第十二周实验报告4

* (程序头部注释开始)

 * 程序的版权和版本声明部分

 * Copyright (c) 2011, 烟台大学计算机学院学生 

 * All rights reserved.

 * 文件名称：类的组合与继承

 

* 作    者：        任小宁                

 * 完成日期：     2012    年 5    月  9  日

 * 版 本 号：      201158504431

 * 对任务及求解方法的描述部分

 * 输入描述：由下面派生类Student1对基类Student的继承…… 

 * 问题描述：（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//自行定义类

 

* 程序输出：

 

* 程序头部的注释结束

 

*/

#include<iostream>
#include<Cmath>
using namespace std;
const double pi=3.1415926;

class Point //定义坐标点类
{
public:
Point(){x=0;y=0;}
Point(double x0,double y0) {x=x0; y=y0;}
~Point ()
{
cout<<"Point类析构函数执行完毕(Destructor function performs ished)"<<endl;
}
double get_x(){return x;}
double get_y(){return y;}
void set_x(double n){ x=n;}
void set_y(double n){y=n;}
friend ostream &operator << (ostream & output, Point & c);
private:
double x,y;   //点的横坐标和纵坐标
};
ostream &operator << (ostream & output, Point & c)
{
output<<"该点的横坐标为："<<c.x<<"    "<<"纵坐标为："<<c.y<<endl;
return output;
}
class Circle: public Point   //利用坐标点类定义圆类, 其基类的数据成员表示圆的中心
{
public:
Circle(double xx,double yy,double dd): Point(xx,yy) ,d(dd){}//构造函数
~Circle()
{
cout<<"Circle类析构函数执行完毕(Destructor function performs finished)"<<endl;
}
friend ostream &operator << (ostream & output, Circle & c);
friend double locate(Point &,Circle &);
friend void crossover_point1(Point &p1,Circle &c1,Point &p4,Point &p5);
//double get_d(){return d;}
bool operator > (Circle &t);
bool operator < (Circle &t);
bool operator >= (Circle &t);
bool operator <= (Circle &t);
bool operator == (Circle &t);
bool operator != (Circle &t);
private:
double d;
};
void crossover_point1(Point &p1,Circle &c1,Point &p4,Point &p5)
{
double n;
n=c1.get_x ()+((p1.get_x ()-c1.get_x ())*c1.d )/(sqrt((p1.get_x ()-c1.get_x ())*(p1.get_x ()-c1.get_x ())+((p1.get_y ()-c1.get_y ())*(p1.get_y ()-c1.get_y ()))));
p4.set_x (n);
n=c1.get_x ()-((p1.get_x ()-c1.get_x ())*c1.d )/(sqrt((p1.get_x ()-c1.get_x ())*(p1.get_x ()-c1.get_x ())+((p1.get_y ()-c1.get_y ())*(p1.get_y ()-c1.get_y ()))));
p5.set_x (n);
n=c1.get_y ()+((p1.get_y ()-c1.get_y ())*c1.d )/(sqrt((p1.get_x ()-c1.get_x ())*(p1.get_x ()-c1.get_x ())+((p1.get_y ()-c1.get_y ())*(p1.get_y ()-c1.get_y ()))));
57.    p4.set_y (n);
58.    n=c1.get_y ()-((p1.get_y ()-c1.get_y ())*c1.d )/(sqrt((p1.get_x ()-c1.get_x ())*(p1.get_x ()-c1.get_x ())+((p1.get_y ()-c1.get_y ())*(p1.get_y ()-c1.get_y ()))));
p5.set_y (n);
}
ostream &operator << (ostream & output, Circle & c)
{
output<<"圆的半径为："<<c.d<<"圆的圆心为"<<"("<<c.get_x()<<","<<c.get_y()<<")"<<endl;
return output;
}
double locate(Point &p,Circle &c)
{
double s,d,m;
s=(c.get_x()-p.get_x () )*(c.get_x()-p.get_x () )+(c.get_y ()-p.get_y () )*(c.get_y ()-p.get_y () );
m=sqrt(s);
d=m-c.d ;
return d;
}
bool Circle::operator > (Circle &t)
{
double s1,s2;
s1=pi*d*d;
s2=pi*t.d*t.d;
if(s1>s2 )
return true;
else
return false;
}
bool Circle::operator < (Circle &t)
{
double s1,s2;
s1=pi*d*d;
s2=pi*t.d*t.d;
if(s1<s2 )
return true;
else
return false;
}
bool Circle::operator >= (Circle &t)
{
double s1,s2;
s1=pi*d*d;
s2=pi*t.d*t.d;
if (s1<s2)
return false;
return true;
}

bool Circle::operator <= (Circle &t)
{
double s1,s2;
s1=pi*d*d;
s2=pi*t.d*t.d;
if (s1>s2)
return false;
return true;
}
bool Circle::operator == (Circle &t)
{
double s1,s2;
s1=pi*d*d;
s2=pi*t.d*t.d;
if (s1<s2)
return false;
if (s1>s2)
return false;
return false;
}

bool Circle::operator != (Circle &t)
{
double s1,s2;
s1=pi*d*d;
s2=pi*t.d*t.d;
if (s1==s2)
return false;
return true;
}
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;
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: "<<c1;
cout<<endl;

Point p4,p5;
crossover_point1(p1,c1, p4, p5);

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: "<<p4;
cout<<"交点: "<<p5;
cout<<endl;

system("pause");
return 0;
}