.idea/misc.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="ExternalStorageConfigurationManager" enabled="true" />
   <component name="ProjectRootManager" version="2" project-jdk-name="25" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>

src/CourseRegistrationStarter/Course.java

@@ -35,3 +35,4 @@ public class Course {
         capacity++;
     }
 }
+

src/CourseRegistrationStarter/Main.java

@@ -1,14 +1,93 @@
-package CourseRegistrationStarter;
+import java.util.Scanner;
 
-public class Main {
-    public static void main(String[] args) {
-        // TODO:
-        // 1. Create at least 3 courses
-        // 2. Create 1 student
-        // 3. Create a registration system
-        // 4. Add courses to the system
-        // 5. Register the student in some courses
-        // 6. Drop one course
-        // 7. Print the final registered course list
+public class Main
+{
+
+    public static void main(String[] args)
+    {
+
+        Scanner input = new Scanner(System.in);
+
+        // Courses
+        Course ap = new Course("Advanced Programming", "AP1404", 2);
+        Course ds = new Course("Data Structures", "DS2201", 1);
+        Course db = new Course("Database Systems", "DB3301", 3);
+
+        // System
+        RegistrationSystem system = new RegistrationSystem();
+        system.addCourseToSystem(ap);
+        system.addCourseToSystem(ds);
+        system.addCourseToSystem(db);
+
+        // Student
+        System.out.print("Enter student name: ");
+        String name = input.nextLine();
+
+        System.out.print("Enter student id: ");
+        String id = input.nextLine();
+
+        Student student = new Student(name, id);
+
+        int choice = 0;
+
+        while (choice != 5)
+        {
+
+            System.out.println("\n--- MENU ---");
+            System.out.println("1. Show all courses");
+            System.out.println("2. Register course");
+            System.out.println("3. Drop course");
+            System.out.println("4. Show my courses");
+            System.out.println("5. Exit");
+
+            System.out.print("Choice: ");
+            choice = input.nextInt();
+            input.nextLine();
+
+            switch (choice)
+            {
+
+                case 1:
+                    system.showAllCourses();
+                    break;
+
+                case 2:
+                    System.out.print("Enter course code: ");
+                    String regCode = input.nextLine();
+                    Course c1 = system.findCourseByCode(regCode);
+                    if (c1 != null)
+                    {
+                        student.addCourse(c1);
+                    } else
+                    {
+                        System.out.println("Course not found");
+                    }
+                    break;
+
+                case 3:
+                    System.out.print("Enter course code: ");
+                    String dropCode = input.nextLine();
+                    Course c2 = system.findCourseByCode(dropCode);
+                    if (c2 != null)
+                    {
+                        student.dropCourse(c2);
+                    } else
+                    {
+                        System.out.println("Course not found");
+                    }
+                    break;
+
+                case 4:
+                    student.showRegisteredCourses();
+                    break;
+
+                case 5:
+                    System.out.println("Goodbye!");
+                    break;
+
+                default:
+                    System.out.println("Invalid choice");
+            }
+        }
     }
-}
+}

src/CourseRegistrationStarter/RegistrationSystem.java

@@ -1,24 +1,44 @@
-package CourseRegistrationStarter;
 import java.util.ArrayList;
 
-public class RegistrationSystem {
+public class RegistrationSystem
+{
     private ArrayList<Course> courses;
 
-    public RegistrationSystem() {
+    public RegistrationSystem()
+    {
         courses = new ArrayList<>();
     }
 
-    public void addCourseToSystem(Course c) {
-        // TODO: Add the course to the system
+    public void addCourseToSystem(Course c)
+    {
+        // Add the course to the system
+        courses.add(c);
     }
 
-    public Course findCourseByCode(String code) {
-        // TODO: Search for a course by course code
-        // Return the matching course if found, otherwise return null
+    public Course findCourseByCode(String code)
+    {
+        // Search for a course by course code
+        for (Course c : courses)
+        {
+            if (c.getCourseCode().equals(code))
+            {
+                return c;
+            }
+        }
         return null;
     }
 
-    public void showAllCourses() {
-        // TODO: Print all courses in the system
+    public void showAllCourses()
+    {
+        // Print all courses in the system
+        for (Course c : courses)
+        {
+            System.out.println(
+                    c.getCourseName() + " - " +
+                            c.getCourseCode() +
+                            " | Remaining capacity: " +
+                            c.getCapacity()
+            );
+        }
     }
 }

src/CourseRegistrationStarter/Student.java

@@ -1,39 +1,60 @@
-package CourseRegistrationStarter;
 import java.util.ArrayList;
 
-public class Student {
+public class Student
+{
     private String name;
     private String studentId;
     private ArrayList<Course> registeredCourses;
 
-    public Student(String name, String studentId) {
+    public Student(String name, String studentId)
+    {
         this.name = name;
         this.studentId = studentId;
         this.registeredCourses = new ArrayList<>();
     }
 
-    public String getName() {
+    public String getName()
+    {
         return name;
     }
 
-    public String getStudentId() {
+    public String getStudentId()
+    {
         return studentId;
     }
 
-    public boolean addCourse(Course c) {
-        // TODO: Register the student in the course if capacity allows
-        // Return true if registration was successful, otherwise false
+    public boolean addCourse(Course c)
+    {
+        // Check capacity > 0
+        if (c.getCapacity() > 0)
+        {
+            registeredCourses.add(c);
+            c.reduceCapacity();
+            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
-        // Return true if the course was dropped, otherwise false
+    public boolean dropCourse(Course c)
+    {
+        if (registeredCourses.remove(c))
+        {
+            c.increaseCapacity();
+            return true;
+        }
         return false;
     }
 
-    public void showRegisteredCourses() {
-        // TODO: Print all registered courses
+    public void showRegisteredCourses()
+    {
+        System.out.println("Registered Courses for " + name + ":");
+        if (registeredCourses.isEmpty())
+        {
+            System.out.println("No courses registered.");
+        }
+        for (Course c : registeredCourses)
+        {
+            System.out.println(c.getCourseName() + " - " + c.getCourseCode());
+        }
     }
 }