基于自写双向循环链表的学生管理系统。
其中链表是模板类，有丰富的功能。

　指令1: 添加若干位学生(学号 成绩)，以0结束。
　指令2: 删除第1位指定学号的学生。
　指令3: 删除所有指定成绩的学生。
　指令4: 显示第1位指定学号的学生的成绩。
　指令5: 显示所有指定成绩的学生的学号。
　指令6: 显示所有学生信息。
　指令-1: 退出。

如果你是因为作业搜索到本代码，学长真心建议你更改一下List部分的代码。小心助教发现。(Student management system based on self writing two way linked list.

The chain table is a template class and has a rich function.



Instruction 1: adds a number of students (student number) to end at 0.

Instruction 2: deletes first students with designated school numbers.

Instruction 3: deletes all assigned students.

The instruction 4: shows the results of first designated student numbers.

The instruction 5: shows the student number of all the students with specified grades.

Instruction 6: displays all student information.

Instruction -1: exits.



If you search the code for homework, the seniors sincerely suggest that you change the code of the List part. Be careful with the assistantship.)