src/CourseRegistrationStarter/Main.java

@@ -1,14 +1,104 @@
 package CourseRegistrationStarter;
+import java.util.Scanner;
 
 public class Main {
+    static Scanner input = new Scanner(System.in);
+    static Course x1 =new Course("Advanced Programming","AP1404",2);
+    static Course x2 =new Course("Data Structures","DS2201",1);
+    static Course x3 =new Course("Database Systems","DB3301",3);
+    static RegistrationSystem n3 = new RegistrationSystem();
+    static Student st = new Student("navid","41148");
+
+
     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
+        n3.addCourseToSystem(x1);
+        n3.addCourseToSystem(x2);
+        n3.addCourseToSystem(x3);
+
+
+        while(true){
+            asli();
+        }
+    }
+    public static boolean asli(){
+        System.out.println("----Course Registration Menu ---"+"\n"+"1. Show all courses "+"\n"+"2. Register course"+"\n"+"3. Drop course"+"\n"+"4. Show my courses"+"\n"+"5. Exit"+"\n"+"Choose an option: ");
+        int n1 = input.nextInt();
+        if(n1 == 1){
+            System.out.println("All courses in system: ");
+            n3.showAllCourses();
+            return (true);
+        }else if (n1 ==2){
+            System.out.println("Choos an option: ");
+            System.out.println("1. Enter course code ");
+            System.out.println("2. Enter course name ");
+            int n2 = input.nextInt();
+            input.nextLine();
+            if (n2 == 1){
+                System.out.println("Enter course code to register: ");
+                String courseCode = input.nextLine();
+                if(n3.findCourseByCode(courseCode) != null ){
+                    if (st.addCourse(n3.findCourseByCode(courseCode))){
+                        System.out.println("Registration was successful."+"\n");
+                        return(true);
+                    }
+                }else{
+                    System.out.println("No course found with this code!"+"\n");
+                    return(true);
+                }
+            }else if (n2 == 2){
+                System.out.println("Enter course name to register: ");
+                String courseName = input.nextLine();
+                if(n3.findCourseByName(courseName) != null ){
+                    if (st.addCourse(n3.findCourseByName(courseName))){
+                        System.out.println("Registration was successful."+"\n");
+                        return(true);
+                    }
+                }else{
+                    System.out.println("No course found with this name!"+"\n");
+                    return(true);
+                }
+            }
+        }else if (n1==3){
+            System.out.println("Choos an option: ");
+            System.out.println("1. Enter course code ");
+            System.out.println("2. Enter course name ");
+            int n2 = input.nextInt();
+            input.nextLine();
+            if (n2 == 1){
+                System.out.println("Enter course code to register: ");
+                String courseCode = input.nextLine();
+                if(n3.findCourseByCode(courseCode) != null ){
+                    if (st.dropCourse(n3.findCourseByCode(courseCode))){
+                        System.out.println("Course dropped successfully."+"\n");
+                        return (true);
+                    }
+                }else{
+                    System.out.println("No course found with this code!"+"\n");
+                    return(true);
+                }
+            }else if (n2==2){
+                System.out.println("Enter course name to register: ");
+                String courseName = input.nextLine();
+                if(n3.findCourseByName(courseName) != null ){
+                    if (st.dropCourse(n3.findCourseByName(courseName))){
+                        System.out.println("Course dropped successfully."+"\n");
+                        return (true);
+                    }
+                }else{
+                    System.out.println("No course found with this name!"+"\n");
+                    return(true);
+                }
+            }
+            return (true);
+        }else if (n1==4 ){
+            System.out.println("Registered courses for "+ st.getName()+":");
+            st.showRegisteredCourses();
+            return (true);
+
+        }else if (n1==5 ){
+            System.exit(0);
+            return (true);
+        }
+        return false;
     }
 }

src/CourseRegistrationStarter/RegistrationSystem.java

@@ -9,16 +9,33 @@ 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
-        // Return the matching course if found, otherwise return null
+        for(int i = 0 ; i <= courses.size()-1; i++){
+            if (code.equals(courses.get(i).getCourseCode())){
+                return (courses.get(i));
+            }
+        }
         return null;
     }
+    public Course findCourseByName(String name){
+        for(int i = 0 ; i < courses.size(); i++){
+            if (name.equals(courses.get(i).getCourseName())){
+                return (courses.get(i));
+            }
+        }
+        return null;
+
+    }
 
     public void showAllCourses() {
-        // TODO: Print all courses in the system
+
+            for (int i = 0; i <= courses.size() - 1; i++) {
+                System.out.println(courses.get(i).getCourseName() + "(" + courses.get(i).getCourseCode() + ")" + " = Remaining capacity: " + courses.get(i).getCapacity() + "\n");
+            }
+
     }
 }

src/CourseRegistrationStarter/Student.java

@@ -21,19 +21,44 @@ public class Student {
     }
 
     public boolean addCourse(Course c) {
-        // TODO: Register the student in the course if capacity allows
-        // Return true if registration was successful, otherwise false
-        return false;
+        if (registeredCourses.contains(c)){
+            System.out.println("You have already registered in this course!"+"\n");
+            return (false);
+        } else if (registeredCourses.size()== 2){
+            System.out.println("You have reached the maximum number of allowed courses!"+"\n");
+            return (false);
+        }
+        else if (c.getCapacity()>0){
+            registeredCourses.add(c);
+            c.reduceCapacity();
+            return (true);
+        }else{
+            System.out.println("Registration was not successful!"+"\n"+"This course has no capacity left."+"\n");
+            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
-        return false;
+        if (registeredCourses.contains(c)){
+            registeredCourses.remove(c);
+            c.increaseCapacity();
+            return (true);
+        }else{
+            System.out.println("Course drop failed!"+"\n"+"You are not registered for this course."+"\n");
+            return (false);
+        }
+
     }
 
     public void showRegisteredCourses() {
-        // TODO: Print all registered courses
+        if(registeredCourses.size()==0){
+            System.out.println(Main.st.getName() + "hasn't registered for any course."+"\n");
+
+        }
+        else {
+            for (int i = 0; i <= registeredCourses.size() - 1; i++) {
+                System.out.println(registeredCourses.get(i).getCourseName() + "(" + registeredCourses.get(i).getCourseCode() + ")" + "\n");
+            }
+        }
     }
 }