Further changes to p23

[dominikmoehrle]

Now compatible with p25. Before, it was not possible to enter a whole list as an argument.

[VictorNicollet]

Formatting: this line is too wide. The n < 0 test can be dropped (we are in the n > 0 case of the condition on line 7), and it would probably be possible to run the n > List.length list check exactly once (to avoid re-computing the length of the list twice on each iteration). In the end, we would have:

let rand_select list n = 
    let length = List.length list in 
    let rec extract n length list = 
        if n == 0 then [] else
            let i = random length in
            List.nth list i :: aux (n-1) (length - 1) (remove_at i list) 
    in
    if n < 0 || n > length then raise Not_found else aux n length list

Also, the comment probably refers to remove_at, not rand_select.