Circular Linked list implementation in java

    Circular Linked list – A linked list which has a circular structure. Last pointer of the linked list points the head node again.

As usual this linked list also has a pointer and data.

Let us create a circular linked list in java.

Program implementation:

This implementation starts from class CirLinkedList.

• It has a class ‘Node’ with two data members. One is integer data and another one is nxt_ptr.
• Constructor initialises the data member’s value.
• ‘insert()’ : This function inserts the data into the circular linked list.
• ‘display()’: This function displays the circular linked list into the output screen.
• ‘main()’ : It creates the object for the circular linked list and calls the member functions ‘insert()’ and ‘display()’.

Program:

class CirLinkedList {

    class Node {

        int data;

        Node nxt_ptr;

        Node(int data) {

            this.data = data;

            this.nxt_ptr = null;

        }

    }

    Node head;

    public void insert(int data) {

        Node newNode = new Node(data);

        if (head == null) {

            head = newNode;

            newNode.nxt_ptr = head;

        } else {

            Node temp = head;

            while (temp.nxt_ptr != head) {

                temp = temp.nxt_ptr;

            }

            temp.nxt_ptr = newNode;

            newNode.nxt_ptr = head;

        }

    }

    public void display() {

        if (head != null) {

            Node temp = head;

            do {

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

                temp = temp.nxt_ptr;

            } while (temp != head);

            System.out.println("(Points back to head)");

        }

    }

}

public class CircularLinkedListEg {

    public static void main(String[] args) {

        CirLinkedList cL1 = new CirLinkedList();

        // Insert the data elements to circular linked list

        cL1.insert(21);

        cL1.insert(56);

        cL1.insert(120);

        cL1.insert(234);

        cL1.insert(301);

        cL1.insert(67);

        // Display the circular linked list

        System.out.println("The data in the Circular Linked List are:");

        cL1.display();

    }

}

Output:

C:\raji\blog>javac CircularLinkedListEg.java

C:\raji\blog>java CircularLinkedListEg

The data in the Circular Linked List are:

21 -> 56 -> 120 -> 234 -> 301 -> 67 -> (Points back to head)

This is the implementation of Circular Linked list in java. Hope this code is useful to you. Keep coding!!!!