简单链表实现

基本功能：

（1）添加记录

先判断链表是否已经存在。若不存在，需首先自动新建一个链表，然后再添加一条或多条通讯记录。

（2）显示记录

显示当前所有记录。

（3）查询记录

按名字查找，并显示该记录。

（4）通信录排序

按姓名的字母顺序排序，涉及到冒泡等排序算法。

（5）删除记录

实现逐条删除和删除全部记录两种功能。

（6）更新记录

修改已存在记录的信息（提示：需首先判断该记录是否存在）。

（7）按关系显示记录

只显示与本人有指定关系（亲戚、朋友、同事、同学）的记录。

（8）保存记录

存储所有记录到某个文件（.txt）或缺省文件（Phonebook.txt）。

（9）读入记录

从某个文件（.txt）或缺省文件（Phonebook.txt）读入所有记录。首先判断当前是否有记录在进行操作，若有，进行存储或放弃存储，然后释放内存空间，之后才能从文件读入记录。

（10）退出

结束通讯录软件操作，释放内存后退出。



-List easy implementation

Basic functions:

(1) Add a Record

First to determine whether the list already exists. Does not exist, first of all need to automatically create a new list, and then add one or more communications records.

(2) Show Record

Displays the current all records.

(3) Record Query

Search by name and displays the record.

(4) recorded a sort of communication

By name in alphabetical order, relating to, such as bubble sort algorithm.

(5) delete Record

Realize one by one and delete all the records to delete two functions.

(6) Update Record

Modify the record information already exists (hint: need to first determine whether the records exist).

(7) by the relationship between the show Record

Only show I have designated Relations (relatives, friends, colleagues, classmates) records.

(8) record-keeping

Store all the records to a file (. Txt) file or the default (Phonebook.txt).

(9) read into the Record

From a file (. Txt) file or the default (