maze_generation.ml

let rec combinations k m = match k, m with
    | k, m when k < 0 || m < 0 -> failwith "ki or mi negative"
    | k, m when k > m -> failwith "k > m"
    | 0, 0 -> [[]]
    | 0, m -> map (concat false) (combinations 0 (m-1))
    | k, m when k = m -> map (concat true) (combinations (k-1) (m-1))
    | k, m -> map (concat true) (combinations (k-1) (m-1)) @ map (concat false) (combinations k (m-1))
;;

let generate m n = 
    let c = combinations ((m-1) * (n-1)) (m*(n-1)+n*(m-1))
    in
    let c_array = map Array.of_list c
    in 
    filter (sanity_check m n) c_array
;;