python
复制代码
from abc import ABC, abstractmethod
from typing import List, Optional
# 菜单项类
class MenuItem:
def __init__(self, name: str, description: str, vegetarian: bool, price: float):
self.name = name
self.description = description
self.vegetarian = vegetarian
self.price = price
def __str__(self) -> str:
veg_str = " [素食]" if self.vegetarian else ""
return f"{self.name} (¥{self.price:.2f}) - {self.description}{veg_str}"
# 迭代器接口
class Iterator(ABC):
@abstractmethod
def has_next(self) -> bool:
pass
@abstractmethod
def next(self) -> MenuItem:
pass
# 煎饼屋菜单 (使用列表)
class PancakeHouseMenu:
def __init__(self):
self.menu_items: List[MenuItem] = []
self.add_item("传统煎饼", "配鸡蛋和吐司", True, 12.99)
self.add_item("蓝莓煎饼", "新鲜蓝莓制作", True, 14.49)
self.add_item("华夫饼", "配蓝莓或草莓", True, 15.59)
def add_item(self, name: str, description: str,
vegetarian: bool, price: float) -> None:
self.menu_items.append(MenuItem(name, description, vegetarian, price))
def create_iterator(self) -> Iterator:
return PancakeHouseMenuIterator(self.menu_items)
# 煎饼屋菜单迭代器
class PancakeHouseMenuIterator(Iterator):
def __init__(self, items: List[MenuItem]):
self.items = items
self.position = 0
def has_next(self) -> bool:
return self.position < len(self.items)
def next(self) -> MenuItem:
item = self.items[self.position]
self.position += 1
return item
# 餐厅菜单 (使用固定大小数组)
class DinerMenu:
MAX_ITEMS = 6
def __init__(self):
self.menu_items: List[Optional[MenuItem]] = [None] * self.MAX_ITEMS
self.number_of_items = 0
self.add_item("蔬菜汤", "时令蔬菜汤", True, 13.29)
self.add_item("热狗", "酸菜配黄芥末", False, 13.05)
self.add_item("烤鸡", "土豆泥配蔬菜", False, 30.99)
def add_item(self, name: str, description: str,
vegetarian: bool, price: float) -> None:
if self.number_of_items >= self.MAX_ITEMS:
print("错误：菜单已满！无法添加新菜品")
return
self.menu_items[self.number_of_items] = MenuItem(
name, description, vegetarian, price
)
self.number_of_items += 1
def create_iterator(self) -> Iterator:
return DinerMenuIterator(self.menu_items, self.number_of_items)
# 餐厅菜单迭代器
class DinerMenuIterator(Iterator):
def __init__(self, items: List[Optional[MenuItem]], item_count: int):
self.items = items
self.item_count = item_count
self.position = 0
def has_next(self) -> bool:
# 跳过空位置
while (self.position < self.item_count and
self.items[self.position] is None):
self.position += 1
return self.position < self.item_count
def next(self) -> MenuItem:
if not self.has_next():
raise StopIteration()
item = self.items[self.position]
self.position += 1
return item
# 女招待 (客户端)
class Waitress:
def __init__(self, pancake_menu: PancakeHouseMenu, diner_menu: DinerMenu):
self.pancake_menu = pancake_menu
self.diner_menu = diner_menu
def print_menu(self) -> None:
print("====== 早餐菜单 ======")
self._print_menu(self.pancake_menu.create_iterator())
print("\n====== 午餐菜单 ======")
self._print_menu(self.diner_menu.create_iterator())
def _print_menu(self, iterator: Iterator) -> None:
while iterator.has_next():
menu_item = iterator.next()
print(menu_item)
# 测试代码
if __name__ == "__main__":
pancake_menu = PancakeHouseMenu()
diner_menu = DinerMenu()
waitress = Waitress(pancake_menu, diner_menu)
waitress.print_menu()
"""运行结果：
====== 早餐菜单 ======
传统煎饼 (¥12.99) - 配鸡蛋和吐司 [素食]
蓝莓煎饼 (¥14.49) - 新鲜蓝莓制作 [素食]
华夫饼 (¥15.59) - 配蓝莓或草莓 [素食]
====== 午餐菜单 ======
蔬菜汤 (¥13.29) - 时令蔬菜汤 [素食]
热狗 (¥13.05) - 酸菜配黄芥末
烤鸡 (¥30.99) - 土豆泥配蔬菜
"""
python
复制代码
from abc import ABC, abstractmethod
from typing import List
class MenuComponent(ABC):
"""菜单组件的抽象基类"""
def add(self, component: 'MenuComponent') -> None:
raise NotImplementedError("不支持添加操作")
def remove(self, component: 'MenuComponent') -> None:
raise NotImplementedError("不支持移除操作")
def get_child(self, i: int) -> 'MenuComponent':
raise NotImplementedError("不支持获取子项")
@abstractmethod
def get_name(self) -> str:
pass
@abstractmethod
def get_description(self) -> str:
pass
@abstractmethod
def get_price(self) -> float:
pass
@abstractmethod
def is_vegetarian(self) -> bool:
pass
@abstractmethod
def print(self) -> None:
pass
class MenuItem(MenuComponent):
"""叶子节点：菜单项"""
def __init__(self, name: str, description: str,
vegetarian: bool, price: float):
self.name = name
self.description = description
self.vegetarian = vegetarian
self.price = price
def get_name(self) -> str:
return self.name
def get_description(self) -> str:
return self.description
def get_price(self) -> float:
return self.price
def is_vegetarian(self) -> bool:
return self.vegetarian
def print(self) -> None:
veg_str = " (素食)" if self.vegetarian else ""
print(f" {self.name}{veg_str}, ¥{self.price:.2f}")
print(f" -- {self.description}")
class Menu(MenuComponent):
"""组合节点：菜单（可以包含菜单项或子菜单）"""
def __init__(self, name: str, description: str):
self.name = name
self.description = description
self.components: List[MenuComponent] = []
def add(self, component: MenuComponent) -> None:
self.components.append(component)
def remove(self, component: MenuComponent) -> None:
self.components.remove(component)
def get_child(self, i: int) -> MenuComponent:
return self.components[i]
def get_name(self) -> str:
return self.name
def get_description(self) -> str:
return self.description
def get_price(self) -> float:
raise NotImplementedError("菜单没有价格")
def is_vegetarian(self) -> bool:
raise NotImplementedError("菜单没有素食属性")
def print(self) -> None:
print(f"\n{self.name}, {self.description}")
print("-" * 50)
for component in self.components:
component.print()
class Waitress:
"""女招待类 - 客户端"""
def __init__(self, all_menus: MenuComponent):
self.all_menus = all_menus
def print_menu(self) -> None:
self.all_menus.print()
def print_vegetarian_menu(self) -> None:
print("\n===== 素食菜单 =====")
self._print_vegetarian(self.all_menus)
def _print_vegetarian(self, component: MenuComponent) -> None:
try:
if component.is_vegetarian():
print(f" {component.get_name()}, ¥{component.get_price():.2f}")
print(f" -- {component.get_description()}")
except NotImplementedError:
pass
try:
for child in component.components:
self._print_vegetarian(child)
except AttributeError:
pass
def build_menu_system() -> MenuComponent:
"""构建整个菜单系统"""
# 顶层菜单
all_menus = Menu("主菜单", "所有菜单的总和")
# 早餐菜单
breakfast_menu = Menu("早餐菜单", "早晨供应")
breakfast_menu.add(MenuItem("煎饼", "配枫糖浆", True, 12.99))
breakfast_menu.add(MenuItem("华夫饼", "配蓝莓", True, 14.99))
breakfast_menu.add(MenuItem("培根鸡蛋", "配吐司", False, 18.99))
# 午餐菜单
lunch_menu = Menu("午餐菜单", "中午供应")
lunch_menu.add(MenuItem("蔬菜汤", "时令蔬菜", True, 16.99))
lunch_menu.add(MenuItem("烤鸡三明治", "配沙拉", False, 22.99))
lunch_menu.add(MenuItem("凯撒沙拉", "新鲜蔬菜", True, 18.99))
# 晚餐菜单
dinner_menu = Menu("晚餐菜单", "晚上供应")
dinner_menu.add(MenuItem("牛排", "配烤土豆", False, 68.99))
dinner_menu.add(MenuItem("烤三文鱼", "配蔬菜", False, 58.99))
dinner_menu.add(MenuItem("素食意面", "配番茄酱", True, 36.99))
# 甜点菜单（作为晚餐的子菜单）
dessert_menu = Menu("甜点菜单", "餐后甜点")
dessert_menu.add(MenuItem("苹果派", "配香草冰淇淋", True, 18.99))
dessert_menu.add(MenuItem("巧克力蛋糕", "双层巧克力", True, 22.99))
dessert_menu.add(MenuItem("奶酪拼盘", "精选奶酪", False, 28.99))
# 添加到晚餐菜单
dinner_menu.add(dessert_menu)
# 咖啡菜单（独立菜单）
cafe_menu = Menu("咖啡菜单", "全天供应")
cafe_menu.add(MenuItem("浓缩咖啡", "纯正意大利风味", True, 12.99))
cafe_menu.add(MenuItem("卡布奇诺", "现磨咖啡", True, 16.99))
cafe_menu.add(MenuItem("热巧克力", "比利时巧克力", True, 14.99))
# 将所有菜单添加到顶层菜单
all_menus.add(breakfast_menu)
all_menus.add(lunch_menu)
all_menus.add(dinner_menu)
all_menus.add(cafe_menu)
return all_menus
if __name__ == "__main__":
# 构建菜单系统
menu_system = build_menu_system()
# 创建女招待
waitress = Waitress(menu_system)
print("=" * 50)
print("餐厅完整菜单:")
print("=" * 50)
waitress.print_menu()
print("\n" + "=" * 50)
print("素食选项:")
print("=" * 50)
waitress.print_vegetarian_menu()
"""运行结果：
==================================================
餐厅完整菜单:
==================================================
主菜单, 所有菜单的总和
--------------------------------------------------
早餐菜单, 早晨供应
--------------------------------------------------
煎饼 (素食), ¥12.99
-- 配枫糖浆
华夫饼 (素食), ¥14.99
-- 配蓝莓
培根鸡蛋, ¥18.99
-- 配吐司
午餐菜单, 中午供应
--------------------------------------------------
蔬菜汤 (素食), ¥16.99
-- 时令蔬菜
烤鸡三明治, ¥22.99
-- 配沙拉
凯撒沙拉 (素食), ¥18.99
-- 新鲜蔬菜
晚餐菜单, 晚上供应
--------------------------------------------------
牛排, ¥68.99
-- 配烤土豆
烤三文鱼, ¥58.99
-- 配蔬菜
素食意面 (素食), ¥36.99
-- 配番茄酱
甜点菜单, 餐后甜点
--------------------------------------------------
苹果派 (素食), ¥18.99
-- 配香草冰淇淋
巧克力蛋糕 (素食), ¥22.99
-- 双层巧克力
奶酪拼盘, ¥28.99
-- 精选奶酪
咖啡菜单, 全天供应
--------------------------------------------------
浓缩咖啡 (素食), ¥12.99
-- 纯正意大利风味
卡布奇诺 (素食), ¥16.99
-- 现磨咖啡
热巧克力 (素食), ¥14.99
-- 比利时巧克力
==================================================
素食选项:
==================================================
===== 素食菜单 =====
煎饼, ¥12.99
-- 配枫糖浆
华夫饼, ¥14.99
-- 配蓝莓
蔬菜汤, ¥16.99
-- 时令蔬菜
凯撒沙拉, ¥18.99
-- 新鲜蔬菜
素食意面, ¥36.99
-- 配番茄酱
苹果派, ¥18.99
-- 配香草冰淇淋
巧克力蛋糕, ¥22.99
-- 双层巧克力
浓缩咖啡, ¥12.99
-- 纯正意大利风味
卡布奇诺, ¥16.99
-- 现磨咖啡
热巧克力, ¥14.99
-- 比利时巧克力
"""
