LeetCode:Excel Sheet Column Number

问题描述：

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 

思路：

将26进制转为10进制。

代码：

public class Solution {    public int titleToNumber(String s) {        int sum = 0;        for(int i = 0; i < s.length(); i++) {            char  item =  s.charAt(i);            sum = sum * 26 + (item - 64);        }        return sum;    }}