Find if a number is a power of two without math function or log function

Question

I want to find if a user entered number is a power of two or not.

My code doesn\'t work.

public class power_of_two
{  
    public static void main         


        

Answer 1

double input = 22;

while(((input != 2) && input % 2 == 0) || input == 1) {
 input = input /2;
}

return input == 2;

Keep dividing it by 2 until you reach 1 or an odd number. If it reaches 1 it's a power of 2, otherwise it isn't.