平面上的点——Point类 (VI)

Posted by 可乐 on March 5, 2017
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.

##代码如下:
#include

using namespace std;
class Point
{
    friend class Line;
    double x,y;
public:
    Point(){x=0;y=0;cout<<"Point : ("<<x<<", "<<y<<") is created."<<endl;}
    Point(double a,double b)
    {
        x=a;y=b;
        cout<<"Point : ("<<x<<", "<<y<<") is created."<<endl;
    }
    void show ()
    {
        cout<<"Point : ("<<x<<", "<<y<<")"<<endl;
    }
    double  w()
    {
        return x;
    }
    double z()
    {
        return y;
    }
    ~Point()
    {
              cout<<"Point : ("<<x<<", "<<y<<") is erased."<<endl;

    }
    Point(const Point &p)
    {
        x=p.x;
        y=p.y;

        cout<<"Point : ("<<x<<", "<<y<<") is copied."<<endl;
    }
};
class Line
{
    friend class Point;
    Point q,w;
public:
    Line(double x1,double y1,double x2,double y2):q(x1,y1),w(x2,y2)
    {

        cout<<"Line : ("<<q.x<<", "<<q.y<<") to ("<<w.x<<", "<<w.y<<") is created."<<endl;
    }
    Line(Point &r,Point &t):q(r),w(t)
    {

        cout<<"Line : ("<<q.x<<", "<<q.y<<") to ("<<w.x<<", "<<w.y<<") is created."<<endl;
    }
    void show ()
    {
        cout<<"Line : ("<<q.x<<", "<<q.y<<") to ("<<w.x<<", "<<w.y<<")"<<endl;
    }
    ~Line()
    {
        cout<<"Line : ("<<q.x<<", "<<q.y<<") to ("<<w.x<<", "<<w.y<<") 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<<"=========================\n";
        std::cin>>x1>>c>>y1>>x2>>c>>y2;
        Line line(x1, y1, x2, y2);
        line.show();
    }
    std::cout<<"=========================\n";
    Line l1(p, q), l2(p, t), l3(q, t), l4(t, q);
    l1.show();
    l2.show();
    l3.show();
    l4.show();
}