下面的程序将一个普通函数作为类的友元函数，求坐标点之和

输入

1 2 1

输出

2,2,4

#include<iostream>

using namespace std;

class point

{

int X;

int Y;

public:

static int Countp;

point(int x = 0, int y = 0)

{

X = x;

Y = y;

Countp++;

}

point( const point &p)

{

X = p.X;

Y = p.Y;

Countp++;

}

~point()

{

Countp--;

}

friend point myfun(point p1, point p2, point p3);

void playshow()

{

cout << X << "," << Y << ",";

}

};

point myfun(point p1,point p2,point p3)

{

point tmp(p1.X+p2.X+p3.X,p1.Y+p2.Y+p3.Y);

return tmp;

}

int point::Countp = 0;

int  main()

{

int a, b, c;

cin >> a >> b >> c;

point pp0, pp1(a,b), pp2(c);

point p = myfun(pp0, pp1, pp2);

p.playshow();

cout << point::Countp << endl;

}