程序代码：

#include <iostream.h>

class yang
{
public:
    yang();
    virtual ~yang();
    yang(const yang&rhs);
    int getage()const{return age;}
    virtual yang* clone(){return new yang(*this);}
    void setage(int t){age=t;}
    virtual void say(){cout << "yang的say\n";}

protected:
    int age;
};
yang::yang():
age(41)
{
    cout << "yang构造函数\n";
}
yang::~yang()
{
    cout << "yang析构函数\n";
}
yang::yang(const yang&rhs)
{
    age=rhs.getage();
    cout << "yang复制函数\n";
}
class lyl:public yang
{
public:
    lyl();
    lyl(const yang& rhs);
    ~lyl();
    yang* clone(){return new lyl(*this);}
    void say(){cout << "lyl的say\n";}
};
lyl::~lyl()
{
    cout << "ly的析构函数\n";
}
lyl::lyl()
{
    cout << "lyl的构造函数\n";
}
lyl::lyl(const yang &rhs):
yang(rhs)
{
    cout << "lyl的复制函数\n";
}
int main()
{
    lyl *p=new lyl;
    yang *q=new yang;
    p->say();
    q=p->clone();

    return 0;
}