Baranje studenti spored index HASH

import java.util.Map;
import java.util.Objects;
import java.util.Scanner;

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;
    }

}

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 Student
{
    String ime;
    String prezime;
    int index;
    String smer;

    Student(){}

    Student(String ime , String prezime , int index , String smer)
    {
        this.ime=ime;
        this.prezime=prezime;
        this.index=index;
        this.smer=smer;
    }

    @Override
    public String toString() {
        return "Ime:"+ime+" "+"Prezime:"+prezime+" "+"Index:"+index+" "+"Smer:"+smer+" ";
    }
}

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

        CBHT<Integer,Student>tabela=new CBHT<>(2*n);

        for(int i=0;i<n;i++)
        {
            String ime=input.next();
            String prezime=input.next();
            int index=input.nextInt();
            String smer=input.next();

            Student s=new Student(ime,prezime,index,smer);
            tabela.insert(index,s);
        }
        System.out.println("Searching...");
        while (true)
        {
            Integer index=input.nextInt();
            if(index.equals(-1))
                break;

            SLLNode<MapEntry<Integer,Student>> curr=tabela.search(index);

            if(curr!=null)
            {
                System.out.println(curr.element.value);
            }
            else
                System.out.println("/");
        }
    }

}