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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 ...
#ALGOL_68
ALGOL 68
PROC analytic fibonacci = (LONG INT n)LONG INT:( LONG REAL sqrt 5 = long sqrt(5); LONG REAL p = (1 + sqrt 5) / 2; LONG REAL q = 1/p; ROUND( (p**n + q**n) / sqrt 5 ) );   FOR i FROM 1 TO 30 WHILE print(whole(analytic fibonacci(i),0)); # WHILE # i /= 30 DO print(", ") OD; print(new line)
http://rosettacode.org/wiki/Factors_of_an_integer
Factors of an integer
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#Asymptote
Asymptote
int[] n = {11, 21, 32, 45, 67, 519};   for(var j : n) { write(j, suffix=none); write(" =>", suffix=none); for(int i = 1; i < (j/2); ++i) { if(j % i == 0) { write(" ", i, suffix=none); } } write(" ", j); }
http://rosettacode.org/wiki/Fast_Fourier_transform
Fast Fourier transform
Task Calculate the   FFT   (Fast Fourier Transform)   of an input sequence. The most general case allows for complex numbers at the input and results in a sequence of equal length, again of complex numbers. If you need to restrict yourself to real numbers, the output should be the magnitude   (i.e.:   sqrt(re2 + im2)...
#Haskell
Haskell
import Data.Complex   -- Cooley-Tukey fft [] = [] fft [x] = [x] fft xs = zipWith (+) ys ts ++ zipWith (-) ys ts where n = length xs ys = fft evens zs = fft odds (evens, odds) = split xs split [] = ([], []) split [x] = ([x], []) split (x:y:xs) = (x:xt, y:y...
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number
Factors of a Mersenne number
A Mersenne number is a number in the form of 2P-1. If P is prime, the Mersenne number may be a Mersenne prime (if P is not prime, the Mersenne number is also not prime). In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,...
#Go
Go
package main   import ( "fmt" "math" )   // limit search to small primes. really this is higher than // you'd want it, but it's fun to factor M67. const qlimit = 2e8   func main() { mtest(31) mtest(67) mtest(929) }   func mtest(m int32) { // the function finds odd prime factors by // search...
http://rosettacode.org/wiki/Farey_sequence
Farey sequence
The   Farey sequence   Fn   of order   n   is the sequence of completely reduced fractions between   0   and   1   which, when in lowest terms, have denominators less than or equal to   n,   arranged in order of increasing size. The   Farey sequence   is sometimes incorrectly called a   Farey series. Each Farey se...
#Phix
Phix
with javascript_semantics function farey(integer n) integer a=0, b=1, c=1, d=n, items=1 if n<=11 then printf(1,"%d: %d/%d",{n,a,b}) end if while c<=n do integer k = floor((n+b)/d) {a,b,c,d} = {c,d,k*c-a,k*d-b} items += 1 if n<=11 then printf(1," %d/%d"...
http://rosettacode.org/wiki/Faulhaber%27s_triangle
Faulhaber's triangle
Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula: ∑ k = 1 n k p = 1 p + 1 ∑ j = 0 p ( p + 1 j ) B j n p + 1 − j {\displaystyle \sum _{k...
#Ruby
Ruby
class Frac attr_accessor:num attr_accessor:denom   def initialize(n,d) if d == 0 then raise ArgumentError.new('d cannot be zero') end   nn = n dd = d if nn == 0 then dd = 1 elsif dd < 0 then nn = -nn dd = -dd ...
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...
#Scala
Scala
import scala.math.Ordering.Implicits.infixOrderingOps   abstract class Frac extends Comparable[Frac] { val num: BigInt val denom: BigInt   def unary_-(): Frac = { Frac(-num, denom) }   def +(rhs: Frac): Frac = { Frac( num * rhs.denom + rhs.num * denom, denom * rhs.denom ) }   def -...
http://rosettacode.org/wiki/Fibonacci_n-step_number_sequences
Fibonacci n-step number sequences
These number series are an expansion of the ordinary Fibonacci sequence where: For n = 2 {\displaystyle n=2} we have the Fibonacci sequence; with initial values [ 1 , 1 ] {\displaystyle [1,1]} and F k 2 = F k − 1 2 + F k − 2 2 {\displaystyle F_{k}^{2}=F_{k-1}^{2}+F_{k-2}^{2}} ...
#FreeBASIC
FreeBASIC
' FB 1.05.0 Win64   ' Deduces the step, n, from the length of the dynamic array passed in ' and fills it out to 'size' elements Sub fibN (a() As Integer, size As Integer) Dim lb As Integer = LBound(a) Dim ub As Integer = UBound(a) Dim length As Integer = ub - lb + 1 If length < 2 OrElse length >= size Then Retu...
http://rosettacode.org/wiki/Find_common_directory_path
Find common directory path
Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories. Test your routine using the forward slash '/' character as the directory separator and the foll...
#Visual_Basic
Visual Basic
Public Function CommonDirectoryPath(ParamArray Paths()) As String Dim v As Variant Dim Path() As String, s As String Dim i As Long, j As Long, k As Long Const PATH_SEPARATOR As String = "/"   For Each v In Paths ReDim Preserve Path(0 To i) Path(i) = v i = i + 1 Next v   k = 1   Do For i = 0 To U...
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.
#Futhark
Futhark
  fun main(as: []int): []int = filter (fn x => x%2 == 0) as  
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) ...
#J
J
  classify =: +/@(1 2 * 0 = 3 5&|~) (":@]`('Fizz'"_)`('Buzz'"_)`('FizzBuzz'"_) @. classify "0) >:i.100  
http://rosettacode.org/wiki/File_input/output
File input/output
File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable. In other words, your program will demonstrate:   how to read from a file into a variable   how to write ...
#NetRexx
NetRexx
/* NetRexx */ options replace format comments java crossref symbols nobinary   import java.nio.   parse arg infileName outfileName .   if infileName = '' | infileName.length = 0 then infileName = 'data/input.txt' if outfileName = '' | outfileName.length = 0 then outfileName = 'data/output.txt'   binaryCopy(infileNam...
http://rosettacode.org/wiki/File_input/output
File input/output
File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable. In other words, your program will demonstrate:   how to read from a file into a variable   how to write ...
#Nim
Nim
import os copyfile("input.txt", "output.txt")
http://rosettacode.org/wiki/Fibonacci_word
Fibonacci word
The   Fibonacci Word   may be created in a manner analogous to the   Fibonacci Sequence   as described here: Define   F_Word1   as   1 Define   F_Word2   as   0 Form     F_Word3   as   F_Word2     concatenated with   F_Word1   i.e.:   01 Form     F_Wordn   as   F_Wordn-1   concatenated with   F_wordn-...
#Ring
Ring
  # Project : Fibonacci word   fw1 = "1" fw2 = "0"   see "N Length Entropy Word" + nl n = 1 see "" + n + " " + len(fw1) + " " + calcentropy(fw1,2) + " " + fw1 + nl n = 2 see "" + n + " " + len(fw2) + " " + calcentropy(fw2,2) + " " + fw2 + nl   for n = 1 to 55 ...
http://rosettacode.org/wiki/Fibonacci_word
Fibonacci word
The   Fibonacci Word   may be created in a manner analogous to the   Fibonacci Sequence   as described here: Define   F_Word1   as   1 Define   F_Word2   as   0 Form     F_Word3   as   F_Word2     concatenated with   F_Word1   i.e.:   01 Form     F_Wordn   as   F_Wordn-1   concatenated with   F_wordn-...
#Ruby
Ruby
#encoding: ASCII-8BIT   def entropy(s) counts = Hash.new(0.0) s.each_char { |c| counts[c] += 1 } leng = s.length   counts.values.reduce(0) do |entropy, count| freq = count / leng entropy - freq * Math.log2(freq) end end   n_max = 37 words = ['1', '0']   for n in words.length ... n_max words << words...
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 ...
#ALGOL_W
ALGOL W
begin  % return the nth Fibonacci number % integer procedure Fibonacci( integer value n ) ; begin integer fn, fn1, fn2; fn2 := 1; fn1 := 0; fn  := 0; for i := 1 until n do begin fn  := fn1 + fn2; fn2 := fn1; ...
http://rosettacode.org/wiki/Factors_of_an_integer
Factors of an integer
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#AutoHotkey
AutoHotkey
msgbox, % factors(45) "`n" factors(53) "`n" factors(64)   Factors(n) { Loop, % floor(sqrt(n)) { v := A_Index = 1 ? 1 "," n : mod(n,A_Index) ? v : v "," A_Index "," n//A_Index } Sort, v, N U D, Return, v }
http://rosettacode.org/wiki/Fast_Fourier_transform
Fast Fourier transform
Task Calculate the   FFT   (Fast Fourier Transform)   of an input sequence. The most general case allows for complex numbers at the input and results in a sequence of equal length, again of complex numbers. If you need to restrict yourself to real numbers, the output should be the magnitude   (i.e.:   sqrt(re2 + im2)...
#Idris
Idris
module Main   import Data.Complex     concatPair : List (a, a) -> List (a) concatPair xs with (unzip xs) | (xs1, xs2) = xs1 ++ xs2   fft' : List (Complex Double) -> Nat -> Nat -> List (Complex Double) fft' (x::xs) (S Z) _ = [x] fft' xs n s = concatPair $ map (\(x1,x2,k) => let eTerm = ((cis (-2 * pi...
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number
Factors of a Mersenne number
A Mersenne number is a number in the form of 2P-1. If P is prime, the Mersenne number may be a Mersenne prime (if P is not prime, the Mersenne number is also not prime). In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,...
#Haskell
Haskell
import Data.List import HFM.Primes (isPrime) import Control.Monad import Control.Arrow   int2bin = reverse.unfoldr(\x -> if x==0 then Nothing else Just ((uncurry.flip$(,))$divMod x 2))   trialfac m = take 1. dropWhile ((/=1).(\q -> foldl (((`mod` q).).pm) 1 bs)) $ qs where qs = filter ...
http://rosettacode.org/wiki/Farey_sequence
Farey sequence
The   Farey sequence   Fn   of order   n   is the sequence of completely reduced fractions between   0   and   1   which, when in lowest terms, have denominators less than or equal to   n,   arranged in order of increasing size. The   Farey sequence   is sometimes incorrectly called a   Farey series. Each Farey se...
#Picat
Picat
go ?=> member(N,1..11), Farey = farey(N), println(N=Farey), fail, nl. go => true.   farey(N) = M => M1 = [0=$(0/1)] ++ [I2/J2=$(I2/J2) : I in 1..N, J in I..N, GCD=gcd(I,J),I2 =I//GCD,J2=J//GCD].sort_remove_dups(), M = [ E: _=E in M1]. % extract the rational representation    
http://rosettacode.org/wiki/Farey_sequence
Farey sequence
The   Farey sequence   Fn   of order   n   is the sequence of completely reduced fractions between   0   and   1   which, when in lowest terms, have denominators less than or equal to   n,   arranged in order of increasing size. The   Farey sequence   is sometimes incorrectly called a   Farey series. Each Farey se...
#Prolog
Prolog
task(1) :- between(1, 11, I), farey(I, F), write(I), write(': '), rwrite(F), nl, fail; true.   task(2) :- between(1, 10, I), I100 is I*100, farey( I100, F), length(F,N), write('|F('), write(I100), write(')| = '), writeln(N), fail; true.   % farey(+Order, Sequence) farey(Order, Sequence) :- bagof( R, I^J^(be...
http://rosettacode.org/wiki/Faulhaber%27s_triangle
Faulhaber's triangle
Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula: ∑ k = 1 n k p = 1 p + 1 ∑ j = 0 p ( p + 1 j ) B j n p + 1 − j {\displaystyle \sum _{k...
#Scala
Scala
import java.math.MathContext   import scala.collection.mutable   abstract class Frac extends Comparable[Frac] { val num: BigInt val denom: BigInt   def unary_-(): Frac = { Frac(-num, denom) }   def +(rhs: Frac): Frac = { Frac( num * rhs.denom + rhs.num * denom, denom * rhs.denom ) } ...
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...
#Sidef
Sidef
const AnyNum = require('Math::AnyNum') const Poly = require('Math::Polynomial')   Poly.string_config(Hash( fold_sign => true, prefix => "", suffix => "", variable => "n" ))   func anynum(n) { AnyNum.new(n.as_rat) }   func faulhaber_formula(p) { (p+1).of { |j| Poly.monomial(p - j + 1)\ ...
http://rosettacode.org/wiki/Fibonacci_n-step_number_sequences
Fibonacci n-step number sequences
These number series are an expansion of the ordinary Fibonacci sequence where: For n = 2 {\displaystyle n=2} we have the Fibonacci sequence; with initial values [ 1 , 1 ] {\displaystyle [1,1]} and F k 2 = F k − 1 2 + F k − 2 2 {\displaystyle F_{k}^{2}=F_{k-1}^{2}+F_{k-2}^{2}} ...
#FunL
FunL
import util.TextTable native scala.collection.mutable.Queue   def fibLike( init ) = q = Queue()   for i <- init do q.enqueue( i )   def fib = q.enqueue( sum(q) ) q.dequeue() # fib()   0 # fib()   def fibN( n ) = fibLike( [1] + [2^i | i <- 0:n-1] )   val lucas = fibLike( [2, 1] )   t = TextTable() t.head...
http://rosettacode.org/wiki/Find_common_directory_path
Find common directory path
Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories. Test your routine using the forward slash '/' character as the directory separator and the foll...
#Wren
Wren
var findCommonDir = Fn.new { |paths, sep| var count = paths.count if (count == 0) return "" if (count == 1) return paths[0] var splits = List.filled(count, null) for (i in 0...count) splits[i] = paths[i].split(sep) var minLen = splits[0].count for (i in 1...count) { var c = splits[i]...
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.
#Gambas
Gambas
sRandom As New String[] '______________________________________________________________________________________________________ Public Sub Main() Dim siCount As Short   For siCount = 0 To 19 sRandom.Add(Rand(1, 100)) Next   Print sRandom.join(",")   NewArray Destructive   End '________________________________________...
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) ...
#Janet
Janet
  (loop [i :range [1 101]  :let [fizz (zero? (% i 3)) buzz (zero? (% i 5))]] (print (cond (and fizz buzz) "fizzbuzz" fizz "fizz" buzz "buzz" i)))  
http://rosettacode.org/wiki/File_input/output
File input/output
File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable. In other words, your program will demonstrate:   how to read from a file into a variable   how to write ...
#Objeck
Objeck
use IO;   bundle Default { class Test { function : Main(args : String[]) ~ Nil { len := File->Size("input.txt"); buffer := Byte->New[len]; in := FileReader->New("input.txt"); if(in->IsOpen() <> Nil) { in->ReadBuffer(0, len, buffer); out := FileWriter->New("output.txt"); ...
http://rosettacode.org/wiki/Fibonacci_word
Fibonacci word
The   Fibonacci Word   may be created in a manner analogous to the   Fibonacci Sequence   as described here: Define   F_Word1   as   1 Define   F_Word2   as   0 Form     F_Word3   as   F_Word2     concatenated with   F_Word1   i.e.:   01 Form     F_Wordn   as   F_Wordn-1   concatenated with   F_wordn-...
#Rust
Rust
struct Fib<T> { curr: T, next: T, }   impl<T> Fib<T> { fn new(curr: T, next: T) -> Self { Fib { curr: curr, next: next, } } }   impl Iterator for Fib<String> { type Item = String; fn next(&mut self) -> Option<Self::Item> { let ret = self.curr.clone(); self.curr = self.ne...
http://rosettacode.org/wiki/Fibonacci_word
Fibonacci word
The   Fibonacci Word   may be created in a manner analogous to the   Fibonacci Sequence   as described here: Define   F_Word1   as   1 Define   F_Word2   as   0 Form     F_Word3   as   F_Word2     concatenated with   F_Word1   i.e.:   01 Form     F_Wordn   as   F_Wordn-1   concatenated with   F_wordn-...
#Scala
Scala
  //word iterator def fibIt = Iterator.iterate(("1","0")){case (f1,f2) => (f2,f1+f2)}.map(_._1)   //entropy calculator def entropy(src: String): Double = { val xs = src.groupBy(identity).map(_._2.length) var result = 0.0 xs.foreach{c => val p = c.toDouble / src.length result -= p * (Math.log(p) / Math.lo...
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 ...
#ALGOL-M
ALGOL-M
INTEGER FUNCTION FIBONACCI( X ); INTEGER X; BEGIN INTEGER M, N, A, I; M := 0; N := 1; FOR I := 2 STEP 1 UNTIL X DO BEGIN A := N; N := M + N; M := A; END; FIBONACCI := N; END;
http://rosettacode.org/wiki/Factors_of_an_integer
Factors of an integer
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#AutoIt
AutoIt
;AutoIt Version: 3.2.10.0 $num = 45 MsgBox (0,"Factors", "Factors of " & $num & " are: " & factors($num)) consolewrite ("Factors of " & $num & " are: " & factors($num)) Func factors($intg) $ls_factors="" For $i = 1 to $intg/2 if ($intg/$i - int($intg/$i))=0 Then $ls_factors=$ls_factors&$i &", " EndI...
http://rosettacode.org/wiki/Fast_Fourier_transform
Fast Fourier transform
Task Calculate the   FFT   (Fast Fourier Transform)   of an input sequence. The most general case allows for complex numbers at the input and results in a sequence of equal length, again of complex numbers. If you need to restrict yourself to real numbers, the output should be the magnitude   (i.e.:   sqrt(re2 + im2)...
#J
J
cube =: ($~ q:@#) :. , rou =: ^@j.@o.@(% #)@i.@-: NB. roots of unity floop =: 4 : 'for_r. i.#$x do. (y=.{."1 y) ] x=.(+/x) ,&,:"r (-/x)*y end.' fft =: ] floop&.cube rou@#
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number
Factors of a Mersenne number
A Mersenne number is a number in the form of 2P-1. If P is prime, the Mersenne number may be a Mersenne prime (if P is not prime, the Mersenne number is also not prime). In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,...
#Icon_and_Unicon
Icon and Unicon
procedure main(A) p := integer(A[1]) | 929 write("M",p," has a factor ",mfactor(p)) end   procedure mfactor(p) if isPrime(p) then { limit := sqrt(2^p)-1 k := 1 while 2*p*k-1 < limit do { q := 2*p*k+1 if isPrime(q) & (q%8 = (1|7)) & btest(p,q) then return q ...
http://rosettacode.org/wiki/Farey_sequence
Farey sequence
The   Farey sequence   Fn   of order   n   is the sequence of completely reduced fractions between   0   and   1   which, when in lowest terms, have denominators less than or equal to   n,   arranged in order of increasing size. The   Farey sequence   is sometimes incorrectly called a   Farey series. Each Farey se...
#PureBasic
PureBasic
EnableExplicit   Structure farey_struc complex.POINT quotient.d EndStructure   #MAXORDER=1000 Global NewList fareylist.farey_struc()   Define v_start.i, v_end.i, v_step.i, order.i, fractions.i, check.b, t$   Procedure farey(order) NewList sequence.farey_struc() Define q...
http://rosettacode.org/wiki/Faulhaber%27s_triangle
Faulhaber's triangle
Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula: ∑ k = 1 n k p = 1 p + 1 ∑ j = 0 p ( p + 1 j ) B j n p + 1 − j {\displaystyle \sum _{k...
#Scheme
Scheme
; Return the first row-count rows of Faulhaber's Triangle as a vector of vectors. (define faulhabers-triangle (lambda (row-count) ; Calculate and store the value of the first column of a row. ; The value is one minus the sum of all the rest of the columns. (define calc-store-first! (lambda (row) ...
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...
#Visual_Basic_.NET
Visual Basic .NET
Module Module1 Function Gcd(a As Long, b As Long) If b = 0 Then Return a End If Return Gcd(b, a Mod b) End Function   Class Frac ReadOnly num As Long ReadOnly denom As Long   Public Shared ReadOnly ZERO As New Frac(0, 1) Public Shared ReadO...
http://rosettacode.org/wiki/Fibonacci_n-step_number_sequences
Fibonacci n-step number sequences
These number series are an expansion of the ordinary Fibonacci sequence where: For n = 2 {\displaystyle n=2} we have the Fibonacci sequence; with initial values [ 1 , 1 ] {\displaystyle [1,1]} and F k 2 = F k − 1 2 + F k − 2 2 {\displaystyle F_{k}^{2}=F_{k-1}^{2}+F_{k-2}^{2}} ...
#F.C5.8Drmul.C3.A6
Fōrmulæ
package main   import "fmt"   func g(i []int, c chan<- int) { var sum int b := append([]int(nil), i...) // make a copy for _, t := range b { c <- t sum += t } for { for j, t := range b { c <- sum b[j], sum = sum, sum+sum-t } } }   func main() { for _, s := range [...]struct { seq string i []i...
http://rosettacode.org/wiki/Find_common_directory_path
Find common directory path
Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories. Test your routine using the forward slash '/' character as the directory separator and the foll...
#Yabasic
Yabasic
x$ = "/home/user1/tmp/coverage/test" y$ = "/home/user1/tmp/covert/operator" z$ = "/home/user1/tmp/coven/members"   a = len(x$) if a > len(y$) a = len(y$) if a > len(z$) a = len(z$) for i = 1 to a if mid$(x$, i, 1) <> mid$(y$, i, 1) break next i a = i - 1   for i = 1 to a if mid$(x$, i, 1) <> mid$(z$, i, 1) ...
http://rosettacode.org/wiki/Find_common_directory_path
Find common directory path
Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories. Test your routine using the forward slash '/' character as the directory separator and the foll...
#zkl
zkl
dirs:=T("/home/user1/tmp/coverage/test", "/home/user1/tmp/covert/operator", "/home/user1/tmp/coven/members"); n:=Utils.zipWith('==,dirs.xplode()).find(False); // character pos which differs n=dirs[0][0,n].rfind("/"); // find last "/" dirs[0][0,n];
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.
#GAP
GAP
# Built-in   Filtered([1 .. 100], IsPrime); # [ 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97 ]   Filtered([1 .. 10], IsEvenInt); # [ 2, 4, 6, 8, 10 ]   Filtered([1 .. 10], IsOddInt); # [ 1, 3, 5, 7, 9 ]
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) ...
#Java
Java
  public class FizzBuzz { public static void main(String[] args) { for (int number = 1; number <= 100; number++) { if (number % 15 == 0) { System.out.println("FizzBuzz"); } else if (number % 3 == 0) { System.out.println("Fizz"); } else if (...
http://rosettacode.org/wiki/File_input/output
File input/output
File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable. In other words, your program will demonstrate:   how to read from a file into a variable   how to write ...
#Object_Pascal
Object Pascal
uses classes; begin with TFileStream.Create('input.txt', fmOpenRead) do try SaveToFile('output.txt'); finally Free; end; end;
http://rosettacode.org/wiki/File_input/output
File input/output
File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable. In other words, your program will demonstrate:   how to read from a file into a variable   how to write ...
#Objective-C
Objective-C
[[NSFileManager defaultManager] copyItemAtPath:@"input.txt" toPath:@"output.txt" error:NULL];
http://rosettacode.org/wiki/Fibonacci_word
Fibonacci word
The   Fibonacci Word   may be created in a manner analogous to the   Fibonacci Sequence   as described here: Define   F_Word1   as   1 Define   F_Word2   as   0 Form     F_Word3   as   F_Word2     concatenated with   F_Word1   i.e.:   01 Form     F_Wordn   as   F_Wordn-1   concatenated with   F_wordn-...
#Scheme
Scheme
  (import (scheme base) (scheme inexact) (scheme write))   (define *words* (make-vector 38 ""))   (define (create-words) (vector-set! *words* 1 "1") (vector-set! *words* 2 "0") (do ((i 3 (+ 1 i))) ((= i (vector-length *words*)) ) (vector-set! *words* i (string-append (vector-ref *words* (-...
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 ...
#Alore
Alore
def fib(n as Int) as Int if n < 2 return 1 end return fib(n-1) + fib(n-2) end
http://rosettacode.org/wiki/Factors_of_an_integer
Factors of an integer
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#AWK
AWK
  # syntax: GAWK -f FACTORS_OF_AN_INTEGER.AWK BEGIN { print("enter a number or C/R to exit") } { if ($0 == "") { exit(0) } if ($0 !~ /^[0-9]+$/) { printf("invalid: %s\n",$0) next } n = $0 printf("factors of %s:",n) for (i=1; i<=n; i++) { if (n % i == 0) { printf(" %d"...
http://rosettacode.org/wiki/Fast_Fourier_transform
Fast Fourier transform
Task Calculate the   FFT   (Fast Fourier Transform)   of an input sequence. The most general case allows for complex numbers at the input and results in a sequence of equal length, again of complex numbers. If you need to restrict yourself to real numbers, the output should be the magnitude   (i.e.:   sqrt(re2 + im2)...
#Java
Java
import static java.lang.Math.*;   public class FastFourierTransform {   public static int bitReverse(int n, int bits) { int reversedN = n; int count = bits - 1;   n >>= 1; while (n > 0) { reversedN = (reversedN << 1) | (n & 1); count--; n >>= 1; ...
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number
Factors of a Mersenne number
A Mersenne number is a number in the form of 2P-1. If P is prime, the Mersenne number may be a Mersenne prime (if P is not prime, the Mersenne number is also not prime). In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,...
#J
J
trialfac=: 3 : 0 qs=. (#~8&(1=|+.7=|))(#~1&p:)1+(*(1x+i.@<:@<.)&.-:)y qs#~1=qs&|@(2&^@[**:@])/ 1,~ |.#: y )
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number
Factors of a Mersenne number
A Mersenne number is a number in the form of 2P-1. If P is prime, the Mersenne number may be a Mersenne prime (if P is not prime, the Mersenne number is also not prime). In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,...
#Java
Java
  import java.math.BigInteger;   class MersenneFactorCheck {   private final static BigInteger TWO = BigInteger.valueOf(2);   public static boolean isPrime(long n) { if (n == 2) return true; if ((n < 2) || ((n & 1) == 0)) return false; long maxFactor = (long)Math.sqrt((double)n); for (...
http://rosettacode.org/wiki/Farey_sequence
Farey sequence
The   Farey sequence   Fn   of order   n   is the sequence of completely reduced fractions between   0   and   1   which, when in lowest terms, have denominators less than or equal to   n,   arranged in order of increasing size. The   Farey sequence   is sometimes incorrectly called a   Farey series. Each Farey se...
#Python
Python
from fractions import Fraction     class Fr(Fraction): def __repr__(self): return '(%s/%s)' % (self.numerator, self.denominator)     def farey(n, length=False): if not length: return [Fr(0, 1)] + sorted({Fr(m, k) for k in range(1, n+1) for m in range(1, k+1)}) else: #return 1 ...
http://rosettacode.org/wiki/Faulhaber%27s_triangle
Faulhaber's triangle
Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula: ∑ k = 1 n k p = 1 p + 1 ∑ j = 0 p ( p + 1 j ) B j n p + 1 − j {\displaystyle \sum _{k...
#Sidef
Sidef
func faulhaber_triangle(p) { { binomial(p, _) * bernoulli(_) / p }.map(p ^.. 0) }   { |p| say faulhaber_triangle(p).map{ '%6s' % .as_rat }.join } << 1..10   const p = 17 const n = 1000   say '' say faulhaber_triangle(p+1).map_kv {|k,v| v * n**(k+1) }.sum
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...
#Wren
Wren
import "/math" for Int import "/rat" for Rat   var bernoulli = Fn.new { |n| if (n < 0) Fiber.abort("Argument must be non-negative") var a = List.filled(n+1, null) for (m in 0..n) { a[m] = Rat.new(1, m+1) var j = m while (j >= 1) { a[j-1] = (a[j-1] - a[j]) * Rat.new(j, 1) ...
http://rosettacode.org/wiki/Fibonacci_n-step_number_sequences
Fibonacci n-step number sequences
These number series are an expansion of the ordinary Fibonacci sequence where: For n = 2 {\displaystyle n=2} we have the Fibonacci sequence; with initial values [ 1 , 1 ] {\displaystyle [1,1]} and F k 2 = F k − 1 2 + F k − 2 2 {\displaystyle F_{k}^{2}=F_{k-1}^{2}+F_{k-2}^{2}} ...
#Go
Go
package main   import "fmt"   func g(i []int, c chan<- int) { var sum int b := append([]int(nil), i...) // make a copy for _, t := range b { c <- t sum += t } for { for j, t := range b { c <- sum b[j], sum = sum, sum+sum-t } } }   func main() { for _, s := range [...]struct { seq string i []i...
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.
#Go
Go
package main   import ( "fmt" "math/rand" )   func main() { a := rand.Perm(20) fmt.Println(a) // show array to filter fmt.Println(even(a)) // show result of non-destructive filter fmt.Println(a) // show that original array is unchanged reduceToEven(&a) // destructive filter ...
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) ...
#JavaScript
JavaScript
var fizzBuzz = function () { var i, output; for (i = 1; i < 101; i += 1) { output = ''; if (!(i % 3)) { output += 'Fizz'; } if (!(i % 5)) { output += 'Buzz'; } console.log(output || i);//empty string is false, so we short-circuit } };
http://rosettacode.org/wiki/File_input/output
File input/output
File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable. In other words, your program will demonstrate:   how to read from a file into a variable   how to write ...
#OCaml
OCaml
let () = let ic = open_in "input.txt" in let oc = open_out "output.txt" in try while true do let s = input_line ic in output_string oc s; output_char oc '\n'; done with End_of_file -> close_in ic; close_out oc; ;;
http://rosettacode.org/wiki/File_input/output
File input/output
File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable. In other words, your program will demonstrate:   how to read from a file into a variable   how to write ...
#Octave
Octave
  in = fopen("input.txt", "r", "native"); out = fopen("output.txt", "w","native"); if (in == -1) disp("Error opening input.txt for reading."); else if (out == -1) disp("Error opening output.txt for writing."); else while (1) [val,count]=fread(in,1,"uchar",0,"native"); if (count > 0) count=fwrite(out,val,"uc...
http://rosettacode.org/wiki/Fibonacci_word
Fibonacci word
The   Fibonacci Word   may be created in a manner analogous to the   Fibonacci Sequence   as described here: Define   F_Word1   as   1 Define   F_Word2   as   0 Form     F_Word3   as   F_Word2     concatenated with   F_Word1   i.e.:   01 Form     F_Wordn   as   F_Wordn-1   concatenated with   F_wordn-...
#Scilab
Scilab
exec('.\entropy.sci',0);   function word=fiboword(n) word_1 = '1'; word_2 = '0'; select n case 1 word = word_1 case 2 word = word_2; case 3 word = strcat([word_2 word_1]); else word = strcat([fiboword(n-1) fiboword(n-2)]) end endfunction   final_length = 37;  ...
http://rosettacode.org/wiki/Fibonacci_word
Fibonacci word
The   Fibonacci Word   may be created in a manner analogous to the   Fibonacci Sequence   as described here: Define   F_Word1   as   1 Define   F_Word2   as   0 Form     F_Word3   as   F_Word2     concatenated with   F_Word1   i.e.:   01 Form     F_Wordn   as   F_Wordn-1   concatenated with   F_wordn-...
#Seed7
Seed7
$ include "seed7_05.s7i"; include "float.s7i"; include "math.s7i";   const func float: entropy (in string: stri) is func result var float: entropy is 0.0; local var hash [char] integer: count is (hash [char] integer).value; var char: ch is ' '; var float: p is 0.0; begin for ch range stri ...
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 ...
#Amazing_Hopper
Amazing Hopper
  #include <hbasic.h>   #define TERM1 1.61803398874989 #define TERM2 -0.61803398874989   #context get Fibonacci number with analitic mode GetArgs(n) get Inv of (M_SQRT5), Mul by( Pow (TERM 1, n), Minus( Pow(TERM 2, n) ) ); then Return\\   #proto fibonacci_recursive(__X__) #synon _fibonacci_recursive ge...
http://rosettacode.org/wiki/Factors_of_an_integer
Factors of an integer
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#BASIC
BASIC
DECLARE SUB factor (what AS INTEGER)   REDIM SHARED factors(0) AS INTEGER   DIM i AS INTEGER, L AS INTEGER   INPUT "Gimme a number"; i   factor i   PRINT factors(0); FOR L = 1 TO UBOUND(factors) PRINT ","; factors(L); NEXT PRINT   SUB factor (what AS INTEGER) DIM tmpint1 AS INTEGER DIM L0 AS INTEGER, L1 AS ...
http://rosettacode.org/wiki/Fast_Fourier_transform
Fast Fourier transform
Task Calculate the   FFT   (Fast Fourier Transform)   of an input sequence. The most general case allows for complex numbers at the input and results in a sequence of equal length, again of complex numbers. If you need to restrict yourself to real numbers, the output should be the magnitude   (i.e.:   sqrt(re2 + im2)...
#JavaScript
JavaScript
/* complex fast fourier transform and inverse from http://rosettacode.org/wiki/Fast_Fourier_transform#C.2B.2B */ function icfft(amplitudes) { var N = amplitudes.length; var iN = 1 / N;   //conjugate if imaginary part is not 0 for(var i = 0 ; i < N; ++i) if(amplitudes[i] instanceof Complex) amplitudes[i].im = -...
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number
Factors of a Mersenne number
A Mersenne number is a number in the form of 2P-1. If P is prime, the Mersenne number may be a Mersenne prime (if P is not prime, the Mersenne number is also not prime). In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,...
#JavaScript
JavaScript
function mersenne_factor(p){ var limit, k, q limit = Math.sqrt(Math.pow(2,p) - 1) k = 1 while ((2*k*p - 1) < limit){ q = 2*k*p + 1 if (isPrime(q) && (q % 8 == 1 || q % 8 == 7) && trial_factor(2,p,q)){ return q // q is a factor of 2**p-1 } k++ } return null }   function isPrime(value){ ...
http://rosettacode.org/wiki/Farey_sequence
Farey sequence
The   Farey sequence   Fn   of order   n   is the sequence of completely reduced fractions between   0   and   1   which, when in lowest terms, have denominators less than or equal to   n,   arranged in order of increasing size. The   Farey sequence   is sometimes incorrectly called a   Farey series. Each Farey se...
#Quackery
Quackery
[ $ "bigrat.qky" loadfile ] now!   [ rot + dip + reduce ] is mediant ( n/d n/d --> n/d )   [ 1+ temp put [] swap dup size 1 - times [ dup i^ peek rot over nested join unrot over i^ 1+ peek join do mediant dup temp share < iff [ join nested rot swap join ...
http://rosettacode.org/wiki/Farey_sequence
Farey sequence
The   Farey sequence   Fn   of order   n   is the sequence of completely reduced fractions between   0   and   1   which, when in lowest terms, have denominators less than or equal to   n,   arranged in order of increasing size. The   Farey sequence   is sometimes incorrectly called a   Farey series. Each Farey se...
#R
R
  farey <- function(n, length_only = FALSE) { a <- 0 b <- 1 c <- 1 d <- n if (!length_only) cat(a, "/", b, sep = "") count <- 1 while (c <= n) { count <- count + 1 k <- ((n + b) %/% d) next_c <- k * c - a next_d <- k * d - b a <- c b <- d c <- next_c d <- next_d if ...
http://rosettacode.org/wiki/Faulhaber%27s_triangle
Faulhaber's triangle
Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula: ∑ k = 1 n k p = 1 p + 1 ∑ j = 0 p ( p + 1 j ) B j n p + 1 − j {\displaystyle \sum _{k...
#Visual_Basic_.NET
Visual Basic .NET
Module Module1   Class Frac Private ReadOnly num As Long Private ReadOnly denom As Long   Public Shared ReadOnly ZERO = New Frac(0, 1) Public Shared ReadOnly ONE = New Frac(1, 1)   Public Sub New(n As Long, d As Long) If d = 0 Then Throw New Argume...
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...
#zkl
zkl
var [const] BN=Import("zklBigNum"); // libGMP (GNU MP Bignum Library)   fcn faulhaberFormula(p){ //-->(Rational,Rational...) [p..0,-1].pump(List(),'wrap(k){ B(k)*BN(p+1).binomial(k) }) .apply('*(Rational(1,p+1))) }
http://rosettacode.org/wiki/Fibonacci_n-step_number_sequences
Fibonacci n-step number sequences
These number series are an expansion of the ordinary Fibonacci sequence where: For n = 2 {\displaystyle n=2} we have the Fibonacci sequence; with initial values [ 1 , 1 ] {\displaystyle [1,1]} and F k 2 = F k − 1 2 + F k − 2 2 {\displaystyle F_{k}^{2}=F_{k-1}^{2}+F_{k-2}^{2}} ...
#Groovy
Groovy
def fib = { List seed, int k=10 -> assert seed : "The seed list must be non-null and non-empty" assert seed.every { it instanceof Number } : "Every member of the seed must be a number" def n = seed.size() assert n > 1 : "The seed must contain at least two elements" List result = [] + seed if (k ...
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.
#Groovy
Groovy
def evens = [1, 2, 3, 4, 5].findAll{it % 2 == 0}
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) ...
#Joy
Joy
DEFINE one == [[[dup 15 rem 0 =] "FizzBuzz"] [[dup 3 rem 0 =] "Fizz"] [[dup 5 rem 0 =] "Buzz"] [dup]] cond. 1 [100 <=] [dup one put succ] while.
http://rosettacode.org/wiki/File_input/output
File input/output
File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable. In other words, your program will demonstrate:   how to read from a file into a variable   how to write ...
#Oforth
Oforth
: fcopy(in, out) | f g | File newMode(in, File.BINARY) dup open(File.READ) ->f File newMode(out, File.BINARY) dup open(File.WRITE) ->g   while(f >> dup notNull) [ g addChar ] drop f close g close ;
http://rosettacode.org/wiki/File_input/output
File input/output
File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable. In other words, your program will demonstrate:   how to read from a file into a variable   how to write ...
#OpenEdge.2FProgress
OpenEdge/Progress
COPY-LOB FROM FILE "input.txt" TO FILE "output.txt".
http://rosettacode.org/wiki/Fibonacci_word
Fibonacci word
The   Fibonacci Word   may be created in a manner analogous to the   Fibonacci Sequence   as described here: Define   F_Word1   as   1 Define   F_Word2   as   0 Form     F_Word3   as   F_Word2     concatenated with   F_Word1   i.e.:   01 Form     F_Wordn   as   F_Wordn-1   concatenated with   F_wordn-...
#Sidef
Sidef
func entropy(s) { [0] + (s.chars.freq.values »/» s.len) -> reduce { |a,b| a - b*b.log2 } }   var n_max = 37 var words = ['1', '0']   { words.append(words[-1] + words[-2]) } * (n_max - words.len)   say ('%3s %10s %15s  %s' % <N Length Entropy Fibword>...)   for i in ^words { var word = words[i] ...
http://rosettacode.org/wiki/Fibonacci_word
Fibonacci word
The   Fibonacci Word   may be created in a manner analogous to the   Fibonacci Sequence   as described here: Define   F_Word1   as   1 Define   F_Word2   as   0 Form     F_Word3   as   F_Word2     concatenated with   F_Word1   i.e.:   01 Form     F_Wordn   as   F_Wordn-1   concatenated with   F_wordn-...
#Swift
Swift
import Foundation   struct Fib: Sequence, IteratorProtocol { private var cur: String private var nex: String   init(cur: String, nex: String) { self.cur = cur self.nex = nex }   mutating func next() -> String? { let ret = cur   cur = nex nex = "\(ret)\(nex)"   return ret } }   func g...
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 ...
#AntLang
AntLang
/Sequence fib:{<0;1> {x,<x[-1]+x[-2]>}/ range[x]} /nth fibn:{fib[x][x]}
http://rosettacode.org/wiki/Factors_of_an_integer
Factors of an integer
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#Batch_File
Batch File
@echo off set res=Factors of %1: for /L %%i in (1,1,%1) do call :fac %1 %%i echo %res% goto :eof   :fac set /a test = %1 %% %2 if %test% equ 0 set res=%res% %2
http://rosettacode.org/wiki/Fast_Fourier_transform
Fast Fourier transform
Task Calculate the   FFT   (Fast Fourier Transform)   of an input sequence. The most general case allows for complex numbers at the input and results in a sequence of equal length, again of complex numbers. If you need to restrict yourself to real numbers, the output should be the magnitude   (i.e.:   sqrt(re2 + im2)...
#jq
jq
  # multiplication of real or complex numbers def cmult(x; y): if (x|type) == "number" then if (y|type) == "number" then [ x*y, 0 ] else [x * y[0], x * y[1]] end elif (y|type) == "number" then cmult(y;x) else [ x[0] * y[0] - x[1] * y[1], x[0] * y[1] + x[1] * y[0]] end;   def cplus...
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number
Factors of a Mersenne number
A Mersenne number is a number in the form of 2P-1. If P is prime, the Mersenne number may be a Mersenne prime (if P is not prime, the Mersenne number is also not prime). In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,...
#Julia
Julia
# v0.6   using Primes   function mersennefactor(p::Int)::Int q = 2p + 1 while true if log2(q) > p / 2 return -1 elseif q % 8 in (1, 7) && Primes.isprime(q) && powermod(2, p, q) == 1 return q end q += 2p end end   for i in filter(Primes.isprime, push!(colle...
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number
Factors of a Mersenne number
A Mersenne number is a number in the form of 2P-1. If P is prime, the Mersenne number may be a Mersenne prime (if P is not prime, the Mersenne number is also not prime). In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,...
#Kotlin
Kotlin
// version 1.0.6   fun isPrime(n: Int): Boolean { if (n < 2) return false if (n % 2 == 0) return n == 2 if (n % 3 == 0) return n == 3 var d = 5 while (d * d <= n) { if (n % d == 0) return false d += 2 if (n % d == 0) return false d += 4 } return true }   fun m...
http://rosettacode.org/wiki/Farey_sequence
Farey sequence
The   Farey sequence   Fn   of order   n   is the sequence of completely reduced fractions between   0   and   1   which, when in lowest terms, have denominators less than or equal to   n,   arranged in order of increasing size. The   Farey sequence   is sometimes incorrectly called a   Farey series. Each Farey se...
#Racket
Racket
#lang racket (require math/number-theory) (define (display-farey-sequence order show-fractions?) (define f-s (farey-sequence order)) (printf "-- Farey Sequence for order ~a has ~a fractions~%" order (length f-s))  ;; racket will simplify 0/1 and 1/1 to 0 and 1 respectively, so deconstruct into numerator and  ;; d...
http://rosettacode.org/wiki/Farey_sequence
Farey sequence
The   Farey sequence   Fn   of order   n   is the sequence of completely reduced fractions between   0   and   1   which, when in lowest terms, have denominators less than or equal to   n,   arranged in order of increasing size. The   Farey sequence   is sometimes incorrectly called a   Farey series. Each Farey se...
#Raku
Raku
sub farey ($order) { my @l = 0/1, 1/1; (2..$order).map: { push @l, |(1..$^d).map: { $_/$d } } unique @l }   say "Farey sequence order "; .say for (1..11).hyper(:1batch).map: { "$_: ", .&farey.sort.map: *.nude.join('/') }; .say for (100, 200 ... 1000).race(:1batch).map: { "Farey sequence order $_ has " ~ [.&...
http://rosettacode.org/wiki/Faulhaber%27s_triangle
Faulhaber's triangle
Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula: ∑ k = 1 n k p = 1 p + 1 ∑ j = 0 p ( p + 1 j ) B j n p + 1 − j {\displaystyle \sum _{k...
#Vlang
Vlang
import math.fractions import math.big   fn bernoulli(n int) fractions.Fraction { mut a := []fractions.Fraction{len: n+1} for m,_ in a { a[m] = fractions.fraction(1, i64(m+1)) for j := m; j >= 1; j-- { mut d := a[j-1] d = fractions.fraction(i64(j),i64(1)) * (d-a[j]) ...
http://rosettacode.org/wiki/Faulhaber%27s_triangle
Faulhaber's triangle
Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula: ∑ k = 1 n k p = 1 p + 1 ∑ j = 0 p ( p + 1 j ) B j n p + 1 − j {\displaystyle \sum _{k...
#Wren
Wren
import "/fmt" for Fmt import "/math" for Int import "/big" for BigRat   var bernoulli = Fn.new { |n| if (n < 0) Fiber.abort("Argument must be non-negative") var a = List.filled(n+1, null) for (m in 0..n) { a[m] = BigRat.new(1, m+1) var j = m while (j >= 1) { a[j-1] = (a[j...
http://rosettacode.org/wiki/Fibonacci_n-step_number_sequences
Fibonacci n-step number sequences
These number series are an expansion of the ordinary Fibonacci sequence where: For n = 2 {\displaystyle n=2} we have the Fibonacci sequence; with initial values [ 1 , 1 ] {\displaystyle [1,1]} and F k 2 = F k − 1 2 + F k − 2 2 {\displaystyle F_{k}^{2}=F_{k-1}^{2}+F_{k-2}^{2}} ...
#Haskell
Haskell
import Data.List (tails) import Control.Monad (zipWithM_)   fiblike :: [Integer] -> [Integer] fiblike st = xs where xs = st ++ map (sum . take n) (tails xs) n = length st   nstep :: Int -> [Integer] nstep n = fiblike $ take n $ 1 : iterate (2*) 1   main :: IO () main = do print $ take 10 $ fiblike [1,1] print $...
http://rosettacode.org/wiki/Filter
Filter
Task Select certain elements from an Array into a new Array in a generic way. To demonstrate, select all even numbers from an Array. As an option, give a second solution which filters destructively, by modifying the original Array rather than creating a new Array.
#Haskell
Haskell
ary = [1..10] evens = [x | x <- ary, even x]
http://rosettacode.org/wiki/FizzBuzz
FizzBuzz
Task Write a program that prints the integers from   1   to   100   (inclusive). But:   for multiples of three,   print   Fizz     (instead of the number)   for multiples of five,   print   Buzz     (instead of the number)   for multiples of both three and five,   print   FizzBuzz     (instead of the number) ...
#jq
jq
range(1;101) | if . % 15 == 0 then "FizzBuzz" elif . % 5 == 0 then "Buzz" elif . % 3 == 0 then "Fizz" else . end
http://rosettacode.org/wiki/File_input/output
File input/output
File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable. In other words, your program will demonstrate:   how to read from a file into a variable   how to write ...
#Oz
Oz
declare class TextFile from Open.file Open.text end   In = {New TextFile init(name:"input.txt")} Out = {New TextFile init(name:"output.txt" flags:[write text create truncate])}   proc {CopyAll In Out} case {In getS($)} of false then skip [] Line then {Out putS(Line)} {CopyAll In Out} ...
http://rosettacode.org/wiki/File_input/output
File input/output
File input/output is part of Short Circuit's Console Program Basics selection. Task Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable. In other words, your program will demonstrate:   how to read from a file into a variable   how to write ...
#PARI.2FGP
PARI/GP
f=read("filename.in"); write("filename.out", f);
http://rosettacode.org/wiki/Fibonacci_word
Fibonacci word
The   Fibonacci Word   may be created in a manner analogous to the   Fibonacci Sequence   as described here: Define   F_Word1   as   1 Define   F_Word2   as   0 Form     F_Word3   as   F_Word2     concatenated with   F_Word1   i.e.:   01 Form     F_Wordn   as   F_Wordn-1   concatenated with   F_wordn-...
#Tcl
Tcl
proc fibwords {n} { set fw {1 0} while {[llength $fw] < $n} { lappend fw [lindex $fw end][lindex $fw end-1] } return $fw }   proc fibwordinfo {num word} { # Entropy calculator from Tcl solution of that task set log2 [expr log(2)] set len [string length $word] foreach char [split $word "...
http://rosettacode.org/wiki/Fibonacci_sequence
Fibonacci sequence
The Fibonacci sequence is a sequence   Fn   of natural numbers defined recursively: F0 = 0 F1 = 1 Fn = Fn-1 + Fn-2, if n>1 Task Write a function to generate the   nth   Fibonacci number. Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ...
#Apex
Apex
  /* author: snugsfbay date: March 3, 2016 description: Create a list of x numbers in the Fibonacci sequence. - user may specify the length of the list - enforces a minimum of 2 numbers in the sequence because any fewer is not a sequence - enforces a maximum of 47 because further values are too large...
http://rosettacode.org/wiki/Factors_of_an_integer
Factors of an integer
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#BBC_BASIC
BBC BASIC
INSTALL @lib$+"SORTLIB" sort% = FN_sortinit(0, 0)   PRINT "The factors of 45 are " FNfactorlist(45) PRINT "The factors of 12345 are " FNfactorlist(12345) END   DEF FNfactorlist(N%) LOCAL C%, I%, L%(), L$ DIM L%(32) FOR I% = 1 TO SQR(N%) IF (N% MOD I% = 0) TH...
http://rosettacode.org/wiki/Fast_Fourier_transform
Fast Fourier transform
Task Calculate the   FFT   (Fast Fourier Transform)   of an input sequence. The most general case allows for complex numbers at the input and results in a sequence of equal length, again of complex numbers. If you need to restrict yourself to real numbers, the output should be the magnitude   (i.e.:   sqrt(re2 + im2)...
#Julia
Julia
using FFTW # or using DSP   fft([1,1,1,1,0,0,0,0])
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number
Factors of a Mersenne number
A Mersenne number is a number in the form of 2P-1. If P is prime, the Mersenne number may be a Mersenne prime (if P is not prime, the Mersenne number is also not prime). In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,...
#Lingo
Lingo
on modPow (b, e, m) bits = getBits(e) sq = 1 repeat while TRUE tb = bits[1] bits.deleteAt(1) sq = sq*sq if tb then sq=sq*b sq = sq mod m if bits.count=0 then return sq end repeat end   on getBits (n) bits = [] f = 1 repeat while TRUE bi...
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number
Factors of a Mersenne number
A Mersenne number is a number in the form of 2P-1. If P is prime, the Mersenne number may be a Mersenne prime (if P is not prime, the Mersenne number is also not prime). In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,...
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
For[i = 2, i < Prime[1000000], i = NextPrime[i], If[Mod[2^44497, i] == 1, Print["divisible by "<>i]]]; Print["prime test passed; call Lucas and Lehmer"]
http://rosettacode.org/wiki/Farey_sequence
Farey sequence
The   Farey sequence   Fn   of order   n   is the sequence of completely reduced fractions between   0   and   1   which, when in lowest terms, have denominators less than or equal to   n,   arranged in order of increasing size. The   Farey sequence   is sometimes incorrectly called a   Farey series. Each Farey se...
#REXX
REXX
/*REXX program computes and displays a Farey sequence (or the number of fractions). */ parse arg LO HI INC . /*obtain optional arguments from the CL*/ if LO=='' | LO=="," then LO= 1 /*Not specified? Then use the default.*/ if HI=='' | HI=="," then HI= LO ...
http://rosettacode.org/wiki/Faulhaber%27s_triangle
Faulhaber's triangle
Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula: ∑ k = 1 n k p = 1 p + 1 ∑ j = 0 p ( p + 1 j ) B j n p + 1 − j {\displaystyle \sum _{k...
#zkl
zkl
foreach p in (10){ faulhaberFormula(p).apply("%7s".fmt).concat().println(); }   // each term of faulhaberFormula is BigInt/BigInt [1..].zipWith(fcn(n,rat){ rat*BN(1000).pow(n) }, faulhaberFormula(17)) .walk() // -->(0, -3617/60 * 1000^2, 0, 595/3 * 1000^4 ...) .reduce('+) // rat + rat + ... .println();
http://rosettacode.org/wiki/Fibonacci_n-step_number_sequences
Fibonacci n-step number sequences
These number series are an expansion of the ordinary Fibonacci sequence where: For n = 2 {\displaystyle n=2} we have the Fibonacci sequence; with initial values [ 1 , 1 ] {\displaystyle [1,1]} and F k 2 = F k − 1 2 + F k − 2 2 {\displaystyle F_{k}^{2}=F_{k-1}^{2}+F_{k-2}^{2}} ...
#Icon_and_Unicon
Icon and Unicon
procedure main(A) every writes("F2:\t"|right((fnsGen(1,1))\14,5) | "\n") every writes("F3:\t"|right((fnsGen(1,1,2))\14,5) | "\n") every writes("F4:\t"|right((fnsGen(1,1,2,4))\14,5) | "\n") every writes("Lucas:\t"|right((fnsGen(2,1))\14,5) | "\n") every writes("F?:\t"|right((fnsGen!A)\14,5) | "\n") e...
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.
#Icon_and_Unicon
Icon and Unicon
procedure main()   every put(A := [],1 to 10) # make a list of 1..10 every put(B := [],iseven(!A)) # make a second list and filter out odd numbers every writes(!B," ") | write() # show end   procedure iseven(x) #: return x if x is even or fail if x % 2 = 0 then return...
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) ...
#Julia
Julia
for i in 1:100 if i % 15 == 0 println("FizzBuzz") elseif i % 3 == 0 println("Fizz") elseif i % 5 == 0 println("Buzz") else println(i) end end