complete RegistrationSystem class

src/CourseRegistrationStarter/RegistrationSystem.java

@@ -9,16 +9,32 @@ public class RegistrationSystem {
     }
 
     public void addCourseToSystem(Course c) {
-        // TODO: Add the course to the system
+
+        for (int i=0 ; i < courses.size() ; i++) {
+
+            if(courses.get(i).getCourseCode().equals(c.getCourseCode())) {
+                return;
+            }
+        }
+
+        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() ; i++) {
+            if(courses.get(i).getCourseCode().equals(code)) {
+                return courses.get(i);
+            }
+        }
         return null;
     }
 
     public void showAllCourses() {
-        // TODO: Print all courses in the system
+        for(int i=0 ; i < courses.size() ; i++) {
+            System.out.print("Course " + i+1 + ": ");
+            System.out.println(courses.get(i).getCourseName() + "  " + courses.get(i).getCourseCode());
+        }
     }
 }