C++求助，请给详细代码

Question

 

Answer 1

#include<iostream>
#include<Cmath>
#define PI 3.1415926
using namespace std;
class Point //定义坐标点类
{public:
Point(){x=0;y=0;}
~Point();
Point(double x0,double y0) {x=x0; y=y0;}
double setxy(double x0,double y0){x=x0; y=y0;}
double getx(){return x;}
double gety(){return y;}
friend ostream & operator << (ostream &,Point &);
protected:
	double x,y;//点的横坐标和纵坐标
};
class Circle:public Point
{public:
Circle(){r=0;}
Circle(double x,double y,double r);
~Circle();
double setr(double r0){r=r0;}
double getr(){return r;}
friend ostream & operator << (ostream &,Circle &);
public :
	double r;
};

Circle::Circle(double x,double y,double r0):Point(x,y)
{
	r=r0;
}

ostream & operator << (ostream &output,Point &c)
{
	output<<c.x<<c.y<<endl;
	return output;
}
ostream & operator << (ostream &output,Circle &c)
{
	output<<c.r<<endl;
	return output;
}

Point::~Point()
{
}

Circle::~Circle()
{
}


int main()
{
	Circle c1(1,2,3);
	Point p1(3,4);
	cout<<c1;
	cout<<p1;

	return 0;
}