班上一位同学参加了软考，问我这样一道题目，结果出乎我的意料： class SalesTicket {public: virtual void printTicket(){cout<<"\n这里是正文"<<endl;}}; class Decorator:public SalesTicket{ SalesTicket *ticket;public: Decorator(SalesTicket *t){ticket=t;} void printTicket(){  if(ticket!=NULL){   ticket->printTicket();} }}; class HeadDecorator:public Decorator{public: HeadDecorator(SalesTicket *t):Decorator(t){} void printTicket(){  cout<<"\n这里是票据的抬头"<<endl;  Decorator::printTicket(); }}; class FootDecorator:public Decorator{public: FootDecorator(SalesTicket *t):Decorator(t){} void printTicket(){  Decorator::printTicket();  cout<<"\n这里是票据的脚注"<<endl; }}; void main(void){ SalesTicket t; FootDecorator f(&t);    HeadDecorator h(&f); h.printTicket(); cout<<"\n------------------------"<<endl; FootDecorator a(NULL);  HeadDecorator b(&a); b.printTicket(); } 有兴趣的可以做一下啊，使你功力倍增

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