171. Excel Sheet Column Number.md

171. 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 
    ...

Example 1:

Input: "A"
Output: 1

Example 2:

Input: "AB"
Output: 28

Example 3:

Input: "ZY"
Output: 701

Solution

没难度的easy题

Code

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