写出以下程序的运行结果。 #include class B

#include<iostream.h>
class Base(
int a;
public：
Base(int a1=O){a=a1;show();f1();}
virtual void Show(){cout<<"Base::show();";cout<<"a="<<a<<endl;}
void fl()(cout<<"BaSe::f1();";cout<<”a="<<a<<endl;show();}
};
class Derived:public Base{
int a;
public:
Derived(int al=1){a=al;show();fl();}
void show(){cout<<"Derived::show";";cout<<"a="<<a<<endl;}
};
void main(){
Base* p1=new Derived;
p1->show();
delete p1;
}