// poly.cpp -- CopyWrong by tsaiwn@csie.nctu.edu.tw
#include <iostream.h>
class Shape{
   public:
     virtual   // 把這列去掉再 run 看看
       void draw(){ cout << "drawing\n"; }
};
class Line: public Shape{
   public:
      void draw(){ cout << "draw a line\n"; }
};
class Circle: public Shape{
   public:
      void draw(){ cout << "here is a circle\n"; }
};
int main(){
   Circle * ppp;
   Shape * fig[5];
  // ppp = new Shape();   // error
   ppp = (Circle *)new Shape();
   ppp -> draw();
   ppp = (Circle *)new Line();
   ppp -> draw();
   ppp = new Circle();
   ppp -> draw();
   cout << "======" << endl;
   fig[0] = new Line();
   fig[1] = new Circle();
   fig[2] = new Circle();
   fig[3] = new Line();
   fig[4] = new Circle();
   for(int k=0; k<5; k++){
      fig[k] -> draw();
   }
}