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

Similar Problems:

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

Follow up:

Could you do it without using any loop / recursion?

Github: code.dennyzhang.com

Credits To: leetcode.com

Leave me comments, if you have better ways to solve.

class Solution(object): ## Blog link: https://code.dennyzhang.com/power-of-three ## Basic Ideas: power of any prime number ## 3 is a prime ## If 3 % k == 0 and k is a prime, then k is 3. ## Thus 3^19 % n === 0 means n is power of 3 class Solution(object): def isPowerOfThree(self, n): """ :type n: int :rtype: bool """ if n <= 0: return False larget_power3 = pow(3, 19) return larget_power3 % n == 0