c++ 继承

class  a {
    public:
     int add(int a,int b) {
        return a + b;
    }
};
class b :public a {
};
int main()
{
    a a;
    printf("%d\n",a.add(1, 2));
    b b;
    printf("%d\n", b.add(1, 2));
}
结果都是3