Leetcode 0504 Base 7

Problem statement

https://leetcode.com/problems/base-7/

Solution

Just divide number by seven end evaluate reminder. Also handle negative numbers cases.

Complexity

Complexity is O(log n), both time and space, we need to do this number of divisions.

Code

class Solution:
    def convertToBase7(self, num):
        sgn = 1 if num < 0 else 0
        ans, num = "", abs(num)
        while num:
            num, digit = divmod(num, 7)
            ans += str(digit)
            
        return "-"*sgn + ans[::-1] if ans else "0"