src/CourseRegistrationStarter/Main.java

@@ -2,13 +2,26 @@ package CourseRegistrationStarter;
 
 public class Main {
     public static void main(String[] args) {
-        // TODO:
+        Course AP = new Course("Advanced Programming", "4041122334", 40);
-        // 1. Create at least 3 courses
+        Course FM = new Course("Foundation of Math", "4041212334", 30);
-        // 2. Create 1 student
+        Course GM = new Course("General Math","4041234123",60);
-        // 3. Create a registration system
+
-        // 4. Add courses to the system
+        Student farnam = new Student("Farnam", "404111234");
-        // 5. Register the student in some courses
+        farnam.setLimitOfCourses(3);
-        // 6. Drop one course
+        RegistrationSystem regSys = new RegistrationSystem();
-        // 7. Print the final registered course list
+
+        regSys.addCourseToSystem(AP);
+        regSys.addCourseToSystem(FM);
+        regSys.addCourseToSystem(GM);
+
+        farnam.addCourse(AP);
+        farnam.addCourse(FM);
+        farnam.addCourse(GM);
+
+        farnam.dropCourse(FM);
+
+        farnam.showRegisteredCourses();
+
+        regSys.showAllCourses();
     }
 }

src/CourseRegistrationStarter/RegistrationSystem.java

@@ -9,16 +9,35 @@ public class RegistrationSystem {
     }
 
     public void addCourseToSystem(Course c) {
-        // TODO: Add the course to the system
+        courses.add(c);
     }
 
     public Course findCourseByCode(String code) {
-        // TODO: Search for a course by course code
+        for (int i = 0; i < courses.size(); i++) {
-        // Return the matching course if found, otherwise return null
+            if (courses.get(i).getCourseCode().equals(code)){
+                return courses.get(i);
+            }
+        }
+        return null;
+    }
+
+    public Course findCourseByName(String name) {
+        for (int i = 0; i < courses.size(); i++) {
+            if (courses.get(i).getCourseCode().equals(name)){
+                return courses.get(i);
+            }
+        }
         return null;
     }
 
     public void showAllCourses() {
         // TODO: Print all courses in the system
+        System.out.printf("%25s %15s %18s", "Name","Course code","Remaining capacity");
+        System.out.print('\n');
+
+        for (int i = 0; i < courses.size(); i++) {
+            System.out.printf("%25s %15s %d", courses.get(i).getCourseName() , courses.get(i).getCourseCode(), courses.get(i).getCapacity());
+            System.out.print('\n');
+        }
     }
 }

src/CourseRegistrationStarter/Student.java

@@ -5,11 +5,13 @@ public class Student {
     private String name;
     private String studentId;
     private ArrayList<Course> registeredCourses;
+    private int limitOfCourses;
 
     public Student(String name, String studentId) {
         this.name = name;
         this.studentId = studentId;
         this.registeredCourses = new ArrayList<>();
+        this.limitOfCourses = 18;
     }
 
     public String getName() {
@@ -20,20 +22,37 @@ public class Student {
         return studentId;
     }
 
+    public void setLimitOfCourses(int limit){
+        this.limitOfCourses = limit;
+    }
+
     public boolean addCourse(Course c) {
-        // TODO: Register the student in the course if capacity allows
+
-        // Return true if registration was successful, otherwise false
+        if (registeredCourses.contains(c)){
+            return false;
+        }
+
+        if ((c.getCapacity() > 0) && (this.limitOfCourses >= registeredCourses.size() + 1)){
+            c.reduceCapacity();
+            registeredCourses.add(c);
+            return true;
+        }
         return false;
     }
 
     public boolean dropCourse(Course c) {
-        // TODO: Remove the course from the student's list
+
-        // Restore the course capacity if removal was successful
+        if (registeredCourses.remove(c)){
-        // Return true if the course was dropped, otherwise false
+            c.increaseCapacity();
+            return true;
+        }
         return false;
     }
 
     public void showRegisteredCourses() {
-        // TODO: Print all registered courses
+        for (int i = 0; i < registeredCourses.size(); i++) {
+            System.out.printf("%25s %15s", registeredCourses.get(i).getCourseName() , registeredCourses.get(i).getCourseCode());
+            System.out.print('\n');
+        }
     }
 }