Description
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?
Code
class Solution {
public:
bool isPowerOfThree(int n) {
if(n <= 0) return false;
while(n > 1) {
int res = n % 3;
if(res != 0) return false;
n = n / 3;
}
return true;
}
};