![](https://static.youtibao.com/asksite/comm/h5/images/m_q_title.png)
有如下程序: include<iostream> using namespace std; class A { public: virtual void f(){cout
有如下程序:
include<iostream>
using namespace std;
class A
{
public:
virtual void f(){cout<<"1";}
};
class B:public A
{
public:
B (){cout<<"2";}
};
class C:public B
{
public:
virtual void f(){B::f();cout<<"3";}
};
int main()
{
A aa,*p;
B bb;
C cc;
p=&cc;
p->f();
return 0;
}
执行上面程序的输出是______。
![](https://static.youtibao.com/asksite/comm/h5/images/solist_ts.png)