c++多态

#include 

using namespace std;

// 基类
class Shape
{
public:
    Shape(int w,int h):width(w),height(h){


    }
    Shape(){

        std::cout<<"this is Shape"<
      width = w;
   }
   void setHeight(int h)
   {
      height = h;
   }
protected:
   int width;
   int height;
};

// 派生类
class Rectangle: public Shape
{
public:
    Rectangle(int w,int h):Shape(w,h){


    }
    Rectangle(){

        std::cout<<"this is Rectangle"<
      return (width * height);
   }
};
class Triangle: public Shape
{
public:
    Triangle(int w,int h):Shape(w,h){


    }
    Triangle(){

        std::cout<<"this is Triangle"<
      return (width * height)/2;
   }
};
Shape *Rect;
int main(void)
{

   //Triangle  Tri;
   Rect=new Rectangle(8,9);
   cout << "Total Rectangle area: " << Rect->getArea() << endl;
   //delete Rect;
   Rect=new Rectangle(8,12);
   cout << "Total Rectangle area: " << Rect->getArea() << endl;
   Rect=new Triangle(8,12);
   cout << "Total Rectangle area: " << Rect->getArea() << endl;
   //Rect.setWidth(5);
   //Rect.setHeight(7);
   // 输出对象的面积
   //cout << "Total Rectangle area: " << Rect.getArea() << endl;

   //Tri.setWidth(5);
   //Tri.setHeight(7);
   // 输出对象的面积
   //cout << "Total Triangle area: " << Tri.getArea() << endl;

   return 0;
}