Двојно поврзана листа: Раздели по парност

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

class Node<E> {
    E data;
    Node<E> prev,next;

    Node(E data, Node<E> prev, Node<E> next){
        this.data=data;
        this.prev=prev;
        this.next=next;
    }

}

class DLL<E> {
    Node<E> first,last;
    int size;

    DLL(){
        first=null;
        last=null;
        size=0;
    }

    public void insertFirst(E e) {
        if(first==null){
            first=last=new Node<E>(e,null,null);
            return;
        }
        first=new Node<E>(e,null,first);
    }

    public void insertLast(E e) {
        if(last==null){
            insertFirst(e);
            return;
        }
        Node<E> temp=last;
        last=new Node<E>(e,last,null);
        temp.next=last;
    }

    public int size() {
        int s=0;
        Node<E> temp=first;
        while(temp!=null) {
            temp=temp.next;
            s++;
        }
        return s;
    }

    public E getElement(int i) {
        if(i<this.size()) {
            Node<E> temp=first;
            while(i!=0) {
                temp=temp.next;
                i--;
            }
            return temp.data;
        }
        return null;
    }
}


public class DivideOddEven {


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


        DLL<Integer> lista=new DLL<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++) {
            lista.insertLast(Integer.parseInt(pomniza[i]));
        }


        DLL<Integer> oddNumbers=new DLL<Integer>();
        DLL<Integer> evenNumbers=new DLL<Integer>();
        for(int i=0;i<N;i++) {
            if(lista.getElement(i)!=null){
                if(((Integer)lista.getElement(i))%2==0) {
                    evenNumbers.insertLast(lista.getElement(i));
                } else {
                    oddNumbers.insertLast(lista.getElement(i));
                }
            }
        }

        String str=new String("");

        for(int i=0;i<oddNumbers.size();i++) {
            if(i==oddNumbers.size()-1){str+=oddNumbers.getElement(i); break;}
            str+=oddNumbers.getElement(i)+" ";
        }
        int flag=0;
        for(int i=0;i<evenNumbers.size();i++) {
            if(flag==0){flag=1; str+="\n";}
            if(i==evenNumbers.size()-1){str+=evenNumbers.getElement(i); break;}
            str+=evenNumbers.getElement(i)+" ";
        }

        System.out.print(str);
    }
}