//Implementing pure virtual functions
#include <iostream>
using namespace std;

enum BOOL { FALSE, TRUE };

class Shape
{
public:
	Shape(){}
	~Shape(){}
	virtual long GetArea() = 0; // error
	virtual long GetPerim()= 0;
	virtual void Draw() = 0;
	private:
};

void Shape::Draw()
{
	cout << "Abstract drawing mechanism!\n";
}

class Circle : public Shape
{
public:
	Circle(int radius):itsRadius(radius){}
	~Circle(){}
	long GetArea() { return 3 * itsRadius * itsRadius; }
	long GetPerim() { return 9 * itsRadius; }
	void Draw();
private:
	int itsRadius;
	int itsCircumference;
};

void Circle::Draw()
{
	cout << "Circle drawing routine here!\n";
	Shape::Draw();
}

class Rectangle : public Shape
{
public:
	Rectangle(int len, int width):itsLength(len), itsWidth(width){}
	~Rectangle(){}
	long GetArea() { return itsLength * itsWidth; }
	long GetPerim() {return 2*itsLength + 2*itsWidth; }
	virtual int GetLength() { return itsLength; }
	virtual int GetWidth() { return itsWidth; }
	void Draw();
private:
	int itsWidth;
	int itsLength;
};

void Rectangle::Draw()
{
	for (int i = 0; i<itsLength; i++)
	{
		for (int j = 0; j<itsWidth; j++)
			cout << "x ";

		cout << "\n";
	}

	Shape::Draw();
}

class Square : public Rectangle
{
public:
	Square(int len);
	Square(int len, int width);
	~Square(){}
	long GetPerim() {return 4 * GetLength();}
};

Square::Square(int len):Rectangle(len,len)
{}

Square::Square(int len, int width):Rectangle(len,width)
{
	if (GetLength() != GetWidth())
		cout << "Error, not a square... a Rectangle??\n";
}

int main()
{
	int choice;
	BOOL fQuit = FALSE;
	Shape * sp;

	while (1)
	{
		cout << "(1)Circle (2)Rectangle (3)Square (0)Quit: ";
		cin >> choice;

		switch (choice)
		{
		case 1: sp = new Circle(5);
			break;
		case 2: sp = new Rectangle(4,6);
			break;
		case 3: sp = new Square (5);
			break;
		default: fQuit = TRUE;
			break;
		}

		if (fQuit)
			break;

		sp->Draw();
		cout << "\n";
	}
	
	return 0;
}