Data update

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

@@ -0,0 +1,19 @@
+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))