Little Python basic stuff

(*
    n = 0; 0
    n = 1; 1
    n = 2; 3
    n = 3; 6
    n = 4; 10
    n = 5; 15
*)

(* method 0 with a for loop *)

let sumNb0 n =
    let sum = ref 0 in
    for i = 0 to n do
        sum := !sum + i
    done;
    !sum;;

(* method 1 with a direct compute *)

let sumNb1 n = n * (n + 1) / 2;;

(* main *)

(* input *)

(* TODO: scanf ... *)
let n = 5;;
print_int (sumNb0 n);;
print_int (sumNb1 n);;

(* for *)
(* print_int (sumNb1 i);; *)