用链表实现员工信息系统，通过链表实现 通讯录编辑（添加、删除）； 查找； 排序； 将通讯录写入文件； 从文件读入通讯录。-Employee information system, a linked list, address book editor through the list (add, delete) search sort contacts write to a file read from the file into the address book.