326. Power of Three

Given an integer, write a function to determine if it is a power of three.

Example 1:

Input: 27 Output: true Example 2:

Input: 0 Output: false Example 3:

Input: 9 Output: true Example 4:

Input: 45 Output: false Follow up: Could you do it without using any loop / recursion?

思路：常数，呵呵 代码:python3

class Solution:
    def isPowerOfThree(self, n: int) -> bool:
        return n>0 and 3**19%n==0