DM1 Option info - programme "g n m"

let g3 n =
if n=0 then 0 else
if n<=2 then 1 else
let t = ref [|0;1;1|] in
for i=3 to n do
t := [|!t.(1);!t.(2);!t.(0) + !t.(2)|];
done;
!t.(2);;
g3 22;;
g 20 3;;


let g n m =
if n=0 then 0 else if n<=(m-1) then 1 else
let t = ref (Array.make m 1) in
!t.(0) <- 0;
for i=m to n do
    let temp = !t.(0) + !t.(m-1) in
    for j=0 to (m-2) do
    !t.(j) <- !t.(j+1);
    done;
    !t.(m-1) <- temp;
done;
!t.(m-1);;

g 22 4;;
43 mod 42;;

(* Exercice III. 3) et 4) *)
let g_rapide n m=
if n=0 then 0 else if n<=(m-1) then 1 else
let t = ref (Array.make m 1) in
!t.(0) <- 0;
for i=m to n do
    let (a,b) = ( (i-m) mod m , (i-1) mod m ) in
    let temp = !t.( a ) + !t.( b ) in
    !t.( a ) <- temp;
    done;
!t.( (n-m) mod m);;

g 200 3;;
g_rapide (2*(499)-1+1789) 499;;