The following code should compile and run, but the user interface is train wreck. A) Fix the interface so that it makes sense. B) Make it possible to add and remove cars at the front and back of the train. C) Improve and add any classes or functions that you see fit. D) Be sure to write a summary of your work and document the code with sufficient comments

///////////// code

#include

using namespace std;

int current_year = 2017;

const double PI = 3.14159;

class container {

public: int percent_loaded;

container() {

cout << " Calling container default constructor." << endl;

}

};

//Syntax:

//class subclass_name : public superclass_name { };

class box : public container {

public: double height, width, length;

box() {

cout << " Calling box default constructor." << endl;

}

double volume(){

return height * length * width;

}

};

class cylinder : public container {

public:

cylinder(){}

cylinder(double rad, double len)

{radius = rad; length = len;}

double radius, length;

double volume ( ) {return PI * radius * radius * length;}

};

class rail_car {

public: int year_built;

rail_car() {

cout << " Calling rail_car default constructor." << endl;

}

int age() {return current_year - year_built;}

};

class box_car : public rail_car, public box {

public: box_car(){

cout << " Calling box_car default constructor." << endl;

height = 10.0; length = 40.0; width = 9.0;

}

};

class tank_car : public rail_car, public cylinder {

public:

tank_car ( ) : cylinder (3.5, 40.0) { }

};

class engine : public rail_car {

public: engine ( ) { }

};

class caboose : public rail_car {

public: caboose ( ) { }

};

// ??

rail_car *train[100];

main ( ) {

// ??

int car_count, type_code;

// Read type number and create corresponding objects:

for (car_count = 0; cin >> type_code; ++car_count)

if (type_code == 0) train[car_count] = new engine;

else if (type_code == 1) train[car_count] = new box_car;

else if (type_code == 2) train[car_count] = new tank_car;

else if (type_code == 3) train[car_count] = new caboose;

// ??

cout << "There are " << car_count << " cars in the array." << endl;

}