Node
class which represents a node in the list. It has two properties data and next which will point to the next node.deleteEnd()
and display()
.deleteEnd()
will delete the node from the end of the list:current.next!= tail
.a. display()
will show all the nodes present in the list.public class DeleteEnd {
//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 point to head.
tail.next = head;
}
}
//Deletes node from end of the list
public void deleteEnd() {
//Checks whether list is empty
if(head == null) {
return;
}
else {
//Checks whether contain only one element
if(head != tail ) {
Node current = head;
//Loop will iterate till the second last element as current.next is pointing to tail
while(current.next != tail) {
current = current.next;
}
//Second last element will be new tail
tail = current;
//Tail will point to head as it is a circular linked list
tail.next = head;
}
//If the list contains only one element
//Then it will remove it and both head and tail will point to null
else {
head = tail = null;
}
}
}
//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) {
DeleteEnd cl = new DeleteEnd();
//Adds data to the list
cl.add(1);
cl.add(2);
cl.add(3);
cl.add(4);
//Printing original list
System.out.println("Original List: ");
cl.display();
while(cl.head != null) {
cl.deleteEnd();
//Printing updated list
System.out.println("Updated List: ");
cl.display();
}
}
}
Original List:
1 2 3 4
Updated List:
1 2 3
Updated List:
1 2
Updated List:
1
Updated List:
List is empty