阅读下列说明和 C++代码，将应填入(n)处的字句写在答题纸的对应栏内。 【说明】 某快餐厅主要制作井出售儿童套餐，一般包括主餐(各类比萨)、饮料和玩具，其餐品种类可能不同，但其制作过程相同。前台服务员(Waiter)调度厨师制作套餐。现采用生成器(Builder) 模式实现制作过程，得到如图 5-1 所示的类图。图5-1 类图 【C++代码】 include<iostream> include <string> using namespace std; class Pizza { private: string parts; public: void setParts(string parts) { this->parts=parts; } string getParts() { return parts; } }; class PizzaBuilder { protected:Pizza* pizza; public: Pizza* getPizza() { retum pizza; } void createNewPizza() { pizza = new Pizza(); } ( 1 ); } class HawaiianPizzaBuilder :public PizzaBuilder { public: void buildParts() { pizza->setParts("cross +mild + ham&pineapple"); } }; class SpicyPizzaBuider: public PizzaBuilder { public: void buildParts() { pizza->setParts("pan baked +hot + ham&pineapple"); } } Class Waiter{ Private: PizzaBuilder* pizzaBuilder; public: void setPizzaBuilder(PizzaBuilder* pizzaBuilder) { /*设置构建器*/ ( 2 ) } Pizza* getPizza() { return pizzaBuilder->getPizza(); } void construct() { /*构建*/ pizzaBuilder->createNewPizza(); ( 3 ) } }; int main(){ Waiter*waiter=new Waiter(); PizzaBuilder*hawaiian pizzabuilder=new HawaiianPizzaBuilder() ( 4 ); ( 5 ); cout<< "pizza: "<< waiter->getPizza()->getParts()<< endl; } 程序的输出结果为: pizza: cross + mild + ham&pineapple