(* ineq doit être une inégalité stricte *)

let tri_rapide ineq t =

        let ioe a b = ineq a b || a = b in

        let echanger i j =
	        let k = t.(i) in
	        t.(i) <- t.(j);
        	t.(j) <- k;
        in

        let placer inf sup =
	        let n = t.(sup) and
                bi = ref inf and bs = ref (sup-1) in
	        while (!bi < !bs) do
		        while ((!bi < sup) && (ioe t.(!bi) n)) do incr bi done;
        		while ((!bs > inf) && (ioe n t.(!bs))) do decr bs done;
	        	if (!bi < !bs) then (
		        	echanger !bi !bs;
			        incr bi;
        			decr bs;
	        	);
        	done;
	        if (ineq t.(!bi) n) then incr bi;
        	if (!bi < sup) then echanger !bi sup;
	        !bi;
        in

        let rec trier inf sup =
	        if (inf < sup) then (
		        let r = placer inf sup in
        		trier inf (r-1);
	        	trier (r+1) sup;
        	);
        in

        trier 0 ((vect_length t) -1);
;;

let tri_rapide_c = tri_rapide (prefix <) ;;
let tri_rapide_d = tri_rapide (prefix >) ;;