第十周实验报告一

#include<iostream>    
#include<Cmath>    
using namespace std;    
class Point //定义坐标点类    
{    
public:    
    double x,y;   //点的横坐标和纵坐标    
    Point(){x=0;y=0;}    
    Point(double x0,double y0) {x=x0; y=y0;}     
    void PrintP(){cout<<" Point:("<<x<<","<<y<<")";}    
};      
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    
{    
private:    
    class Point pt1,pt2;   //直线的两个端点    
    public:    
        Line(Point pts, Point pte);  //构造函数    
        double Dx(){return pt2.x-pt1.x;}    
        double Dy(){return pt2.y-pt1.y;}    
        double Length();//计算直线的长度    
        void PrintL();  //输出直线的两个端点和直线长度    
};    
//构造函数，分别用参数初始化对应的端点及由基类属性描述的中点    
Line::Line(Point pts, Point pte):Point(((pts.x+pte.x )/2),((pts.y +pte.y )/2))    
{    
    pt1=pts;    
    pt2=pte;    
    /*  if(pt1.x>pt2.x)  
    point((-Dx()/2),(-Dy()/2));  
    else  
    point((Dx()/2),(Dy()/2));*/    
}    
double Line::Length(){return sqrt(Dx()*Dx()+Dy()*Dy());};//计算直线的长度    
void Line::PrintL()    
{    
    cout<<" 1st ";    
    pt1.PrintP();    
    cout<<"\n 2nd ";    
    pt2.PrintP();    
    cout<<"\n The middle point of Line: ";    
    PrintP();    
    cout<<"\n The Length of Line: "<<Length()<<endl;    
}    
int main()    
{    
    Point ps(-2,5),pe(7,9);    
    Line l(ps,pe);    
    l.PrintL(); //输出直线l的信息    
    l.PrintP();//输出直线l中点的信息    
    cout<<endl;    
    system("pause");    
    return 0;    
}    

 1st  Point:(-2,5)
 2nd  Point:(7,9)
 The middle point of Line:  Point:(2.5,7)
 The Length of Line: 9.84886
 Point:(2.5,7)
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