public class RemoveDuplicate {
//Represents the node of list.
public class Node{
int data;
Node next;
public Node(int data) {
this.data = data;
}
}
//Declaring head and tail pointer as null.
public Node head = null;
public Node tail = null;
//This function will add the new node at the end of the list.
public void add(int data){
//Create new node
Node newNode = new Node(data);
//Checks if the list is empty.
if(head == null) {
//If list is empty, both head and tail would point to new node.
head = newNode;
tail = newNode;
newNode.next = head;
}
else {
//tail will point to new node.
tail.next = newNode;
//New node will become new tail.
tail = newNode;
//Since, it is circular linked list tail will points to head.
tail.next = head;
}
}
//Removes duplicate from the list
public void removeDuplicate() {
//Current will point to head
Node current = head, index = null, temp = null;
if(head == null) {
System.out.println("List is empty");
}
else {
do{
//Temp will point to previous node of index.
temp = current;
//Index will point to node next to current
index = current.next;
while(index != head) {
//If current node is equal to index data
if(current.data == index.data) {
//Here, index node is pointing to the node which is duplicate of current node
//Skips the duplicate node by pointing to next node
temp.next = index.next;
}
else {
//Temp will point to previous node of index.
temp = index;
}
index= index.next;
}
current =current.next;
}while(current.next != head);
}
}
//Displays all the nodes in the list
public void display() {
Node current = head;
if(head == null) {
System.out.println("List is empty");
}
else {
do{
//Prints each node by incrementing pointer.
System.out.print(" "+ current.data);
current = current.next;
}while(current != head);
System.out.println();
}
}
public static void main(String[] args) {
RemoveDuplicate cl = new RemoveDuplicate();
//Adds data to the list
cl.add(1);
cl.add(2);
cl.add(3);
cl.add(2);
cl.add(2);
cl.add(4);
System.out.println("Originals list: ");
cl.display();
//Removes duplicate nodes
cl.removeDuplicate();
System.out.println("List after removing duplicates: ");
cl.display();
}
}