Conditional Constructs in Java

Chapter 8

Conditional Constructs in Java

Class 10 - Logix Kips ICSE Computer Applications with BlueJ

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Java Program: Java Menu-Driven Program to check whether a number is a Buzz number or an Automorphic number

31. Write a menu driven program to accept a number from the user and check whether it is a Buzz number or an Automorphic number.

i. Automorphic number is a number, whose square's last digit(s) are equal to that number. For example, 25 is an automorphic number, as its square is 625 and 25 is present as the last two digits.
ii. Buzz number is a number, that ends with 7 or is divisible by 7.

🧫 Definitions Recap

Buzz Number
A number that ends with 7 OR is divisible by 7
Examples: 7, 14, 27, 77
Automorphic Number
A number whose square ends with the number itself
Example:
25² = 625 → Automorphic

Java

import java.util.Scanner;
 
public class BuzzAutomorphic {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
 
        System.out.println("MENU");
        System.out.println("1. Check Buzz Number");
        System.out.println("2. Check Automorphic Number");
        System.out.print("Enter your choice: ");
        int choice = sc.nextInt();
 
        System.out.print("Enter a number: ");
        int num = sc.nextInt();
 
        switch (choice) {
            case 1:
                // Buzz Number Check
                if (num % 7 == 0 || num % 10 == 7)
                    System.out.println(num + " is a Buzz Number");
                else
                    System.out.println(num + " is NOT a Buzz Number");
                break;
 
            case 2:
                // Automorphic Number Check
                int square = num * num;
                int temp = num;
                boolean isAutomorphic = true;
 
                while (temp > 0) {
                    if (temp % 10 != square % 10) {
                        isAutomorphic = false;
                        break;
                    }
                    temp /= 10;
                    square /= 10;
                }
 
                if (isAutomorphic)
                    System.out.println(num + " is an Automorphic Number");
                else
                    System.out.println(num + " is NOT an Automorphic Number");
                break;
 
            default:
                System.out.println("Invalid choice");
        }
 
        sc.close();
    }
}

Output

Sample Run 1

MENU
1. Check Buzz Number
2. Check Automorphic Number
Enter your choice: 1
Enter a number: 27
27 is a Buzz Number

Sample Run 2

MENU
1. Check Buzz Number
2. Check Automorphic Number
Enter your choice: 2
Enter a number: 25
25 is an Automorphic Number

📝 Explanation

Program uses switch-case for menu selection
Buzz number logic:

num % 7 == 0 OR num % 10 == 7

Automorphic logic:

Compare last digits of number and its square using a loop

Displays an error message for incorrect choice