Power of 4

/*  Power of 4 */
/*
    Given an integer, check if it is a power of 4
    Approach : Check if it is power of 2 and the number of zeros is even
*/

 #include<iostream>  
 using namespace std;  
 bool isPowerOfFour(int num) {  
   if(num < 0)  
     return false;  
   //power of 2  
   if(num && !(num & (num - 1))){  
     int count = 0;  
     while(num > 1){  
       num = num >> 1;  
       count++;  
     }  
     //if number of zeros is even, return true  
     if(count % 2 == 0){  
       return true;  
     }  
   }  
   return false;  
 }  
 int main(){  
   int n = 15;  
   cout << isPowerOfFour(n);  
   return 0;  
 }