在数学上，平面直角坐标系上的点用X轴和Y轴上的两个坐标值唯一确定，两点确定一条线段。现在我们封装一个“Point类”和“Line类”来实现平面上的点的操作。
根据“append.cc”，完成Point类和Line类的构造方法和show()方法，输出各Line对象和Point对象的构造和析构次序。
接口描述：
Point::show()方法：按格式输出Point对象。
Point::x()方法：取x坐标。
Point::y()方法：取y坐标。
Line::show()方法：按格式输出Line对象。
Line::SetLine(double, double, double, double)方法：设置Line对象起点的x,y坐标（第一个和第二参数）和终点的x,y坐标（第三个和第四个坐标），并返回本对象
Line::SetLine(const Point &, const Point &)方法：设置Line对象的起点（第一个参数）和终点（第二个坐标），并返回本对象
Line::SetLine(const Line&)方法：设置Line对象，复制参数的坐标，并返回本对象
Line::readLine()方法：从标准输入上读入坐标，格式见Sample
Line::start()方法：取Line的起点
Line::end()方法：取Line的终点
Line::setStart()方法：设置Line的起点
Line::setEnd()方法：设置Line的终点
以下三个函数用于输出Line对象，格式同sample
showLineCoordinate(const Line&)
showLinePoint(const Line&)
showLine(const Line&)
输入的第一行为N，表示后面有N行测试样例。
每行为两组坐标“x,y”，分别表示线段起点和终点的x坐标和y坐标，两组坐标间用一个空格分开，x和y的值都在double数据范围内。
输出为多行，每行为一条线段，起点坐标在前终点坐标在后，每个点的X坐标在前，Y坐标在后，Y坐标前面多输出一个空格，用括号包裹起来。输出格式见sample。
C语言的输入输出被禁用。
Point : (1, -2) is created.
Point : (2, -1) is created.
Point : (0, 0) is created.
Point : (0, 0)
Point : (0, 0) is created.
Point : (0, 0) is created.
Line : (0, 0) to (0, 0) is created.
Point : (0, 0) is created.
Point : (0, 0) is created.
Line : (0, 0) to (0, 0) is created.
Point : (0, 0) is created.
Point : (0, 0) is created.
Line : (0, 0) to (0, 0) is created.
Point : (0, 0) is created.
Point : (0, 0) is created.
Line : (0, 0) to (0, 0) is created.
Point : (0, 0) is created.
Point : (0, 0) is created.
Line : (0, 0) to (0, 0) is created.
Line : (0, 0) to (1, 1)
Line : (1, 1) to (2, 3)
Line : (2, 3) to (4, 5)
Line : (0, 1) to (1, 0)
Point : (1, -2) is copied.
Point : (2, -1) is copied.
Line : (1, -2) to (2, -1) is created.
Point : (1, -2) is copied.
Point : (0, 0) is copied.
Line : (1, -2) to (0, 0) is created.
Point : (2, -1) is copied.
Point : (0, 0) is copied.
Line : (2, -1) to (0, 0) is created.
Point : (1, -2) is copied.
Point : (2, -1) is copied.
Line : (1, -2) to (2, -1) is copied.
Line : (1, -2) to (2, -1)
Line : Point : (1, -2) to Point : (0, 0)
Line : Point : (1, -2) to Point : (2, -1)
Line : (0, 0) to (2, -1)
Line : (0, 0) to (2, -1) is erased.
Point : (2, -1) is erased.
Point : (0, 0) is erased.
Line : (1, -2) to (2, -1) is erased.
Point : (2, -1) is erased.
Point : (1, -2) is erased.
Line : (1, -2) to (0, 0) is erased.
Point : (0, 0) is erased.
Point : (1, -2) is erased.
Line : (1, -2) to (2, -1) is erased.
Point : (2, -1) is erased.
Point : (1, -2) is erased.
Line : (0, 1) to (1, 0) is erased.
Point : (1, 0) is erased.
Point : (0, 1) is erased.
Line : (2, 3) to (4, 5) is erased.
Point : (4, 5) is erased.
Point : (2, 3) is erased.
Line : (1, 1) to (2, 3) is erased.
Point : (2, 3) is erased.
Point : (1, 1) is erased.
Line : (0, 0) to (1, 1) is erased.
Point : (1, 1) is erased.
Point : (0, 0) is erased.
Line : (0, 0) to (2, -1) is erased.
Point : (2, -1) is erased.
Point : (0, 0) is erased.
Point : (0, 0) is erased.
Point : (2, -1) is erased.
Point : (1, -2) is erased.
#include <iostream>
using namespace std;
class Point
{
friend class Line;
private:
double st,ed;
public:
Point():st(0),ed(0){cout << "Point : (" <<st<< ", " <<ed<<") is created." << endl;}
Point(double stt ,double edd ):st(stt),ed(edd){cout << "Point : (" <<st<< ", " <<ed<<") is created." << endl;}
Point (const Point &p)
{
st = p.st;
ed= p.ed;
cout << "Point : (" << st<< ", " << ed<<") is copied." << endl;
}
double x() const {return st;}
double y() const {return ed;}
void show()
{cout << "Point : (" <<st<< ", "<<ed<< ")" <<endl;}
~Point ()
{cout << "Point : (" <<st<< ", " <<ed <<") is erased." << endl;}
void showNoEndOfLine()const{cout<<"Point : ("<<st<<", "<<ed<<")";}
};
class Line
{
friend class Point;
private :
Point st_,ed_;
public:
Line():st_(0,0),ed_(0,0)
{cout << "Line : (" << st_.x() << ", " << st_.y()<< ") to (" <<ed_.x() <<", " << ed_.y() << ")" << " is created." << endl;}
Line(Point &sst, Point &eed):st_(sst),ed_(eed)
{cout << "Line : (" << st_.x() << ", " << st_.y()<< ") to (" <<ed_.x() <<", " << ed_.y() << ")" << " is created." << endl;}
Line(double x1,double y1,double x2,double y2):st_(x1,y1),ed_(x2,y2)
{cout << "Line : (" << st_.x() << ", " << st_.y()<< ") to (" <<ed_.x() <<", " << ed_.y() << ")" << " is created." << endl;}
void show() const
{cout << "Line : (" << st_.x() << ", " << st_.y()<< ") to (" <<ed_.x() <<", " << ed_.y() << ")" <<endl;}
~Line()
{ cout <<"Line : (" << st_.x() << ", " << st_.y()<< ") to (" <<ed_.x() <<", " << ed_.y() << ")" << " is erased." << endl;}
Line(const Line &l):st_(l.st_),ed_(l.ed_)
{cout << "Line : (" << st_.x() << ", " << st_.y()<< ") to (" <<ed_.x() <<", " << ed_.y() << ")" << " is copied." <<endl;}
Line setLine(double x1,double y1,double x2,double y2)
{
st_.st=x1;
st_.ed=y1;
ed_.st=x2;
ed_.ed=y2;
return *this;}
Line &setLine(const Point &p ,const Point &q)
{
st_=p;
ed_=q;
return *this;
}
Line &setLine(const Line &p)
{
st_=p.st_;
ed_=p.ed_;
return *this;
}
void readLine()
{
double x1,y1,x2,y2;
char in;
cin>>x1>>in>>y1>>x2>>in>>y2;
st_.st=x1;
st_.ed=y1;
ed_.st=x2;
ed_.ed=y2;
}
const Point &start()const
{return st_;}
const Point &end()const
{return ed_;}
void setStart(Point &s)
{st_=s;}
void setEnd(Point &e)
{ed_=e;}
};
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);
}
