In this Linked List tutorial, we will see all about the delete operation in a circular linked list. In the delete operation, we will delete an existing node from the circular linked list from any position.
In a Circular Linked List, we can delete a node at the following positions:
Delete node at the beginning
Delete node at the specific position
Delete node at the end
Create a node class
public class Node {
public int data;
public Node next;
// Constructor
public Node(int data) {
this.data = data;
this.next = null;
}
}1. Delete a node from the beginning of the circular linked list
In the below given example we will see how to delete an existing node from the beginning or front the circular linked list.
// Java program to delete a node at the beginning
public class DeleteAtBeginningInCLL {
// Method to delete first node
static Node deleteFirstNode(Node last) {
// Possibility 1: If list is an empty
if (last == null) {
System.out.println("List is empty, Deletion is not possible.");
return null;
}
Node head = last.next;
// Possibility 2: If list has only one element
if (head.next == last) {
last = null;
} else {
// Possibility 3: If list has more than one element
last.next = head.next;
}
return last;
}
// Method to print list elements
public static void printList(Node last) {
if (last == null)
return;
Node head = last.next;
while (true) {
System.out.print(head.data + " ");
head = head.next;
if (head == last.next)
break;
}
System.out.println();
}
public static void main(String[] args) {
// Create a circular linked list
// List: 50 -> 20 -> 40 -> 10 -> 30
Node firstNode = new Node(50);
firstNode.next = new Node(20);
firstNode.next.next = new Node(40);
firstNode.next.next.next = new Node(10);
firstNode.next.next.next.next = new Node(30);
Node lastNode = firstNode.next.next.next.next;
lastNode.next = firstNode;
System.out.print("Original List Elements: ");
printList(lastNode);
// Delete the first node
lastNode = deleteFirstNode(lastNode);
System.out.print("List elements, after deleting the first node: ");
printList(lastNode);
}
} Output
Original List Elements: 50 20 40 10 30 List elements, after deleting the first node: 20 40 10 30
2. Delete a node at the specific position of the circular linked list
In the below given example we will see how to delete an existing node from the any position of the circular linked list.
// Java program to delete a node at the specific position
public class DeleteAtSpecPositionInCLL {
static Node deleteSpecificNode(Node last, int key) {
// Possibility 1: If list is an empty
if (last == null) {
System.out.println("List is empty, Deletion is not possible.");
return null;
}
Node head = last.next;
Node prev = last;
// Possibility 2: If list has only one element
if (head == last && head.data == key) {
last = null;
return last;
}
// Possibility 3: If we want to delete first node from the list
if (head.data == key) {
last.next = head.next;
return last;
}
// Possibility 4: If list has more elements
// Traverse the list to find the node to be deleted
while (head != last && head.data != key) {
prev = head;
head = head.next;
}
// If the node to be deleted is found
if (head.data == key) {
prev.next = head.next;
if (head == last) {
last = prev;
}
} else {
// If the node to be deleted is not found
System.out.println("Node with data " + key + " not found.");
}
return last;
}
// Method to print list elements
public static void printList(Node last) {
if (last == null) {
System.out.println("List is Empty");
return;
}
Node head = last.next;
while (true) {
System.out.print(head.data + " ");
head = head.next;
if (head == last.next)
break;
}
System.out.println();
}
public static void main(String[] args) {
// Create a circular linked list
// List: 50 -> 20 -> 40 -> 10 -> 30
Node firstNode = new Node(50);
firstNode.next = new Node(20);
firstNode.next.next = new Node(40);
firstNode.next.next.next = new Node(10);
firstNode.next.next.next.next = new Node(30);
Node lastNode = firstNode.next.next.next.next;
lastNode.next = firstNode;
System.out.print("Original List Elements: ");
printList(lastNode);
// Delete a specific node (40) from the list
int key = 40;
lastNode = deleteSpecificNode(lastNode, key);
System.out.print("List elements, after deleting the node " + key + ": ");
printList(lastNode);
}
} Output
Original List Elements: 50 20 40 10 30 List elements, after deleting the node 40: 50 20 10 30
3. Delete a node from the end of the circular linked list
In the below given example we will see how to delete an existing node from the end or last the circular linked list.
// Java program to delete the end or last node of circular linked list
public class DeleteAtEndInCLL {
public static Node deleteLastNode(Node last) {
// Possibility 1: If list is an empty
if (last == null) {
System.out.println("List is empty, Deletion is not possible.");
return null;
}
Node head = last.next;
// Possibility 2: If list has only one element
if (head == last) {
last = null;
return last;
}
// Possibility 3: If list has more than one element
Node temp = head;
while (temp.next != last) {
temp = temp.next;
}
temp.next = head;
last = temp;
return last;
}
// Method to print list elements
public static void printList(Node last) {
if (last == null)
return;
Node head = last.next;
while (true) {
System.out.print(head.data + " ");
head = head.next;
if (head == last.next)
break;
}
System.out.println();
}
public static void main(String[] args) {
// Create a circular linked list
// List: 50 -> 20 -> 40 -> 10 -> 30
Node firstNode = new Node(50);
firstNode.next = new Node(20);
firstNode.next.next = new Node(40);
firstNode.next.next.next = new Node(10);
firstNode.next.next.next.next = new Node(30);
Node lastNode = firstNode.next.next.next.next;
lastNode.next = firstNode;
System.out.print("Original List Elements: ");
printList(lastNode);
// Delete the last node
lastNode = deleteLastNode(lastNode);
System.out.print("List elements, after deleting the last node: ");
printList(lastNode);
}
} Output
Original List Elements: 50 20 40 10 30 List elements, after deleting the last node: 50 20 40 10