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September 2017 Update

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Ingy döt Net 2017-09-23 10:01:46 +02:00
parent bba7bfd280
commit ba8067c3b7
14570 changed files with 153136 additions and 63871 deletions
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24
Task/Fibonacci-sequence/OCaml/fibonacci-sequence-3.ocaml
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@ -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)