complet classes and write tese class

src/CourseRegistrationStarter/Main.java

@@ -2,6 +2,33 @@ package CourseRegistrationStarter;
 
 public class Main {
     public static void main(String[] args) {
+
+        Course riazi2 = new Course("riazi2" , "200" , 5);
+        Course ap = new Course("ap" , "201" , 2);
+        Course bp = new Course("bp" , "202" , 5);
+        Course riazi1 = new Course("riazi1" , "203" , 7);
+        Course os = new Course("os" , "204" , 10);
+
+        Student daneshjo = new Student("ali" , "11111");
+
+
+        RegistrationSystem regis = new RegistrationSystem();
+
+        regis.addCourseToSystem(riazi1);
+        regis.addCourseToSystem(riazi2);
+        regis.addCourseToSystem(ap);
+        regis.addCourseToSystem(bp);
+        regis.addCourseToSystem(os);
+
+        daneshjo.addCourse(os);
+        daneshjo.addCourse(bp);
+        daneshjo.addCourse(riazi1);
+
+        daneshjo.dropCourse(os);
+
+        daneshjo.showRegisteredCourses();
+
+        regis.showAllCourses();
         // TODO:
         // 1. Create at least 3 courses
         // 2. Create 1 student

src/CourseRegistrationStarter/RegistrationSystem.java

@@ -5,20 +5,34 @@ public class RegistrationSystem {
     private ArrayList<Course> courses;
 
     public RegistrationSystem() {
-        courses = new ArrayList<>();
+        courses = new ArrayList<Course>();
     }
 
     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
+        int n = courses.size();
-        // Return the matching course if found, otherwise return null
+        for(int i = 0 ; i < n ; i++){
+            if(courses.get(i).getCourseCode() == code){
+                return courses.get(i);
+            }
+
+        }
         return null;
     }
 
     public void showAllCourses() {
-        // TODO: Print all courses in the system
+        int n = courses.size();
+        System.out.println("All courses :");
+        for(int i = 0 ; i < n ; i++){
+
+            System.out.printf("course name: %10s   "  , courses.get(i).getCourseName());
+            System.out.printf("cours capacity: %10s   " , courses.get(i).getCapacity());
+            System.out.println("");
+
+
+        }
     }
 }

src/CourseRegistrationStarter/Student.java

@@ -21,19 +21,33 @@ public class Student {
     }
 
     public boolean addCourse(Course c) {
-        // TODO: Register the student in the course if capacity allows
+        if(c.getCapacity() > 0){
-        // Return true if registration was successful, otherwise false
+            registeredCourses.add(c);
+            c.reduceCapacity();
+            return true;
+        }
         return false;
     }
 
     public boolean dropCourse(Course c) {
-        // TODO: Remove the course from the student's list
+        int n = registeredCourses.size();
-        // Restore the course capacity if removal was successful
+        for(int i = 0 ; i < n ; i++){
-        // Return true if the course was dropped, otherwise false
+            if(registeredCourses.get(i).getCourseName() == c.getCourseName()){
+                registeredCourses.remove(i);
+                c.increaseCapacity();
+                return true;
+            }
+        }
         return false;
     }
 
     public void showRegisteredCourses() {
-        // TODO: Print all registered courses
+        int n = registeredCourses.size();
+        System.out.println(this.name + "\'s Courses :");
+        for(int i = 0 ; i < n ; i++){
+            System.out.printf("course name: %10s   "  , registeredCourses.get(i).getCourseName());
+            System.out.printf("cours code: %10s   " , registeredCourses.get(i).getCourseCode());
+            System.out.println("");
+        }
     }
 }