[Swift]LeetCode753. 破解保险箱 | Cracking the Safe
Thereisaboxprotectedbyapassword.Thepasswordis n digits,whereeachlettercanbeoneofthefirst k digits 0,1,...,k-1.Youcankeepinputtingthepassword,thepasswordwillautomaticallybematchedagainstthelast n digitsentered.Fore