?#include?<iostream>
#include?<cmath>
using?namespace?std;

class?Point
{
public:
Point(int?xx=0,int?yy=0){X=xx;Y=yy;};
Point(Point?&p);
int?GetX()?{return?X;}
int?GetY()?{return?Y;}
private:
int?X,Y;
};
Point::Point(Point?&p)
{
X=p.X;
Y=p.Y;
cout?<<"point拷貝構造函數(shù)被調(diào)用;"<<endl;
}
class?Line
{
public:
Line(Point?xp1,Point?xp2); ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?//不懂
Line(Line?&); ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?//不懂
double?GetLen()?{return?len;}
private:
Point?p1,p2; ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? //不懂
double?len;
};
Line::Line(Point?xp1,Point?xp2)
:p1(xp1),p2(xp2) ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? //不懂
{
cout?<<"Line的構造函數(shù)被調(diào)用"<<endl;
double?x=double(p1.GetX()-p2.GetX());
double?y=double(p1.GetX()-p2.GetY());
len=sqrt(x*x+y*y);
}
Line::Line(Line?&L):p1(L.p1),p2(L.p2) ? ? ? ? ? ? ? ? ? ? ?//不懂
{
cout<<"Line拷貝構造函數(shù)被調(diào)用"<<endl;
len=L.len;

}

void?main()
{
Point?myp1(1,1),myp2(4,5);
Line?line(myp1,myp2);
Line?line2(line);
cout<<"第一條線的長度是：";
cout<<line.GetLen()<<endl;
cout<<"第二條線的長度是：";
cout<<line2.GetLen()<<endl;
}