leetcode 168. Excel Sheet Column Title（python）

描述

Given an integer columnNumber, return its corresponding column title as it appears in an Excel sheet.

For example:

A -> 1
B -> 2
C -> 3
...
Z -> 26
AA -> 27
AB -> 28 
...
 

Example 1:

Input: columnNumber = 1
Output: "A"	

Example 2:

Input: columnNumber = 28
Output: "AB"

Example 3:

Input: columnNumber = 701
Output: "ZY"

Example 4:

Input: columnNumber = 2147483647
Output: "FXSHRXW"

Note:

1 <= columnNumber <= 2^31 - 1

解析

根据题意，就是用 26 进制的大写字母表示数字，思路比较简单，和对十进制数通过取模和整除 10 的得到每个数字的过程类似，只不过将每个数字都换成了对应的字母，最后记得将字符串倒序返回，因为在拼接过程中是从后向前的。

解答

class Solution(object):
    def convertToTitle(self, columnNumber):
        """
        :type columnNumber: int
        :rtype: str
        """
        chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
        r = ''
        while columnNumber > 0:
            m = (columnNumber-1) % 26
            r += chars[m]
            columnNumber = (columnNumber-1) // 26
        return r[::-1]
        	      
		

运行结果

Runtime: 20 ms, faster than 34.68% of Python online submissions for Excel Sheet Column Title.
Memory Usage: 13.1 MB, less than 100.00% of Python online submissions for Excel Sheet Column Title.

原题链接：leetcode.com/problems/ex…

您的支持是我最大的动力