友元函數

#include <iostream>
#include <cmath>
using namespace std;
class point
{
private:
 int x,y;
 friend int dist1(point p1,point p2);
public:
 point(int a=10,int b=10)
 {
x=a; y=b;
 }
 int getx() {return x;}
 int gety() {return y;}
};

int dist1(point p1,point p2)
{
double x=(p2.x-p1.x);
double y=(p2.y-p1.y);
return sqrt(x*x+y*y);
}

int dist2(point p1,point p2)
{
double x=p2.getx()-p1.getx();
double y=p2.gety()-p1.gety();
return sqrt(x*x+y*y);
}

void main()
{
point p1(2,5),p2(4,20);
cout<<dist1(p1,p2)<<endl;
cout<<dist2(p1,p2)<<endl;
}