import java.io.*;
import java.util.*;
class Node{
	int data;
	Node next;
	Node(int d){
        data=d;
        next=null;
    }
	
}
class Solution
{
    public static Node removeDuplicates(Node head) {
        Set<Integer> values = new HashSet<Integer>();
        Node res = new Node(head.data);
        values.add(res.data);
        Node p = res;
        Node next = head.next;
        while (next != null) {
            if (!values.contains(next.data)) {
                values.add(next.data);
                p.next = new Node(next.data);
                p = p.next;
            }
            next = next.next;
        }
        return res;
    }
	 public static  Node insert(Node head,int data)
     {
        Node p=new Node(data);			
        if(head==null)
            head=p;
        else if(head.next==null)
            head.next=p;
        else
        {
            Node start=head;
            while(start.next!=null)
                start=start.next;
            start.next=p;

        }
        return head;
    }
    public static void display(Node head)
        {
              Node start=head;
              while(start!=null)
              {
                  System.out.print(start.data+" ");
                  start=start.next;
              }
        }
        public static void main(String args[])
        {
              Scanner sc=new Scanner(System.in);
              Node head=null;
              int T=sc.nextInt();
              while(T-->0){
                  int ele=sc.nextInt();
                  head=insert(head,ele);
              }
              head=removeDuplicates(head);
              display(head);

       }
    }

Create Day_24_More_Linked_Lists.java