c++作业2-D(1330)平面上的点和线——Point类、Line类 (IV)

Problem D: 平面上的点和线——Point类、Line类 (IV)

Time Limit: 1 Sec  Memory Limit: 128 MB
Submit: 8574  Solved: 5899
[Submit][Status]

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(一句一行)

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. ========================= 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 : (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. 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. Point : (0, 0) is erased. Point : (2, -1) is erased. Point : (1, -2) is erased.

HINT

 

Append Code

append.cc,

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;
    Line line[num];
    for(i = 0; i < num; i++)
    {
        std::cout<<"=========================\n";
        std::cin>>x1>>c>>y1>>x2>>c>>y2;
        line[i].SetLine(x1, y1, x2, y2);
        line[i].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();
}

答案

#include<iostream>
using namespace std;
class Point
{
private:
    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;
    }
    Point(const Point& p)
    {
        x=p.x;
        y=p.y;
        cout<<"Point : ("<<x<<", "<<y<<") is copied."<< endl;
    }
    ~Point()
    {
        cout<<"Point : ("<<x<<", "<<y<<") is erased."<< endl;
    }
    void show()
    {
        cout<<"Point : ("<<x<<", "<<y<<")"<< endl;
    }
    double getx(){return x;}
    double gety(){return y;}
    void setx(double a){x=a;}
    void sety(double b){y=b;}
};
class Line
{
private:
    Point p,q;
    int n,i;
public:
  Line(Point& a,Point& b):p(a),q(b)
  {
    cout<<"Line : ("<<p.getx()<<", "<<p.gety()<<") to ("<<q.getx()<<", "<<q.gety()<<") is created."<< endl;
  }
  Line(double x1=0,double y1=0,double x2=0,double y2=0):p(x1,y1),q(x2,y2)
  {
    cout<<"Line : ("<<p.getx()<<", "<<p.gety()<<") to ("<<q.getx()<<", "<<q.gety()<<") is created."<< endl;
  }
  ~Line()
  {
      cout<<"Line : ("<<p.getx()<<", "<<p.gety()<<") to ("<<q.getx()<<", "<<q.gety()<<") is erased."<< endl;
  }
  void show()
  {
      cout<<"Line : ("<<p.getx()<<", "<<p.gety()<<") to ("<<q.getx()<<", "<<q.gety()<<")"<< endl;
  }
  void SetLine(double x1,double y1,double x2,double y2)
  {
      p.setx(x1);
      p.sety(y1);
      q.setx(x2);
      q.sety(y2);
  }
};
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;
    Line line[num];
    for(i = 0; i < num; i++)
    {
        std::cout<<"=========================\n";
        std::cin>>x1>>c>>y1>>x2>>c>>y2;
        line[i].SetLine(x1, y1, x2, y2);
        line[i].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();
}

疑惑：

Line line[num];

line[i].SetLine(x1, y1, x2, y2)；

line[i].show();