LeetCode 326. Power of Three

326. Power of Three
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?

//记住考虑特殊条件 n <= 0 。。否则会超时。。class Solution {public: bool isPowerOfThree(int n) { if(n <= 0) return false; return pow(3, (round)(log(n) / log(3))) == n; }};