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 

Credits:
Special thanks to @ts for adding this problem and creating all test cases.

26进制转10进制，注意以‘A‘而不是0开头，因此要“+1”

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

【LeetCode】Excel Sheet Column Number