#include <iostream>

 using namespace std;

 //含有一个或多个纯虚函数的类成为抽象类，注意：此处指的是纯虚函数而不是虚函数

 //纯虚函数的定义：virtual void draw() = 0;

 //如果继承抽象类，则必须实现父类中所有的纯虚函数，否则该子类也为抽象类

 //如果一个类中包含虚函数，则必须将本类的析构函数声明为虚函数。

 class Shape

 {

 public:

     Shape(){

     }

     virtual ~Shape(){

     }

     virtual double getArea() = ;//纯虚函数

     virtual double getP() = ;

     virtual void draw() = ;

 };

 class Circle : public Shape

 {

 public:

     Circle(double r):itsRadius(r){

     }

     virtual ~Circle(){

     }

     double getArea(){

         return 3.14 * itsRadius * itsRadius;

     }

     double getP(){

         return  * 3.14 * itsRadius;

     }

     void draw(){

         cout<<"draw Circle..."<<endl;

     }

 private:

     double itsRadius;

 } ;

 class Rectangle : public Shape

 {

 public:

     Rectangle(int w,int h):wid(w),hei(h){

     }

     virtual    ~Rectangle(){

     }

     double getArea()

     {

         return wid * hei;

     }

     double getP()

     {

         return *(wid + hei);

     }

     void draw()

     {

         for(int i = ;i < ;i++)

         {

             for(int j = ;j < ;j++)

             {

                 cout<<"X  ";

             }

             cout<<endl;

         }

     }

 private:

     int wid;

     int hei;

 };

 int main()

 {

     int number;

     bool flag = false;

     Shape *shape;

     while(flag == false)

     {

         cout<<"请输入数字：（1）圆形  （2）矩形  （0）退出：";

         cin>>number;

         switch(number)

         {

             case :

             shape = new Circle(10.0);

             break;

             case :

             shape = new Rectangle(,);

             break;

             case :

             flag = true;

             break;

         }

         if(flag == false)

         {

             shape->draw();

             delete shape;

         }

     }

     return ;

 }