b.wav",
"-d",
"trim", "4", "6",
"repeat", "5",
}
cmd := exec.Command("sox", args...)
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
... | Give a code snippet in #Go
Load at least two prerecorded sounds, and demonstrate as many of these features as you can:
playing them individually and simultaneously
stopping before the end of the sound
looping (preferably glitch-free)
setting the volume of each sound
stereo or 3D positional mixing
performing oth... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #Raku | Raku | given lc prompt("Done? ") {
when 'yes' { return }
when 'no' { next }
default { say "Please answer either yes or no." }
} | Give a code snippet in #Raku
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common c... | christopher/rosetta-code |
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