Program/Source Code:

The source code to count the number of bits to be flipped to convert a number to another number is given below. The given program is compiled and executed successfully.

// Java program to count the number of bits to be flipped 
// to convert a number to another number

import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner SC = new Scanner(System.in);

    int num1 = 0;
    int num2 = 0;

    int cnt = 0;
    int lsb1 = 0;
    int lsb2 = 0;

    System.out.printf("Enter Number1: ");
    num1 = SC.nextInt();

    System.out.printf("Enter Number2: ");
    num2 = SC.nextInt();

    while ((num1 > 0) || (num2 > 0)) {
      lsb1 = num1 & 1;
      lsb2 = num2 & 1;

      if (lsb1 != lsb2)
        cnt++;

      num1 = num1 >> 1;
      num2 = num2 >> 1;
    }
    System.out.printf("Number of bits flipped: %d\n", cnt);
  }
}

Output:

Enter Number1: 11
Enter Number2: 15
Number of bits flipped: 1