Remove duplicate element from sorted Linked List Java

PROGRAM TO REMOVE DUPLICATES FROM A SORTED LINKED LIST

class LinkedList

{

    // head of list

    Node head;

  

    // Linked list Node

    class Node

    {

        int data;

        Node next;

        Node(int d) {

          data = d;

          next = null;

        }

    }

 

    // Function to remove duplicates

    // from the given linked list

    void removeDuplicates()

    {

        // Two references to head

        // temp will iterate to the

        // whole Linked List

        // prev will point towards

        // the first occurence of every element

        Node temp = head,prev=head;

 

        // Traverse list till the last node

        while (temp != null) {

            

           // Compare values of both pointers

           if(temp.data!=prev.data)

           {

             /* if the value of prev is

             not equal to the value of

             temp that means there are no

             more occruences of the prev data.

             So we can set the next of

             prev to the temp node.*/

             prev.next=temp;

             prev=temp;

           }

            /*Set the temp to the next node*/

            temp=temp.next;

        }

      /*This is the edge case if there

      are more than one occurrences

      of the last element*/

      if(prev!=temp){

            prev.next=null;

        }

    }

                     

    /* Utility functions */

 

    /* Inserts a new Node at front of the list. */

    public void push(int new_data)

    {

        /* 1 & 2: Allocate the Node &

                  Put in the data*/

        Node new_node = new Node(new_data);

  

        /* 3. Make next of new Node as head */

        new_node.next = head;

  

        /* 4. Move the head to point to new Node */

        head = new_node;

    }

 

    /* Function to print linked list */

     void printList()

     {

         Node temp = head;

         while (temp != null)

         {

            System.out.print(temp.data+" ");

            temp = temp.next;

         } 

         System.out.println();

     }

 

     /* Driver program to test above functions */

    public static void main(String args[])

    {

        LinkedList llist = new LinkedList();

        llist.push(20);

        llist.push(13);

        llist.push(13);

        llist.push(11);

        llist.push(11);

        llist.push(11);

         

        System.out.print("List before ");

        System.out.println("removal of duplicates");

        llist.printList();

         

        llist.removeDuplicates();

         

        System.out.println("List after removal of elements");

        llist.printList();

    }

}




OUTPUT

List before removal of duplicates
11 11 11 13 13 20 
List after removal of elements
11 13 20

CREDITS: https://www.geeksforgeeks.org/remove-duplicates-from-a-sorted-linked-list/