【LeetCode】171. Excel Sheet Column Number

原题链接：https://leetcode.com/problems/excel-sheet-column-number/description/

题目要求：

Related to question Excel Sheet Column Title

Given a column title as appear in an Excel sheet, return its corresponding column number.

For example:

A -> 1

B -> 2

C -> 3 ...

Z -> 26

AA -> 27

AB -> 28

想法：这个问题是Excel Sheet Column Title的关联问题，上个问题想明白了自然就都明白了。

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