将下面程序补充完整。 include <iostream> using namespace std; class Base{ public: 【 】fun(){r
将下面程序补充完整。
include <iostream>
using namespace std;
class Base{
public:
【 】 fun(){return 0;} //声明虚函数
};
class Derived:public Base{
public:
x,y;
void SetVal(int a,int b){}
int fun(){return x+y;}
};
void 【 】 SetVal(int a,int b){x=a;y=b;} //类Derived成员函数
void main(){
Derived d;
cout<<d.fun()<<endl;
}