Description
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。
Line::show()方法：按格式输出Line对象。
Input
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。
Output
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。
Sample Input
4
0,0 1,1
1,1 2,3
2,3 4,5
0,1 1,0
Sample Output
Point : (1, -2) is created.
Point : (2, -1) is created.
Point : (0, 0) is created.
Point : (0, 0)
=========================
Point : (0, 0) is created.
Point : (1, 1) is created.
Line : (0, 0) to (1, 1) is created.
Line : (0, 0) to (1, 1)
Line : (0, 0) to (1, 1) is erased.
Point : (1, 1) is erased.
Point : (0, 0) is erased.
=========================
Point : (1, 1) is created.
Point : (2, 3) is created.
Line : (1, 1) to (2, 3) is created.
Line : (1, 1) to (2, 3)
Line : (1, 1) to (2, 3) is erased.
Point : (2, 3) is erased.
Point : (1, 1) is erased.
=========================
Point : (2, 3) is created.
Point : (4, 5) is created.
Line : (2, 3) to (4, 5) is created.
Line : (2, 3) to (4, 5)
Line : (2, 3) to (4, 5) is erased.
Point : (4, 5) is erased.
Point : (2, 3) is erased.
=========================
Point : (0, 1) is created.
Point : (1, 0) is created.
Line : (0, 1) to (1, 0) is created.
Line : (0, 1) to (1, 0)
Line : (0, 1) to (1, 0) is erased.
Point : (1, 0) is erased.
Point : (0, 1) is erased.
=========================
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 : (0, 0) is copied.
Point : (2, -1) is copied.
Line : (0, 0) to (2, -1) is created.
Line : (1, -2) to (2, -1)
Line : (1, -2) to (0, 0)
Line : (2, -1) to (0, 0)
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 : (2, -1) to (0, 0) is erased.
Point : (0, 0) is erased.
Point : (2, -1) 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.
Point : (0, 0) is erased.
Point : (2, -1) is erased.
Point : (1, -2) is erased.
HINT
Append Code
#include<iostream>using namespace std;class Point{private: double x,y;public: Point(double a=0,double b=0):x(a),y(b){cout<<"Point : ("<<x<<", "<<y<<") is created."<<endl;} ~Point(){cout<<"Point : ("<<x<<", "<<y<<") is erased."<<endl;} Point(const Point &q){x=q.x;y=q.y;cout<<"Point : ("<<x<<", "<<y<<") is copied."<<endl;} double getX(){return x;} double getY(){return y;} void show(){cout<<"Point : ("<<x<<", "<<y<<")"<<endl;}};class Line{private: Point xx,yy;public: Line(double a,double b,double c,double d):xx(a,b),yy(c,d){cout<<"Line : ("<<xx.getX()<<", "<<xx.getY()<<") to ("<<yy.getX()<<", "<<yy.getY()<<") is created."<<endl;} Line(Point &a,Point &b):xx(a),yy(b){cout<<"Line : ("<<xx.getX()<<", "<<xx.getY()<<") to ("<<yy.getX()<<", "<<yy.getY()<<") is created."<<endl;} void show(){cout<<"Line : ("<<xx.getX()<<", "<<xx.getY()<<") to ("<<yy.getX()<<", "<<yy.getY()<<")"<<endl;} ~Line(){cout<<"Line : ("<<xx.getX()<<", "<<xx.getY()<<") to ("<<yy.getX()<<", "<<yy.getY()<<") is erased."<<endl;}};int main(){ char c; int num, i; double x1, x2, y1, y2; Point p(1, -2), q(2, -1), t; t.show(); std::cin>>num; for(i = 1; i <= num; i++) { std::cout<<"=========================
"; std::cin>>x1>>c>>y1>>x2>>c>>y2; Line line(x1, y1, x2, y2); line.show(); } std::cout<<"=========================
"; Line l1(p, q), l2(p, t), l3(q, t), l4(t, q); l1.show(); l2.show(); l3.show(); l4.show();}