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Power of Four - Easy - LeetCode

Power of Four - Easy - LeetCode

Given an integer (signed 32 bits), write a function to check whether it is a power of 4.

Example 1:

Input: 16
Output: true
Example 2:

Input: 5
Output: false
Follow up: Could you solve it without loops/recursion?

public class Solution {
    public bool IsPowerOfFour(int num) {
        if(num<=0){
            return false;            
        }
        
        if((num & (num-1))!= 0){
            return false;
        }
        
        return (num-1)%3==0;
    }
}

Time Complexity: O(1)

Space Complexity: O(1)