C$++.$ I$$m currently working on a visual studio project based on the below header file. The project is supposed to be derived from GraphInterface.h and use an adjacency matrix to represent the graph, as well as an adjacency list to represent the graph, and allow the graph to be either weighted or unweighted and either directed or undirected. I would appreciate a practical example of this and I would greatly appreciate comments.

GraphInterface.h:

#ifndef $\_$GRAPH$\_$INTERFACE

#define $\_$GRAPH$\_$INTERFACE

$//$Declare the template class GraphInterface

template

class GraphInterface

$\{$

$//$Access specifier

public:

$//$Declare the method getNumVertices$()$

virtual int getNumVertices$()$ const $=0$;

$//$Declare the method getNumEdges$()$

virtual int getNumEdges$()$ const $=0$;

$//$Declare the method add$()$ to add the vertices

virtual void add$($LabelType start, LabelType end$)=0$;

$/*$Declare the method remove$()$ to remove the vertices$*/$

virtual bool remove$($LabelType start, LabelType end$)=0$;

$/*$Declare the method getEdgeWeight$()$ to get edge weight$*/$

virtual int getEdgeWeight$($LabelType start, LabelType end$)$ const $=0$;

$//$Declare the method display$()$

virtual void display$()=0$;

$\}$;

#endif