阅读下列程序，写出运行结果： #include usi

#include <iostream>
using namespace std;
class Bclass
{
public:
Bclass( int i, int j )
{
x = i;
y = j;
}
virtual int fun()
{
return 0;
}
protected:
int x, y;
};
class Iclass:public Bclass
{
public :
Iclass(int i, int j, int k):Bclass(i, j)
{
z = k;
}
int fun()
{
return ( x + y + z ) / 3;
}
private :
int z;
};
int main()
{
Iclass obj( 2, 4, 10 );
Bclass p1 = obj;
cout << p1.fun() << endl;
Bclass &p2 = obj;
cout << p2.fun() << endl;
cout << p2.Bclass :: fun() << endl;
Bclass *p3 = &obj;
cout << p3 -> fun() << endl;
}