c++第三次作业

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

class CPoint
{
private:
double x;  // 横坐标
double y;  // 纵坐标
public:
CPoint(double xx = 0, double yy = 0):x(xx),y(yy){}
void juli1(CPoint p);
friend void juli2(CPoint p1,CPoint p2);
double getx(){return x;}
double gety(){return y;}
};
void CPoint::juli1(CPoint p)
{
double s=sqrt((p.x-x)*(p.x-x)+(p.y-y)*(p.y-y));

cout<<"两点的距离为："<<s<<endl;
}
void juli2(CPoint p1, CPoint p2)
{
double s=sqrt((p1.x-p2.x)*(p1.x-p2.x)+(p1.y-p2.y)*(p1.y-p2.y));

cout<<"两点的距离为"<<s<<endl;
}
void juli3(CPoint p1,CPoint p2)
{
double s=sqrt((p1.getx()-p2.getx())*(p1.getx()-p2.getx())+(p1.gety()-p2.gety())*(p1.gety()-p2.gety()));

cout<<"两点的距离为："<<s<<endl;
}

int main()
{
CPoint p1,p2(3,3);
cout<<"以成员函数求距离："<<endl;
p1.juli1(p2);
cout<<"以友元函数求距离："<<endl;
juli2(p1, p2);
cout<<"以一般函数求距离："<<endl;
juli3(p1,p2);
return 0;
}