#ifndef GRAPH_HEADER_H#define GRAPH_HEADER_H//graph_header.h by Cal Zabel for CS163 Program 5#include <iostream>#include <string>using namespace std;struct vertex{ //constructor to initialize variables vertex(); //name of the course string courseName; bool visit; bool used; //pointer to the attached node list node * head;};//edge list is made of these nodesstruct node{ //which vertex is it connected to int index; //next spot in the list node * next;};class Graph{public: //constructor with size Graph(int n); //destructor ~Graph(); void addClass();private: //pointer to the start of the adjacency list array vertex * AdjacencyList; int numVertices; int used;};#endif