DouKaku?

open System;;
open List;;

let rec take n ls =
    match n, ls with
    | n, _ when n <= 0 -> []
    | _, [] -> []
    | n, (hd::tl) -> hd :: take (n-1) tl;;

let shuffle ls =
    let rnd = new Random() in
    sort (fun x y-> rnd.Next(-1,2)) ls;;

let choice m n = take m (shuffle (init n (fun x -> x)));;