Java remove duplicates from linked list

Question

I want to remove duplicates from sorted linked list {0 1 2 2 3 3 4 5}.

`

public Node removeDuplicates(Node header)
{
    Node tempHeader = null;
    if(         


        

Answer 1

By DoublyLinked List and using HashSet,

  public static void deleteDups(Node n) {
    HashSet set = new HashSet();
    Node previous = null;
    while (n != null) {
        if (set.contains(n.data)) {
            previous.next = n.next;
        } else {
            set.add(n.data);
            previous = n;
        }
        n = n.next;
    }
}

doublylinkedList

class Node{

public Node next;
public Node prev;
public Node last;
public int data;
public Node (int d, Node n, Node p) {
    data = d;
    setNext(n);
    setPrevious(p);
}

public Node() { }

public void setNext(Node n) {
    next = n;
    if (this == last) {
        last = n;
    }
    if (n != null && n.prev != this) {
        n.setPrevious(this);
    }
}

public void setPrevious(Node p) {
    prev = p;
    if (p != null && p.next != this) {
        p.setNext(this);
    }
}}