原题链接https://leetcode.com/problems/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?
import math
class Solution:
def isPowerOfThree(self, n: int) -> bool:
if not isinstance(n, int):
return -1
if n <= 0:
return False
return 3 ** round(math.log(n, 3)) == n
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