Question

JAVA

Write a method that finds out if a number is a power of two. Create a tester to demonstrate if it works.

Answer 1

//IsPowerOf2.java
import java.util.Scanner;
public class IsPowerOf2 {
    public static boolean isPowerOfTwo(int n){
        if(n==0)
            return false;

        return (int)(Math.ceil((Math.log(n) / Math.log(2)))) ==
                (int)(Math.floor(((Math.log(n) / Math.log(2)))));
    }

    // Testing
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter a number: ");
        int n = scanner.nextInt();
        if(isPowerOfTwo(n)){
            System.out.println(n+" is a power of 2");
        }
        else{
            System.out.println(n+" is NOT a power of 2");
        }
    }
}