# LeetCode - 0171. Excel Sheet Column Number
### 題目網址：https://leetcode.com/problems/excel-sheet-column-number/
###### tags: `LeetCode` `Easy` `數學`

/*
    -LeetCode format-
    Problem: 171. Excel Sheet Column Number
    Difficulty: Easy
    
    by Inversionpeter
*/



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