BLOG3

import java.text.Collator;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Scanner;
public class Main {
    private static final int COURSE_RECORD_TYPE = 1;
    private static final int SCORE_RECORD_TYPE = 2;
    private final ParseInput parseInput;

    public Main() {
        parseInput = new ParseInput();
    }

    public static void main(String[] args) {
        Main main = new Main();
        main.run();
    }

    private void run() {
        Scanner scanner = new Scanner(System.in);
        String input = scanner.nextLine();
        while (!input.equals("end")) {
            parseInput.parseInput(input);
            input = scanner.nextLine();
        }
        parseInput.showStudents();
        parseInput.showCourses();
        parseInput.showClasses();
    }}
class Cls implements Comparable<Cls> {
    private final String id;
    private final ArrayList<Student> students;

    public Cls(String id) {
        this.id = id;
        students = new ArrayList<>();
    }

    public String getId() {
        return id;
    }

    public void addStudent(Student student) {
        students.add(student);
    }

    public ArrayList<Student> getStudents() {
        return students;
    }

    @Override

    public int compareTo(Cls o) {
        return id.compareTo(o.getId());
    }}
class Student implements Comparable<Student> {
    private final String id;
    private final String name;
    private Cls cls;

    public Student(String name, String id) {
        this.name = name;
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setCls(Cls cls) {
        this.cls = cls;
    }

    public Cls getCls() {
        return cls;
    }

    public String getId() {
        return id;
    }

    @Override

    public int compareTo(Student o) {
        return id.compareTo(o.getId());
    }}
class ParseInput {
    private static final int COURSE_RECORD_TYPE = 0;
    private static final int SCORE_RECORD_TYPE =0 ;
    private final ArrayList<Course> courses;
    private final ArrayList<Student> students;
    private final ArrayList<ChooseCourse> chooseCourses;
    private final ArrayList<Cls> classes;

    public ParseInput() {
        courses = new ArrayList<>();
        students = new ArrayList<>();
        chooseCourses = new ArrayList<>();
        classes = new ArrayList<>();
    }

    public void parseInput(String input) {
        String[] items = input.split(" ");
        int type = InputMatching.matchingInput(input);
        if (type == 1/*COURSE_RECORD_TYPE*/) {
            parseCourseRecord(items);
        } else if (type == /*SCORE_RECORD_TYPE*/2) {
            parseScoreRecord(items);
        } else {
            System.out.println("wrong format");
        }
    }

    private void parseCourseRecord(String[] items) {
        String courseName = items[0];
        String courseType = items[1];
        String checkType = items[2];
        Course course = new Course(courseName, courseType, checkType);
        if (!checkCourse(course)) {
            return;
        }
        if (getCourse(courseName) == null) {
            course = new Course(courseName, courseType, checkType);
            courses.add(course);
        }
    }

    private boolean checkCourse(Course course) {
        int courseType, accessType;
        if (course.getType().equals("必修")) {
            courseType = 0;
        } else if (course.getType().equals("选修")) {
            courseType = 1;
        } else {
            courseType = -1;
        }

        if (course.getMethod().equals("考试")) {
            accessType = 0;
        } else if (course.getMethod().equals("考察")) {
            accessType = 1;
        } else {
            accessType = -1;
        }
        if (courseType == 0 && (accessType == 0)) {
            return true;
        }
        if (courseType == 1 && (accessType == 0 || accessType == 1)) {
            return true;
        }
        System.out.println(course.getName() + " : course type & access mode mismatch");
        return false;
    }

    private void parseScoreRecord(String[] items) {
        String stuId = items[0];
        String stuName = items[1];
        String courseName = items[2];
        String clsId = stuId.substring(0, 6);
        Cls cls;
        Student stu;
        cls = getCls(clsId);
        if (cls == null) {
            cls = new Cls(clsId);
            classes.add(cls);
        }
        stu = getStudent(stuId);
        if (stu == null) {
            stu = new Student(stuName, stuId);
            students.add(stu);
            cls.addStudent(stu);
        }
        stu.setCls(cls);
        Course course = getCourse(courseName);
        if (course == null) {
            System.out.println(courseName + " does not exist");
            return;
        }
        if (!checkGrade(items, course)) {
            return;
        }
        Grade grade;
        if (items.length == 4) {
            int finalScore = Integer.parseInt(items[3]);
            grade = new AssessmentGrade(finalScore);
        } else {
            int usualScore = Integer.parseInt(items[3]);
            int finalScore = Integer.parseInt(items[4]);
            grade = new ExaminationGrade(usualScore, finalScore);
        }
        if (existChooseCourse(stu, course)) {
            return;
        }
        ChooseCourse chooseCourse = new ChooseCourse(course, stu, grade);
        chooseCourses.add(chooseCourse);
    }

    private boolean existChooseCourse(Student stu, Course course) {
        for (ChooseCourse chooseCourse : chooseCourses) {
            if (chooseCourse.getCourse().getName().equals(course.getName())) {
                if (chooseCourse.getStudent().getName().equals(stu.getName())) {
                    return true;
                }
            }
        }
        return false;
    }

    private boolean checkGrade(String[] items, Course course) {
        String courseType = course.getMethod();
        if (courseType.equals("考试") && items.length == 5) {
            return true;
        }
        if (courseType.equals("考察") && items.length == 4) {
            return true;
        }
        System.out.println(items[0] + " " + items[1] + " : access mode mismatch");
        return false;
    }

    public void showStudents() {
        Collections.sort(students);
        for (Student student : students) {
            ArrayList<ChooseCourse> studentCourseSelects = getStudentSelects(student.getId());
            if (studentCourseSelects.size() != 0) {
                System.out.println(student.getId() + " " + student.getName() + " " + getAvgTotalScore(studentCourseSelects));
            } else {
                System.out.println(student.getId() + " " + student.getName() + " did not take any exams");
            }
           
        }
    }

    public void showCourses() {
        for (Course course : courses) {
            ArrayList<ChooseCourse> courseSelects = getCourseSelects(course.getName());
            if (courseSelects.size() == 0) {
                System.out.println(course.getName() + " has no grades yet");
            } else {
                if (course.getMethod().equals("考试")) {
                    System.out.println(course.getName() + " " + getAvgUsualScore(courseSelects)
                            + " " + getAvgFinalScore(courseSelects) + " " + getAvgTotalScore(courseSelects));
                } else {
                    System.out.println(course.getName() + " " + getAvgFinalScore(courseSelects)
                            + " " + getAvgTotalScore(courseSelects));
                }
               
            }
        }
    }

    public void showClasses() {
        Collections.sort(classes);
        for (Cls cls : classes) {
            ArrayList<ChooseCourse> classCourseSelects = getClassSelects(cls.getId());
            if (classCourseSelects.size() == 0) {
                System.out.println(cls.getId() + " has no grades yet");
            } else {
                System.out.println(cls.getId() + " " + getAvgTotalScore(classCourseSelects));
            }
        }
    }

    private static int getAvgUsualScore(ArrayList<ChooseCourse> courseSelects) {
        int sum = 0;
        for (ChooseCourse cs : courseSelects) {
            sum += ((ExaminationGrade) cs.getGrade()).getUsualScore();
        }
        return sum / courseSelects.size();
    }

    public int getAvgTotalScore(ArrayList<ChooseCourse> listChooseCourse) {
        int sum = 0;
        for (ChooseCourse cs : listChooseCourse) {
            sum += cs.getGrade().getTotalScore();
        }
        return sum / listChooseCourse.size();
    }

    private static int getAvgFinalScore(ArrayList<ChooseCourse> courseSelects) {
        int sum = 0;
        for (ChooseCourse cs : courseSelects) {
            sum += cs.getGrade().getFinalScore();
        }
        return sum / courseSelects.size();
    }

    private ArrayList<ChooseCourse> getClassSelects(String className) {
        getCls(className);
        ArrayList<ChooseCourse> classSelects = new ArrayList<>();
        for (ChooseCourse cs : chooseCourses) {
            if (className.equals(cs.getStudent().getCls().getId())) {
                classSelects.add(cs);
            }
        }
        return classSelects;
    }

    private ArrayList<ChooseCourse> getStudentSelects(String stuId) {
        ArrayList<ChooseCourse> stuSelects = new ArrayList<>();
        for (ChooseCourse cs : chooseCourses) {
            if (stuId.equals(cs.getStudent().getId())) {
                stuSelects.add(cs);
            }
        }
        return stuSelects;
    }

    private ArrayList<ChooseCourse> getCourseSelects(String courseName) {
        ArrayList<ChooseCourse> courseSelects = new ArrayList<>();
        for (ChooseCourse cs : chooseCourses) {
            if (courseName.equals(cs.getCourse().getName())) {
                courseSelects.add(cs);
            }
        }
        return courseSelects;
    }

    private Cls getCls(String clsId) {
        for (Cls cls : classes) {
            if (cls.getId().equals(clsId)) {
                return cls;
            }
        }
        return null;
    }

    private Student getStudent(String stuId) {
        for (Student student : students) {
            if (student.getId().equals(stuId)) {
                return student;
            }
        }
        return null;
    }

    private Course getCourse(String courseName) {
        for (Course course : courses) {
            if (course.getName().equals(courseName)) {
                return course;
            }
        }
        return null;
    }}
class ChooseCourse {
    private final Course course;
    private final Student student;
    private final Grade grade;

    public ChooseCourse(Course course, Student student, Grade grade) {
        this.course = course;
        this.grade = grade;
        this.student = student;
    }

    public Student getStudent() {
        return student;
    }

    public Course getCourse() {
        return course;
    }

    public Grade getGrade() {
        return grade;
    }}
class InputMatching {
    private static final String STU_NUM_MATCHING = "\\d{8}";
    private static final String STU_NAME_MATCHING = "[^ \t]{1,10}";
    private static final String SCORE_MATCHING = "([1-9]?[0-9]|100)";
    private static final String COURSE_NAME_MATCHING = "[^ \t]{1,10}";
    private static final String COURSE_TYPE_MATCHING = "(选修|必修)";
    private static final String CHECK_COURSE_TYPE_MATCHING = "(考试|考察)";

    private static final String SCORE_MATCHING1 = "(\\s([1-9]?[0-9]|100))?";

    private static final String COURSE_INPUT_PATTERN = COURSE_NAME_MATCHING + " " + COURSE_TYPE_MATCHING + " "
            + CHECK_COURSE_TYPE_MATCHING;
    private static final String SCORE_INPUT_PATTERN = STU_NUM_MATCHING + " " + STU_NAME_MATCHING + " "
            + COURSE_NAME_MATCHING + " " + SCORE_MATCHING + SCORE_MATCHING1;
    

    public static int matchingInput(String input) {
        if (matchingCourse(input)) {
            return 1;
        }
        if (matchingScore(input)) {
            return 2;
        }
        return 0;
    }

    private static boolean matchingCourse(String input) {
        return input.matches(COURSE_INPUT_PATTERN);
    }

    private static boolean matchingScore(String input) {
        return input.matches(SCORE_INPUT_PATTERN);
    }}
class Course implements Comparable<Course> {
    private final String name;
    private final String type;
    private final String method;

    public Course(String name, String type, String method) {
        this.name = name;
        this.type = type;
        this.method = method;
    }

    public String getName() {
        return name;
    }

    public String getType() {
        return type;
    }

    public String getMethod() {
        return method;
    }

    @Override

    public int compareTo(Course o) {
        Comparator<Object> compare = Collator.getInstance(java.util.Locale.CHINA);
        return compare.compare(name, o.getName());
    }}
abstract class Grade {
    protected final int finalScore;
    protected final int totalScore;

    public Grade(int finalScore) {
        this.finalScore = finalScore;
        this.totalScore = finalScore;
    }

    public int getTotalScore() {
        return totalScore;
    }

    public int getFinalScore() {
        return finalScore;
    }}
class ExaminationGrade extends Grade {
    private final int usualScore;

    public ExaminationGrade(int usualScore, int finalScore) {
        super(finalScore);
        this.usualScore = usualScore;
    }

    public int getUsualScore() {
        return usualScore;
    }

    @Override

    public int getTotalScore() {
        return (int) (finalScore * 0.7 + usualScore * 0.3);
    }}
class AssessmentGrade extends Grade {
    public AssessmentGrade(int finalScore) {
        super(finalScore);
    }}

这段代码是一个学生成绩管理系统的实现。它包含了一些类和方法来处理输入数据并计算学生成绩的平均值。

首先呢先来讲讲各个类的作用

1. Main（主要类）：这个类是程序的入口点，包含了主要的方法，负责运行程序并处理用户输入。

2. Cls（班级类）：表示一个班级，以其ID来标识，并包含一个属于该班级的学生列表。

3. Student（学生类）：表示一个学生，以姓名和ID来标识。它还拥有一个指向所属班级的引用。

4. ParseInput（解析输入类）：负责解析用户输入并根据输入执行相应的操作。它维护了课程、学生、选课（学生、课程和成绩的组合）和班级的列表。它还提供了分析和显示基于输入数据的各种统计信息的方法。

5. ChooseCourse（选课类）：表示学生选择的课程，并存储相关的课程、学生和成绩信息。

6. InputMatching（输入匹配类）：这个工具类包含了将用户输入进行匹配和分类到不同类型（课程或成绩记录）的方法。

7. Course（课程类）：表示一门课程，以课程名来标识。它还存储了课程的类型（必修课或选修课）和评估方式（考试或评估）。

8. Grade（成绩类）：这是一个抽象类，是其他不同类型成绩的基类。它存储了课程的最终成绩和总分。

9. ExaminationGrade（考试成绩类）：表示基于考试评估的成绩，包括平时成绩和计算最终成绩的总分（最终成绩和平时成绩的加权平均）。

10. AssessmentGrade（评估成绩类）：表示基于评估的成绩，只包含最终成绩。

这道题目看起来十分难，但是只要静下心来把结构分析清楚，其实并不是一个非常难的题目，只是类比较多也比较麻烦。

这一道题目最主要的踩坑点就是，非常建议使用Arrylist类来写代码，不然十分容易导致运行超时，还有一些地方需要添加return0，不然的话就会造成非零返回，具体原理是啥其实我自己也没有搞清楚，但是需要注意的是就是一定要静下心来，不然的话这道题目的代码量很大，很容易就会写烦躁，就会越写越烦然后导致根本写不出来。

至于有哪些地方可以改进，我认为是注释太少了，因为我本人其实是没有写注释的习惯的，但是大家要养成写注释的习惯，这一点我在以后也会改进。

import java.util.HashMap;
import java.util.Scanner;

class Main{
    public static void main(String[] args) {
        HashMap<String, Student> map = new HashMap<>();
        Scanner sc = new Scanner(System.in);

        while (true) {
            String input = sc.nextLine();
            if (input.equals("end")) {
                break;
            }

            // 根据输入直接创建 Student 对象，并将其添加至 HashMap 中
            String[] info = input.split(" ");
            Student student = new Student(info[0], info[1], Integer.parseInt(info[2]));
            map.put(student.getId(), student);
        }

        // 根据学号直接从 HashMap 中获取对应的学生信息，并输出查询结果
        String id = sc.nextLine();
        Student student = map.get(id);
        if (student != null) {
            System.out.println(student.getId() + " " + student.getName() + " " + student.getScore());
        } else {
            System.out.println("The student " + id + " does not exist");
        }
    }
}

// 定义学生类，包括学号、姓名和成绩属性
class Student {
    private String id;
    private String name;
    private int score;

    public Student(String id, String name, int score) {
        this.id = id;
        this.name = name;
        this.score = score;
    }

    public String getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public int getScore() {
        return score;
    }
}

首先先分析一下新的知识点：

HashMap类：这个类用于存储键值对，并支持基于键快速查找对应的值。在这个代码中，HashMap被用于存储学生对象，使用学号作为键。字符串处理：代码中使用了split方法将输入的字符串按空格分割成数组，以提取学生信息。

那么首先我们先来分析一下这段代码的逻辑：

1. 导入必要的类：HashMap和Scanner。
2. 创建了一个HashMap对象和一个Scanner对象。
3. 进入一个无限循环，循环内部读取控制台的输入。
4. 将输入按空格分割成字符串数组。
5. 使用字符串数组中的元素创建一个Student对象，并将其添加到HashMap中，使用学号作为键。
6. 循环结束后，读取控制台的输入并将其存储在变量id中。
7. 使用id在HashMap中查找对应的Student对象。
8. 如果找到了学生对象，则输出学生的学号、姓名和成绩。
9. 如果未找到学生对象，则输出错误消息。

踩坑心得：这段代码如果实在写不出来的话可以不用死磕HashMap类来写，可以试试更为简单的。

改进建议：老问题，还是注释，还有便是封装实现的不是很好，目前的代码采用简单的方式处理学生信息，只有学号、姓名和成绩。可以考虑创建更复杂的学生类，包含更多的属性和方法，例如课程列表、班级信息等。目前的代码主要集中在Main类中，包含了输入处理、学生对象的创建和查询等功能。可以考虑将不同的功能部分封装到独立的方法或类中，以提高代码的可重用性和可维护性。

import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;

public class Main {
    public static void main(String[] args) {
        Map<String, Student> map = new TreeMap<>((o1, o2) -> Integer.parseInt(o2) - Integer.parseInt(o1));
        Scanner sc = new Scanner(System.in);

        while (true) {
            String input = sc.nextLine();
            if (input.equals("end")) {
                break;
            }
            String[] info = input.split(" ");
            String id = info[0];
            String name = info[1];
            int score = Integer.parseInt(info[2]);

            Student student = new Student(name, score);
            map.put(id, student);
        }

        for (Map.Entry<String, Student> entry : map.entrySet()) {
            System.out.println(entry.getKey() + " " + entry.getValue().getName() + " " + entry.getValue().getScore());
        }
    }
}

class Student {
    private String name;
    private int score;

    public Student(String name, int score) {
        this.name = name;
        this.score = score;
    }

    public String getName() {
        return name;
    }

    public int getScore() {
        return score;
    }
}

同上，首先先来梳理一下他的结构：

1. 导入必要的类：Map、Scanner和TreeMap。
2. 创建了一个TreeMap对象和一个Scanner对象。
3. 进入一个无限循环，循环内部读取控制台的输入。
4. 如果输入为"end"，则跳出循环。
5. 将输入按空格分割成字符串数组，并提取出学号、姓名和成绩。
6. 使用姓名和成绩创建一个Student对象。
7. 将学号作为键，学生对象作为值，将键值对添加到TreeMap中。
8. 循环结束后，遍历TreeMap，按学号逆序输出学生的学号、姓名和成绩。
9. TreeMap会根据学号的自然顺序（递减）对键进行排序，从而实现逆序输出。

这段代码是根据上一题改进的，改进后的代码主要在保存学生对象的数据结构上使用了TreeMap，这使得按学号逆序输出学生信息变得更加简单。同样，学生对象的创建和学生信息的输出也保持了之前代码的逻辑。通过这些改进，代码的可读性和排序功能得到了提升。

踩坑心得：这段代码如果实在写不出来的话可以不用死磕HashMap类来写，可以试试更为简单的。

import java.util.*;
import java.text.Collator;
import java.util.ArrayList;
import java.util.Locale;
import java.util.Objects;
import java.util.ArrayList;
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        HashSet<CourseSelection> courseSelectionHashSet = new HashSet<>();
        HashSet<String> courseNameSet = new HashSet<>();
        HashMap<Student, Boolean> studentScorehashMap = new HashMap<>();
        TreeMap<Student, Integer> averageStudentScore = new TreeMap<>();
        TreeMap<Course, Integer> courseUsualAverage = new TreeMap<>();
        TreeMap<Course, Integer> courseFinalAverage = new TreeMap<>();
        TreeMap<Course, Integer> courseCombinedAverage = new TreeMap<>();
        TreeMap<String, Integer> classCombinedAverage = new TreeMap<>();
        StringBuilder stringBuilder = new StringBuilder();
        while (true) {
            String temp = scanner.nextLine();
            if (temp.equals("end")) {
                break;
            }
            String[] s = temp.split(" ");
            if (s[0].matches("[0-9]{0,100}")) {
                Student student = new Student(s[0], s[1]);
                Course course = null;
                if(s.length>=5) {
                    int flag = 0;
                    for (int i = 4; i < s.length; i++) {
                        if (!s[i].matches("[0-9]{1,3}")) {
                            System.out.println("wrong format");
                            flag = 1;
                            break;
                        } else if (Integer.parseInt(s[i]) < 0 || Integer.parseInt(s[i]) > 100) {
                            System.out.println("wrong format");
                            flag = 1;
                            break;
                        }
                    }
                    if (flag == 1)
                        continue;
                }
                if (s[0].length() != 8 || s[1].length() > 10 || s[2].length() > 10 || !s[3].matches("[0-9]{1,3}") || (Integer.parseInt(s[3]) < 0 || Integer.parseInt(s[3]) > 100)) {
                    System.out.println("wrong format");
                    continue;
                }
                if (courseNameSet.contains(s[2])) {
                    for (Course tempCourse : courseUsualAverage.keySet()) {
                        if (tempCourse.name.equals(s[2])) {
                            course = tempCourse;
                            break;
                        }
                    }
                }
                if (s.length == 5 && ((Integer.parseInt(s[4]) < 0) || (Integer.parseInt(s[4]) > 100))) {
                    System.out.println("wrong format");
                    continue;
                } else if(course!=null&&course.mode==2){
                    if (!s[3].matches("[4-9]")) {
                        System.out.println("wrong format");
                        continue;
                    }
                    if (s.length != Integer.parseInt(s[3]) + 4) {
                        System.out.println(s[0] + " " + s[1] + " " + ": access mode mismatch");
                        classCombinedAverage.put(s[0].substring(0, 6), 0);
                        averageStudentScore.put(student, 0);
                        continue;
                    }
                }

                if(!courseNameSet.contains(s[2])) {
                    System.out.println(s[2] + " does not exist");
                    averageStudentScore.put(student, 0);
                    classCombinedAverage.put(s[0].substring(0, 6), 0);
                    continue;
                }
                Grade grade = new ExamScore();
                if (s.length == 4 && course.mode == 1) {
                    grade = new ExamineGrade();
                    grade.finalGrade = Integer.parseInt(s[3]);
                } else if (s.length == 5 && course.mode == 0) {
                    grade = new ExamScore();
                    grade.usualGrade = Integer.parseInt(s[3]);
                    grade.finalGrade = Integer.parseInt(s[4]);
                } else if (course.mode == 2) {
                    grade = new ExperimentalScore();
                    for (int i = 4; i < s.length; i++) {
                        grade.experimentalGrades.add(Integer.parseInt(s[i]));
                    }
                }
                classCombinedAverage.put(s[0].substring(0, 6), 0);
                if ((s.length == 4 && course.mode == 0) || (s.length == 5 && course.mode == 1)) {
                    System.out.println(s[0] + " " + s[1] + " " + ": access mode mismatch");
                    averageStudentScore.put(student, 0);
                    continue;
                }

                //获取每个同学，以便计算平均分
                averageStudentScore.put(student, 0);
                CourseSelection courseSelection = new CourseSelection(course, student, grade);
                courseSelectionHashSet.add(courseSelection);
            } else {
                if (s.length != 3 && s.length != 2) {
                    System.out.println("wrong format");
                    continue;
                }
                if ((s.length == 3) && (s[0].length() > 10 || ((!s[1].equals("必修") && !s[1].equals("选修") && !s[1].equals("实验")) || (!s[2].equals("考试") && !s[2].equals("考察") && !s[2].equals("实验"))))) {
                    System.out.println("wrong format");
                    continue;
                } else if ((s.length == 2) && (s[0].length() > 10 || !s[1].equals("必修"))) {
                    System.out.println("wrong format");
                    continue;
                }
                int type = 0;
                if (s[1].equals("必修")) type = 0;
                if (s[1].equals("选修")) type = 1;
                if (s[1].equals("实验")) type = 2;
                Course course = new Course(s[0], type);
                if (s.length == 3) {
                    int mode = 0;
                    if (s[2].equals("考试")) mode = 0;
                    if (s[2].equals("考察")) mode = 1;
                    if (s[2].equals("实验")) mode = 2;
                    course.mode = mode;
                }
                if ((course.type == 0 && course.mode == 1) || (course.mode == 2 && course.type != 2) || course.type == 2 && course.mode != 2) {
                    System.out.println(s[0] + " : course type & access mode mismatch");
                    continue;
                }
                courseUsualAverage.put(course, 0);
                courseFinalAverage.put(course, 0);
                courseCombinedAverage.put(course, 0);
                courseNameSet.add(s[0]);
            }
        }
        //courseSelectionHashSet.stream().map(s->s.course.name).forEach(System.out::println);
        //1.求每个同学平均成绩，排序打印
        for (Student student : averageStudentScore.keySet()) {
            List<Integer> list = new ArrayList<>();
            for (CourseSelection courseSelection : courseSelectionHashSet) {
                if (courseSelection.student.id.equals(student.id)) {
                    list.add(courseSelection.grade.getGrade());
                }
            }
            //List<Integer> list = courseSelectionHashSet.stream().filter(s -> s.student.id.equals(student.id)).map(s -> s.grade.getGrade()).toList();
            for (Integer tempScore : list) {
                averageStudentScore.replace(student, averageStudentScore.get(student) + tempScore);
            }
            if (list.size() != 0)
                averageStudentScore.replace(student, averageStudentScore.get(student) / list.size());
            if (list.size() == 0) {
                studentScorehashMap.put(student, false);
                System.out.println(student.id + " " + student.name + " " + "did not take any exams");
            } else {
                studentScorehashMap.put(student, true);
                System.out.println(student.id + " " + student.name + " " + averageStudentScore.get(student));
            }
        }
        //2.计算每门课程的平均 平时分，期末分，综合分
        for (Course course : courseUsualAverage.keySet()) {
            List<Integer> list = new ArrayList<>();
            List<Integer> list1 = new ArrayList<>();
            List<Integer> list2 = new ArrayList<>();
            //平时分
            for (CourseSelection courseSelection : courseSelectionHashSet) {
                if (courseSelection.course.name.equals(course.name)) {
                    list.add(courseSelection.grade.usualGrade);
                }
            }
            //list = courseSelectionHashSet.stream().filter(s -> s.course.name.equals(course.name)).map(s -> s.grade.usualGrade).toList();
            //期末分
            for (CourseSelection courseSelection : courseSelectionHashSet) {
                if (courseSelection.course.name.equals(course.name)) {
                    list1.add(courseSelection.grade.finalGrade);
                }
            }
            //list1 = courseSelectionHashSet.stream().filter(s -> s.course.name.equals(course.name)).map(s -> s.grade.finalGrade).toList();
            //综合分
            for (CourseSelection courseSelection : courseSelectionHashSet) {
                if (courseSelection.course.name.equals(course.name)) {
                    list2.add(courseSelection.grade.getGrade());
                }
            }
            //list2 = courseSelectionHashSet.stream().filter(s -> s.course.name.equals(course.name)).map(s -> s.grade.getGrade()).toList();
            for (Integer tempScore : list) {
                courseUsualAverage.replace(course, courseUsualAverage.get(course) + tempScore);
            }
            for (Integer tempScore : list1) {
                courseFinalAverage.replace(course, courseFinalAverage.get(course) + tempScore);
            }
            for (Integer tempScore : list2) {
                courseCombinedAverage.replace(course, courseCombinedAverage.get(course) + tempScore);
            }
            if (list.size() != 0)
                courseUsualAverage.replace(course, courseUsualAverage.get(course) / list.size());
            if (list1.size() != 0)
                courseFinalAverage.replace(course, courseFinalAverage.get(course) / list1.size());
            if (list2.size() != 0)
                courseCombinedAverage.replace(course, courseCombinedAverage.get(course) / list2.size());
            if (list.size() == 0) {
                System.out.println(course.name + " has no grades yet");
            } else {
               if (course.mode == 0)
                    System.out.println(course.name + " " + courseUsualAverage.get(course) + " " + courseFinalAverage.get(course) + " " + courseCombinedAverage.get(course));
                else if(course.mode!=2)
                    System.out.println(course.name + " " + courseFinalAverage.get(course) + " " + courseCombinedAverage.get(course));
                else
                    System.out.println(course.name +" "+ courseCombinedAverage.get(course));
            }
        }
        //3.计算班级的分数
        for (String classId : classCombinedAverage.keySet()) {
            int sum = 0;//人数
            boolean flag = false;//班级是否有分数记录
            for (Student student : averageStudentScore.keySet()) {
                if (student.id.substring(0, 6).equals(classId)) {
                    classCombinedAverage.replace(classId, classCombinedAverage.get(classId) + averageStudentScore.get(student));
                    if (studentScorehashMap.get(student)) {
                        flag = true;
                        sum++;
                    }
                }
            }
            if (sum != 0)
                classCombinedAverage.replace(classId, classCombinedAverage.get(classId) / sum);
            if (flag) {
                System.out.println(classId + " " + classCombinedAverage.get(classId));
            } else {
                System.out.println(classId + " " + "has no grades yet");
            }
        }
    }
}
class Course implements Comparable<Course>{
    protected String name;
    protected int type;//0为必修，1为选修,2为实验
    protected int mode=0;//0为考试，1为考察,2为实验
    public Course(String name, int type, int mode) {
        this.name = name;
        this.type = type;
        this.mode = mode;
    }
    public Course(String name){
        this.name=name ;
    };
    public Course(String name,int type){
        this.name=name;
        this.type=type;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Course course = (Course) o;
        return Objects.equals(name, course.name);
    }

    @Override
    public int hashCode() {
        return Objects.hash(name);
    }

    @Override
    public int compareTo(Course o) {
        return Collator.getInstance(Locale.CHINA).compare(this.name, o.name);
    }
}
class CourseSelection {
    protected Course course;
    protected Student student;
    protected Grade grade;

    public CourseSelection(Course course, Student student, Grade grade) {
        this.course = course;
        this.student = student;
        this.grade = grade;
    }
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        CourseSelection that = (CourseSelection) o;
        return Objects.equals(course, that.course) && Objects.equals(student, that.student);
    }
    @Override
    public int hashCode() {
        return Objects.hash(course, student);
    }

}
class ExamineGrade extends Grade{
    @Override
    Integer getGrade() {
        return this.finalGrade;
    }
    public ExamineGrade(){
        type=1;
    }
}
class ExamScore extends Grade{
    @Override
    Integer getGrade() {
        return (int)( this.usualGrade*0.3+this.finalGrade*0.7);
    }
    public ExamScore(){
        type=0;
    }
}
class ExperimentalScore extends Grade{
    Integer getGrade(){
        Integer result=0;
        for(Integer integer:experimentalGrades){
            result+=integer;
        }
        return result/experimentalGrades.size();
    }
}
abstract class Grade {
    protected Integer finalGrade=0;
    protected int type;
    protected Integer usualGrade=0;
    protected ArrayList<Integer>experimentalGrades=new ArrayList<>();
    abstract Integer getGrade();
}
class Student implements Comparable<Student>{
    protected String id;
    protected String name;

    public Student() {
    }

    public Student(String id, String name) {
        this.id = id;
        this.name = name;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Student student = (Student) o;
        return Objects.equals(id, student.id);
    }

    @Override
    public int hashCode() {
        return Objects.hash(id);
    }

    @Override
    public int compareTo(Student s) {
        return this.id.compareTo(s.id);
    }
}

分析代码的逻辑：

该程序初始化了几个数据结构，如HashSet、HashMap和TreeMap，用于存储有关课程选择、学生成绩和课程平均分的信息。它使用Course、Student、CourseSelection和Grade等类来表示实体及其关系。

各个类的作用：

1. Course（课程）类：表示一个课程，它有课程名称等属性，并提供访问和设置这些属性的方法。

2. Student（学生）类：表示一个学生，它有学生的姓名、学号等属性，并提供访问和设置这些属性的方法。

3. CourseSelection（课程选择）类：表示学生选择的课程，它关联了学生和课程，并提供了相关方法来添加、移除和获取学生的课程选择。

4. Grade（成绩）类：表示学生在某门课程上的成绩，它关联了学生、课程和成绩，并提供了相关方法来设置和获取学生成绩。

5. CourseManagement（课程管理）类：这个类是程序的主要逻辑部分，它包含了主要的方法和循环，用于处理用户的输入和执行相应的操作。它使用上述类来管理学生、课程和成绩，并进行平均分的计算和显示。

踩坑心得：踩坑的同第一次的基本雷同

改进建议：使用更具表达力的类和方法命名：通过使用更具描述性的类和方法名称，可以提高代码的可读性。这样其他人在查看代码时能够更好地理解其功能，降低出错的可能性。优化数据结构的选择：根据实际需求和使用情况，可以优化选择数据结构。例如，在存储学生和课程的信息时，可以考虑使用ArrayList或LinkedHashMap等数据结构。添加更多的注释：为代码中的关键部分添加注释，可以增加代码的可维护性。注释应清晰地解释代码的意图和功能，这有助于团队成员理解和修改代码。

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;
import java.text.Collator;
import java.util.Comparator;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner (System.in);
        //初始化一个Work类，开始读入数据
        Work work = new Work();
        //读入数据
        String message = in.nextLine();
        while (!message.equals("end")){   //当message不是end的时候
            work.manage(message);   //在Work类里面处理类
            message = in.nextLine();  //读入下一行
        }
        //输出学生
        work.show_Student();
        //输出课程
        work.show_Course();
        //输出班级
        work.show_Classroom();
    }
}
class Work {
    ArrayList<Student> listStudent = new ArrayList<>();   //学生表
    ArrayList<Classroom> listClassroom = new ArrayList<>();    //班级表
    ArrayList<Course> listCourse = new ArrayList<>();   //课程表
    ArrayList<Message_Box> listMessage_Box = new ArrayList<>();   //选课记录表
    InputMatching matching = new InputMatching();
    public void manage(String message) {
        String Line[] = message.split(" " );
        switch (matching.matchingInput(message)) {
            case 1 : {   //输入的是课程
                Course course = new Course(Line[0],Line[1],Line[2]);
                if (Error_Course((course))) {  //性质没有问题
                    if (Exist_Course(course)) {//是否存在,应该放在最后???
                        if (Weight_error(Line)) {    //是否权重数量对不上
                            if (Weight_sum_error(Line)) {//是否权重数量和==1
                                if (Line[2].equals("实验")) {
                                    for (int i = 4; i < Line.length; i++) {
                                        course.addWeight(Double.parseDouble(Line[i]));
                                    }
                                } else if (Line[2].equals("考试")) {
                                    course.addWeight(Double.parseDouble(Line[3]));
                                    course.addWeight(Double.parseDouble(Line[4]));
                                } else {
                                    course.addWeight(1);
                                }
                                listCourse.add(course);
                            } else {
                                System.out.println(Line[0] + " : weight value error");
                            }
                        } else {
                            System.out.println(Line[0] + " : number of scores does not match");
                        }
                }
                }
                else {
                    System.out.println(course.getName() + " : course type & access mode mismatch");
                }
                break;
            }
            case 2: {   //输入的是学生
                Course course = find_CourseByName(Line[2]);
                Student student = new Student(Integer.parseInt(Line[0]),Line[1]);
                Classroom classroom = new Classroom(student.getId()/100);
                if (Exist_Student(student))
                    listStudent.add(student);
                if (Exist_Classroom(classroom))
                    listClassroom.add(classroom);
                if (course!= null) {
                    if (Line.length == 4) {
                        if (course.getGrade_Way().equals("考察")){
                            Grade_Course grade_course = new Grade_Course(course,Line);
//                            Grade grade = new Grade_Exam(Line[3]);  //成绩加入得要改
                            Message_Box messageBox = new Message_Box(student,course,grade_course);
                            if (Exist_Message(messageBox))
                                listMessage_Box.add(messageBox);
                        } else {
                            System.out.println(Line[0] + " " + Line[1] + " : " +"access mode mismatch");
                        }
                    } else {
                        if (course.getGrade_Way().equals("考试") && Line.length == 5) {
                            Grade_Course grade_course = new Grade_Course(course,Line);
//                            Grade grade = new Grade_daily(Line[3],Line[4]);  //成绩加入得要改
                            Message_Box messageBox = new Message_Box(student,course,grade_course);
                            if (Exist_Message(messageBox))
                                listMessage_Box.add(messageBox);
                        }
                        else if (course.getGrade_Way().equals("实验") && Line.length-3 == course.get_Weight_size()) {
                            Grade_Course grade_course = new Grade_Course(course,Line);
//                            Grade grade = new Grade_Lab(Line);  //成绩加入得要改
                            Message_Box messageBox = new Message_Box(student,course,grade_course);
                            if (Exist_Message(messageBox))
                                listMessage_Box.add(messageBox);
                        }
                        else {
                            System.out.println(Line[0] + " " + Line[1] + " : " +"access mode mismatch");
                        }
                    }
                }
                else {
                    System.out.println(Line[2] + " " + "does not exist");
                }
                break;
            }
            default: {
                System.out.println("wrong format");
            }
        }
    }

    private boolean Exist_Message(Message_Box messageBox) {
        for(Message_Box messageBox1 : listMessage_Box){
            if ((messageBox.student.getId() == messageBox1.student.getId()) && (messageBox1.course.getName().equals(messageBox.course.getName()))){
                return false;
            }
        }
        return true;
    }
    private boolean Exist_Classroom(Classroom classroom) {
        for(Classroom classroom1 : listClassroom){
            if (classroom1.getClass_ID()==classroom.getClass_ID()){
                return false;
            }
        }
        return true;
    }
    private boolean Exist_Student(Student student) {
        for (Student student1 : listStudent){
            if (student1.getId() == student.getId()){
                return false;
            }
        }
        return true;
    }
    private boolean Exist_Course(Course course) {
        for (Course course1 : listCourse){
            if (course1.getName().equals(course.getName())){
                return false;
            }
        }
        return true;
    }
    private boolean Weight_error(String[] Line) {
        if (Line[2].equals("实验")) {
            int number = Integer.parseInt(Line[3]);
            if (Line.length - 4 == number)
                return true;
            else
                return false;
        } else if (Line[2].equals("考试")){
            if (Line.length - 3 == 2)
                return true;
            else
                return false;
        } else {
            return true;
        }
    }
    private boolean Weight_sum_error(String[] Line){
        if (Line[2].equals("实验")) {
            double total = 0;
            int number = Integer.parseInt(Line[3]);
            for (int i = 4 ; i < number + 4 ; i++) {
                total += Double.parseDouble(Line[i]);
            }
            if (total==1)
                return true;
            else
                return false;
        } else if (Line[2].equals("考试")) {
            double total = Double.parseDouble(Line[3]) + Double.parseDouble(Line[4]);
            if (total==1)
                return true;
            else
                return false;
        } else {
            return true;
        }
    }
    private Course find_CourseByName(String name) {
        for (int i = 0 ; i < listCourse.size() ; i++) {
            if (listCourse.get(i).getName().equals((name))){
                return listCourse.get(i);
            }
        }
        return null;
    }
    private boolean Error_Course(Course course) {
        if (course.getCourse_Message().equals("必修") && course.getGrade_Way().equals("考察")){
            return false;
        }
        else if ((course.getCourse_Message().equals("实验") && !course.getGrade_Way().equals("实验")) || (!course.getCourse_Message().equals("实验") && course.getGrade_Way().equals("实验"))){
            return false;
        }
        else {
            return true;
        }
    }
    public void show_Student() {
        //按学号排序
        Collections.sort(listStudent);
        for (int i = 0 ; i < listStudent.size() ; i++) {   //这里的循环是用来遍历每一位学生
            Student stu = listStudent.get(i);
            //从总课表listChooseCourse中获取该学生的选课记录集合
            ArrayList<Message_Box> stuCourseSelects = getStudentSelects(stu.getId());
            if (stuCourseSelects.size() != 0) {
                System.out.println(stu.getId() + " " + stu.getName() + " " + getAvgTotalScore(stuCourseSelects));
            }  else  {
                System.out.println(stu.getId() + " " + stu.getName() + " " + "did not take any exams");
            }
        }
    }
    //获得该学生选课记录的情况下返回该学生的总成绩
    private int getAvgTotalScore(ArrayList<Message_Box> stuCourseSelects) {
        int total = 0;
        for (Message_Box messageBox : stuCourseSelects) {
            total += messageBox.grade_course.get_grade_Total();
        }
        return (int)(1.0*total/stuCourseSelects.size());
    }
    //通过学生的Id查找选课记录表，返回该学生的选课记录
    private ArrayList<Message_Box> getStudentSelects(int id) {
        ArrayList<Message_Box> student_Message = new ArrayList<>();
        for (Message_Box messageBox : listMessage_Box) {
            if (messageBox.student.getId() == id) {
                student_Message.add(messageBox);
            }
        }
        return student_Message;
    }
    public void show_Course() {
        //按中文拼音进行排序
        Collections.sort(listCourse);
        for (int i = 0 ; i < listCourse.size() ; i++) {   //这里的循环是用来遍历每一位课程
            Course course = listCourse.get(i);
            //从总选课记录listCourse中获取该课程的学生信息集合
            ArrayList<Message_Box> courseStudentSelects = getcourseStudentSelects(course.getName());
            if (courseStudentSelects.size() != 0) {
                System.out.println(course.getName() + " " + getAvgTotalCourse(courseStudentSelects));
            }
            else {
                System.out.println(course.getName() + " " + "has no grades yet");
            }
        }
    }
    private int getAvgTotalCourse(ArrayList<Message_Box> courseStudentSelects) {
        int total = 0;
        for (Message_Box messageBox : courseStudentSelects) {
            total += messageBox.grade_course.get_grade_Total();
        }
        return (int)(1.0*total/courseStudentSelects.size());
    }
    private ArrayList<Message_Box> getcourseStudentSelects(String name) {
        ArrayList<Message_Box> course_Message = new ArrayList<>();
        for (Message_Box messageBox : listMessage_Box) {
            if (messageBox.course.getName().equals(name)) {
                course_Message.add(messageBox);
            }
        }
        return course_Message;
    }
    public void show_Classroom() {
        Collections.sort(listClassroom);
        for (int i = 0 ; i < listClassroom.size() ; i++) {
            Classroom classroom = listClassroom.get(i);
            ArrayList<Message_Box> classroomSelects = getClassSelects(classroom.getClass_ID());
            if (classroomSelects.size() != 0) {
                System.out.println(classroom.getClass_ID() + " " + getAvgTotalClassScore(classroomSelects));
            }  else {
                System.out.println(classroom.getClass_ID() + " " + "has no grades yet");
            }
        }
    }
    private int getAvgTotalClassScore(ArrayList<Message_Box> classroomSelects) {
        int total = 0;
        for (Message_Box messageBox : classroomSelects) {
            total += messageBox.grade_course.get_grade_Total();
        }
        return (int)(1.0*total/classroomSelects.size());
    }
    private ArrayList<Message_Box> getClassSelects(int classId) {
        ArrayList<Message_Box> class_Message = new ArrayList<>();
        for (Message_Box messageBox : listMessage_Box) {
            if (messageBox.student.getId()/100 == classId) {
                class_Message.add(messageBox);
            }
        }
        return class_Message;
    }
    class InputMatching {
        String Lab_Times_Matching = "[4-9]{1}";  //1个4-9的数字
        String stuNumMatching = "[0-9]{8}";//8个0-9的数字
        String stuNameMatching = "\\S{1,10}";//1到10个非空格（TAB）字符
        String scoreMatching = "([1-9]?[0-9]|100)";
        String courseNameMatching = "\\S{1,10}";//1到10个非空格（TAB）字符
        String courseTypeMatching = "(选修|必修|实验)";
        String checkCourseTypeMatching = "(考试|考察|实验)";
        String rate = "^(0(\\.\\d+)?|1(\\.0+)?)$";
        //courseInput用于定义课程信息模式（正则表达式）   /*这里的正则表达式考虑到了长度为二的情况吗？ 这里的测试测试点似乎并不考虑这给error问题*/
        String courseInput_1 = courseNameMatching + " " + courseTypeMatching + " " + checkCourseTypeMatching;
        String courseInput_2 = courseNameMatching + " " + courseTypeMatching + " " + checkCourseTypeMatching + " " + rate + " " + rate;
        String courseInput_3 = courseNameMatching + " " + courseTypeMatching + " " + checkCourseTypeMatching + " " + Lab_Times_Matching;
        //scoreInput用于定义成绩信息模式（正则表达式）
        String scoreInput_1 = stuNumMatching + " " + stuNameMatching + " " + courseNameMatching + " " +
                scoreMatching + "(scoreMatching)?";
        String scoreInput_2 = stuNumMatching + " " + stuNameMatching + " " + courseNameMatching + " " +
                scoreMatching + " " + scoreMatching;
        String scoreInput_3 = stuNumMatching + " " + stuNameMatching + " " + courseNameMatching;
        public int matchingInput(String s) {
            String[] input = s.split(" ");
            String Lab_up = "";
            String Lab_down = "";
            if (input.length >= 4) {//防止报错
                Lab_up = input[0] + " " + input[1] + " " + input[2] + " " + input[3];
                Lab_down = input[0] + " " + input[1] + " " + input[2];
            }
            if (matchingCourse(s)) {//课程之考试、考察匹配
                return 1;
            }
            if (matching_Lab(Lab_up)){//课程之实验匹配
                for (int i = 4 ; i < input.length ; i++) {//查看后续条件是否符合
                    if (!input[i].matches(rate)) {//如果找到一个不符合的
                        return 0;
                    }
                }
                return 1;
            }
            if (matchingScore(s)) {//成绩之考试、考察
                return 2;
            }
            if (matching_Score_Lab(Lab_down)) {//成绩之实验
                for (int i = 4 ; i < input.length ; i++) {//查看后续条件是否符合
                    if (!input[i].matches(scoreMatching)) {//如果找到一个不符合的
                        return 0;
                    }
                }
                return 2;
            }
            return 0;
        }
        private boolean matchingCourse(String s) {
            String[] ppp = s.split(" ");
            if (ppp.length==5){
                if (ppp[0].matches(courseNameMatching) && ppp[1].matches(courseTypeMatching) && ppp[2].matches(checkCourseTypeMatching) && ppp[3].matches(rate) && ppp[4].matches(rate)){
                    return true;
                }
            }
            if (s.matches(courseInput_1) || s.matches(courseInput_2))
                return true;
            else
                return false;
        }
        private boolean matchingScore(String s) {
            if (s.matches(scoreInput_1) || s.matches(scoreInput_2))
                return true;
            else
                return false;
        }
        private boolean matching_Lab (String s) {
            return s.matches(courseInput_3);
        }
        private boolean matching_Score_Lab(String s) {
            return s.matches(scoreInput_3);
        }
    }
}
class Student implements Comparable<Student>{
    private int id;
    private String name;
    Student(int id , String name) {
        this.name = name;
        this.id = id;
    }
    @Override
    //学号排序
    public int compareTo(Student o) {
        return (this.id - o.getId());
    }
    public int getId() {
        return id;
    }
    public String getName() {
        return name;
    }
}
class Course implements Comparable<Course>{
    Course(String name , String Course_Message , String Grade_Way) {
        this.name = name;
        this.Course_Message = Course_Message;
        this.Grade_Way = Grade_Way;
    }
    private String name;
    private String Course_Message;
    private String Grade_Way;
    private ArrayList<Double> Weight = new ArrayList<>();
    public int compareTo(Course o) {
        Comparator<Object> compare = Collator.getInstance(java.util.Locale.CHINA);
        return compare.compare(name,o.getName());
    }
    public String getName() {
        return name;
    }
    public String getGrade_Way() {
        return Grade_Way;
    }
    public String getCourse_Message() {
        return Course_Message;
    }
    public void addWeight(double weight) {
        Weight.add(weight);
    }
    public double getWeight(int i) {
        return Weight.get(i);
    }
    public int get_Weight_size(){
        return Weight.size();
    }
}
class Classroom implements Comparable<Classroom>{
    Classroom(int Id) {
        this.class_ID = Id;
    }
    private int class_ID;
    @Override
    public int compareTo(Classroom o) {
        return this.class_ID - o.getClass_ID();
    }
    public int getClass_ID() {
        return class_ID;
    }
}
class Message_Box {
    Student student;
    Course course;
//    Grade grade;
    Grade_Course grade_course;
    Message_Box(Student student , Course course , Grade_Course grade_course) {
        this.student = student;
        this.course = course;
        this.grade_course = grade_course;
    }
}
class Grade_Course {
    ArrayList<Grade_itemize> grade_itemizes = new ArrayList<>();
    Grade_Course(Course course, String[] Line) {
        int num = course.get_Weight_size();
        if (num == 1) {
            grade_itemizes.add(new Grade_itemize(Integer.parseInt(Line[3]),course.getWeight(0)));
        } else if (num == 2) {
            for (int i = 0 ; i < num ; i++){
                grade_itemizes.add(new Grade_itemize(Integer.parseInt(Line[i+3]),course.getWeight(i)));
            }
        } else if (num >=4 && num <=9){
            for (int i = 0 ; i < num ; i++){
                grade_itemizes.add(new Grade_itemize(Integer.parseInt(Line[i+3]),course.getWeight(i)));
            }
        }
    }
    public int get_grade_Total() {
        double total = 0;
        for (Grade_itemize gradeItemize : grade_itemizes) {
            total += gradeItemize.get_grade_One();
        }
        return (int)Math.round(total);
    }
}
class Grade_itemize {
    private int score;
    private double date;
    Grade_itemize(int score , double date) {
        this.score = score;
        this.date = date;
    }
    public int getScore() {
        return score;
    }
    public double getDate() {
        return date;
    }
    public double get_grade_One() {
        return score*date;
    }
}

下面来分析一下代码的逻辑以及各个类的作用：

1. InputMatching类：该类用于匹配输入的字符串，并根据匹配结果判断输入属于课程信息、成绩信息、实验课程还是实验成绩。

2. Student类：表示学生对象，包括学号和姓名属性，并实现了Comparable接口以便进行排序。

3. Course类：表示课程对象，包括课程名称、课程信息和成绩计算方式属性。它还包括一个ArrayList来存储权重，可以根据索引获取每个权重值。也实现了Comparable接口以便进行排序。

4. Classroom类：表示班级对象，只包含班级ID属性。

5. Message_Box类：用于存储学生、课程和成绩信息的封装对象。

6. Grade_Course类：管理课程的成绩项。根据课程的权重和分数创建Grade_itemize对象，并计算课程的总成绩。

7. Grade_itemize类：表示单个成绩项，包括分数和权重。

代码的结构主要是通过类与类之间的关联，来实现程序的功能。例如，Message_Box类中封装了学生、课程和成绩信息，在需要时可以通过访问Message_Box对象来获取这些信息。另外，类之间还实现了Comparable接口来进行排序，如Student和Course类可以根据学号和课程名称进行排序。

踩坑心得：同题目 1 2雷同

改进建议：提取共用的正则表达式模式：在代码中有多个地方使用了正则表达式，可以将共用的模式提取为常量或变量，使其更易于维护和修改。优化字符串拆分：在InputMatching类的matchingInput方法中，通过split方法将字符串拆分为数组。如果输入的字符串较长，这可能会导致性能下降。可以考虑使用更高效的方法，如使用StringTokenizer类或针对特定分隔符的split方法。使用StringBuilder来拼接字符串：在多个地方使用了字符串拼接（如InputMatching类中的Lab_up和Lab_down），可以考虑使用StringBuilder类来提高性能和内存使用效率。引入异常处理：在代码中没有实现异常处理机制。可以考虑使用try-catch块来捕获异常，并对异常进行处理或提供适当的反馈信息给用户。增加注释和文档：为了更好地理解代码的功能和实现方式，可以添加注释和文档，解释每个类、方法和变量的作用，以及代码中的算法思路和数据结构使用。优化代码结构和命名：可以对类、方法和变量的命名进行优化，使其更加清晰、具有描述性。另外，可以考虑重构代码结构，将相关的方法和逻辑进行归类和封装，提高代码的可读性和可维护性。

总结：在其中考试之后，我们将更多的学习重心放在了JAVAFX的学习上，在正则表达式这一类题目上花的时间相对较少，其实正则表达式也是一个比较难的知识点，还有后续的HashMap类等等，就像老师说的，其实这些类都没有ArrayList类好用，用的最多的还是ArrayList类，学习Java最重要的还是把面向过程思想改为面向对象思想。