How do I write the scheduler one? I have no idea.

package scheduler;

import java.util.List; import java.util.ArrayList;

public class Scheduler { /** * Instantiates a new, empty scheduler. */ public Scheduler() { } /** * Adds a course to the scheduler. * * @param course the course to be added */ public void addCourse(Course course) { } /** * Returns the list of courses that this scheduler knows about. * * This returned object does not share state with the internal state of the Scheduler. * * @return the list of courses */ public List getCourses() { } /** * Adds a student to the scheduler. * * @param student the student to add */ public void addStudent(Student student) { } /** * Returns a list of the students this scheduler knows about. * * This returned object does not share state with the internal state of the Scheduler. * @return */ public List getStudents() {

} /** * Assigns all students to courses in the following manner: * * For a given student, check their list of preferred courses. Add them to the course that: * - exists in the scheduler's list of courses * - the student most prefers (that is, comes first in their preference list) * - the student is not not already enrolled in * - and is not full (in other words, at capacity) * Adds courses to the *end* of the student's current list of classes. Adds students to * the *end* of the course's roster. * * Repeat this process for each student, one-by-one; each student will now have one course, * usually (but not always) their most preferred course. * * Then repeat this whole process (adding one course per student, when possible, proceeding * round-robin among students), until there is nothing left to do: Students might * all be at their maximum number of courses, or there may be no available seats in courses * that students want. */ public void assignAll() {

}

/** * Drops a student from a course. * * @param student * @param course * @throws IllegalArgumentException if either the student or the course are not known to this scheduler */ public void drop(Student student, Course course) throws IllegalArgumentException {

} /** * Drops a student from all of their courses. * * @param student * @throws IllegalArgumentException if the student is not known to this scheduler */ public void unenroll(Student student) throws IllegalArgumentException{ } }

package scheduler;

import java.util.List; import java.util.ArrayList;

/** * A class representing a student. * * @author liberato * */ public class Student { private String name; private int maxCourses; private List preferences; private List Schedule; /** * * Instantiates a new Student object. The student's maximum course load must be greater * than zero, and the preferences list must contain at least one course. * * The preference list is copied into this Student object. * * @param name the student's name * @param maxCourses the maximum number of courses that can be on this student's schedule * @param preferences the student's ordered list of preferred courses * @throws IllegalArgumentException thrown if the maxCourses or preferences are invalid */ public Student(String name, int maxCourses, List preferences) throws IllegalArgumentException { this.name= name; this.maxCourses= maxCourses; this.preferences= preferences; Schedule = new ArrayList<>(); if(maxCourses<=0) throw new IllegalArgumentException("the student's maximum course load must"+" be greater than zero");

else if(preferences.isEmpty()) throw new IllegalArgumentException("the preferences list must contain at "+"least one course"); //else if(Schedule.isEmpty()) //throw new IllegalArgumentException("m"); } /** * * @return the student's name */ public String getName() { return name; } /** * * @return the student's max course load */ public int getMaxCourses() { return maxCourses; } /** * Returns the student's list of course preferences, ordered from most- to least-desired. * * This returned object does not share state with the internal state of the Student. * * @return the student's preference list */ public List getPreferences() { return preferences; } /** * Returns the student's current schedule. * * This returned object does not share state with the internal state of the Student. * * @return the student's schedule */ public List getSchedule() { return Schedule; } }

package scheduler;

import java.util.List; import java.util.ArrayList; /** * A class representing a Course. * * @author liberato * */ public class Course { /** * Instantiates a new Course object. The course number must be non-empty, and the * capacity must be greater than zero. * @param courseNumber a course number, like "COMPSCI190D" * @param capacity the maximum number of students that can be in the class * @throws IllegalArgumentException thrown if the courseNumber or capacity are invalid */ private String courseNumber; private int capacity; private List Roster; public Course(String courseNumber, int capacity) throws IllegalArgumentException { this.courseNumber=courseNumber;

this.capacity=capacity;

Roster=new ArrayList<>();

if(courseNumber.isEmpty())

throw new IllegalArgumentException

("the course number must be nonempty");

else if(capacity<=0)

throw new IllegalArgumentException

("the course number must be nonempty"); } /** * * @return the capacity of the course */ public int getCapacity() { return capacity; } /** * * @return the course number */ public String getCourseNumber() { return courseNumber; }

/** * Returns the list of students enrolled in the course. * * This returned object does not share state with the internal state of the Course. * * @return the list of students currently in the course */ public List getRoster() { return Roster; } }