[Solved] Given an integer n, return true if it is a power of four. Otherwise, return false.

Question

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

An integer n is a power of four, if there exists an integer x such that n == 4x.

Example 1:

Input: n = 16
Output: true

Example 2:

Input: n = 5
Output: false

Example 3:

Input: n = 1
Output: true

Constraints:

• -231 <= n <= 231 - 1

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

Python Solution

class Solution:
    def isPowerOfFour(self, num: int) -> bool:
        if num<=0:
            return False
        while num%4==0:
            num = num/4
        return True if num==1 else False