Adjacency list representation of undirected graph in c++

C++ program for Adjacency list representation of undirected graph. Here problem description and explanation.

// Include header file
#include <iostream>
using namespace std;
/*
    C++ Program for 
    Undirected graph representation by using adjacency list 
*/
class AjlistNode
{
	public:
	// Vertices node key
	int id;
	AjlistNode *next;
	AjlistNode(int id)
	{
		// Set value of node key
		this->id = id;
		this->next = nullptr;
	}
};
class Vertices
{
	public: int data;
	AjlistNode *next;
	AjlistNode *last;
	Vertices(int data)
	{
		this->data = data;
		this->next = nullptr;
		this->last = nullptr;
	}
	Vertices()
    {
        this->data = 0;
        this->next = nullptr;
        this->last = nullptr;
    }
};
class Graph
{
	public:
	// Number of Vertices
	int size;
	Vertices *node;
	Graph(int size)
	{
		// Set value
		this->size = size;
		this->node = new Vertices[size];
		this->setData();
	}
	// Set initial node value
	void setData()
	{
		if (this->size <= 0)
		{
			cout << "\nEmpty Graph" << endl;
		}
		else
		{
			for (int index = 0; index < this->size; index++)
			{
				this->node[index].data = index;
			}
		}
	}
	// Connect two nodes
	void connect(int start, int last)
	{
		AjlistNode *edge = new AjlistNode(last);
		if (this->node[start].next == nullptr)
		{
			this->node[start].next = edge;
		}
		else
		{
			// Add edge at the end
			this->node[start].last->next = edge;
		}
		// Get last edge 
		this->node[start].last = edge;
	}
	//  Handling the request of adding new edge
	void addEdge(int start, int last)
	{
		if (start >= 0 && start < this->size && 
            last >= 0 && last < this->size)
		{
			this->connect(start, last);
			if (start == last)
			{
				// When self loop
				return;
			}
			this->connect(last, start);
		}
		else
		{
			// When invalid nodes
			cout << "\nHere Something Wrong" << endl;
		}
	}
	void printGraph()
	{
		if (this->size > 0)
		{
			// Print graph ajlist Node value
			for (int index = 0; index < this->size; ++index)
			{
				cout << "\nAdjacency list of vertex " << index << " :";
				AjlistNode *temp = this->node[index].next;
				while (temp != nullptr)
				{
					// Display graph node 
					cout << "  " << this->node[temp->id].data;
					// Visit to next edge
					temp = temp->next;
				}
			}
		}
	}
};
int main()
{
	// 5 implies the number of nodes in graph
	Graph *g = new Graph(5);
	// Connect node with an edge
	g->addEdge(0, 1);
	g->addEdge(0, 2);
	g->addEdge(0, 4);
	g->addEdge(1, 2);
	g->addEdge(1, 4);
	g->addEdge(2, 3);
	g->addEdge(3, 4);
	// print graph element
	g->printGraph();
	return 0;
}

Output

Adjacency list of vertex 0 :  1  2  4
Adjacency list of vertex 1 :  0  2  4
Adjacency list of vertex 2 :  0  1  3
Adjacency list of vertex 3 :  2  4
Adjacency list of vertex 4 :  0  1  3