171. Excel Sheet Column Number

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 

輸入字符串然後判斷對應的數字

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思路
很巧妙，自己想不出來23333

class Solution {
public:
    int titleToNumber(string s) {

        int n=0;
        int m=0;

        for(int i=0; i<s.size(); i++)
        {
            n = s[i]-'A'+1;
            m = m*26+n;
        }
        return m;
    }
};