本演示程序用TC编写，完成城市单链表的生成，查询城市名或坐标，插入新的城市信息，删除无用城市信息，城市范围信息，查找退出城市管理系统。-TC with the demo program to prepare, complete list of cities in a single generation, inquiry or city coordinates, insert a new city information, delete the useless city information,