3114. Latest Time You Can Obtain After Replacing Characters

You are given a string s representing a 12-hour format time where some of the digits (possibly none) are replaced with a "?".

12-hour times are formatted as "HH:MM", where HH is between 00 and 11, and MM is between 00 and 59. The earliest 12-hour time is 00:00, and the latest is 11:59.

You have to replace all the "?" characters in s with digits such that the time we obtain by the resulting string is a valid 12-hour format time and is the latest possible.

Return the resulting string.

class Solution {
    bool match(char a, char b, string& s) {
        if(s.length() == 1) s = "0" + s;
        if(a != '?' and s[0] != a) return false;
        if(b != '?' and s[1] != b) return false;
        return true;
    }
public:
    string findLatestTime(string s) {
        string t = "", m = "";
        for(int i = 0; i < 12; i++) {
            string now = to_string(i);
            if(match(s[0], s[1], now)) t = now;
        }
        for(int i = 0; i < 60; i++) {
            string now = to_string(i);
            if(match(s[3], s[4], now)) m = now;
        }
        return t + ":" + m;
    }
};