September 2017 Update

Task/Fibonacci-sequence/00DESCRIPTION

@@ -1,8 +1,8 @@
 The '''Fibonacci sequence''' is a sequence &nbsp; <big> F<sub>n</sub> </big> &nbsp;  of natural numbers defined recursively:
 
-      <big><big> F<sub>0</sub> = 0                                           </big></big>
-      <big><big> F<sub>1</sub> = 1                                           </big></big>
-      <big><big> F<sub>n</sub> = F<sub>n-1</sub> + F<sub>n-2</sub>, if n>1   </big></big>
+      <big><big> F<sub>0</sub> = 0 </big></big>
+      <big><big> F<sub>1</sub> = 1 </big></big>
+      <big><big> F<sub>n</sub> = F<sub>n-1</sub> + F<sub>n-2</sub>, if n>1 </big></big>
 
 
 ;Task:
@@ -17,8 +17,9 @@ The sequence is sometimes extended into negative numbers by using a straightforw
 support for negative &nbsp; &nbsp; <big> n </big> &nbsp; &nbsp; in the solution is optional.
 
 
-;Related task:
+;Related tasks:
 * &nbsp; [[Fibonacci n-step number sequences‎]]
+* &nbsp; [[Leonardo numbers]]
 
 
 ;References:

Task/Fibonacci-sequence/ABAP/fibonacci-sequence-1.abap

@@ -0,0 +1,14 @@
+FORM fibonacci_iter USING index TYPE i
+                    CHANGING number_fib TYPE i.
+  DATA: lv_old type i,
+        lv_cur type i.
+  Do index times.
+    If sy-index = 1 or sy-index = 2.
+      lv_cur = 1.
+      lv_old = 0.
+    endif.
+    number_fib = lv_cur + lv_old.
+    lv_old = lv_cur.
+    lv_cur = number_fib.
+  enddo.
+ENDFORM.

Task/Fibonacci-sequence/ABAP/fibonacci-sequence-2.abap

@@ -0,0 +1,9 @@
+cl_demo_output=>display( REDUCE #( INIT fibnm = VALUE stringtab( ( |0| ) ( |1| ) )
+                                        n TYPE string
+                                        x = `0`
+                                        y = `1`
+                                      FOR i = 1 WHILE i <= 100
+                                     NEXT n = ( x + y )
+                                          fibnm = VALUE #( BASE fibnm ( n ) )
+                                          x = y
+                                          y = n ) ).

Task/Fibonacci-sequence/ALGOL-M/fibonacci-sequence-1.algol-m

@@ -0,0 +1,13 @@
+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;

Task/Fibonacci-sequence/ALGOL-M/fibonacci-sequence-2.algol-m

@@ -0,0 +1,7 @@
+INTEGER FUNCTION FIBONACCI( X ); INTEGER X;
+BEGIN
+    IF X < 3 THEN
+        FIBONACCI := 1
+    ELSE
+        FIBONACCI := FIBONACCI( X - 2 ) + FIBONACCI( X - 1 );
+END;

Task/Fibonacci-sequence/AppleScript/fibonacci-sequence-3.applescript

@@ -1,19 +1,18 @@
 -- fib :: Int -> Int
 on fib(n)
 
-    -- (Int, Int) -> (Int, Int)
+    -- lastTwo : (Int, Int) -> (Int, Int)
     script lastTwo
-        on lambda([a, b])
+        on |λ|([a, b])
             [b, a + b]
-        end lambda
+        end |λ|
     end script
 
-    item 1 of foldl(lastTwo, {0, 1}, range(1, n))
+    item 1 of foldl(lastTwo, {0, 1}, enumFromTo(1, n))
 end fib
 
 
-
--- TEST
+-- TEST -----------------------------------------------------------------------
 on run
 
     fib(32)
@@ -21,9 +20,21 @@ on run
     --> 2178309
 end run
 
+-- GENERIC FUNCTIONS ----------------------------------------------------------
 
-
--- GENERIC FUNCTIONS
+-- enumFromTo :: Int -> Int -> [Int]
+on enumFromTo(m, n)
+    if n < m then
+        set d to -1
+    else
+        set d to 1
+    end if
+    set lst to {}
+    repeat with i from m to n by d
+        set end of lst to i
+    end repeat
+    return lst
+end enumFromTo
 
 -- foldl :: (a -> b -> a) -> a -> [b] -> a
 on foldl(f, startValue, xs)
@@ -31,7 +42,7 @@ on foldl(f, startValue, xs)
         set v to startValue
         set lng to length of xs
         repeat with i from 1 to lng
-            set v to lambda(v, item i of xs, i, xs)
+            set v to |λ|(v, item i of xs, i, xs)
         end repeat
         return v
     end tell
@@ -44,21 +55,7 @@ on mReturn(f)
         f
     else
         script
-            property lambda : f
+            property |λ| : f
         end script
     end if
 end mReturn
-
--- range :: Int -> Int -> [Int]
-on range(m, n)
-    if n < m then
-        set d to -1
-    else
-        set d to 1
-    end if
-    set lst to {}
-    repeat with i from m to n by d
-        set end of lst to i
-    end repeat
-    return lst
-end range

Task/Fibonacci-sequence/BASIC/fibonacci-sequence-5.basic

@@ -0,0 +1,8 @@
+10 INPUT "ENTER VALUE OF N"; N
+20 N1 = 0 : N2 = 1
+30 FOR K=1 TO N
+40   SUM = N1+N2
+50   N1 = N2
+60   N2 = SUM
+70 NEXT K
+80 PRINT N1

Task/Fibonacci-sequence/BASIC/fibonacci-sequence-6.basic

@@ -0,0 +1,10 @@
+ 10 INPUT N
+ 20 A=0
+ 30 B=1
+ 40 FOR I=2 TO N
+ 50 C=B
+ 60 B=A+B
+ 70 A=C
+ 80 NEXT I
+ 90 PRINT B
+100 END

Task/Fibonacci-sequence/BASIC/fibonacci-sequence-7.basic

@@ -0,0 +1,2 @@
+ 10 INPUT N
+ 20 PRINT INT (0.5+(((SQR 5+1)/2)**N)/SQR 5)

Task/Fibonacci-sequence/BASIC/fibonacci-sequence-8.basic

@@ -0,0 +1,9 @@
+ 10 INPUT N
+ 20 LET A=0
+ 30 LET B=1
+ 40 FOR I=2 TO N
+ 50 LET C=B
+ 60 LET B=A+B
+ 70 LET A=C
+ 80 NEXT I
+ 90 PRINT B

Task/Fibonacci-sequence/BASIC/fibonacci-sequence-9.basic

@@ -0,0 +1,13 @@
+ 10 INPUT N
+ 20 LET A=0
+ 30 LET B=1
+ 40 GOSUB 70
+ 50 PRINT B
+ 60 STOP
+ 70 IF N=1 THEN RETURN
+ 80 LET C=B
+ 90 LET B=A+B
+100 LET A=C
+110 LET N=N-1
+120 GOSUB 70
+130 RETURN

Task/Fibonacci-sequence/Bc/fibonacci-sequence.bc

@@ -0,0 +1,15 @@
+#! /usr/bin/bc -q
+
+define fib(x) {
+    if (x <= 0) return 0;
+    if (x == 1) return 1;
+
+    a = 0;
+    b = 1;
+    for (i = 1; i < x; i++) {
+        c = a+b; a = b; b = c;
+    }
+    return c;
+}
+fib(1000)
+quit

Task/Fibonacci-sequence/Beeswax/fibonacci-sequence-1.beeswax

@@ -0,0 +1,4 @@
+                        #>'#{;
+_`Enter n: `TN`Fib(`{`)=`X~P~K#{;
+                         #>~P~L#MM@>+@'q@{;
+                                    b~@M<

Task/Fibonacci-sequence/Beeswax/fibonacci-sequence-2.beeswax

@@ -0,0 +1,29 @@
+julia> beeswax("n-th Fibonacci number.bswx")
+Enter n: i0
+
+Fib(0)=0
+Program finished!
+
+julia> beeswax("n-th Fibonacci number.bswx")
+Enter n: i10
+
+Fib(10)=55
+Program finished!
+
+julia> beeswax("n-th Fibonacci number.bswx")
+Enter n: i92
+
+Fib(92)=7540113804746346429
+Program finished!
+
+julia> beeswax("n-th Fibonacci number.bswx")
+Enter n: i93
+
+Fib(93)=12200160415121876738
+Program finished!
+
+julia> beeswax("n-th Fibonacci number.bswx")
+Enter n: i94
+
+Fib(94)=1293530146158671551
+Program finished!

Task/Fibonacci-sequence/Comefrom0x10/fibonacci-sequence.comefrom0x10

@@ -0,0 +1,15 @@
+stop = 6
+a = 1
+i = 1  # start
+a      # print result
+
+fib
+  comefrom if i is 1  # start
+  b = 1
+  comefrom fib        # start of loop
+  i = i + 1
+  next_b = a + b
+  a = b
+  b = next_b
+
+  comefrom fib if i > stop

Task/Fibonacci-sequence/Common-Lisp/fibonacci-sequence-7.lisp

@@ -1,21 +0,0 @@
-(defconstant +2x2-identity+ '(1 0 0 1))
-(defconstant +fib-seed+ '(1 1 1 0))
-
-(defun multiply-2x2 (matrix-1 matrix-2)
-  (let* ((a (first matrix-1)) (b (second matrix-1)) (c (third matrix-1)) (d (fourth matrix-1))
-	 (e (first matrix-2)) (f (second matrix-2)) (g (third matrix-2)) (h (fourth matrix-2))
-	 (ae (* a e)) (bg (* b g)) (af (* a f)) (bh (* b h))
-	 (ce (* c e)) (dg (* d g)) (cf (* c f)) (dh (* d h)))
-    (list (+ ae bg) (+ af bh) (+ ce dg) (+ cf dh))))
-
-(defun square-2x2 (matrix)
-  (multiply-2x2 matrix matrix))
-
-(defun 2x2-exponentiation (matrix n)
-  (cond ((zerop n) +2x2-identity+)
-	((eql n 1) matrix)
-	((evenp n) (square-2x2 (2x2-exponentiation matrix (/ n 2))))
-	(t (multiply-2x2 (square-2x2 (2x2-exponentiation matrix (/ (1- n) 2))) matrix))))
-
-(defun fib (n)
-  (car (2x2-exponentiation +fib-seed+ (1- n))))

Task/Fibonacci-sequence/Erlang/fibonacci-sequence-1.erl

@@ -1,5 +1,5 @@
 -module(fib).
--export([fib/1).
+-export([fib/1]).
 
 fib(0) -> 1;
 fib(1) -> 1;

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-1.hs

@@ -1 +1,6 @@
-[floor(0.01+(1/p**n+p**n)/sqrt 5)|let p=(1+sqrt 5)/2, n<-[0..42]]
+main :: IO ()
+main =
+  print
+    [ floor (0.01 + (1 / p ** n + p ** n) / sqrt 5)
+    | let p = (1 + sqrt 5) / 2
+    , n <- [0 .. 42] ]

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-10.hs

@@ -1,15 +1,44 @@
-import Data.List
+import Data.List (transpose)
 
-xs <+> ys = zipWith (+) xs ys
-xs <*> ys = sum $ zipWith (*) xs ys
+fib
+  :: (Integral b, Num a)
+  => b -> a
+fib 0 = 0 -- this line is necessary because "something ^ 0" returns "fromInteger 1", which unfortunately
+-- in our case is not our multiplicative identity (the identity matrix) but just a 1x1 matrix of 1
+fib n = (last . head . unMat) (Mat [[1, 1], [1, 0]] ^ n)
 
-newtype Mat a = Mat {unMat :: [[a]]} deriving Eq
+-- Code adapted from Matrix exponentiation operator task ---------------------
+(<+>)
+  :: Num c
+  => [c] -> [c] -> [c]
+(<+>) = zipWith (+)
 
-instance Show a => Show (Mat a) where
+(<*>)
+  :: Num a
+  => [a] -> [a] -> a
+(<*>) = (sum .) . zipWith (*)
+
+newtype Mat a = Mat
+  { unMat :: [[a]]
+  } deriving (Eq)
+
+instance Show a =>
+         Show (Mat a) where
   show xm = "Mat " ++ show (unMat xm)
 
-instance Num a => Num (Mat a) where
+instance Num a =>
+         Num (Mat a) where
   negate xm = Mat $ map (map negate) $ unMat xm
-  xm + ym   = Mat $ zipWith (<+>) (unMat xm) (unMat ym)
-  xm * ym   = Mat [[xs <*> ys | ys <- transpose $ unMat ym] | xs <- unMat xm]
+  xm + ym = Mat $ zipWith (<+>) (unMat xm) (unMat ym)
+  xm * ym =
+    Mat
+      [ [ xs Main.<*> ys -- to distinguish from standard applicative operator
+        | ys <- transpose $ unMat ym ]
+      | xs <- unMat xm ]
   fromInteger n = Mat [[fromInteger n]]
+  abs = undefined
+  signum = undefined
+
+-- TEST ----------------------------------------------------------------------
+main :: IO ()
+main = (print . take 10 . show . fib) (10 ^ 5)

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-11.hs

@@ -1,3 +1,35 @@
-fib 0 = 0 -- this line is necessary because "something ^ 0" returns "fromInteger 1", which unfortunately
-          -- in our case is not our multiplicative identity (the identity matrix) but just a 1x1 matrix of 1
-fib n = last $ head $ unMat $ (Mat [[1,1],[1,0]]) ^ n
+import Control.Arrow ((&&&))
+
+fibstep :: (Integer, Integer) -> (Integer, Integer)
+fibstep (a, b) = (b, a + b)
+
+fibnums :: [Integer]
+fibnums = map fst $ iterate fibstep (0, 1)
+
+fibN2 :: Integer -> (Integer, Integer)
+fibN2 m
+  | m < 10 = iterate fibstep (0, 1) !! fromIntegral m
+fibN2 m = fibN2_next (n, r) (fibN2 n)
+  where
+    (n, r) = quotRem m 3
+
+fibN2_next (n, r) (f, g)
+  | r == 0 = (a, b) -- 3n  ,3n+1
+  | r == 1 = (b, c) -- 3n+1,3n+2
+  | r == 2 = (c, d) -- 3n+2,3n+3   (*)
+  where
+    a =
+      5 * f ^ 3 +
+      if even n
+        then 3 * f
+        else (-3 * f) -- 3n
+    b = g ^ 3 + 3 * g * f ^ 2 - f ^ 3 -- 3n+1
+    c = g ^ 3 + 3 * g ^ 2 * f + f ^ 3 -- 3n+2
+    d =
+      5 * g ^ 3 +
+      if even n
+        then (-3 * g)
+        else 3 * g -- 3(n+1)   (*)
+
+main :: IO ()
+main = print $ (length &&& take 20) . show . fst $ fibN2 (10 ^ 2)

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-12.hs

@@ -1,20 +1,2 @@
-fibsteps (a,b) n
-    | n <= 0    = (a,b)
-    | otherwise = fibsteps (b, a+b) (n-1)
-
-fibnums :: [Integer]
-fibnums = map fst $ iterate (`fibsteps` 1) (0,1)
-
-fibN2 :: Integer -> (Integer, Integer)
-fibN2 m | m < 10 = fibsteps (0,1) m
-fibN2 m          = fibN2_next (n,r) (fibN2 n)
-                     where (n,r) = quotRem m 3
-
-fibN2_next (n,r) (f,g) | r==0 = (a,b)    -- 3n  ,3n+1
-                       | r==1 = (b,c)    -- 3n+1,3n+2
-                       | r==2 = (c,d)    -- 3n+2,3n+3   (*)
-  where
-      a = ( 5*f^3 + if even n then 3*f else (- 3*f) ) -- 3n
-      b = (   g^3 + 3 * g * f^2 - f^3               ) -- 3n+1
-      c = (   g^3 + 3 * g^2 * f + f^3               ) -- 3n+2
-      d = ( 5*g^3 + if even n then (- 3*g) else 3*g ) -- 3(n+1)   (*)
+ *Main> (length &&& take 20) . show . fst $ fibN2 (10^6)
+(208988,"19532821287077577316")

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-13.hs

@@ -1,2 +1 @@
- *Main> take 10 $ show $ fst $ fibN2 (10^6)
- "1953282128"
+f (n,(a,b)) = (2*n,(a*a+b*b,2*a*b+b*b))     -- iterate f (1,(0,1)) ; b is nth

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-14.hs

@@ -0,0 +1 @@
+g (n,(a,b)) = (2*n,(2*a*b-a*a,a*a+b*b))     -- iterate g (1,(1,1)) ; a is nth

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-2.hs

@@ -1 +1,6 @@
-fib x = if x < 1 then 0 else if x < 2 then 1 else fib(x - 1) + fib(x - 2)
+fib x =
+  if x < 1
+    then 0
+    else if x < 2
+           then 1
+           else fib (x - 1) + fib (x - 2)

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-3.hs

@@ -1,5 +1,8 @@
-fib x = if x < 1 then 0
-                 else if x==1 then 1
-                 else fibs!!(x - 1) + fibs!!(x - 2)
+fib x =
+  if x < 1
+    then 0
+    else if x == 1
+           then 1
+           else fibs !! (x - 1) + fibs !! (x - 2)
   where
-  fibs = map fib [0..]
+    fibs = map fib [0 ..]

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-4.hs

@@ -1,2 +1,5 @@
-fib :: Integer -> Integer
-fib n = fst $ foldl (\(a, b) _ -> (b, a + b)) (0, 1) [1 .. n]
+fib n = go n 0 1
+  where
+    go n a b
+      | n == 0 = a
+      | otherwise = go (n - 1) b (a + b)

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-5.hs

@@ -1,4 +1 @@
-fib n = go n 0 1
-    where
-    go n a b | n==0 = a
-             | otherwise = go (n-1) b (a+b)
+fib = 0 : 1 : zipWith (+) fib (tail fib)

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-6.hs

@@ -1 +1 @@
-fib = 0 : 1 : zipWith (+) fib (tail fib)
+fib = 0 : 1 : (zipWith (+) <*> tail) fib

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-7.hs

@@ -1 +1 @@
- fib = 0 : 1 : (zipWith (+) <*> tail) fib
+fib = 0 : 1 : next fib where next (a: t@(b:_)) = (a+b) : next t

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-8.hs

@@ -1 +1 @@
-fib = 0 : 1 : next fib where next (a: t@(b:_)) = (a+b) : next t
+fib = 0 : scanl (+) 1 fib

Task/Fibonacci-sequence/Haskell/fibonacci-sequence-9.hs

@@ -1 +1,9 @@
-fib = 0 : scanl (+) 1 fib
+import Data.List (foldl') --'
+
+fib :: Integer -> Integer
+fib n =
+  fst $
+  foldl' --'
+    (\(a, b) _ -> (b, a + b))
+    (0, 1)
+    [1 .. n]

Task/Fibonacci-sequence/JavaScript/fibonacci-sequence-1.js

@@ -1,5 +1,3 @@
 function fib(n) {
-  return function(n,a,b) {
-    return n>0 ? arguments.callee(n-1,b,a+b) : a;
-  }(n,0,1);
+  return n<2?n:fib(n-1)+fib(n-2);
 }

Task/Fibonacci-sequence/JavaScript/fibonacci-sequence-10.js

@@ -0,0 +1,22 @@
+(() => {
+    'use strict';
+
+    // fib :: Int -> Int
+    let fib = n => range(1, n)
+        .reduce(([a, b]) => [b, a + b], [0, 1])[0];
+
+
+    // GENERIC [m..n]
+
+    // range :: Int -> Int -> [Int]
+    let range = (m, n) =>
+        Array.from({
+            length: Math.floor(n - m) + 1
+        }, (_, i) => m + i);
+
+
+    // TEST
+    return fib(32);
+
+    // --> 2178309
+})();

Task/Fibonacci-sequence/JavaScript/fibonacci-sequence-2.js

@@ -1,10 +1,3 @@
 function fib(n) {
-  var a = 0, b = 1, t;
-  while (n-- > 0) {
-    t = a;
-    a = b;
-    b += t;
-    console.log(a);
-  }
-  return a;
+ if (n<2) { return n; } else { return fib(n-1)+fib(n-2); }
 }

Task/Fibonacci-sequence/JavaScript/fibonacci-sequence-3.js

@@ -1,7 +1,5 @@
-var fib = (function(cache){
-    return cache = cache || {}, function(n){
-        if (cache[n]) return cache[n];
-        else return cache[n] = n == 0 ? 0 : n < 0 ? -fib(-n)
-            : n <= 2 ? 1 : fib(n-2) + fib(n-1);
-    };
-})();
+function fib(n) {
+  return function(n,a,b) {
+    return n>0 ? arguments.callee(n-1,b,a+b) : a;
+  }(n,0,1);
+}

Task/Fibonacci-sequence/JavaScript/fibonacci-sequence-4.js

@@ -1,17 +1,10 @@
-(function () {
-    'use strict';
-
-    function fib(n) {
-        return Array.apply(null, Array(n + 1))
-            .map(function (_, i, lst) {
-                return lst[i] = (
-                    i ? i < 2 ? 1 :
-                    lst[i - 2] + lst[i - 1] :
-                    0
-                );
-            })[n];
-    }
-
-    return fib(32);
-
-})();
+function fib(n) {
+  var a = 0, b = 1, t;
+  while (n-- > 0) {
+    t = a;
+    a = b;
+    b += t;
+    console.log(a);
+  }
+  return a;
+}

Task/Fibonacci-sequence/JavaScript/fibonacci-sequence-5.js

@@ -1,17 +1,7 @@
-function Y(dn) {
-    return (function(fn) {
-        return fn(fn);
-    }(function(fn) {
-        return dn(function() {
-            return fn(fn).apply(null, arguments);
-        });
-    }));
-}
-var fib = Y(function(fn) {
-    return function(n) {
-        if (n === 0 || n === 1) {
-            return n;
-        }
-        return fn(n - 1) + fn(n - 2);
+var fib = (function(cache){
+    return cache = cache || {}, function(n){
+        if (cache[n]) return cache[n];
+        else return cache[n] = n == 0 ? 0 : n < 0 ? -fib(-n)
+            : n <= 2 ? 1 : fib(n-2) + fib(n-1);
     };
-});
+})();

Task/Fibonacci-sequence/JavaScript/fibonacci-sequence-6.js

@@ -1,10 +1,17 @@
-function* fibonacciGenerator() {
-    var prev = 0;
-    var curr = 1;
-    while (true) {
-        yield curr;
-        curr = curr + prev;
-        prev = curr - prev;
+(function () {
+    'use strict';
+
+    function fib(n) {
+        return Array.apply(null, Array(n + 1))
+            .map(function (_, i, lst) {
+                return lst[i] = (
+                    i ? i < 2 ? 1 :
+                    lst[i - 2] + lst[i - 1] :
+                    0
+                );
+            })[n];
     }
-}
-var fib = fibonacciGenerator();
+
+    return fib(32);
+
+})();

Task/Fibonacci-sequence/JavaScript/fibonacci-sequence-7.js

@@ -1,35 +1,17 @@
-(() => {
-    'use strict';
-
-    // Nth member of fibonacci series
-
-    // fib :: Int -> Int
-    function fib(n) {
-        return mapAccumL(([a, b]) => [
-            [b, a + b], b
-        ], [0, 1], range(1, n))[0][0];
+function Y(dn) {
+    return (function(fn) {
+        return fn(fn);
+    }(function(fn) {
+        return dn(function() {
+            return fn(fn).apply(null, arguments);
+        });
+    }));
+}
+var fib = Y(function(fn) {
+    return function(n) {
+        if (n === 0 || n === 1) {
+            return n;
+        }
+        return fn(n - 1) + fn(n - 2);
     };
-
-    // GENERIC FUNCTIONS
-
-    // mapAccumL :: (acc -> x -> (acc, y)) -> acc -> [x] -> (acc, [y])
-    let mapAccumL = (f, acc, xs) => {
-        return xs.reduce((a, x) => {
-            let pair = f(a[0], x);
-
-            return [pair[0], a[1].concat(pair[1])];
-        }, [acc, []]);
-    }
-
-    // range :: Int -> Int -> Maybe Int -> [Int]
-    let range = (m, n) =>
-        Array.from({
-            length: Math.floor(n - m) + 1
-        }, (_, i) => m + i);
-
-
-    // TEST
-    return fib(32);
-
-    // --> 2178309
-})();
+});

Task/Fibonacci-sequence/JavaScript/fibonacci-sequence-8.js

@@ -1,22 +1,10 @@
-(() => {
-    'use strict';
-
-    // fib :: Int -> Int
-    let fib = n => range(1, n)
-        .reduce(([a, b]) => [b, a + b], [0, 1])[0];
-
-
-    // GENERIC [m..n]
-
-    // range :: Int -> Int -> [Int]
-    let range = (m, n) =>
-        Array.from({
-            length: Math.floor(n - m) + 1
-        }, (_, i) => m + i);
-
-
-    // TEST
-    return fib(32);
-
-    // --> 2178309
-})();
+function* fibonacciGenerator() {
+    var prev = 0;
+    var curr = 1;
+    while (true) {
+        yield curr;
+        curr = curr + prev;
+        prev = curr - prev;
+    }
+}
+var fib = fibonacciGenerator();

Task/Fibonacci-sequence/JavaScript/fibonacci-sequence-9.js

@@ -0,0 +1,35 @@
+(() => {
+    'use strict';
+
+    // Nth member of fibonacci series
+
+    // fib :: Int -> Int
+    function fib(n) {
+        return mapAccumL(([a, b]) => [
+            [b, a + b], b
+        ], [0, 1], range(1, n))[0][0];
+    };
+
+    // GENERIC FUNCTIONS
+
+    // mapAccumL :: (acc -> x -> (acc, y)) -> acc -> [x] -> (acc, [y])
+    let mapAccumL = (f, acc, xs) => {
+        return xs.reduce((a, x) => {
+            let pair = f(a[0], x);
+
+            return [pair[0], a[1].concat(pair[1])];
+        }, [acc, []]);
+    }
+
+    // range :: Int -> Int -> Maybe Int -> [Int]
+    let range = (m, n) =>
+        Array.from({
+            length: Math.floor(n - m) + 1
+        }, (_, i) => m + i);
+
+
+    // TEST
+    return fib(32);
+
+    // --> 2178309
+})();

Task/Fibonacci-sequence/Kotlin/fibonacci-sequence.kotlin

@@ -1,12 +1,10 @@
-package fibonacci
-
 enum class Fibonacci {
     ITERATIVE {
-        override fun invoke(n: Long) = if (n < 2 )
+        override fun invoke(n: Long) = if (n < 2) {
             n
-        else {
-            var n1: Long = 0
-            var n2: Long = 1
+        } else {
+            var n1 = 0L
+            var n2 = 1L
             var i = n
             do {
                 val sum = n1 + n2

Task/Fibonacci-sequence/LOLCODE/fibonacci-sequence.lol

@@ -0,0 +1,16 @@
+HAI 1.2
+HOW DUZ I fibonacci YR N
+  EITHER OF BOTH SAEM N AN 1 AN BOTH SAEM N AN 0
+  O RLY?
+    YA RLY, FOUND YR 1
+    NO WAI
+      I HAS A N1
+      I HAS A N2
+      N1 R DIFF OF N AN 1
+      N2 R DIFF OF N AN 2
+      N1 R fibonacci N1
+      N2 R fibonacci N2
+      FOUND YR SUM OF N1 AN N2
+  OIC
+IF U SAY SO
+KTHXBYE

Task/Fibonacci-sequence/Nimrod/fibonacci-sequence-1.nimrod

@@ -1,5 +0,0 @@
-proc Fibonacci(n: int): int64 =
-  var fn = float64(n)
-  var p: float64 = (1.0 + sqrt(5.0)) / 2.0
-  var q: float64 = 1.0 / p
-  return int64((pow(p, fn) + pow(q, fn)) / sqrt(5.0))

Task/Fibonacci-sequence/Nimrod/fibonacci-sequence-2.nimrod

@@ -1,10 +0,0 @@
-proc Fibonacci(n: int): int =
-  var
-    first = 0
-    second = 1
-
-  for i in 0 .. <n:
-    swap first, second
-    second += first
-
-  result = first

Task/Fibonacci-sequence/Nimrod/fibonacci-sequence-3.nimrod

@@ -1,5 +0,0 @@
-proc Fibonacci(n: int): int64 =
-  if n <= 2:
-    result = 1
-  else:
-    result = Fibonacci(n - 1) + Fibonacci(n - 2)

Task/Fibonacci-sequence/Nimrod/fibonacci-sequence-4.nimrod

@@ -1,7 +0,0 @@
-proc Fibonacci(n: int, current: int64, next: int64): int64 =
-  if n == 0:
-    result = current
-  else:
-    result = Fibonacci(n - 1, next, current + next)
-proc Fibonacci(n: int): int64 =
-  result = Fibonacci(n, 0, 1)

Task/Fibonacci-sequence/Nimrod/fibonacci-sequence-5.nimrod

@@ -1,11 +0,0 @@
-iterator fib: int {.closure.} =
-  var a = 0
-  var b = 1
-  while true:
-    yield a
-    swap a, b
-    b = a + b
-
-var f = fib
-for i in 0.. <10:
-  echo f()

Task/Fibonacci-sequence/OCaml/fibonacci-sequence-2.ocaml

@@ -1,12 +1,19 @@
-let rec fib_rec n =
-  if n < 2 then
-    n
-  else
-    fib_rec (n - 1) + fib_rec (n - 2)
+open Num
 
-(* with support for negatives *)
-let rec fib = function
-    0 -> 0
-  | 1 -> 1
-  | n -> if n > 0 then fib (n-1) + fib (n-2)
-         else fib (n+2) - fib (n+1)
+let fib =
+  let rec fib_aux f0 f1 = function
+    | 0 -> f0
+    | 1 -> f1
+    | n -> fib_aux f1 (f1 +/ f0) (n - 1)
+  in
+  fib_aux (num_of_int 0) (num_of_int 1)
+
+(* support for negatives *)
+let fib n =
+      if n < 0 && n mod 2 = 0 then minus_num (fib (abs n))
+      else fib (abs n)
+;;
+(* It can be called from the command line with an argument *)
+(* Result is send to standart output *)
+let n = int_of_string Sys.argv.(1) in
+print_endline (string_of_num (fib n))

Task/Fibonacci-sequence/OCaml/fibonacci-sequence-3.ocaml

@@ -1,12 +1,16 @@
-let fib n =
-  let rec fib_aux n a b =
-    match n with
-    | 0 -> a
-    | _ -> fib_aux (n-1) b (a+b)
-  in
-  fib_aux n 0 1
+open Num
+
+let mul (a,b,c) (d,e,f) = let bxe = b*/e in
+  (a*/d +/ bxe, a*/e +/ b*/f, bxe +/ c*/f)
+
+let id = (Int 1, Int 0, Int 1)
+let rec pow a n =
+  if n=0 then id else
+    let b = pow a (n/2) in
+    if (n mod 2) = 0 then mul b b else mul a (mul b b)
 
-(* support for negatives *)
 let fib n =
-      if n < 0 && n mod 2 = 0 then -fib (abs n)
-      else fib (abs n)
+  let (_,y,_) = (pow (Int 1, Int 1, Int 0) n) in
+  string_of_num y
+;;
+Printf.printf "fib %d = %s\n" 300 (fib 300)

Task/Fibonacci-sequence/OCaml/fibonacci-sequence-4.ocaml

@@ -1,19 +0,0 @@
-open Num
-
-let fib =
-  let rec fib_aux f0 f1 = function
-    | 0 -> f0
-    | 1 -> f1
-    | n -> fib_aux f1 (f1 +/ f0) (n - 1)
-  in
-  fib_aux (num_of_int 0) (num_of_int 1)
-
-(* support for negatives *)
-let fib n =
-      if n < 0 && n mod 2 = 0 then minus_num (fib (abs n))
-      else fib (abs n)
-;;
-(* It can be called from the command line with an argument *)
-(* Result is send to standart output *)
-let n = int_of_string Sys.argv.(1) in
-print_endline (string_of_num (fib n))

Task/Fibonacci-sequence/OCaml/fibonacci-sequence-5.ocaml

@@ -1,16 +0,0 @@
-open Num
-
-let mul (a,b,c) (d,e,f) = let bxe = b*/e in
-  (a*/d +/ bxe, a*/e +/ b*/f, bxe +/ c*/f)
-
-let id = (Int 1, Int 0, Int 1)
-let rec pow a n =
-  if n=0 then id else
-    let b = pow a (n/2) in
-    if (n mod 2) = 0 then mul b b else mul a (mul b b)
-
-let fib n =
-  let (_,y,_) = (pow (Int 1, Int 1, Int 0) n) in
-  string_of_num y
-;;
-Printf.printf "fib %d = %s\n" 300 (fib 300)

Task/Fibonacci-sequence/Phix/fibonacci-sequence-1.phix

@@ -1,18 +1,16 @@
-sequence fcache = {1,1}
-
-function fibonamem(integer n)   -- memoized, works for -ve numbers, inaccurate above 78
-integer absn = abs(n)
+function fibonacci(integer n)     -- iterative, works for -ve numbers
+atom a=0, b=1
     if n=0 then return 0 end if
-    if absn>length(fcache) then
-        fcache = append(fcache,fibonamem(absn-1)+fibonamem(absn-2))
-        if absn!=length(fcache) then ?9/0 end if
-    end if
+    if abs(n)>=79 then ?9/0 end if  -- inaccuracies creep in above 78
+    for i=1 to abs(n)-1 do
+        {a,b} = {b,a+b}
+    end for
     if n<0 and remainder(n,2)=0 then return -fcache[absn] end if
     return fcache[absn]
 end function
 
-for i=0 to 30 do
-    printf(1,"%d", fibonamem(i))
-    if i!=30 then puts(1,", ") end if
+for i=0 to 28 do
+    if i then puts(1,", ") end if
+    printf(1,"%d", fibonacci(i))
 end for
 puts(1,"\n")

Task/Fibonacci-sequence/Phix/fibonacci-sequence-2.phix

@@ -5,18 +5,17 @@ sequence fcacheba = {BA_ONE,BA_ONE}
 function fibonamemba(integer n) -- memoized, works for -ve numbers, yields bigatom
 integer absn = abs(n)
     if n=0 then return BA_ZERO end if
-    if absn>length(fcacheba) then
-        fcacheba = append(fcacheba,ba_add(fibonamemba(absn-1),fibonamemba(absn-2)))
-        if absn!=length(fcacheba) then ?9/0 end if
-    end if
+    while length(fcacheba)<absn do
+        fcacheba = append(fcacheba,ba_add(fcacheba[$],fcacheba[$-1]))
+    end while
     if n<0 and remainder(n,2)=0 then return ba_sub(0,fcacheba[absn]) end if
     return fcacheba[absn]
 end function
 
-for i=0 to 30 do
+for i=0 to 28 do
+    if i then puts(1,", ") end if
     ba_printf(1,"%B", fibonamemba(i))
-    if i!=30 then puts(1,", ") end if
 end for
 puts(1,"\n")
-ba_printf(1,"%B", fibonamemba(777))
+ba_printf(1,"%B", fibonamemba(705))
 puts(1,"\n")

Task/Fibonacci-sequence/Python/fibonacci-sequence-1.py

@@ -1,10 +1,5 @@
-from math import *
+def fib(n,x=[0,1]):
+   for i in range(abs(n)-1): x=[x[1],sum(x)]
+   return x[1]*pow(-1,abs(n)-1) if n<0 else x[1] if n else 0
 
-def analytic_fibonacci(n):
-  sqrt_5 = sqrt(5);
-  p = (1 + sqrt_5) / 2;
-  q = 1/p;
-  return int( (p**n + q**n) / sqrt_5 + 0.5 )
-
-for i in range(1,31):
-  print analytic_fibonacci(i),
+for i in range(-30,31): print fib(i),

Task/Fibonacci-sequence/Python/fibonacci-sequence-10.py

@@ -1,10 +1,7 @@
-def fib():
-    """Yield fib[n+1] + fib[n]"""
-    yield 1  # have to start somewhere
-    lhs, rhs = fib(), fib()
-    yield next(lhs) # move lhs one iteration ahead
-    while True:
-        yield next(lhs)+next(rhs)
+def fib(n, c={0:1, 1:1}):
+    if n not in c:
+        x = n // 2
+        c[n] = fib(x-1) * fib(n-x-1) + fib(x) * fib(n - x)
+    return c[n]
 
-f=fib()
-print [next(f) for _ in range(9)]
+fib(10000000)  # calculating it takes a few seconds, printing it takes eons

Task/Fibonacci-sequence/Python/fibonacci-sequence-11.py

@@ -1,11 +1,10 @@
-from itertools import islice
-
 def fib():
-    yield 0
-    yield 1
-    a, b = fib(), fib()
-    next(b)
+    """Yield fib[n+1] + fib[n]"""
+    yield 1  # have to start somewhere
+    lhs, rhs = fib(), fib()
+    yield next(lhs) # move lhs one iteration ahead
     while True:
-        yield next(a)+next(b)
+        yield next(lhs)+next(rhs)
 
-print(tuple(islice(fib(), 10)))
+f=fib()
+print [next(f) for _ in range(9)]

Task/Fibonacci-sequence/Python/fibonacci-sequence-12.py

@@ -0,0 +1,11 @@
+from itertools import islice
+
+def fib():
+    yield 0
+    yield 1
+    a, b = fib(), fib()
+    next(b)
+    while True:
+        yield next(a)+next(b)
+
+print(tuple(islice(fib(), 10)))

Task/Fibonacci-sequence/Python/fibonacci-sequence-2.py

@@ -1,8 +1,10 @@
-def fibIter(n):
-    if n < 2:
-        return n
-    fibPrev = 1
-    fib = 1
-    for num in xrange(2, n):
-        fibPrev, fib = fib, fib + fibPrev
-    return fib
+from math import *
+
+def analytic_fibonacci(n):
+  sqrt_5 = sqrt(5);
+  p = (1 + sqrt_5) / 2;
+  q = 1/p;
+  return int( (p**n + q**n) / sqrt_5 + 0.5 )
+
+for i in range(1,31):
+  print analytic_fibonacci(i),

Task/Fibonacci-sequence/Python/fibonacci-sequence-3.py

@@ -1,5 +1,8 @@
-def fibRec(n):
+def fibIter(n):
     if n < 2:
         return n
-    else:
-        return fibRec(n-1) + fibRec(n-2)
+    fibPrev = 1
+    fib = 1
+    for num in xrange(2, n):
+        fibPrev, fib = fib, fib + fibPrev
+    return fib

Task/Fibonacci-sequence/Python/fibonacci-sequence-4.py

@@ -1,11 +1,5 @@
-def fibMemo():
-    pad = {0:0, 1:1}
-    def func(n):
-        if n not in pad:
-            pad[n] = func(n-1) + func(n-2)
-        return pad[n]
-    return func
-
-fm = fibMemo()
-for i in range(1,31):
-    print fm(i),
+def fibRec(n):
+    if n < 2:
+        return n
+    else:
+        return fibRec(n-1) + fibRec(n-2)

Task/Fibonacci-sequence/Python/fibonacci-sequence-5.py

@@ -1,7 +1,11 @@
-def fibFastRec(n):
-    def fib(prvprv, prv, c):
-        if c < 1:
-            return prvprv
-        else:
-            return fib(prv, prvprv + prv, c - 1)
-    return fib(0, 1, n)
+def fibMemo():
+    pad = {0:0, 1:1}
+    def func(n):
+        if n not in pad:
+            pad[n] = func(n-1) + func(n-2)
+        return pad[n]
+    return func
+
+fm = fibMemo()
+for i in range(1,31):
+    print fm(i),

Task/Fibonacci-sequence/Python/fibonacci-sequence-6.py

@@ -1,5 +1,7 @@
-def fibGen(n):
-    a, b = 0, 1
-    while n>0:
-        yield a
-        a, b, n = b, a+b, n-1
+def fibFastRec(n):
+    def fib(prvprv, prv, c):
+        if c < 1:
+            return prvprv
+        else:
+            return fib(prv, prvprv + prv, c - 1)
+    return fib(0, 1, n)

Task/Fibonacci-sequence/Python/fibonacci-sequence-7.py

@@ -1,3 +1,5 @@
->>> [i for i in fibGen(11)]
-
-[0,1,1,2,3,5,8,13,21,34,55]
+def fibGen(n):
+    a, b = 0, 1
+    while n>0:
+        yield a
+        a, b, n = b, a+b, n-1

Task/Fibonacci-sequence/Python/fibonacci-sequence-8.py

@@ -1,30 +1,3 @@
-def prevPowTwo(n):
-    'Gets the power of two that is less than or equal to the given input'
-    if ((n & -n) == n):
-        return n
-    else:
-        n -= 1
-        n |= n >> 1
-        n |= n >> 2
-        n |= n >> 4
-        n |= n >> 8
-        n |= n >> 16
-        n += 1
-        return (n/2)
+>>> [i for i in fibGen(11)]
 
-def crazyFib(n):
-    'Crazy fast fibonacci number calculation'
-    powTwo = prevPowTwo(n)
-
-    q = r = i = 1
-    s = 0
-
-    while(i < powTwo):
-        i *= 2
-        q, r, s = q*q + r*r, r * (q + s), (r*r + s*s)
-
-    while(i < n):
-        i += 1
-        q, r, s = q+r, q, r
-
-    return q
+[0,1,1,2,3,5,8,13,21,34,55]

Task/Fibonacci-sequence/Python/fibonacci-sequence-9.py

@@ -1,7 +1,30 @@
-def fib(n, c={0:1, 1:1}):
-    if n not in c:
-        x = n // 2
-        c[n] = fib(x-1) * fib(n-x-1) + fib(x) * fib(n - x)
-    return c[n]
+def prevPowTwo(n):
+    'Gets the power of two that is less than or equal to the given input'
+    if ((n & -n) == n):
+        return n
+    else:
+        n -= 1
+        n |= n >> 1
+        n |= n >> 2
+        n |= n >> 4
+        n |= n >> 8
+        n |= n >> 16
+        n += 1
+        return (n/2)
 
-fib(10000000)  # calculating it takes a few seconds, printing it takes eons
+def crazyFib(n):
+    'Crazy fast fibonacci number calculation'
+    powTwo = prevPowTwo(n)
+
+    q = r = i = 1
+    s = 0
+
+    while(i < powTwo):
+        i *= 2
+        q, r, s = q*q + r*r, r * (q + s), (r*r + s*s)
+
+    while(i < n):
+        i += 1
+        q, r, s = q+r, q, r
+
+    return q

Task/Fibonacci-sequence/R/fibonacci-sequence-1.r

@@ -0,0 +1,6 @@
+fib=function(n,x=c(0,1)) {
+   if (abs(n)>1) for (i in seq(abs(n)-1)) x=c(x[2],sum(x))
+   if (n<0) return(x[2]*(-1)^(abs(n)-1)) else if (n) return(x[2]) else return(0)
+}
+
+sapply(seq(-31,31),fib)

Task/Fibonacci-sequence/Ruby/fibonacci-sequence-5.rb

@@ -1,11 +1,7 @@
-require 'generator'
-
-def fib_gen
-    Generator.new do |g|
-        f0, f1 = 0, 1
-        loop do
-            g.yield f0
-            f0, f1 = f1, f0 + f1
-        end
-    end
+fib = Enumerator.new do |y|
+  f0, f1 = 0, 1
+  loop do
+    y <<  f0
+    f0, f1 = f1, f0 + f1
+  end
 end

Task/Fibonacci-sequence/Rust/fibonacci-sequence-3.rust

@@ -6,9 +6,9 @@ fn main() {
     }
 }
 
-fn fibonacci_gen(terms: i32) -> impl Iterator<Item=f64> {
+fn fibonacci_gen(terms: i32) -> impl Iterator<Item=u64> {
     let sqrt_5 = 5.0f64.sqrt();
-    let p  = (1.0 +sqrt_5) / 2.0;
+    let p  = (1.0 + sqrt_5) / 2.0;
     let q = 1.0/p;
-    (1..terms).map(move |n| ((p.powi(n) + q.powi(n)) / sqrt_5 + 0.5).floor())
+    (1..terms).map(move |n| ((p.powi(n) + q.powi(n)) / sqrt_5 + 0.5) as u64)
 }

Task/Fibonacci-sequence/SPL/fibonacci-sequence-1.spl

@@ -0,0 +1,4 @@
+fibo(n)=
+  s5 = #.sqrt(5)
+  <= (((1+s5)/2)^n-((1-s5)/2)^n)/s5
+.

Task/Fibonacci-sequence/SPL/fibonacci-sequence-2.spl

@@ -0,0 +1,11 @@
+fibo(n)=
+  ? n<2, <= n
+  f2 = 0
+  f1 = 1
+  > i, 2..n
+    f = f1+f2
+    f2 = f1
+    f1 = f
+  <
+  <= f
+.

Task/Fibonacci-sequence/SPL/fibonacci-sequence-3.spl

@@ -0,0 +1,4 @@
+fibo(n)=
+  ? n<2, <= n
+  <= fibo(n-1)+fibo(n-2)
+.

Task/Fibonacci-sequence/SQL/fibonacci-sequence-3.sql

@@ -1,27 +1,16 @@
-CREATE FUNCTION fib(n int) RETURNS numeric AS $$
-    -- This recursive with generates endless list of Fibonacci numbers.
-    WITH RECURSIVE fibonacci(current, previous) AS (
-        -- Initialize the current with 0, so the first value will be 0.
-        -- The previous value is set to 1, because its only goal is not
-        -- special casing the zero case, and providing 1 as the second
-        -- number in the sequence.
-        --
-        -- The numbers end with dots to make them numeric type in
-        -- Postgres. Numeric type has almost arbitrary precision
-        -- (technically just 131,072 digits, but that's good enough for
-        -- most purposes, including calculating huge Fibonacci numbers)
-        SELECT 0., 1.
-    UNION ALL
-        -- To generate Fibonacci number, we need to add together two
-        -- previous Fibonacci numbers. Current number is saved in order
-        -- to be accessed in the next iteration of recursive function.
-        SELECT previous + current, current FROM fibonacci
-    )
-    -- The user is only interested in current number, not previous.
-    SELECT current FROM fibonacci
-    -- We only need one number, so limit to 1
-    LIMIT 1
-    -- Offset the query by the requested argument to get the correct
-    -- position in the list.
-    OFFSET n
-$$ LANGUAGE SQL RETURNS NULL ON NULL INPUT IMMUTABLE;
+SQL> with fib(e,f) as (select 1, 1 from dual union all select e+f,e from fib where e <= 55) select f from fib;
+
+         F
+----------
+         1
+         1
+         2
+         3
+         5
+         8
+        13
+        21
+        34
+        55
+
+10 rows selected.

Task/Fibonacci-sequence/SQL/fibonacci-sequence-4.sql

@@ -0,0 +1,27 @@
+CREATE FUNCTION fib(n int) RETURNS numeric AS $$
+    -- This recursive with generates endless list of Fibonacci numbers.
+    WITH RECURSIVE fibonacci(current, previous) AS (
+        -- Initialize the current with 0, so the first value will be 0.
+        -- The previous value is set to 1, because its only goal is not
+        -- special casing the zero case, and providing 1 as the second
+        -- number in the sequence.
+        --
+        -- The numbers end with dots to make them numeric type in
+        -- Postgres. Numeric type has almost arbitrary precision
+        -- (technically just 131,072 digits, but that's good enough for
+        -- most purposes, including calculating huge Fibonacci numbers)
+        SELECT 0., 1.
+    UNION ALL
+        -- To generate Fibonacci number, we need to add together two
+        -- previous Fibonacci numbers. Current number is saved in order
+        -- to be accessed in the next iteration of recursive function.
+        SELECT previous + current, current FROM fibonacci
+    )
+    -- The user is only interested in current number, not previous.
+    SELECT current FROM fibonacci
+    -- We only need one number, so limit to 1
+    LIMIT 1
+    -- Offset the query by the requested argument to get the correct
+    -- position in the list.
+    OFFSET n
+$$ LANGUAGE SQL RETURNS NULL ON NULL INPUT IMMUTABLE;

Task/Fibonacci-sequence/Sed/fibonacci-sequence.sed

@@ -0,0 +1,40 @@
+#!/bin/sed -f
+
+# First we need to convert each number into the right number of ticks
+# Start by marking digits
+s/[0-9]/<&/g
+
+# We have to do the digits manually.
+s/0//g; s/1/|/g; s/2/||/g; s/3/|||/g; s/4/||||/g; s/5/|||||/g
+s/6/||||||/g; s/7/|||||||/g; s/8/||||||||/g; s/9/|||||||||/g
+
+# Multiply by ten for each digit from the front.
+:tens
+s/|</<||||||||||/g
+t tens
+
+# Done with digit markers
+s/<//g
+
+# Now the actual work.
+:split
+# Convert each stretch of n >= 2 ticks into two of n-1, with a mark between
+s/|\(|\+\)/\1-\1/g
+# Convert the previous mark and the first tick after it to a different mark
+# giving us n-1+n-2 marks.
+s/-|/+/g
+# Jump back unless we're done.
+t split
+# Get rid of the pluses, we're done with them.
+s/+//g
+
+# Convert back to digits
+:back
+s/||||||||||/</g
+s/<\([0-9]*\)$/<0\1/g
+s/|||||||||/9/g;
+s/|||||||||/9/g; s/||||||||/8/g; s/|||||||/7/g; s/||||||/6/g;
+s/|||||/5/g; s/||||/4/g; s/|||/3/g; s/||/2/g; s/|/1/g;
+s/</|/g
+t back
+s/^$/0/

Task/Fibonacci-sequence/Sidef/fibonacci-sequence-1.sidef

@@ -1,7 +1,5 @@
 func fib_iter(n) {
-    var fib = [1, 1];
-    (n - fib.len).times {
-        fib = [fib[-1], fib[-2] + fib[-1]]
-    };
-    fib[-1];
+    var (a, b) = (0, 1)
+    { (a, b) = (b, a+b) } * n
+    return a
 }

Task/Fibonacci-sequence/Sidef/fibonacci-sequence-2.sidef

@@ -1,3 +1,3 @@
 func fib_rec(n) {
-    n < 2 ? n : (__FUNC__(n-1) + __FUNC__(n-2));
+    n < 2 ? n : (__FUNC__(n-1) + __FUNC__(n-2))
 }

Task/Fibonacci-sequence/Sidef/fibonacci-sequence-3.sidef

@@ -1,3 +1,3 @@
 func fib_mem (n) is cached {
-    n < 2 ? n : (__FUNC__(n-1) + __FUNC__(n-2));
+    n < 2 ? n : (__FUNC__(n-1) + __FUNC__(n-2))
 }

Task/Fibonacci-sequence/Sidef/fibonacci-sequence-4.sidef

@@ -1,5 +1,5 @@
 func fib_closed(n) {
-    define S = (1.25.sqrt + 0.5);
-    define T = (-S + 1);
-    (S**n - T**n) / (-T + S) -> roundf(0);
+    define S = (1.25.sqrt + 0.5)
+    define T = (-S + 1)
+    (S**n - T**n) / (-T + S) -> round
 }

Task/Fibonacci-sequence/Sidef/fibonacci-sequence-5.sidef

@@ -0,0 +1 @@
+say fib(12)    #=> 144

Task/Fibonacci-sequence/Smart-BASIC/fibonacci-sequence.smart

@@ -0,0 +1,31 @@
+FOR i = 0 TO 15
+    PRINT fibR(i),fibI(i),fibN(i)
+NEXT i
+
+/* Recursive Method */
+DEF fibR(n)
+    IF n <= 1 THEN
+        fibR = n
+    ELSE
+        fibR = fibR(n-1) + fibR(n-2)
+    ENDIF
+END DEF
+
+/* Iterative Method */
+DEF fibI(n)
+    a = 0
+    b = 1
+    FOR i = 1 TO n
+        temp = a + b
+        a = b
+        b = temp
+    NEXT i
+    fibI = a
+END DEF
+
+/* N-th Term Method */
+DEF fibN(n)
+    uphi = .5 + SQR(5)/2
+    lphi = .5 - SQR(5)/2
+    fibN = (uphi^n-lphi^n)/SQR(5)
+END DEF

Task/Fibonacci-sequence/Standard-ML/fibonacci-sequence.ml

@@ -1,7 +0,0 @@
-fun fib n =
-    let
-	fun fib' (0,a,b) = a
-	  | fib' (n,a,b) = fib' (n-1,a+b,a)
-    in
-	fib' (n,0,1)
-    end

Task/Fibonacci-sequence/Stata/fibonacci-sequence.stata

@@ -0,0 +1,12 @@
+. mata
+: function fib(n) {
+        return((((1+sqrt(5))/2):^n-((1-sqrt(5))/2):^n)/sqrt(5))
+}
+
+: fib(0..10)
+        1    2    3    4    5    6    7    8    9   10   11
+    +--------------------------------------------------------+
+  1 |   0    1    1    2    3    5    8   13   21   34   55  |
+    +--------------------------------------------------------+
+
+: end

Task/Fibonacci-sequence/TI-83-BASIC/fibonacci-sequence-3.ti-83

@@ -1,3 +0,0 @@
-:Prompt N
-:.5(1+√(5))→P
-:(P^N–(-1/P)^N)/√(5)

Task/Fibonacci-sequence/Wart/fibonacci-sequence-3.wart

@@ -1,5 +1,5 @@
 def (fib n saved)
-  # all args in wart are optional, and we expect callers to not provide saved
+  # all args in Wart are optional, and we expect callers to not provide `saved`
   default saved :to (table 0 0 1 1)  # pre-populate base cases
   default saved.n :to
     (+ (fib n-1 saved) (fib n-2 saved))

Task/Fibonacci-sequence/X86-Assembly/fibonacci-sequence.x86

@@ -0,0 +1,51 @@
+TITLE i hate visual studio 4			(Fibs.asm)
+;       __         __/--------\
+;      >__ \      /  |        |\
+;         \  \___/ @  \      /   \__________________
+;           \____       \  /                         \\\
+;                \____         Coded with love by:    |||
+;                      \      Alexander Alvonellos    |||
+;                       |          9/29/2011         / ||
+;                       |                           |  MM
+;                       |      |--------------|     |
+;                       |<     |              |<    |
+;                       |      |              |     |
+;                       |mmmmmm|              |mmmmm|
+;; Epic Win.
+
+INCLUDE Irvine32.inc
+
+.data
+	BEERCOUNT = 48;
+	Fibs dd 0, 1, BEERCOUNT DUP(0);
+
+.code
+main PROC
+; I am not responsible for this code.
+; They made me write it, against my will.
+	;Here be dragons
+	mov esi, offset Fibs; offset array;  ;;were to start (start)
+	mov ecx, BEERCOUNT; 		;;count of items (how many)
+	mov ebx, 4; 		;;size (in number of bytes)
+	call DumpMem;
+	
+	mov ecx, BEERCOUNT; 	;//http://www.wolframalpha.com/input/?i=F ib%5B47%5D+%3E+4294967295
+	mov esi, offset Fibs
+	NextPlease:;
+		mov eax, [esi]; 	;//Get me the data from location at ESI
+		add eax, [esi+4];	;//add into the eax the data at esi + another double (next mem loc)
+		mov [esi+8], eax;	;//Move that data into the memory location after the second number
+		add esi, 4;			;//Update the pointer
+	loop NextPlease;	;//Thank you sir, may I have another?
+	
+	
+	;Here be dragons
+	mov esi, offset Fibs; offset array;  ;;were to start (start)
+	mov ecx, BEERCOUNT; 		;;count of items (how many)
+	mov ebx, 4; 		;;size (in number of bytes)
+	call DumpMem;
+
+	exit		; exit to operating system
+main ENDP
+
+END main

Task/Fibonacci-sequence/XEec/fibonacci-sequence.xeec

@@ -0,0 +1,7 @@
+h#1 h#1 h#1 o#
+h#10 o$ p
+>f
+  o# h#10 o$ p
+  ma h? jnext p
+  t
+jnf

Task/Fibonacci-sequence/XLISP/fibonacci-sequence-3.xlisp

@@ -0,0 +1,8 @@
+(defun fibonacci (x)
+    (defun fib (a b n)
+        (if (= n 2)
+            b
+            (fib b (+ a b) (- n 1)) ) )
+    (if (< x 2)
+        x
+        (fib 1 1 x) ) )

Task/Fibonacci-sequence/ZX-Spectrum-Basic/fibonacci-sequence-2.zx

@@ -0,0 +1 @@
+10 DEF FN f(x)=INT (0.5+(((SQR 5+1)/2)^x)/SQR 5)

Task/Fibonacci-sequence/Zkl/fibonacci-sequence.zkl

@@ -0,0 +1 @@
+var fibShift=fcn(ab){ab.append(ab.sum()).pop(0)}.fp(L(0,1));