阅读下列程序，写出运行结果： #include usi

#include <iostream>
using namespace std;
class Base
{
public:
virtual void getxy( int i,int j = 0 )
{
x = i;  
y = j;
}
virtual void fun() = 0;
protected:
int x , y;
};
class A : public Base
{
public:
      void fun()
      {
cout<<"x = "<<x<<'\t'<<"y = x * x = "<<x*x<<endl;
}
};
class B : public Base
{
public:
void fun()
{
cout << "x = " << x << '\t' << "y = " << y << endl;
cout << "y = x / y = " << x / y << endl;
}
};
int main()
{
Base * pb;
A obj1;
B obj2;
pb = &obj1;
pb -> getxy( 10 );
pb -> fun();
pb = &obj2;
pb -> getxy( 100, 20 );
pb -> fun();
}