c语电话簿，（1）加入一个新电话号码；（2）删除一个电话号码；（3）显示保存的所有电话号码；（4）修改功能；（5）排序功能，-c language telephone directory (1) add a new phone number　(2) to delete a phone number　(3) display all the phone numbers saved　(4) modify the function　(5) sorting functionality.