You could probably use an array of arrays (AoA), an array of hashes (AoH), an hash or arrays (HoA) or a hash of hashes (HoH). Your could even use 2 arrays, or 2 hashes, or an array and a hash, but that is sort of less interesting. You could even use a simple array (or a simple hash) and concatenate the Boolean and the int into it, but that starts to be quite ugly.