September 2017 Update

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)