Insert node at beginning of doubly linked list in c++

C++ program for Insert node at beginning of doubly linked list. Here problem description and other solutions.

// Include header file
#include <iostream>
using namespace std;
// C++ Program For
// insert new node at beginning of doubly linked list

// Define class of linked list Node
class LinkNode
{
	public: int data;
	LinkNode *next;
	LinkNode *prev;
	LinkNode(int data)
	{
		this->data = data;
		this->next = nullptr;
		this->prev = nullptr;
	}
};
class DoublyLinkedList
{
	public: LinkNode *head;
	DoublyLinkedList()
	{
		this->head = nullptr;
	}
	// Insert new node at beginning position
	void insert(int value)
	{
		// Create a node
		LinkNode *node = new LinkNode(value);
		node->next = this->head;
		// When linked list is not empty
		if (this->head != nullptr)
		{
			this->head->prev = node;
		}
		// Make new head
		this->head = node;
	}
	// Display node element of doubly linked list
	void display()
	{
		if (this->head == nullptr)
		{
			cout << "Empty Linked List" << endl;
		}
		else
		{
			cout << "  Doubly Linked List Element :" << endl;
			// Get first node of linked list
			LinkNode *temp = this->head;
			// iterate linked list 
			while (temp != nullptr)
			{
				// Display node value
				cout << "  " << temp->data;
				// Visit to next node
				temp = temp->next;
			}
		}
	}
};
int main()
{
	DoublyLinkedList *dll = new DoublyLinkedList();
	// Insert following linked list nodes
	dll->insert(70);
	dll->insert(60);
	dll->insert(50);
	dll->insert(40);
	dll->insert(30);
	dll->insert(20);
	dll->insert(10);
	//  NULL <- 10 <--> 20 <--> 30 <--> 40 <--> 50 <--> 60 <--> 70->NULL
	dll->display();
	return 0;
}

Output

  Doubly Linked List Element :
  10  20  30  40  50  60  70