Help with Vectors and Dynamic Objects

Hi there,

Hopefully I won't fit the stereotype of the typical student posting his
assignment to be written for him, but I am quite stuck. If anyone could
give me some help in how to create dynamic objects (which inherit from
a base class) and storing them in a vector, it would be absolutely
wonderful at this point. I think from there I might be able to sculpt
the rest of the program without (too much) trouble. I'll post what I've
been trying to do so far and also the header file.

Thanks in advance for any help.

 #include "a3.h"

 string queryInput;

// Don't forget to supply your information in the function below . . .
void displayInfo()
{
        cout << "----------------------------------------" << endl;
        cout << "Assignment 3 Semester 1 2006" << endl;
        cout << " Submitted by: Donald, Duck, 00000000" << endl;

        cout << "----------------------------------------" << endl;
        cout << endl << queryInput << endl;
}

//Driver for the Media/Movie classes for assignment 3,
//2006, Semester 1
int main()
{

    cout<<"Media Database Control Program v0.4b\n\n"<<
          "Please enter the title of the media record you wish to view: ";
    getline(cin, queryInput);
    cout<<"\n\nAccessing record for "<<queryInput<<"...."<<endl<<endl;

    // Call the global function to print Student/Group names and IDs
    displayInfo();

    // Container of Media pointers
    vector<Media *> mediaItems;

    Media::readFromFile("/a3-input.txt", mediaItems);

    // Display to the screen
    for(unsigned i = 0; i < mediaItems.size(); i++)
    {
        mediaItems[i]->display(); // use the polymorphic display function
        cout<<endl;
    }

    // Work out total stock value, StockInfo functions are inaccessible
    // unless we recast
    int value = 0;
    int nItems = 0;

    for(unsigned i=0; i<mediaItems.size(); i++)
    {
        Movie *ptr = static_cast<Movie *>(mediaItems[i]);
        value += ptr->getPrice() * ptr->getNumberInStock();
        nItems += ptr->getNumberInStock();
    }

    cout << "Total stock value of " << nItems << " items is " << value <<
endl;
    return 0;
}

// Implement your member function classes here

Movie::Movie()
{

}

void display()
{
}

void Movie::setDirector(const string& d)
{
    director = d;
}

void Movie::setTime(int t)
{
    time = t;
}

void Movie::setQuality(int q)
{
    quality = q;
}

void Media::setTitle(const string& t)
{
    title = t;
}

void Media::getData(ifstream& fin)
{

}

void Media::readFromFile(const string& filename, vector<Media*>&
mediaItems)
{

    mediaItems.resize(20);

    cout<<filename<<endl;

    char tempData[10000];
    string recordData;
    ifstream dataBase("/a3-input.txt");

    while(recordData != "ENDOFRECORDS")
    {
        int i = 0;

        dataBase.getline(tempData, 10000);
        recordData = tempData;

        if(recordData == "Movie")
        {
            Movie* mediaItems[i];
            mediaItems[i].setDirector(recordData);

            i++;
        }
    }

    dataBase.close();
}

Here is the header file....

/* Assignment A3, Header file, See A3.doc for specification.
 *
 * Class Hierarchy:
 *
 * Media StockItem
 * | |
 * +--------------------------+
 * |
 * V
 * Movie
 * |
 * V
 * +------------+-------------+
 * | |
 * V V
 * Revised Foreign
 *
 *
 * *** DO NOT CHANGE THIS FILE ***
 */

#include <iostream>
#include <fstream>
#include <string>
#include <vector>

using namespace std;

// Base class to provide stock control info
class StockItem{
 public:
  void readStockInfo( ifstream& fin ); // read in price and
numberInStock
  void displayStockInfo();
  int getPrice(){ return price; }
  int getNumberInStock(){ return numberInStock; }
 protected:
  int price; // in cents
  int numberInStock;
};

// Abstract base class for all media products
class Media{
 public:
  virtual ~Media(){}
  virtual void getData( ifstream& fin) = 0; // get a single record
  virtual void display() = 0; // print out to cout the details of a
record

  void setTitle( const string& t);

  // Open stated file, and read in records into the vector of Media
  // pointers (which is passed by reference) allocating a new object
  // of the right type, dynamically, to the i'th pointer
  static void readFromFile( const string& filename, vector<Media*>& m);

 protected:
  string title;
};

// Declaration/definition of Movie
class Movie : public Media, public StockItem{
public:
  Movie();
  void setDirector( const string& d );
  void setTime( int t = 0);
  void setQuality( int q = 0 );

  virtual void display(); // print out to cout the details of a
record
  virtual void getData( ifstream& fin); // get a single record

protected:
  string director;
  int time; // in minutes
  int quality; // 0 (bad) to 4 (excellent)

  // These are optional but allow code reuse for polymorphs display
  // and getDataprotected:
  void commonDisplay();
  void getCommonData( ifstream& fin);

};

// Declaration of Foreign
class Foreign : public Movie {
public:
  void setLanguage( const string& lang );
  virtual void display(); // see descriptions in Movie
  virtual void getData( ifstream& fin);
private:
  string language; // language of a foreign film
};

// Declaration of Revised
class Revised : public Movie{
public:
  void setRevisedTime( int rt = 0);
  void setChanges( const string& ch );
  virtual void display(); // see descriptions in Movie
  virtual void getData( ifstream& fin);
private:
  int revisedTime; // the revised running time in minutes
  string changes; // description of any changes made
};