leetcode: 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

类似于26进制转10进制。

class Solution {
    public int titleToNumber(String s) {
        int result  = 0;
        for (int i = 0; i < s.length(); i++){
            result *= 26;
            result += ((s.charAt(i) - 'A') + 1);    
        }
        return result;
    }
}