#include<iostream>using namespace std;class Point{public:    Point():x_(0),y_(0){cout<<"Point : (0, 0) is created."<<endl;}    Point(double x, double y):x_(x),y_(y){cout<<"Point : ("<<x_<<", "<<y_<<") is created."<<endl;}    Point(const Point &p);    ~Point();    const double x()const{return x_;}    const double y()const{return y_;}    void show()const{    cout << "Point : ("<<x_<<", "<<y_<<")"<<endl;    }   const void showNoEndOfLine()const{cout << "Point : ("<<x_<<", "<<y_<<")" ;}    double x_, y_;};Point::Point(const Point &p):x_(p.x_),y_(p.y_){cout<<"Point : ("<<x_<<", "<<y_<<") is copied."<<endl;}Point::~Point(){cout<<"Point : ("<<x_<<", "<<y_<<") is erased."<<endl;}istream &operator>>(istream &is, Point &p){    char z;    is >> p.x_ >>z>> p.y_;    return is;}class Line{public:    Line():sta_(0,0),ed_(0,0){cout<<"Line : ("<<sta_.x_<<", "<<sta_.y_<<") to ("<<ed_.x_<<", "<<ed_.y_<<") is created."<<endl;}    Line(double x1,double y1,double x2,double y2 ):sta_(x1,y1),ed_(x2,y2){cout<<"Line : ("<<sta_.x_<<", "<<sta_.y_<<") to ("<<ed_.x_<<", "<<ed_.y_<<") is created."<<endl;}    Line(Point &sta, Point &ed):sta_(sta),ed_(ed){cout<<"Line : ("<<sta_.x_<<", "<<sta_.y_<<") to ("<<ed_.x_<<", "<<ed_.y_<<") is created."<<endl;}    Line(const Line &z);    ~Line();    Line& setLine(double x1,double y1,double x2,double y2){    sta_.x_=x1;    ed_.x_=x2;    sta_.y_=y1;    ed_.y_=y2;    return *this;    }    Line& setLine(const Point &g, const Point &h){    sta_.x_=g.x_;ed_.x_=h.x_;    sta_.y_=g.y_;ed_.y_=h.y_;    return *this;    }    Line& setLine(const Line &k){    sta_.x_=k.sta_.x_;ed_.x_=k.ed_.x_;    sta_.y_=k.sta_.y_;ed_.y_=k.ed_.y_;    return *this;    }    void readLine(){cin>>sta_>>ed_;}    void show()const{    cout << "Line : ("<<sta_.x_<<", "<<sta_.y_<<") to ("<<ed_.x_<<", "<<ed_.y_<<")"<<endl;    }    Point setStart(Point &p){sta_.x_ = p.x_; sta_.y_ = p.y_;}    Point setEnd(Point &q){ed_.x_ = q.x_; ed_.y_ = q.y_;}//调用析构//    Point& l = sta_;//    Point& o = ed_;//    Point& start()const{return l;}//    Point& end()const{return o;}    const Point& start()const{return sta_;}//调用拷贝    const Point& end()const{return ed_;}private:    Point sta_, ed_;};Line::Line(const Line &z):sta_(z.sta_),ed_(z.ed_){//wo        cout<<"Line : ("<<sta_.x_<<", "<<sta_.y_<<") to ("<<ed_.x_<<", "<<ed_.y_<<") is copied."<<endl;}Line::~Line(){cout<<"Line : ("<<sta_.x_<<", "<<sta_.y_<<") to ("<<ed_.x_<<", "<<ed_.y_<<") is erased."<<endl;}void showLineCoordinate(const Line& line){    std::cout<<"Line : ";    std::cout<<"("<<line.start().x()<<", "<<line.start().y()<<")";    std::cout<<" to ";    std::cout<<"("<<line.end().x()<<", "<<line.end().y()<<")";    std::cout<<std::endl;}void showLinePoint(const Line& line){    std::cout<<"Line : ";    line.start().showNoEndOfLine();    std::cout<<" to ";    line.end().showNoEndOfLine();    std::cout<<std::endl;}void showLine(const Line& line){    line.show();}int main(){    int num, i;    Point p(1, -2), q(2, -1), t;    t.show();    std::cin>>num;    Line line[num + 1];    for(i = 1; i <= num; i++)    {        line[i].readLine();        showLine(line[i]);    }    Line l1(p, q), l2(p,t), l3(q,t), l4(l1);    showLineCoordinate(l1);    showLinePoint(l2);    showLinePoint(l3.setLine(l1));    showLineCoordinate(l4.setLine(t,q));    line[0].setStart(t);    line[0].setEnd(q);}