(* list_make *)
let rec list_make (n : int) (x : 'a) : 'a list =
  match n with
  | 0 -> []
  | _ -> x :: list_make (n - 1) x ;;


list_make 5 'e' ;;
    
(* long_prefixe *)
let rec long_prefixe (liste : 'a list) : int =
  match liste with
  | [] -> 0
  (*  | [_] -> 1 *)
  | t1 :: t2 :: q when t1 = t2 -> 1 + long_prefixe (t2 :: q)
  | _ -> 1 ;;

long_prefixe [] ;;
long_prefixe [1] ;;
long_prefixe [1; 2] ;;
long_prefixe [1; 1] ;;
long_prefixe [1; 1; 2] ;;
long_prefixe [1; 1; 2; 2] ;;
long_prefixe [1; 1; 1; 1; 2; 1; 4] ;;  


(* minmax *)
let rec minmax (liste : int list) : int * int =
  match liste with
  | [] -> failwith "Liste vide"
  | [t] -> (t, t)
  | t :: q -> let (mi, ma) = minmax q in
              (min t mi, max t ma) ;;
  
minmax [4; 2; 6; 8; 3; 9] ;;


(* fusion *)
let rec fusion (l1 : 'a list) (l2 : 'a list) : 'a list =
  match l1 with
  | [] -> l2
  | t1 :: q1 -> let t2 = (List.hd l2) in if t1 < t2 then t1 :: (fusion q1 l2) else t2 :: fusion l1 (List.tl l2) ;;

fusion [1; 3; 4; 6; 8; 10] [2; 3; 5; 11] ;;