问题详情

下列程序的输出结果是______。
include＜iostream＞
using namespace std;
class base
{
public:
int n;
base(int x){n=x;}
virtual void set(int m){n=m;cout＜＜n＜＜"";}
};
class deriveA:public base
{
public:
deriveA(int x):base(x){}
void set(int m){n+=m;cout＜＜n＜＜"";}
};
class deriveB:public base
{
public:
deriveB(int x):base(x){}
void set(int m){n+=m;cout＜＜n＜＜"";}
};
int main()
{
deriveA d1(1);
deriveB.d2(3);
base*pbase;
pbase=&d1;
pbase-＞set(1);
pbase=&d2;
pbase-＞set(2);
return 0;
}请帮忙给出正确答案和分析，谢谢！