[171] Excel Sheet Column Number

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

• algorithms
• Easy (50.16%)
• Source Code: 171.excel-sheet-column-number.py
• Total Accepted: 214.1K
• Total Submissions: 418K
• Testcase Example: '"A"'

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

class Solution(object):
    def titleToNumber(self, s):
        """
        :type s: str
        :rtype: int
        """
        if not s: return 0

        lens = len(s)
        result = 0

        for idx, char in enumerate(s):
            result += (ord(char)-ord('A')+1) * pow(26, lens-idx-1)

        return result
#
#
# s = Solution()
# print s.titleToNumber('A')
# print s.titleToNumber('B')
#