Data update

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

@@ -0,0 +1,16 @@
+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)