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Menu Driven Program to implement all the operations of Doubly Circular Linked List

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Circular Doubly Linked List has properties of both Doubly Linked List and Circular Linked List in which two consecutive elements are linked or connected by previous and next pointer and the last node points to the first node by next pointer and also the first node points to the last node by the previous pointer. The program implements all the functions and operations that are possible on a doubly circular list following functions in a menu-driven program.

Approach: Each function (except display) takes the address of the pointer to the head i.e. the first element of the list. This allows us to change the address of the head pointer. The idea is the use only one pointer, which is of type node, to perform all the operations. node is the class that contains three data members. One member is of type int which stores data of the node and two members of type node*, one store’s address of next element and other stores address of the previous element. This way it is possible to traverse the list in either direction. It is possible to modify, insert, delete search for the element using a single pointer.

Functions Covered:

  • void insert_front (node **head): This function allows the user to enter a new node at the front of the list.
  • void insert_end (node **head): This function allows the user to enter a new node at the end of the list.
  • void inser_after (node **head): This function allows the user to enter a new node after a node is entered by the user.
  • void insert_before (node **head): This function allows the user to enter a new node before a node is entered by the user.
  • void delete_front (node **head): This function allows the user to delete a  node from the front of the list.
  • void delete_end(node**head): This function allows the user to delete a node from the end of the list.
  • void delete_mid( node **head): This function allows deletion of a node entered by the user.
  • void search (node *head): Function to search for the location of the array entered by the user.
  • void reverse (node **head): Function to reverse the list and make the last element of the list head.
  • void display (node *head): Function to print the list.

Below is the C++ program to implement the above approach:

C++
// C++ program for the above approach
#include <iostream>
using namespace std;

class node {
public:
    node* next;
    node* prev;
    int data;
};

// Function to add the node at the front
// of the doubly circular LL
void insert_front(node** head)
{
    // Function to insert node
    // in front of list
    cout << "\nEnter Data for New Node:";

    // Create a new node named
    // new_node
    node* new_node = new node;

    // Enter data for new_node
    cin >> new_node->data;

    if (*head == NULL) {

        // If there is no node in
        // the list, create a node
        // pointing to itself and
        // make it head
        new_node->next = new_node;
        new_node->prev = new_node;
        *head = new_node;
    }

    else {

        // If there already exists
        // elements in the list

        // Next of new_node will point
        // to head
        new_node->next = *head;

        // prev of new_node will point
        // to prev of head
        new_node->prev = (*head)->prev;

        // next of prev of head i.e. next
        // of last node will point to
        // new_node
        ((*head)->prev)->next = new_node;

        // prev of head will point
        // to new_node
        (*head)->prev = new_node;

        // new_node will become the
        // head of list
        *head = new_node;
    }
}

// Function to add the node at the end
// of the doubly circular LL
void insert_end(node** head)
{
    // Function to insert node at
    // last of list
    cout << "\nEnter Data for New Node:";

    // Create new node
    node* new_node = new node;
    cin >> new_node->data;

    if (*head == NULL) {

        // If there is no element in the
        // list create a node pointing
        // to itself and make it head
        new_node->next = new_node;
        new_node->prev = new_node;
        *head = new_node;
    }
    else {

        // If there are elements in the
        // list then create a temp node
        // pointing to current element
        node* curr = *head;

        while (curr->next != *head)

            // Traverse till the end of
            // list
            curr = curr->next;

        // next of new_node will point to
        // next of current node
        new_node->next = curr->next;

        // prev of new_node will
        // point to current element
        new_node->prev = curr;

        // prev of next of current node
        // i.e. prev of head will point to
        // new_node
        (curr->next)->prev = new_node;

        // next of current node will
        // point to new_node
        curr->next = new_node;
    }
}

// Function to add the node after the
// given node of doubly circular LL
void insert_after(node** head)
{
    // Function to enter a node after
    // the element entered by user

    // Create new node
    node* new_node = new node;
    cout << "\nEnter Data for New Node:";
    cin >> new_node->data;

    if (*head == NULL) {

        // If there is no element in
        // the list then create a node
        // pointing to itself and make
        // it head
        cout << "\nThere is No element in the List";
        cout << "\nCreating a new node";
        new_node->prev = new_node;
        new_node->next = new_node;
        *head = new_node;
    }
    else {
        int num;

        // Ask user after which node new
        // node is to be inserted
        cout << "Enter After Element:";
        cin >> num;

        // temp node to traverse list
        // and point to current element
        node* curr = *head;

        while (curr->data != num) {
            curr = curr->next;

            // If current becomes equal
            // to head i.e. if entire list
            // has been traversed then
            // element entered is not found
            // in list
            if (curr == *head) {

                cout << "\nEntered Element"
                     << " Not Found in "
                        "List\n";
                return;
            }
        }

        // Control will reach here only if
        // element is found in list

        // next of new node will point to
        // next of current node
        new_node->next = curr->next;

        // prev of new node will
        // point to current node
        new_node->prev = curr;

        // prev of next of current node
        // will point to new node
        (curr->next)->prev = new_node;

        // next of current node will
        // point to new node
        curr->next = new_node;
    }
}

// Function to add the node before the
// given node of doubly circular LL
void insert_before(node** head)
{
    // Function to enter node before
    // a node entered by the user
    node* new_node = new node;

    if (*head == NULL) {

        // If there is no element in the
        // list create new node and make
        // it head
        cout << "List is Empty!! Creating New node...";
        cout << "\nEnter Data for New Node:";
        cin >> new_node->data;

        new_node->prev = new_node;
        new_node->next = new_node;
        *head = new_node;
    }

    else {
        int num;

        // Ask user before which node
        // new node is to be inserted
        cout << "\nEnter Before Element:";
        cin >> num;

        // If user wants to enter new node
        // before the first node i.e.
        // before head then call insert_front
        // function
        if ((*head)->data == num)
            insert_front(head);

        else {

            // temp node current for traversing
            // the list and point to current
            // element we assign curr to
            // *head->next this time because
            // data of head has already been
            // checked in previous condition
            node* curr = (*head)->next;

            while (curr->data != num) {
                if (curr == *head) {

                    // If current equal head then
                    // entire list has been traversed
                    // and the entered element is not
                    // found in list
                    cout << "\nEntered Element Not Found "
                            "in List!!\n";
                    return;
                }
                curr = curr->next;
            }

            cout << "\nEnter Data For New Node:";
            cin >> new_node->data;

            // Control will reaach here only
            // if entered node exists in list
            // and current has found the element

            // next of new node will point to
            // current node
            new_node->next = curr;

            // prev of new node will point
            // to prev of current node
            new_node->prev = curr->prev;

            // next of prev of current node
            // will point to new node
            (curr->prev)->next = new_node;

            // prev of current will
            // point to new node
            curr->prev = new_node;
        }
    }
}

// Function to delete the front node
// of doubly circular LL
void delete_front(node** head)
{
    // Function to delete a node
    // from front of list
    if (*head == NULL) {

        // If list is already empty
        // print a message
        cout << "\nList in empty!!\n";
    }
    else if ((*head)->next == *head) {

        // If head is the only element
        // in the list delete head and
        // assign it to NULL
        delete *head;
        *head = NULL;
    }
    else {
        node* curr = new node;

        // temp node to save address
        // of node next to head
        curr = (*head)->next;

        // prev of temp will
        // point to prev of head
        curr->prev = (*head)->prev;

        // next of prev of head i.e.
        // next of last node will point
        // to temp
        ((*head)->prev)->next = curr;

        // delete head
        delete *head;

        // assign head to temp
        *head = curr;
    }
}

// Function to delete the end node
// of doubly circular LL
void delete_end(node** head)
{
    // Function to delete a node
    // from end of list
    if (*head == NULL) {

        // If list is already empty
        // print a message
        cout << "\nList is Empty!!\n";
    }
    else if ((*head)->next == *head) {

        // If head is the only element
        // in the list delete head and
        // assign it to NULL
        delete *head;
        *head = NULL;
    }
    else {

        // Create temporary node curr
        // to traverse list and point
        // to current element
        node* curr = new node;

        // Assign curr to head
        curr = *head;
        while (curr->next != (*head)) {

            // Traverse till end of list
            curr = curr->next;
        }

        // next of prev of curr will point
        // to next of curr
        (curr->prev)->next = curr->next;

        // prev of next of curr will point
        // to prev of curr
        (curr->next)->prev = curr->prev;

        // delete curr
        delete curr;
    }
}

// Function to delete the middle node
// of doubly circular LL
void delete_mid(node** head)
{
    // Function to delete a node
    // entered by user
    if (*head == NULL) {

        // If list is already empty
        // print a message
        cout << "\nList is Empty!!!";
    }

    else {
        cout << "\nEnter Element to be deleted:";
        int num;
        cin >> num;

        if ((*head)->data == num) {

            // If user wants to delete
            // the head node i.e front
            // node call delete_front(head)
            // function
            delete_front(head);
        }

        else {

            // temp node to traverse list
            // and point to current node
            node* curr = (*head)->next;
            while ((curr->data) != num) {
                if (curr == (*head)) {

                    // If curr equals head then
                    // entire list has been
                    // traversed element to be
                    // deleted is not found
                    cout << "\nEntered Element Not Found "
                            "in List!!\n";
                    return;
                }

                curr = curr->next;
            }

            // control will reach here only
            // if element is found in the list

            // next of prev of curr will
            // point to next of curr
            (curr->prev)->next = curr->next;

            // prev of next of curr will
            // point to prev of curr
            (curr->next)->prev = curr->prev;
            delete curr;
        }
    }
}

// Function to search any node in the
// doubly circular LL
void search(node* head)
{
    if (head == NULL) {

        // If head is null list is empty
        cout << "List is empty!!";
        return;
    }

    int item;
    cout << "Enter item to be searched:";

    // Ask user to enter item to
    // be searched
    cin >> item;

    // curr pointer is used to
    // traverse list it will point
    // to the current element
    node* curr = head;

    int index = 0, count = 0;

    do {

        // If data in curr is equal to item
        // to be searched print its position
        // index+1
        if (curr->data == item) {
            cout << "\nItem found at position:"
                 << index + 1;

            // increment count
            count++;
        }

        // Index will increment by 1 in
        // each iteration
        index++;
        curr = curr->next;

    } while (curr != head);

    // If count is still 0 that means
    // item is not found
    if (count == 0)
        cout << "Item searched not found in list";
}

// Function to reverse the doubly
// circular Linked List
void reverse(node** head)
{
    if (*head == NULL) {

        // If head is null list is empty
        cout << "List is Empty !!";
        return;
    }

    // curr is used to traverse list
    node* curr = *head;
    while (curr->next != *head) {

        // use a temp node to store
        // address of next of curr
        node* temp = curr->next;

        // make next of curr to point
        // its previous
        curr->next = curr->prev;

        // make previous of curr to
        // point its next
        curr->prev = temp;

        // After each iteration move
        // to element which was earlier
        // next of curr
        curr = temp;
    }

    // Update the last node separately
    node* temp = curr->next;
    curr->next = curr->prev;
    curr->prev = temp;

    // only change is this node will now
    // become head
    *head = curr;
}

// Function to display the doubly
// circular linked list
void display(node* head)
{
    node* curr = head;
    if (curr == NULL)
        cout << "\n List is Empty!!";
    else {
        do {
            cout << curr->data << "->";
            curr = curr->next;
        } while (curr != head);
    }
}

void display_menu()
{
    cout << "=============================================="
            "======================";
    cout << "\nMenu:\n";
    cout << "1. Insert At Front\n";
    cout << "2. Insert At End\n";
    cout << "3. Insert After Element\n";
    cout << "4. Insert Before Element\n";
    cout << "5. Delete From Front\n";
    cout << "6. Delete From End\n";
    cout << "7. Delete A Node\n";
    cout << "8. Search for a element\n";
    cout << "9. Reverse a the list\n";
    cout << "=============================================="
            "======================";
}

// Driver Code
int main()
{
    int choice;
    char repeat_menu = 'y';

    // Declaration of head node
    node* head = NULL;
    display_menu();
    do {
        cout << "\nEnter Your Choice:";
        cin >> choice;
        switch (choice) {
        case 1: {
            insert_front(&head);
            display(head);
            break;
        }
        case 2: {
            insert_end(&head);
            display(head);
            break;
        }
        case 3: {
            insert_after(&head);
            display(head);
            break;
        }
        case 4: {
            insert_before(&head);
            display(head);
            break;
        }
        case 5: {
            delete_front(&head);
            display(head);
            break;
        }
        case 6: {
            delete_end(&head);
            display(head);
            break;
        }
        case 7: {
            delete_mid(&head);
            display(head);
            break;
        }
        case 8: {
            search(head);
            break;
        }
        case 9: {
            reverse(&head);
            display(head);
            break;
        }
        default: {
            cout << "\nWrong Choice!!!";
            display_menu();
            break;
        }
        }
        cout << "\nEnter More(Y/N)";
        cin >> repeat_menu;

    } while (repeat_menu == 'y' || repeat_menu == 'Y');
    return 0;
}
Java
import java.util.Scanner;

class Node {
    int data;
    Node next;
    Node prev;
}

public class Main {
    static Scanner scanner = new Scanner(System.in);

    public static void displayMenu() {
        System.out.println("==============================================");
        System.out.println("Menu:");
        System.out.println("1. Insert At Front");
        System.out.println("2. Insert At End");
        System.out.println("3. Insert After Element");
        System.out.println("4. Insert Before Element");
        System.out.println("5. Delete From Front");
        System.out.println("6. Delete From End");
        System.out.println("7. Delete A Node");
        System.out.println("8. Search for an element");
        System.out.println("9. Reverse the list");
        System.out.println("==============================================");
    }

    static Node insertFront(Node head) {
        System.out.println("\nEnter Data for New Node:");
        Node newNode = new Node();
        newNode.data = scanner.nextInt();

        if (head == null) {
            newNode.next = newNode;
            newNode.prev = newNode;
            head = newNode;
        } else {
            newNode.next = head;
            newNode.prev = head.prev;
            head.prev.next = newNode;
            head.prev = newNode;
            head = newNode;
        }
        return head;
    }

    // Function to insert node at the end of the doubly circular LL
    static Node insertEnd(Node head) {
        System.out.println("\nEnter Data for New Node:");
        Node newNode = new Node();
        newNode.data = scanner.nextInt();

        if (head == null) {
            newNode.next = newNode;
            newNode.prev = newNode;
            head = newNode;
        } else {
            Node curr = head;
            while (curr.next != head)
                curr = curr.next;

            newNode.next = curr.next;
            newNode.prev = curr;
            curr.next.prev = newNode;
            curr.next = newNode;
        }
        return head;
    }

    // Function to insert node after a specific node in the doubly circular LL
    static Node insertAfter(Node head) {
        System.out.println("\nEnter Data for New Node:");
        Node newNode = new Node();
        newNode.data = scanner.nextInt();

        if (head == null) {
            System.out.println("\nThere is No element in the List");
            System.out.println("\nCreating a new node");
            newNode.prev = newNode;
            newNode.next = newNode;
            head = newNode;
        } else {
            System.out.println("Enter After Element:");
            int num = scanner.nextInt();
            Node curr = head;

            while (curr.data != num) {
                curr = curr.next;
                if (curr == head) {
                    System.out.println("\nEntered Element Not Found in List\n");
                    return head;
                }
            }

            newNode.next = curr.next;
            newNode.prev = curr;
            curr.next.prev = newNode;
            curr.next = newNode;
        }
        return head;
    }

    // Function to insert node before a specific node in the doubly circular LL
    static Node insertBefore(Node head) {
        System.out.println("\nEnter Before Element:");
        int num = scanner.nextInt();

        if (head == null || head.data == num) {
            return insertFront(head);
        } else {
            Node curr = head.next;
            while (curr.data != num) {
                if (curr == head) {
                    System.out.println("\nEntered Element Not Found in List!!\n");
                    return head;
                }
                curr = curr.next;
            }

            System.out.println("\nEnter Data For New Node:");
            Node newNode = new Node();
            newNode.data = scanner.nextInt();

            newNode.next = curr;
            newNode.prev = curr.prev;
            curr.prev.next = newNode;
            curr.prev = newNode;
        }
        return head;
    }

    // Function to delete the front node of the doubly circular LL
    static Node deleteFront(Node head) {
        if (head == null) {
            System.out.println("\nList is empty!!\n");
        } else if (head.next == head) {
            head = null;
        } else {
            Node curr = head.next;
            curr.prev = head.prev;
            head.prev.next = curr;
            head = curr;
        }
        return head;
    }

    // Function to delete the end node of the doubly circular LL
    static Node deleteEnd(Node head) {
        if (head == null) {
            System.out.println("\nList is Empty!!\n");
        } else if (head.next == head) {
            head = null;
        } else {
            Node curr = head;
            while (curr.next != head)
                curr = curr.next;

            curr.prev.next = curr.next;
            curr.next.prev = curr.prev;
        }
        return head;
    }

    // Function to delete a specific node in the doubly circular LL
    static Node deleteMid(Node head) {
        if (head == null) {
            System.out.println("\nList is Empty!!!");
        } else {
            System.out.println("\nEnter Element to be deleted:");
            int num = scanner.nextInt();

            if (head.data == num) {
                head = deleteFront(head);
            } else {
                Node curr = head.next;
                while (curr.data != num) {
                    if (curr == head) {
                        System.out.println("\nEntered Element Not Found in List!!\n");
                        return head;
                    }
                    curr = curr.next;
                }

                curr.prev.next = curr.next;
                curr.next.prev = curr.prev;
            }
        }
        return head;
    }

    // Function to search any node in the doubly circular LL
    static void search(Node head) {
        if (head == null) {
            System.out.println("List is empty!!");
            return;
        }

        System.out.println("Enter item to be searched:");
        int item = scanner.nextInt();

        Node curr = head;
        int index = 0, count = 0;

        do {
            if (curr.data == item) {
                System.out.println("\nItem found at position:" + (index + 1));
                count++;
            }
            index++;
            curr = curr.next;
        } while (curr != head);

        if (count == 0)
            System.out.println("Item searched not found in list");
    }

    // Function to reverse the doubly circular Linked List
    static Node reverse(Node head) {
        if (head == null) {
            System.out.println("List is Empty !!");
            return head;
        }

        Node curr = head;
        while (curr.next != head) {
            Node temp = curr.next;
            curr.next = curr.prev;
            curr.prev = temp;
            curr = temp;
        }

        Node temp = curr.next;
        curr.next = curr.prev;
        curr.prev = temp;
        head = curr;

        return head;
    }

    // Function to display the doubly circular linked list
    static void display(Node head) {
        Node curr = head;
        if (curr == null)
            System.out.println("\n List is Empty!!");
        else {
            do {
                System.out.print(curr.data + "->");
                curr = curr.next;
            } while (curr != head);
        }
    }

    public static void main(String[] args) {
        Node head = null;
        char repeatMenu = 'y';
        int choice;

        displayMenu();  // Display the menu

        do {
            System.out.println("\nEnter Your Choice:");
            choice = scanner.nextInt();
            switch (choice) {
                case 1:
                    head = insertFront(head);
                    display(head);
                    break;
                case 2:
                    head = insertEnd(head);
                    display(head);
                    break;
                case 3:
                    head = insertAfter(head);
                    display(head);
                    break;
                case 4:
                    head = insertBefore(head);
                    display(head);
                    break;
                case 5:
                    head = deleteFront(head);
                    display(head);
                    break;
                case 6:
                    head = deleteEnd(head);
                    display(head);
                    break;
                case 7:
                    head = deleteMid(head);
                    display(head);
                    break;
                case 8:
                    search(head);
                    break;
                case 9:
                    head = reverse(head);
                    display(head);
                    break;
                default:
                    System.out.println("\nWrong Choice!!!");
                    break;
            }
            System.out.println("\nEnter More(Y/N)");
            repeatMenu = scanner.next().charAt(0);
        } while (repeatMenu == 'y' || repeatMenu == 'Y');
    }
}
C#
using System;

public class Node
{
    public int data;
    public Node next;
    public Node prev;
}

public class DoublyCircularLinkedList
{
    Node head;

    // Insert node at the front of the list
    public void InsertFront(int data)
    {
        Node newNode = new Node { data = data };

        if (head == null)
        {
            newNode.next = newNode;
            newNode.prev = newNode;
            head = newNode;
        }
        else
        {
            newNode.next = head;
            newNode.prev = head.prev;
            head.prev.next = newNode;
            head.prev = newNode;
            head = newNode;
        }
    }

    // Insert node at the end of the list
    public void InsertEnd(int data)
    {
        Node newNode = new Node { data = data };

        if (head == null)
        {
            newNode.next = newNode;
            newNode.prev = newNode;
            head = newNode;
        }
        else
        {
            Node curr = head;
            while (curr.next != head)
            {
                curr = curr.next;
            }
            newNode.next = curr.next;
            newNode.prev = curr;
            curr.next.prev = newNode;
            curr.next = newNode;
        }
    }

    // Insert node after a specific element
    public void InsertAfter(int data, int element)
    {
        Node newNode = new Node { data = data };

        if (head == null)
        {
            Console.WriteLine("List is empty. Creating new node.");
            newNode.prev = newNode;
            newNode.next = newNode;
            head = newNode;
        }
        else
        {
            Node curr = head;
            do
            {
                if (curr.data == element)
                {
                    newNode.next = curr.next;
                    newNode.prev = curr;
                    curr.next.prev = newNode;
                    curr.next = newNode;
                    return;
                }
                curr = curr.next;
            } while (curr != head);
            Console.WriteLine("Element not found in the list.");
        }
    }

    // Insert node before a specific element
    public void InsertBefore(int data, int element)
    {
        Node newNode = new Node { data = data };

        if (head == null)
        {
            Console.WriteLine("List is empty. Creating new node.");
            newNode.prev = newNode;
            newNode.next = newNode;
            head = newNode;
        }
        else
        {
            if (head.data == element)
            {
                InsertFront(data);
            }
            else
            {
                Node curr = head.next;
                while (curr.data != element)
                {
                    if (curr == head)
                    {
                        Console.WriteLine("Element not found in the list.");
                        return;
                    }
                    curr = curr.next;
                }
                newNode.next = curr;
                newNode.prev = curr.prev;
                curr.prev.next = newNode;
                curr.prev = newNode;
            }
        }
    }

    // Delete node from the front of the list
    public void DeleteFront()
    {
        if (head == null)
        {
            Console.WriteLine("List is empty.");
        }
        else if (head.next == head)
        {
            head = null;
        }
        else
        {
            Node curr = head.next;
            curr.prev = head.prev;
            head.prev.next = curr;
            head = curr;
        }
    }

    // Delete node from the end of the list
    public void DeleteEnd()
    {
        if (head == null)
        {
            Console.WriteLine("List is empty.");
        }
        else if (head.next == head)
        {
            head = null;
        }
        else
        {
            Node curr = head;
            while (curr.next != head)
            {
                curr = curr.next;
            }
            curr.prev.next = curr.next;
            curr.next.prev = curr.prev;
        }
    }

    // Delete a specific element
    public void DeleteElement(int element)
    {
        if (head == null)
        {
            Console.WriteLine("List is empty.");
        }
        else
        {
            if (head.data == element)
            {
                DeleteFront();
            }
            else
            {
                Node curr = head.next;
                while (curr.data != element)
                {
                    if (curr == head)
                    {
                        Console.WriteLine("Element not found in the list.");
                        return;
                    }
                    curr = curr.next;
                }
                curr.prev.next = curr.next;
                curr.next.prev = curr.prev;
            }
        }
    }

    // Search for an element
    public void Search(int element)
    {
        if (head == null)
        {
            Console.WriteLine("List is empty.");
            return;
        }

        Node curr = head;
        int index = 0;
        do
        {
            if (curr.data == element)
            {
                Console.WriteLine($"Element found at position: {index + 1}");
                return;
            }
            index++;
            curr = curr.next;
        } while (curr != head);

        Console.WriteLine("Element not found in the list.");
    }

    // Reverse the list
    public void Reverse()
    {
        if (head == null)
        {
            Console.WriteLine("List is empty.");
            return;
        }

        Node curr = head;
        do
        {
            Node temp = curr.next;
            curr.next = curr.prev;
            curr.prev = temp;
            curr = temp;
        } while (curr != head);

        head = curr.prev;
    }

    // Display the list
    public void Display()
    {
        if (head == null)
        {
            Console.WriteLine("List is empty.");
            return;
        }

        Node curr = head;
        do
        {
            Console.WriteLine(curr.data);
            curr = curr.next;
        } while (curr != head);
    }
}

class Program
{
    static void Main(string[] args)
    {
        DoublyCircularLinkedList list = new DoublyCircularLinkedList();
        char repeatMenu = 'y';
        int choice;

        do
        {
            Console.WriteLine("==============================================");
            Console.WriteLine("Menu:");
            Console.WriteLine("1. Insert At Front");
            Console.WriteLine("2. Insert At End");
            Console.WriteLine("3. Insert After Element");
            Console.WriteLine("4. Insert Before Element");
            Console.WriteLine("5. Delete From Front");
            Console.WriteLine("6. Delete From End");
            Console.WriteLine("7. Delete A Node");
            Console.WriteLine("8. Search for a element");
            Console.WriteLine("9. Reverse a the list");
            Console.WriteLine("==============================================");

            Console.WriteLine("\nEnter Your Choice:");
            choice = Convert.ToInt32(Console.ReadLine());

            switch (choice)
            {
                case 1:
                    Console.WriteLine("Enter data:");
                    list.InsertFront(Convert.ToInt32(Console.ReadLine()));
                    list.Display();
                    break;
                case 2:
                    Console.WriteLine("Enter data:");
                    list.InsertEnd(Convert.ToInt32(Console.ReadLine()));
                    list.Display();
                    break;
                case 3:
                    Console.WriteLine("Enter data and element after which to insert:");
                    list.InsertAfter(Convert.ToInt32(Console.ReadLine()), Convert.ToInt32(Console.ReadLine()));
                    list.Display();
                    break;
                case 4:
                    Console.WriteLine("Enter data and element before which to insert:");
                    list.InsertBefore(Convert.ToInt32(Console.ReadLine()), Convert.ToInt32(Console.ReadLine()));
                    list.Display();
                    break;
                case 5:
                    list.DeleteFront();
                    list.Display();
                    break;
                case 6:
                    list.DeleteEnd();
                    list.Display();
                    break;
                case 7:
                    Console.WriteLine("Enter element to delete:");
                    list.DeleteElement(Convert.ToInt32(Console.ReadLine()));
                    list.Display();
                    break;
                case 8:
                    Console.WriteLine("Enter element to search:");
                    list.Search(Convert.ToInt32(Console.ReadLine()));
                    break;
                case 9:
                    list.Reverse();
                    list.Display();
                    break;
                default:
                    Console.WriteLine("\nWrong Choice!!!");
                    break;
            }

            Console.WriteLine("\nEnter More(Y/N)");
            repeatMenu = Convert.ToChar(Console.ReadLine());

        } while (repeatMenu == 'y' || repeatMenu == 'Y');
    }
}
Python3
class Node:
    def __init__(self, data):
        self.data = data
        self.next = None
        self.prev = None

# Function to add a node at the front of the doubly circular LL
def insert_front(head):
    data = int(input("\nEnter Data for New Node: "))
    new_node = Node(data)
    if head is None:
        new_node.next = new_node
        new_node.prev = new_node
        return new_node
    else:
        new_node.next = head
        new_node.prev = head.prev
        head.prev.next = new_node
        head.prev = new_node
        return new_node

# Function to add a node at the end of the doubly circular LL
def insert_end(head):
    data = int(input("\nEnter Data for New Node: "))
    new_node = Node(data)
    if head is None:
        new_node.next = new_node
        new_node.prev = new_node
        return new_node
    else:
        curr = head
        while curr.next != head:
            curr = curr.next
        new_node.next = curr.next
        new_node.prev = curr
        curr.next.prev = new_node
        curr.next = new_node
        return head

# Function to add a node after the given node of doubly circular LL
def insert_after(head):
    data = int(input("\nEnter Data for New Node: "))
    if head is None:
        print("\nThere is No element in the List")
        print("Creating a new node")
        new_node = Node(data)
        new_node.next = new_node
        new_node.prev = new_node
        return new_node
    else:
        num = int(input("Enter After Element: "))
        curr = head
        while curr.data != num:
            curr = curr.next
            if curr == head:
                print("\nEntered Element Not Found in List")
                return head
        new_node = Node(data)
        new_node.next = curr.next
        new_node.prev = curr
        curr.next.prev = new_node
        curr.next = new_node
        return head

# Function to add a node before the given node of doubly circular LL
def insert_before(head):
    if head is None:
        print("List is Empty!! Creating New node...")
        data = int(input("\nEnter Data for New Node: "))
        new_node = Node(data)
        new_node.next = new_node
        new_node.prev = new_node
        return new_node
    else:
        num = int(input("\nEnter Before Element: "))
        if head.data == num:
            return insert_front(head)
        else:
            curr = head.next
            while curr.data != num:
                if curr == head:
                    print("\nEntered Element Not Found in List!!")
                    return head
                curr = curr.next
            data = int(input("\nEnter Data For New Node: "))
            new_node = Node(data)
            new_node.next = curr
            new_node.prev = curr.prev
            curr.prev.next = new_node
            curr.prev = new_node
            return head

# Function to delete the front node of doubly circular LL
def delete_front(head):
    if head is None:
        print("\nList is empty!!")
        return None
    elif head.next == head:
        del head
        return None
    else:
        curr = head.next
        curr.prev = head.prev
        head.prev.next = curr
        del head
        return curr

# Function to delete the end node of doubly circular LL
def delete_end(head):
    if head is None:
        print("\nList is Empty!!")
        return None
    elif head.next == head:
        del head
        return None
    else:
        curr = head
        while curr.next != head:
            curr = curr.next
        curr.prev.next = curr.next
        curr.next.prev = curr.prev
        del curr
        return head

# Function to delete the middle node of doubly circular LL
def delete_mid(head):
    if head is None:
        print("\nList is Empty!!!")
        return None
    else:
        num = int(input("\nEnter Element to be deleted: "))
        if head.data == num:
            return delete_front(head)
        else:
            curr = head.next
            while curr.data != num:
                if curr == head:
                    print("\nEntered Element Not Found in List!!")
                    return head
                curr = curr.next
            curr.prev.next = curr.next
            curr.next.prev = curr.prev
            del curr
            return head

# Function to search any node in the doubly circular LL
def search(head):
    if head is None:
        print("List is empty!!")
        return
    item = int(input("Enter item to be searched: "))
    curr = head
    index = 0
    count = 0
    while True:
        if curr.data == item:
            print("\nItem found at position:", index + 1)
            count += 1
        index += 1
        curr = curr.next
        if curr == head:
            break
    if count == 0:
        print("Item searched not found in list")

# Function to reverse the doubly circular Linked List
def reverse(head):
    if head is None:
        print("List is Empty !!")
        return None
    curr = head
    while curr.next != head:
        temp = curr.next
        curr.next = curr.prev
        curr.prev = temp
        curr = temp
    temp = curr.next
    curr.next = curr.prev
    curr.prev = temp
    head = curr
    return head

# Function to display the doubly circular linked list
def display(head):
    if head is None:
        print("\nList is Empty!!")
    else:
        curr = head
        while True:
            print(curr.data, "->", end=" ")
            curr = curr.next
            if curr == head:
                break

def display_menu():
    print("=============================================="
            "======================")
    print("Menu:")
    print("1. Insert At Front")
    print("2. Insert At End")
    print("3. Insert After Element")
    print("4. Insert Before Element")
    print("5. Delete From Front")
    print("6. Delete From End")
    print("7. Delete A Node")
    print("8. Search for a element")
    print("9. Reverse the list")
    print("=============================================="
            "======================")

# Driver Code
if __name__ == "__main__":
    choice = None
    repeat_menu = 'y'
    head = None
    display_menu()
    while repeat_menu.lower() == 'y':
        choice = int(input("\nEnter Your Choice: "))
        if choice == 1:
            head = insert_front(head)
            display(head)
        elif choice == 2:
            head = insert_end(head)
            display(head)
        elif choice == 3:
            head = insert_after(head)
            display(head)
        elif choice == 4:
            head = insert_before(head)
            display(head)
        elif choice == 5:
            head = delete_front(head)
            display(head)
        elif choice == 6:
            head = delete_end(head)
            display(head)
        elif choice == 7:
            head = delete_mid(head)
            display(head)
        elif choice == 8:
            search(head)
        elif choice == 9:
            head = reverse(head)
            display(head)
        else:
            print("\nWrong Choice!!!")
            display_menu()
        repeat_menu = input("\nEnter More(Y/N): ")

 
 

Output:


 

1. void insert_front (node **head):


 

Insert front node


 

2. void insert_end (node **head):


 

Insert End


 

3.  void insert_after (node **head):


 

Insert After


 

4.  void insert_before (node **head):


 

Insert Before


 

5.  void delete_front (node **head):


 

Delete Front


 

6.  void delete_end (node **head):


 

Delete End


 

7.  void delete_mid (node **head):


 

Delete Mid


 

8.  void search (node *head):


 

Search


 

9.  void reverse (node **head):


 

Reverse Node


 



Last Updated : 18 Mar, 2024
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