Data structure practice 1: Project preparation and design

1. Practice content

Student Records Management System

(1) Practical tasks

• Entry of student information, including student ID, name, major, grades of four courses, total score, and ranking;
• The system can browse, add, delete and modify student information;
• The ranking and information output are determined according to the students' scores, with bidirectional bubble sorting, hill sorting, quick sorting, and heap sorting.
• The student information can be inquired upon request, according to the student number or name;
• Information modification can only modify the scores of four courses;
• File access student information.

(2) Project requirements

• Add student information (including student ID, name, major, 4 course results...)
• Browse student information (browse the information after sorting the students)
• Delete student information (delete the information of the specified student, and the user can choose to retrieve the specified item)
• Find student information (find a record that meets the conditions)
• Save student information (save student score file information to a text file)
• Load student information (after logging in to the system, read the student score information saved in the disk file into the memory)

2. Development environment

Implementation language: Java
development platform: IntelliJ IDEA

3. Project design

(1) Class definition

• Student Information

 stuNum  //学号
 stuName  //姓名
 stuMajor  //专业
 stuScore1  //课程1成绩
 stuScore2  //课程2成绩
 stuScore3  //课程3成绩
 stuScore4  //课程4成绩
 stuTotalScore  //总成绩
 stuRank  //排名

• System user class

accountNum  //用户账号
accountPassword  //账户密码

• Database class

accountList  //用户列表
stuList  //学生列表

• Text interaction

学生信息写入导出

• System user method class

系统用户信息增删改查

• Student Information Method

学生信息增删改查

• Account login system class

系统登录界面及具体方法

• Student Information Management

学生信息管理界面及具体方法

• Main system class

系统入口界面及具体方法

(2) Sorting algorithm

• Two-way bubble sort

比较相邻两个元素的大小。如果前一个元素比后一个元素大，则两元素位置交换；
对数组中所有元素的组合进行第1步的比较；
奇数趟时从左向右进行比较和交换；
偶数趟时从右向左进行比较和交换；
当从左端开始遍历的指针与从右端开始遍历的指针相遇时，排序结束。

• Hill sort

先取一个小于n的步长d1，把表中全部元素怒分成d1个组，所有距离为d1的倍数的记录放在同一个组中，在各组中进行直接插入排序；
取第二个步长d2<d1，重复上述过程，直到所取到的d=1，即所有元素已放在同一组中，再进行直接插入排序。

• Quick sort

先从数列中取出一个数作为基准数；
将比这个数大的数全放到它的右边，小于或等于它的数全放到它的左边；
再对左右区间重复上述二步，直到各区间只有一个数。

• Heap sort

首先将待排序的数组构造成一个大根堆，此时，整个数组的最大值就是堆结构的顶端；
将顶端的数与末尾的数交换，此时，末尾的数为最大值，剩余待排序数组个数为n-1；
将剩余的n-1个数再构造成大根堆，再将顶端数与n-1位置的数交换，如此反复执行，便能得到有序数组。