Delete 'Course.java'

Course.java

@@ -1,90 +0,0 @@
-package basic;
-
-/**
- * 课程类，与学科建立多对一关系
- */
-public class Course {
-    private int id;
-    private String name;
-    private int credit;
-    
-    // 所属学科（多对一关系）
-    private Subject subject;
-    
-    // 先修课程（一门课程可能有多门先修课程）
-    private java.util.List<Course> prerequisiteCourses;
-    
-    public Course(int id, String name, int credit) {
-        this.id = id;
-        this.name = name;
-        this.credit = credit;
-        this.prerequisiteCourses = new java.util.ArrayList<>();
-    }
-    
-    // 添加先修课程
-    public void addPrerequisiteCourse(Course course) {
-        if (course != null) {
-            prerequisiteCourses.add(course);
-        }
-    }
-    
-    // 移除先修课程
-    public void removePrerequisiteCourse(Course course) {
-        if (course != null) {
-            prerequisiteCourses.remove(course);
-        }
-    }
-    
-    // 设置学科
-    public void setSubject(Subject subject) {
-        this.subject = subject;
-    }
-    
-    // Getters and Setters
-    public int getId() {
-        return id;
-    }
-    
-    public void setId(int id) {
-        this.id = id;
-    }
-    
-    public String getName() {
-        return name;
-    }
-    
-    public void setName(String name) {
-        this.name = name;
-    }
-    
-    public int getCredit() {
-        return credit;
-    }
-    
-    public void setCredit(int credit) {
-        this.credit = credit;
-    }
-    
-    public Subject getSubject() {
-        return subject;
-    }
-    
-    public java.util.List<Course> getPrerequisiteCourses() {
-        return prerequisiteCourses;
-    }
-    
-    public void setPrerequisiteCourses(java.util.List<Course> prerequisiteCourses) {
-        this.prerequisiteCourses = prerequisiteCourses;
-    }
-    
-    @Override
-    public String toString() {
-        return "Course{" +
-                "id=" + id +
-                ", name='" + name + '\'' +
-                ", credit=" + credit +
-                ", subject=" + (subject != null ? subject.getName() : "null") +
-                ", prerequisites.size()=" + prerequisiteCourses.size() +
-                '}';
-    }
-}