Graph program

[Jobengals5]

Given this code i need to create the destructor for a vertex vector but i'm not exactly sure how to clear the vertex vector, can anyone help me out, thanks.


#include "graph.h"
using namespace std;

// default constructor at work here; pretty cute!
graph::graph()
{
}

// destructor is easy, we just clear our vertex vector and our edge map
graph::~graph()
{
}

// add a vertex to the graph by adding it to the vector
void graph::add_vertex(const vertex& v)
{
}

// add an edge to the graph as long as it's under the distance limit
void graph::add_edge(vertex* v, vertex* u, double limit)
{
}

// compute distance from one lat/long to another as the crow flies
double graph::great_circle_distance(const vertex& v, const vertex& u) const
{
double PI = 3.1415926535897932;
double lat1, lat2, long1, long2, dist;

lat1 = ((double) v.get_latitude_degrees()) + (((double) v.get_latitude_minutes()) / 60.0);
lat1 *= PI/180.0;
long1 = ((double) v.get_longitude_degrees()) + (((double) v.get_longitude_minutes()) / 60.0);
long1 *= PI/180.0;
lat2 = ((double) u.get_latitude_degrees()) + (((double) u.get_latitude_minutes()) / 60.0);
lat2 *= PI/180.0;
long2 = ((double) u.get_longitude_degrees()) + (((double) u.get_longitude_minutes()) / 60.0);
long2 *= PI/180.0;

// from http://www.meridianworlddata.com/Distance-Calculation.asp
// result in km
dist = 6378.7 * acos((sin(lat1) * sin(lat2)) + (cos(lat1) * cos(lat2) * cos(long2 - long1)));

return dist;
}

// read in 120 cities and their latitude/longitude
// cities within limit km of each other are connected by edges
void init_graph_from_file(graph& g, const string& filename, double limit)
{
string line;
string city_name;
int lat1, lat2, long1, long2;
ifstream file_to_read;
char compass_dir;

// open the data file of cities
open_for_read(file_to_read, filename);


// now we are done with our file
file_to_read.close();

}

// function defined by Michael Main for input data
void open_for_read(ifstream& f, string filename)
{
f.open(filename);
if (f.fail())
{
cerr << "Could not open input file." << endl;
exit(0);
}
}

// function defined by Michael Main for input data
bool is_more_stuff_there(ifstream& f)
{
return (f && (f.peek() != EOF));
}