Example: Automorphic Number Checker in Java

// Automorphic Number Checker
import java.util.Scanner;

// Main class containing the entry point of the program
public class Main {
    public static void main(String[] args) {
        // Step 1: Create a Scanner object to read input from the user
        Scanner scanner = new Scanner(System.in);

        // Step 2: Prompt the user to enter a number
        System.out.print("Enter an integer: ");
        int number = scanner.nextInt();

        // Step 3: Calculate the square of the number
        long square = (long) number * number; // Use long to prevent overflow for larger numbers

        // Step 4: Determine the number of digits in the original number
        // This is needed to extract the correct number of last digits from the square
        int tempNumber = number;
        int numberOfDigits = 0;
        if (tempNumber == 0) { // Handle the case for number 0
            numberOfDigits = 1;
        } else {
            while (tempNumber > 0) {
                tempNumber /= 10;
                numberOfDigits++;
            }
        }

        // Step 5: Calculate the divisor to extract the last 'numberOfDigits' from the square
        // For example, if number is 5 (1 digit), divisor is 10^1 = 10
        // If number is 25 (2 digits), divisor is 10^2 = 100
        long divisor = 1;
        for (int i = 0; i < numberOfDigits; i++) {
            divisor *= 10;
        }

        // Step 6: Extract the last digits of the square
        long lastDigitsOfSquare = square % divisor;

        // Step 7: Compare the original number with the extracted last digits
        if (number == lastDigitsOfSquare) {
            System.out.println(number + " is an automorphic number.");
        } else {
            System.out.println(number + " is not an automorphic number.");
        }

        // Step 8: Close the scanner
        scanner.close();
    }
}