有如下程序:
include <iostream>
using namespaee std;
class ONE{
public:
virtual void f( ){cout<<"1";}
};
class TWO:public ONE{
public:
TWO( )1 cout<<"2";}
{;
class THREE:public TWO{
public:
virtual void f( )}TWO::f( );cout<<"3";}
};
int main( ){
ONE aa,*P;
TWO bb;
THREE cc;
P=&cc;
p->f( );
return 0;
}
程序的输出结果是______。