let blocks = [
('B', 'O'); ('X', 'K'); ('D', 'Q'); ('C', 'P');
('N', 'A'); ('G', 'T'); ('R', 'E'); ('T', 'G');
('Q', 'D'); ('F', 'S'); ('J', 'W'); ('H', 'U');
('V', 'I'); ('A', 'N'); ('O', 'B'); ('E', 'R');
('F', 'S'); ('L', 'Y'); ('P', 'C'); ('Z', 'M');
]
let find_letter blocks c =
let found, remaining =
List.partition (fun (c1, c2) -> c1 = c || c2 = c) blocks
in
match found with
| _ :: res -> Some (res @ remaining)
| _ -> None
let can_make_word w =
let n = String.length w in
let rec aux i _blocks =
if i >= n then true else
match find_letter _blocks w.[i] with
| None -> false
| Some rem_blocks ->
aux (succ i) rem_blocks
in
aux 0 blocks
let test label f (word, should) =
Printf.printf "- %s %S = %B (should: %B)\n" label word (f word) should
let () =
List.iter (test "can make word" can_make_word) [
"A", true;
"BARK", true;
"BOOK", false;
"TREAT", true;
"COMMON", false;
"SQUAD", true;
"CONFUSE", true;
]