test9.txt

思路很清晰的c++课件。例子很简明

class Point{
protected:
   int x,y;
   Point(int a,int b){ x=a;y=b; }
   int GetX(){ return x; }
   int GetY(){ return y; }
};
class Rectangle{
private:
   Point p1;
   Point p2;
public:
   Rectangle(int px1,int py1,int px2,int py2):p1(px1,py1),p2(px2,py2)
   {}
   int Area()
   {
      return abs((p2.GetX()-p1.GetX())*(p2.GetY()-p1.GetY());
   }
};