Excel Sheet Column Number.md

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

My code:

class Solution(object):
    def titleToNumber(self, s):
        """
        :type s: str
        :rtype: int
        """
        c=0
        sum=0
        for i in s[::-1]:
            sum+=(ord(i)-64)*26**c#Notice we can use ord in python to ascii
            c+=1
        return sum

Solution: https://leetcode.com/problems/excel-sheet-column-number/