第十一周项目三：点类派生直线类

#include<iostream>
#include<Cmath>
using namespace std;
class Point //定义坐标点类
{
public:
Point():x(0),y(0) {};
Point(double x0, double y0):x(x0), y(y0) {};
void PrintPoint(); //输出点的信息
protected:
double x,y;   //点的横坐标和纵坐标
};
void Point::PrintPoint()
{
cout<<"Point: ("<<x<<","<<y<<")";    //输出点
}
class Line: public Point   //利用坐标点类定义直线类, 其基类的数据成员表示直线的中点
{
public:
Line(Point pts, Point pte); //构造函数，用初始化直线的两个端点及由基类数据成员描述的中点
double Length();    //计算并返回直线的长度
void PrintLine();   //输出直线的两个端点和直线长度
private:
class Point pts,pte;   //直线的两个端点，从Point类继承的数据成员表示直线的中点
};

int main()
{
Point ps(-2,5),pe(7,9);
Line l(ps,pe);
cout<<"About the Line: "<<endl;
l.PrintLine();  //输出直线l的信息：两端点及长度
cout<<"The middle point of Line is: ";
l.PrintPoint(); //输出直线l中点的信息
return 0;
}

#include<iostream>
#include<Cmath>
using namespace std;
class Point //定义坐标点类
{
public:
Point():x(0),y(0) {};
Point(double x0, double y0):x(x0), y(y0) {};
void PrintPoint(); //输出点的信息
double getx(){return x;}
double gety(){return y;}
protected:
double x,y;   //点的横坐标和纵坐标
};
void Point::PrintPoint()
{
cout<<"Point: ("<<x<<","<<y<<")";    //输出点
}
class Line: public Point   //利用坐标点类定义直线类, 其基类的数据成员表示直线的中点
{
public:
Line(Point pts, Point pte); //构造函数，用初始化直线的两个端点及由基类数据成员描述的中点
double Length();    //计算并返回直线的长度
void PrintLine();   //输出直线的两个端点和直线长度
private:
class Point pts,pte;   //直线的两个端点，从Point类继承的数据成员表示直线的中点
};
Line::Line(Point pt1,Point pt2):Point((pt1.getx()+pt2.getx())/2,(pt1.gety()+pt2.gety())/2)
{
pts=pt1;
pte=pt2;
}
double Line::Length()
{
double dx=pts.getx()-pte.getx();
double dy=pts.gety()-pte.gety();
return sqrt(dx*dx+dy*dy);
}
void Line::PrintLine()
{
cout<<"1st:"<<endl;
pts.PrintPoint();
cout<<endl;
cout<<"2nd:"<<endl;
pte.PrintPoint();
cout<<endl;
cout<<"The Length of Line:"<<Length()<<endl;
}
int main()
{
Point ps(-2,5),pe(7,9);
Line l(ps,pe);
cout<<"About the Line: "<<endl;
l.PrintLine();  //输出直线l的信息：两端点及长度
cout<<"The middle point of Line is: ";
l.PrintPoint(); //输出直线l中点的信息
return 0;
}