// Chapter 8 - Program 6 - INHERIT6.CPP
#include <iostream.h>
#include <stdlib.h>

class vehicle 
{
protected:
   int wheels;
   double weight;
public:
   void initialize(int in_wheels, double in_weight);
   int get_wheels(void)        {return wheels;}
   double get_weight(void)     {return weight;}
   double wheel_loading(void)  {return weight/wheels;}
};



class car : public vehicle 
{
   int passenger_load;
public:
   void initialize(int in_wheels, double in_weight, int people = 4);
   int passengers(void)        {return passenger_load;}
};



class truck : public vehicle 
{
   int passenger_load;
   double payload;
public:
   void init_truck(int how_many = 2, double max_load = 24000.0);
   double efficiency(void);
   int passengers(void)        {return passenger_load;}
};



int main()
{
vehicle unicycle;

   unicycle.initialize(1, 12.5);
   cout << "The unicycle has " <<
                                unicycle.get_wheels() << " wheel.\n";
   cout << "The unicycle's wheel loading is " <<
         unicycle.wheel_loading() << " pounds on the single tire.\n";
   cout << "The unicycle weighs " <<
                             unicycle.get_weight() << " pounds.\n\n";

car sedan[3];
int index;

   for (index = 0 ; index < 3 ; index++)
   {
      sedan[index].initialize(4, 3500.0, 5);
      cout << "The sedan carries " << sedan[index].passengers() <<
                                                    " passengers.\n";
      cout << "The sedan weighs " << sedan[index].get_weight() << 
                                                        " pounds.\n";
      cout << "The sedan's wheel loading is " <<
                            sedan[index].wheel_loading() << 
                                             " pounds per tire.\n\n";
   }

truck *semi;

   semi = new truck;
   if (semi == NULL)
   {
      cout << "Memory allocation failed\n";
      exit (EXIT_FAILURE);
   }
   semi->initialize(18, 12500.0);
   semi->init_truck(1, 33675.0);
   cout << "The semi weighs " << semi->get_weight() << " pounds.\n";
   cout << "The semi's efficiency is " <<
                         100.0 * semi->efficiency() << " percent.\n";
   delete semi;

   return 0;
}



// initialize to any data desired
void vehicle::initialize(int in_wheels, double in_weight)
{
   wheels = in_wheels;
   weight = in_weight;
}



void car::initialize(int in_wheels, double in_weight, int people)
{
   passenger_load = people;
   wheels = in_wheels;
   weight = in_weight;
}



void truck::init_truck(int how_many, double max_load)
{
   passenger_load = how_many;
   payload = max_load;
}



double truck::efficiency(void)
{
   return payload / (payload + weight);
}



// Result of execution
//
// The unicycle has 1 wheel.
// The unicycle's wheel loading is 12.5 pounds on the single tire.
// The unicycle weighs 12.5 pounds.
//
// The sedan carries 5 passengers.
// The sedan weighs 3500 pounds.
// The sedan's wheel loading is 875 pounds per tire.
//
// The sedan carries 5 passengers.
// The sedan weighs 3500 pounds.
// The sedan's wheel loading is 875 pounds per tire.
//
// The sedan carries 5 passengers.
// The sedan weighs 3500 pounds.
// The sedan's wheel loading is 875 pounds per tire.
//
// The semi weighs 12500 pounds.
// The semi's efficiency is 72.929072 percent.