implement tasks based on README

src/CourseRegistrationStarter/Main.java

@@ -3,6 +3,20 @@ package CourseRegistrationStarter;
 public class Main {
     public static void main(String[] args) {
         // TODO:
+        Course BP = new Course("Basic Programming", "BP1404", 3);
+        Course AP = new Course("Advanced Programming", "AP1405", 2);
+        Course DS = new Course("Data Structure", "DS1406", 2);
+        Student saeedJam = new Student("Saeed Jamali", "404222000");
+        RegistrationSystem register = new RegistrationSystem();
+
+        register.addCourseToSystem(BP);
+        register.addCourseToSystem(AP);
+        register.addCourseToSystem(DS);
+
+        saeedJam.addCourse(AP);
+        saeedJam.addCourse(DS);
+        saeedJam.dropCourse(DS);
+        saeedJam.showRegisteredCourses();
         // 1. Create at least 3 courses
         // 2. Create 1 student
         // 3. Create a registration system

src/CourseRegistrationStarter/RegistrationSystem.java

@@ -9,16 +9,25 @@ public class RegistrationSystem {
     }
 
     public void addCourseToSystem(Course c) {
+        this.courses.add(c);
         // TODO: Add the course to the system
     }
 
     public Course findCourseByCode(String code) {
+        for (Course c: this.courses) {
+            if (c.getCourseCode().equals(code)) {
+                return c;
+            }
+        }
         // TODO: Search for a course by course code
         // Return the matching course if found, otherwise return null
         return null;
     }
 
     public void showAllCourses() {
+        for(Course c: this.courses) {
+            System.out.println(c.getCourseName() + ", code: " + c.getCourseCode());
+        }
         // TODO: Print all courses in the system
     }
 }

src/CourseRegistrationStarter/Student.java

@@ -21,12 +21,22 @@ public class Student {
     }
 
     public boolean addCourse(Course c) {
+        if (c.getCapacity() > 0 && !this.registeredCourses.contains(c)) {
+            this.registeredCourses.add(c);
+            c.reduceCapacity();
+            return true;
+        }
         // TODO: Register the student in the course if capacity allows
         // Return true if registration was successful, otherwise false
         return false;
     }
 
     public boolean dropCourse(Course c) {
+        if (this.registeredCourses.contains(c)) {
+            this.registeredCourses.remove(c);
+            c.increaseCapacity();
+            return true;
+        }
         // 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
@@ -34,6 +44,9 @@ public class Student {
     }
 
     public void showRegisteredCourses() {
+        for(Course c: this.registeredCourses) {
+            System.out.println(c.getCourseName() + ", code: " + c.getCourseCode());
+        }
         // TODO: Print all registered courses
     }
 }