Bulls and cows! I've done that, cows don't get loose you just have one when you run out of turns ;-)) No bull!
Update: @SierraKen
Bulls and cows: https://staging.qb64phoenix.com/showthread.php?tid=212
Update: @SierraKen
Bulls and cows: https://staging.qb64phoenix.com/showthread.php?tid=212
b = b + ...