[TODO] FDS (LV) Ass 7 - DE Queue using CDLL

#include <iostream>
#include <string>
using namespace std;

struct Node {
    Node *prev;
    Node *next;
    string data;

    Node(string dat) {
        this->data = dat;
        this->next = nullptr;
        this->prev = nullptr;
    }
};

class DeQue {
private:
    // head is not needed in a CDLL / DE Queue
    // front and rear will do the job
    // Node *head;
    Node *front;
    Node *rear;

public:
    DeQue() {
        // head = nullptr;
        front = nullptr;
        rear = nullptr;
    }

    void frontInsert(string dat) {
        Node *newNode = new Node(dat);

        if (front == nullptr) {
            front = rear = newNode;
            newNode->next = newNode;
            newNode->prev = newNode;
        } else {
            // SOME NICE DOCUMENTATION :P
            // Make the newly inserted node's next point to the current first node
            // ok this is a DE queue so we dont need a head pointer.
            // the front poiints to the first element and rear points to the last element.
            // newNode->next = head;
            newNode->next = front;
            // Make the newly inserted node point to the last node in the LL
            // correct logik when currently there are more than 1 nodes in the LL
            // newNode->prev = head -> does not maintain the correct structure for circular LL
            // newNode->prev = head->prev;
            newNode->prev = rear;
            // Make the current first node's previous point to the newly inserted Node
            // head->prev = newNode;
            front->prev = newNode;
            // Make the last node point to the newly inserted node
            // head->prev->next = newNode;
            rear->next = newNode;
            // Now update the head to point to the newly inserted Node
            // head = newNode;
            front = newNode;
            // END DOCUMENTATION
        }
    }

    void rearInsert(string dat) {
        Node *newNode = new Node(dat);
        if (head == nullptr) {
            front = newNode;
            newNode->next = newNode;
            newNode->prev = newNode;
        } else {
            // front and rear ftw!
            newNode->next = front;
            newNode->prev = rear;
            rear->next = newNode;
            front->prev = newNode;
            rear = newNode;
        }
    }

    void display() {
        if (front == nullptr) {
            cout << "Queuwue is Empty" << endl;
        }

    }


};