Leetcode: Excel Sheet Column Number

题目：

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 

解答：

其实质是将26进制数转成十进制数字

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