点 圆柱类的设计2

#include <iostream>  

using namespace std;  

class Point  

{  

public:  

    Point(double xx=0,double yy=0)  

    {  

        x=xx;  

        y=yy;  

    }  

    void setpoint(double ,double);  

    double getx(){return x;}  

    double gety(){return y;}  

    void Point_show();  

protected:  

    double x,y;  

};  

void Point::setpoint(double xx,double yy)  

{  

    x=xx;  

    y=yy;  

}  

void Point::Point_show()  

{  

    cout<<"x="<<x<<"   y="<<y<<endl;  

}  

class Circle:public Point  

{  

public:  

    Circle(double xx=0,double yy=0,double rr=0);  

    void setRaidus(double rr);  

    double getradius(){return radius;}  

    double area() const;  

    void show();  

protected:  

    double radius;  

};  

Circle::Circle(double xx,double yy,double rr):Point(xx,yy),radius(rr){}  

void Circle::setRaidus(double rr)  

{  

        radius=rr;  

}  

double Circle::area() const  

{  

    return 3.14159*radius*radius;  

}  

void Circle::show()  

{  

    cout<<"圆心为：（"<<x<<","<<y<<")  radius="<<radius<<"  area="<<area()<<endl;  

}  

int main()  

{  

    Circle c(1.2,2.1,3.6);  

    c.show();  

    c.setpoint(2.5,2.5);  

    c.show();  

    return 0;  

}