Problem B: 平面上的点——Point类 (II)

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。现在我们封装一个“Point类”来实现平面上的点的操作。

根据“append.cc”，完成Point类的构造方法和show()方法，输出各Point对象的构造和析构次序。

接口描述：
Point::show()方法：按输出格式输出Point对象。
Input

输入多行，每行为一组坐标“x,y”，表示点的x坐标和y坐标，x和y的值都在double数据范围内。
Output

输出每个Point对象的构造和析构行为。对每个Point对象，调用show()方法输出其值：X坐标在前，Y坐标在后，Y坐标前面多输出一个空格。每个坐标的输出精度为最长16位。输出格式见sample。

C语言的输入输出被禁用。
Sample Input
1,2
3,3
2,1
Sample Output
Point : (0, 0) is created.
Point : (1, 2) is created.
Point : (1, 2)
Point : (1, 2) is erased.
Point : (3, 3) is created.
Point : (3, 3)
Point : (3, 3) is erased.
Point : (2, 1) is created.
Point : (2, 1)
Point : (2, 1) is erased.
Point : (0, 0) is copied.
Point : (1, 1) is created.
Point : (0, 0)
Point : (1, 1)
Point : (0, 0)
Point : (1, 1) is erased.
Point : (0, 0) is erased.
Point : (0, 0) is erased.

#include <iostream>#include <string>#include <vector>#include <iomanip>using namespace std;class Point{private:    double x, y;public:    Point(double a ,double b = 1):x(a),y(b){    cout<<"Point : ("<<setprecision(16)<<x<<", "<<y<<") is created."<<endl;    }    Point():x(0),y(0)    {         cout<<"Point : ("<<setprecision(16)<<x<<", "<<y<<") is created."<<endl;    }    void show()    {        cout<<"Point : ("<<setprecision(16)<<x<<", "<<y<<")"<<endl;    }    Point(const Point &t)    {        x = t.x;        y = t.y;        cout<<"Point : ("<<setprecision(16)<<x<<", "<<y<<") is copied."<<endl;    }    ~Point()    {        cout<<"Point : ("<<setprecision(16)<<x<<", "<<y<<") is erased."<<endl;    }};int main(){    char c;    double a, b;    Point q;    while(std::cin>>a>>c>>b)    {        Point p(a, b);        p.show();    }    Point q1(q), q2(1);    q1.show();    q2.show();    q.show();}