#include<iostream.h>
class point
{
protected:
    int x;
    int y;
public:
    point(int c,int k):x(c),y(k){}
    friend ostream & operator << (ostream & output,point & p);
    friend istream & operator >> (istream & input ,point & p);
};
istream & operator >> (istream & input,point & p)
{
    char a;
    input>>a>>p.x>>a>>p.y>>a;
    return input;
}
ostream & operator << (ostream & output,point & p)
{
    cout<<"the point is :"<< "(" << p.x << "," << p.y << ")"<<endl;
    return output;
}
class circle:public point
{
private:
    int r;
public:
    circle(int x,int y,int r1):point(x,y){ r = r1;}
    friend ostream & operator << (ostream & output,circle & c);
};
/**/ostream & operator << (ostream & output,circle & c)
{   

    cout<<c;
    return output;
}
int main()
{
    circle c1(0,1,2);
    cout<<c1;
    return 0;
}

看不懂