hangman.zok

import "hashes/sha256/sha256Padded" as sha256;

/*
 * @notice This program proofs whether a certain symbol exists in the secret word. 
 *   For example, for word "Hello" and symbol 'l' it will output [false, false, true, true, false, ... false]
 * @param word Secret word as an array of ASCII characters. If shorter than 16 characters, padded with 0's
 * @param hash sha-256 hash of the word
 * @param symbol ASCII symbol to verify
 * @returns A mask indicating whether @symbol exists in the @word and at which positions
 */
def main(private u8[16] word, u32[8] hash, u8 symbol) -> bool[16] {
    u32[8] computedHash = sha256(word);
    for u32 i in 0..7 {
        assert(computedHash[i] == hash[i]);
    }

    bool[16] mut result = [false;16];
    for u32 i in 0..16 {
        bool match = word[i] == symbol;
        result[i] = match;
        assert(result[i] == match);
    }
    
    return result;
}