NetworkAddressCalculator.java

import java.util.Scanner;

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

        // Get user input
        System.out.print("Enter IP address : ");
        String ipAddress = scanner.nextLine();
        System.out.print("Enter prefix length : ");
        int prefixLength = scanner.nextInt();
        scanner.close();

        // Compute Network Address, Subnet Mask, and Total Hosts
        String subnetMask = calculateSubnetMask(prefixLength);
        String networkAddress = calculateNetworkAddress(ipAddress, subnetMask);
        int totalHosts = (int) Math.pow(2, 32 - prefixLength) - 2; // -2 for Network & Broadcast

        // Display results
        System.out.println("Network Address: " + networkAddress);
        System.out.println("Subnet Mask: " + subnetMask);
        System.out.println("Total Number of Hosts: " + totalHosts);
    }

    public static String calculateSubnetMask(int prefix) {
        int mask = 0xFFFFFFFF << (32 - prefix);
        return ((mask >> 24) & 0xFF) + "." +
               ((mask >> 16) & 0xFF) + "." +
               ((mask >> 8) & 0xFF) + "." +
               (mask & 0xFF);
    }

    public static String calculateNetworkAddress(String ip, String subnetMask) {
        String[] ipParts = ip.split("\\.");
        String[] maskParts = subnetMask.split("\\.");

        int ipInt = (Integer.parseInt(ipParts[0]) << 24) |
                    (Integer.parseInt(ipParts[1]) << 16) |
                    (Integer.parseInt(ipParts[2]) << 8) |
                    Integer.parseInt(ipParts[3]);

        int maskInt = (Integer.parseInt(maskParts[0]) << 24) |
                      (Integer.parseInt(maskParts[1]) << 16) |
                      (Integer.parseInt(maskParts[2]) << 8) |
                      Integer.parseInt(maskParts[3]);

        int networkInt = ipInt & maskInt;

        return ((networkInt >> 24) & 0xFF) + "." +
               ((networkInt >> 16) & 0xFF) + "." +
               ((networkInt >> 8) & 0xFF) + "." +
               (networkInt & 0xFF);
    }
}