[ADS] Static Routing

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Date;
import java.util.Scanner;

class MapEntry<K extends Comparable<K>, E> implements Comparable<K> {

    // Each MapEntry object is a pair consisting of a key (a Comparable
    // object) and a value (an arbitrary object).
    K key;
    E value;

    public MapEntry(K key, E val) {
        this.key = key;
        this.value = val;
    }

    public int compareTo(K that) {
        // Compare this map entry to that map entry.
        @SuppressWarnings("unchecked")
        MapEntry<K, E> other = (MapEntry<K, E>) that;
        return this.key.compareTo(other.key);
    }

    public String toString() {
        return "<" + key + "," + value + ">";
    }
}

class SLLNode<E> {
    protected E element;
    protected SLLNode<E> succ;

    public SLLNode(E elem, SLLNode<E> succ) {
        this.element = elem;
        this.succ = succ;
    }

    @Override
    public String toString() {
        return element.toString();
    }
}

class CBHT<K extends Comparable<K>, E> {

    // An object of class CBHT is a closed-bucket hash table, containing
    // entries of class MapEntry.
    private SLLNode<MapEntry<K, E>>[] buckets;

    @SuppressWarnings("unchecked")
    public CBHT(int m) {
        // Construct an empty CBHT with m buckets.
        buckets = (SLLNode<MapEntry<K, E>>[]) new SLLNode[m];
    }

    private int hash(K key) {
        // Translate key to an index of the array buckets.
        return Math.abs(key.hashCode()) % buckets.length;
    }

    public SLLNode<MapEntry<K, E>> search(K targetKey) {
        // Find which if any node of this CBHT contains an entry whose key is
        // equal
        // to targetKey. Return a link to that node (or null if there is none).
        int b = hash(targetKey);
        for (SLLNode<MapEntry<K, E>> curr = buckets[b]; curr != null; curr = curr.succ) {
            if (targetKey.equals(((MapEntry<K, E>) curr.element).key))
                return curr;
        }
        return null;
    }

    public void insert(K key, E val) {        // Insert the entry <key, val> into this CBHT.
        MapEntry<K, E> newEntry = new MapEntry<K, E>(key, val);
        int b = hash(key);
        for (SLLNode<MapEntry<K, E>> curr = buckets[b]; curr != null; curr = curr.succ) {
            if (key.equals(((MapEntry<K, E>) curr.element).key)) {
                // Make newEntry replace the existing entry ...
                curr.element = newEntry;
                return;
            }
        }
        // Insert newEntry at the front of the 1WLL in bucket b ...
        buckets[b] = new SLLNode<MapEntry<K, E>>(newEntry, buckets[b]);
    }

    public void delete(K key) {
        // Delete the entry (if any) whose key is equal to key from this CBHT.
        int b = hash(key);
        for (SLLNode<MapEntry<K, E>> pred = null, curr = buckets[b]; curr != null; pred = curr, curr = curr.succ) {
            if (key.equals(((MapEntry<K, E>) curr.element).key)) {
                if (pred == null)
                    buckets[b] = curr.succ;
                else
                    pred.succ = curr.succ;
                return;
            }
        }
    }

    public String toString() {
        String temp = "";
        for (int i = 0; i < buckets.length; i++) {
            temp += i + ":";
            for (SLLNode<MapEntry<K, E>> curr = buckets[i]; curr != null; curr = curr.succ) {
                temp += curr.element.toString() + " ";
            }
            temp += "\n";
        }
        return temp;
    }


    public SLLNode<MapEntry<K, E>> mySearch(K targetKey) {

        int b = hash(targetKey);
        System.out.println(String.format("b = %d", b));
        for (SLLNode<MapEntry<K, E>> curr = buckets[b]; curr != null; curr = curr.succ) {
            if (targetKey.equals(((MapEntry<K, E>) curr.element).key))
                return curr;
        }
        return null;
    }

}

public class RoutingHashJava {

    public static void main(String[] args) throws IOException, ParseException {
        Scanner scanner = new Scanner(System.in);

        int numberOfRouters = scanner.nextInt();

        CBHT<String, String[]> table = new CBHT<>(2 * numberOfRouters);

        for (int i = 1; i <= numberOfRouters; i++) {
            String routerInterface = scanner.next();
            scanner.nextLine(); // Fire off to go to next line
            String routingTable = scanner.nextLine();
            String parts[] = routingTable.split(",");

            table.insert(routerInterface, parts);
        }


        int triesToRoutePackets = scanner.nextInt();
        for (int i = 0; i < triesToRoutePackets; i++) {

            String inputInterface = scanner.next();
            String ipAddress = scanner.next();

            SLLNode<MapEntry<String, String[]>> searchNode = table.search(inputInterface);

            if (searchNode != null) {
                String subnetMasks[] = searchNode.element.value;
                boolean valid = false;
                for (int j = 0; j < subnetMasks.length; j++) {

                    String ipAddressParts[] = ipAddress.split("\\.");
                    String subnetParts[] = subnetMasks[j].split("\\.");

                    for (int k = 0; k < subnetParts.length - 1; k++) {

                        if (ipAddressParts[k].equals(subnetParts[k])) {
                            valid = true;
                        } else {
                            valid = false;
                            break;
                        }
                    }

                    if (valid) {
                        System.out.println("postoi"); break;
                    }
                    /*SimpleDateFormat simpleDateFormat = new SimpleDateFormat("ddd:ddd:ddd:ddd");
                    Date date = simpleDateFormat.parse(subnetMasks[j]);
                    System.out.println(date);*/
                }
                 if (!valid){
                    System.out.println("ne postoi");
                }
            } else {
                System.out.println("ne postoi");
            }
        }

    }
}