// An example of using Inheritance, Overloading and polymorphism
// This time using C++

#include <iostream.h>
#include <string.h>

class Book {
protected:
  char title[30];
  int npages;

public:
  Book() { // Default constructor
    strcpy(title, "No title"); npages = 0;
  }
  
  /** A second constructor */
  Book(char *booktitle, int pages) {
    strcpy(title, booktitle); npages = pages;
  }
  
  /** A public method */
  virtual void Read(int pagestart, int pageend) {
    if (pageend < npages) {
      cout << "Reading " << title << " from page " <<
	pagestart << " to " << pageend << endl;
    }
    else {
      cout << "Give me another book!" << endl;
    }
  }
};

/** The first subclass - hardly anything extra, just to show things */
class ComicBook:public Book {
public:
  ComicBook(char *booktitle, int pages) {
    strcpy(title, booktitle); /* title is not in this class - INHERITED */
    npages = pages;    /* likewise */
  }

};

class TextBook:public Book {
private:
  char Course[10];

public:
  TextBook(char *booktitle, int pages, char *incourse) {
    Book(booktitle, pages);
    strcpy(Course, incourse);
  }

  void Read(int pagestart, int pageend) {
    cout << Course << "has a very dull textbook!" << endl;
  }
};

//In C++, the main does not need to be in a class!

int main(int argc, char **argv) {

  // create a new Comic Book
  ComicBook * favoriteComic = new ComicBook("Yukon Ho!", 85); 
  favoriteComic->Read(75, 95); // Read is not in ComicBook, still works!
  // *** Inheritance ***
  
  // create a new text book, but assign it to a variable of tyep Book!
  // *** Polymorphism ***
  Book * a201Text = new TextBook("CCJ", 625, "A201");
  a201Text->Read(475, 525);	// This time use the overloaded Read
				// method in Textbook.
				// *** Overloading ***
}