第十三周项目五——点类，派生类圆类的应用

/**【项目5（选做）】类的组合与继承* 程序的版权和版本声明部分* Copyright (c)2012, 烟台大学计算机学院学生* All rightsreserved.* 文件名称： object.cpp* 攻城菜鸟：蛋蛋* 完成日期：2013年  5 月  27 日* 版本号：  Code Blocks10.05* 输入描述：点坐标及圆半径* 问题描述：要求：（1）先建立一个Point(点)类，包含数据成员x,y(坐标点)；（2）以Point为基类，派生出一个Circle(圆)类，增加数据成员(半径)，基类的成员表示圆心；（3）编写上述两类中的构造、析构函数及必要的输入输出函数（4）定义友元函数int locate，判断点p在圆c上、圆c内或圆c外，返回值<0圆内，==0圆上，>0 圆外；（5）重载关系运算符（6种）运算符，使之能够按圆的面积比较两个圆的大小；（6）给定一点p，求出该点与圆心相连成的直线与圆的两个交点并输出，下面给出用于测试的main()函数，涉及到的类请自行定义* 程序输出：圆的相关数据*/#include<iostream>#include<cmath>using namespace std;class Point{    public:    Point(double X=0,double Y=0):x(X),y(Y){}    void setX(double X){x=X;}    void setY(double Y){y=Y;}    double getX()const{return x;}    double getY()const{return y;}    //~Point(){delete x;delete y;}    friend ostream &operator<<(ostream &output,const Point &p);    protected:    double x,y;};ostream &operator<<(ostream &output,const Point &p){    output<<"点坐标："<<"("<<p.x<<","<<p.y<<")"<<endl;    return output;}struct Two_points   //专为crossover_point()函数返回值定义的结构体{Point p1;Point p2;};class Circle:public Point{    public:     Circle(double X,double Y,double r):Point(X,Y),radius(r){}     void setCircle(double r){radius=r;}     double getRadius(){return radius;}     friend ostream &operator <<(ostream &output,const Circle &c);     //void printCircle(){cout<<printPoint()<<endl;    //~printCircle(){delete r;}    //friend int locate( )    friend int locate(const Point &p,const Circle &c);    friend bool operator>(const  Circle &c1,const Circle &c2);    friend bool operator<(const Circle &c1,const Circle &c2);    friend bool operator>=(const Circle &c1,const Circle &c2);    friend bool operator<=(const Circle &c1,const Circle &c2);    friend bool operator==(const Circle &c1,const Circle &c2);    friend bool operator!=(const Circle &c1,const Circle &c2);    Two_points crossover_point(Point &p);    //crossover_point    protected:    double radius;};ostream &operator <<(ostream &output,const Circle &c)    {        output<<"圆中：圆心为：（"<<c.x<<","<<c.y<<"），半径为："<<c.radius<<endl;    }int locate(const Point &p,const Circle &c){if((c.getX()-p.getX())*(c.getX()-p.getX())+(c.getY()-p.getY())*(c.getY()-p.getY())>c.radius*c.radius)return 1;else if((c.getX()-p.getX())*(c.getX()-p.getX())+(c.getY()-p.getY())*(c.getY()-p.getY())==c.radius*c.radius)return 0;else if((c.getX()-p.getX())*(c.getX()-p.getX())+(c.getY()-p.getY())*(c.getY()-p.getY())<c.radius*c.radius)return -1;} bool operator>(Circle &c1,Circle &c2){if(c1.getRadius()>c2.getRadius())return true;else return false;} bool operator<(Circle &c1,Circle &c2){if(c1.getRadius()<c2.getRadius())return true;else return false;} bool operator>=(Circle &c1,Circle &c2){if(c1.getRadius()>=c2.getRadius())return true;else return false;} bool operator<=(Circle &c1,Circle &c2){if(c1.getRadius()<=c2.getRadius())return true;else return false;} bool operator==(Circle &c1,Circle &c2){if(c1.getRadius()==c2.getRadius())return true;else return false;} bool operator!=(Circle &c1,Circle &c2){if(c1.getRadius()!=c2.getRadius())return true;else return false;} Two_points Circle::crossover_point(Point &p){Two_points pp;pp.p1.setX ( x + sqrt(radius*radius/(1+((y-p.getY())/(x-p.getX()))*((y-p.getY())/(x-p.getX())))));pp.p2.setX ( x - sqrt(radius*radius/(1+((y-p.getY())/(x-p.getX()))*((y-p.getY())/(x-p.getX())))));pp.p1.setY ( p.getY() + (pp.p1.getX() -p.getX())*(y-p.getY())/(x-p.getX()));pp.p2.setY ( p.getY() + (pp.p2.getX() -p.getX())*(y-p.getY())/(x-p.getX()));return pp;} int main( ){Circle c1(3,2,4),c2(4,5,5);      //c2应该大于c1Point 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;cout<<endl;cout<<"圆c1: "<<c1;if(c1>c2) cout<<"大于"<<endl;if(c1<c2) cout<<"小于"<<endl;if(c1>=c2) cout<<"大于等于"<<endl;if(c1<=c2) cout<<"小于等于"<<endl;if(c1==c2) cout<<"等于"<<endl;if(c1!=c2) cout<<"不等于"<<endl;cout<<"圆c2: "<<c2;cout<<endl;cout<<"用另外一种方法求交点："<<endl;Two_points twoPoint = c1.crossover_point(p1);cout<<"点p1: "<<p1;cout<<"与圆c1: "<<c1;cout<<"的圆心相连，与圆交于两点，分别是："<<endl;cout<<"交点: "<<twoPoint.p1;cout<<"交点: "<<twoPoint.p2;return 0;}