[实验任务一]：打包员
在我们课堂上的“购物车”的例子中，增加一个新的访问者：打包员，负责对购物车中货物装包。
实验要求：
1. 画出对应的类图；
2. 提交源代码；
#include <iostream>
#include <string>
#include <list>
using namespace std;
class Product;
class Book;
class Apple;
class Visitor
{
protected:
string name;
public:
void SetName(string name) {
this->name = name;
}
virtual void Visit(Apple *apple) {};
virtual void Visit(Book *book) {};
};
class Product
{
public:
// Methods
virtual void Accept(Visitor *visitor) {};
};
// "ConcreteElement"
class Apple : public Product {
public:
void Accept(Visitor *visitor) {
visitor->Visit(this);
}
};
class Book :public Product {
public:
void Accept(Visitor* visitor) {
visitor->Visit(this);
}
};
class Customer : public Visitor {
public:
void Visit(Book *book) {
cout << "顾客" << name << "买书" << endl;
}
void Visit(Apple *apple) {
cout << "顾客" << name << "选苹果" << endl;
}
};
class Saler : public Visitor {
public:
void Visit(Book *book) {
cout << "收银员" << name << "直接计算书的价格" << endl;
}
void Visit(Apple *apple) {
cout << "收银员" << name << "给苹果过秤，然后计算其价格" << endl;
}
};
class Packer : public Visitor {
public:
void Visit(Book *book) {
cout << "打包员" << name << "给书打包" << endl;
}
void Visit(Apple *apple) {
cout << "打包员" << name << "给苹果打包" << endl;
}
};
// "ObjectStructure"
class BuyBasket
{
private:
list<Product*> products;
public:
void Attach(Product *product)
{
products.push_back(product);
}
void Detach(Product *product)
{
products.remove(product);
}
void Accept(Visitor *visitor)
{
for (std::list<Product*>::iterator it = products.begin(); it != products.end(); ++it)
(*it)->Accept(visitor);
}
};
int main()
{
BuyBasket *buybasket = new BuyBasket();
Product* apple = new Apple();
Product* book = new Book();
buybasket->Attach(apple);
buybasket->Attach(book);
Customer *customer = new Customer();
customer->SetName("张三");
Saler* saler = new Saler();
saler->SetName("李四");
Packer* packer = new Packer();
packer->SetName("王五");
// Employees are visited
cout << "----customer----" << endl;
buybasket->Accept(customer);
cout << "----saler----" << endl;
buybasket->Accept(saler);
cout << "----packer----" << endl;
buybasket->Accept(packer);
}
3. 注意编程规范。
