1218上机3

```cpp

#include<iostream>
using namespace std;
#include<cmath>
#define PI 3.14159
class Point {
private:
	double m_x = 0, m_y = 0;

public:
	void setx(double x) {
		m_x = x;
	}
	void sety(double y) {
		m_y = y;
	}
	double getx() const { return m_x; }
	double gety() const { return m_y; }
	

	Point(double x = 0, double y = 0) : m_x(x), m_y(y) {
		cout << "Constructor of Point" << endl;
	
	}
	Point(const Point& p) :m_x(p.m_x), m_y(p.m_y) {
		cout << "Copy constructor of Point" << endl;
	}

	void getpoint() {
		Point p;
		p.getx();
		p.gety();
		
		cout<<"点的坐标为" <<"("<< p.getx() << "," << p.gety()<<")";
	}
	~Point() {
		cout << "Destructor of Point" << endl;
	}

};



class Circle {
	Point m_center; double m_radius = 1.0;
public:
	friend void distance(Circle& c1, Circle& c2);

	void setRadius(double r ) {
		m_radius = r;
	}
	double getRadius() {
		return m_radius;
	}
	Circle(double r = 1, const Point& p = Point()) :m_center(p), m_radius(r) {
		cout << "Constructor of Circle" << endl;
	}
	void setcenter(Point center) {
		m_center = center;
	}
	Point getcenter() {
		return m_center;
	}

	void circumference() {
		Circle c;
		cout << "周长为： "<<2 * PI * c.getRadius() << endl;
	}
	void area() {
		Circle c;
		cout << "面积为： " << PI * c.getRadius() * c.getRadius()<<endl;
	}
	~Circle() {
		cout << "Destructor of Circle" << endl;
	}
};
 

void distance(Circle& c1, Circle& c2) {
	double x = (c1.getcenter().getx() - c2.getcenter().getx()) * (c1.getcenter().getx() - c2.getcenter().getx());
	double y = (c2.getcenter().gety() - c1.getcenter().gety()) * (c2.getcenter().gety() - c1.getcenter().gety());
	double distance1 = x + y;
	cout << "两点间的距离为"<<sqrt(distance1) << endl;
	
}



int main()
{
	Point b(1, 0);
	b.getpoint();
	Circle c1(3,Point(2,3));
	c1.circumference();
	c1.area();
	Circle a(2, Point(1, 1));
	distance(c1, a);
	cout << "end" << endl;
	return 0;
}