LeetCode – Refresh – Exceel Sheet Column Number

No tricks.

class Solution {
public:
    int titleToNumber(string s) {
        int result = 0, len = s.size();
        for (int i = 0; i < len; i++) {
            result = result*26 + int(s[i] - 'A') + 1;
        }
        return result;
    }
};