一个餐饮指南程序。帮助游客查找小吃店和餐馆，以及哪个小吃店的卤煮最好，哪个餐馆的烤鸭最好等。该程序具有下列功能：

(1) 从文件读取小吃店和餐馆的信息；

(2) 保存小吃店和餐馆的信息到文件；

(3) 增加一个小吃店；

(4) 增加一个餐馆；

(5) 删除一个小吃店；

(6) 删除一个餐馆；

(7) 修改食品的价格；

(8) 修改食品的受欢迎程度。

(9) 显示小吃店的信息；

(10) 显示餐馆的信息；

(11) 显示指定小吃店最便宜的食品

(12) 显示指定餐馆最受欢迎的食品；

-A restaurant guide program. Help visitors find the snack bar and restaurant, and snack bar Luzhu which the best roast duck restaurant which is best and so on. The program has the following features:

(1) snack bars and restaurants from a file of information

(2) save the snack bar and restaurant information to a file

(3) Add a snack bar

(4) add a restaurant

(5) Delete a snack bar

(6) Delete a restaurant

(7) modified food prices

(8) to amend the food s popularity.

(9) shows the snack bar of the information

(10) shows information about the restaurant

(11) shows the cheapest snack foods specified

(12) Display the most popular food restaurants