171. 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.

Solution:

The implementation is straightforward.



Code:

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