leetcode：Excel Sheet Column Number

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 这题题目的意思就是：将26进制字母转化为10进制数字

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

　　编译的时候开始总是出现