设计线段类Line，成员数据包括线段两个端点的坐标（double startx,starty,endx,endy）。根据给定的main函数设计必要的成员函数。 main函数已给定，提交时只需要提交main函数外的代码部分。 #include<iostream> #include<cmath> using namespace std; //你提交的代码在这里 int main() { Line L1; cout<<"Show object L1:"; L1.Show(); double x1,y1,x2,y2; cin>>x1>>y1>>x2>>y2; Line L2(x1,y1,x2,y2); cout<<"Show object L2:"; L2.Show(); cin>>x1>>y1>>x2>>y2; cout<<"Reset and Show object L1:"; L1.Set(x1,y1,x2,y2); L1.Show(); cout<<"Reset and Show object L2:"; L2.Set(); L2.Show(); return 0; }

#include<iostream>
#include<cmath>
using namespace std;

class Line{
private:
    double startx, starty, endx, endy;
public:
    Line(){
        startx = 0;
        starty = 0;
        endx = 0;
        endy = 0;
    }
    Line(double x1, double y1, double x2, double y2){
        startx = x1;
        starty = y1;
        endx = x2;
        endy = y2;
    }
    void Set(double x1, double y1, double x2, double y2){
        startx = x1;
        starty = y1;
        endx = x2;
        endy = y2;
    }
    void Set(){
        cin >> startx >> starty >> endx >> endy;
    }
    void Show(){
        cout << "(" << startx << "," << starty << ")" << "--(" << endx << "," << endy << ")" << endl;
    }
};

int main() {
    Line L1;
    cout<<"Show object L1:";
    L1.Show();
    double x1,y1,x2,y2;
    cin>>x1>>y1>>x2>>y2;
    Line L2(x1,y1,x2,y2);
    cout<<"Show object L2:";
    L2.Show();
    cin>>x1>>y1>>x2>>y2;
    cout<<"Reset and Show object L1:";
    L1.Set(x1,y1,x2,y2);
    L1.Show();
    cout<<"Reset and Show object L2:";
    L2.Set();
    L2.Show();
    return 0;
}