Aips lab2 Spoj listi naizmenicno

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

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

    public SLLNode(E element,SLLNode<E> succ) {
        this.element=element;
        this.succ=succ;
    }
    @Override
    public String toString() {
        return element.toString();
    }
}

class SLL<E extends Comparable<E>> {
    private SLLNode<E> first;

    public SLL() {
        this.first=null;
    }
    public SLLNode<E> getFirst() {
        return first;
    }

    public void insertLast(E ob) {
        if(first!=null) {
            SLLNode<E> temp = first;
            while(temp.succ != null) {
                temp = temp.succ;
            }
            SLLNode<E> ins = new SLLNode<E>(ob,null);
            temp.succ = ins;

        } else {
            SLLNode<E> temp = new SLLNode<E>(ob,first);
            first=temp;
        }

    }

    public SLL<E> specialJoin(SLL<E> list2) {
        SLL<E> rezultat = new SLL<E>();
        SLLNode<E> jazol1 = this.getFirst();
        SLLNode<E> jazol2 = list2.getFirst();
        int counter=0;
        while(jazol1 != null&&jazol2 != null) {
            if(counter<2) {
                rezultat.insertLast(jazol1.element);
                jazol1=jazol1.succ;
                counter++;
            } else if(counter>=2) {
                rezultat.insertLast(jazol2.element);
                jazol2=jazol2.succ;
                counter++;
                if(counter>=4) {
                    counter = 0;
                }
            }
        }
		if(jazol1 != null){
            while(jazol1 !=null){
            	rezultat.insertLast(jazol1.element);
                jazol1=jazol1.succ;
            }
        }
        if(jazol2 != null){
            while(jazol2 !=null){
            	rezultat.insertLast(jazol2.element);
                jazol2=jazol2.succ;
            }
    }
    return rezultat;
}

@Override
public String toString() {
    String print = new String();
    if(first != null) {
        SLLNode<E> temp = first;
        print+=first;
        while(temp.succ != null) {
            temp=temp.succ;
            print+=" " + temp;
        }
    }
    return print;
}

}

public class SpecialSLLJoin {


    public static void main(String[] args) throws IOException {

        SLL<Integer> lista1 = new SLL<Integer>();
        SLL<Integer> lista2 = new SLL<Integer>();

        BufferedReader stdin = new BufferedReader(new InputStreamReader(
                    System.in));
        String s = stdin.readLine();
        int N = Integer.parseInt(s);
        s = stdin.readLine();
        String[] pomniza = s.split(" ");
        for (int i = 0; i < N; i++) {
            lista1.insertLast(Integer.parseInt(pomniza[i]));
        }

        s = stdin.readLine();
        N = Integer.parseInt(s);
        s = stdin.readLine();
        pomniza = s.split(" ");
        for (int i = 0; i < N; i++) {
            lista2.insertLast(Integer.parseInt(pomniza[i]));
        }

        //spoeni = specialJoin(lista1,lista2);
        SLL<Integer> spoeni = lista1.specialJoin(lista2);
        System.out.println(spoeni);


    }
}