点与园

/*
*Corpyright (c)2013,烟台大学计算机学院
*All right reseved.
*作者：周经纬
*完成日期：2014年5月25日
*版本号：v1.0
*输入描述：
*问题描述:
*程序输出：
*问题分析：
*算法设计：
*/
#include <iostream>
#include <cmath>
using namespace std;
class Point
{
public:
    Point(double a=0,double b=0):x(a),y(b){}
    double getx()
    {
        return x;
    }
    double gety()
    {
        return y;
    }
    friend ostream& operator<<(ostream&output,Point&s);
protected:
    double x;
    double y;
};
ostream& operator<<(ostream&output,Point&s)
{
    output<<"("<<s.getx()<<","<<s.gety()<<")"<<endl;
    return output;
}
class Circle:public Point
{
public:
    Circle(double a=0,double b=0,double c=0):Point(a,b),r(c){}
    friend double locate(Point&s,Point&s1);
    friend ostream& operator<<(ostream&output,Circle&s);
    double getr()
    {
        return r;
    }
private:
    double r;
};
ostream& operator<<(ostream&output,Circle&s)
{
    output<<"("<<s.getx()<<","<<s.gety()<<","<<s.r<<")"<<endl;
    return output;
}
double locate(Point&s,Circle&s1)
{
    double num,num1;
    num=sqrt((s1.getx()-s.getx())*(s1.getx()-s.getx())+(s1.gety()-s.gety())*(s1.gety()-s.gety()));
    num1=num-s1.getr();
    return num1;
}
int main( )
{
	Circle c1(3,2,4),c2(4,5,5);      //c2应该大于c1
	Point p1(1,1),p2(3,-2),p3(7,3);  //分别位于c1内、上、外




	cout<<"圆c1: "<<c1;


	cout<<"点p1: "<<p1;
	cout<<"点p1在圆c1之"<<((locate(p1, c1)>0)?"外":((locate(p1, c1)<0)?"内":"上"))<<endl;


	cout<<"点p2: "<<p2;
	cout<<"点p2在圆c1之"<<((locate(p2, c1)>0)?"外":((locate(p2, c1)<0)?"内":"上"))<<endl;


	cout<<"点p3: "<<p3;
	cout<<"点p3在圆c1之"<<((locate(p3, c1)>0)?"外":((locate(p3, c1)<0)?"内":"上"))<<endl;
	return 0;
}