LeetCode326. Power of Three

一、题目

Given an integer n, return true if it is a power of three. Otherwise, return false.

An integer n is a power of three, if there exists an integer x such that n == 3x.

Example 1:

Input: n = 27
Output: true
Explanation: 27 = 33
Example 2:

Input: n = 0
Output: false
Explanation: There is no x where 3x = 0.
Example 3:

Input: n = -1
Output: false
Explanation: There is no x where 3x = (-1).

Constraints:

-231 <= n <= 231 - 1

Follow up: Could you solve it without loops/recursion?

二、题解

class Solution {
public:
    bool isPowerOfThree(int n) {
        return n > 0 && 1162261467 % n == 0;
    }
};