Leetcode 171. Excel Sheet Column Number

文章作者：Tyan
博客：noahsnail.com  |  CSDN  |  简书

1. Description

2. Solution

• Version 1

class Solution:
    def titleToNumber(self, s):
        result = 0
        mapping = {chr(64+i): i for i in range(1, 27)}
        s = list(s)
        s.reverse()

        for index, ch in enumerate(s):
            result = result + mapping[ch] * math.pow(26, index)
        return int(result)

• Version 2

class Solution:
    def titleToNumber(self, s):
        result = 0
        for ch in s:
            result = result * 26 + ord(ch) - 64
        return result

Reference

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