class Shape{
public:Shape(){ //public里的Shape构造函数可以没有参数(根据题的意思）
}
virtual ~Shape(){}
virtual float area()=0;
};
class Circle:public Shape{
public:
~Circle(){}
float area(){
return 3.1415926*radius*radius;
}
Circle(int x1,int y1,float radius1){
x=x1;//Circle类中输出圆的面积，构造函数中有参数
y=y1;
radius=radius1;
}
private:int x,y;
float radius;
};
class Rectangle:public Shape
{public:
~Rectangle(){}
float area(){
return width*height;
}
Rectangle(int w,int h){
width=w;
height=h;
}
private:int width,height;
};
