3.3

package opgave3_3;

import java.util.TreeMap;

public class Skole {
	private String name;
	private static TreeMap<Integer, Student> students = new TreeMap<>();

	public Skole(String name) {
		this.name = name;
	}

	public String getNavn() {
		return name;
	}

	public void setNavn(String name) {
		this.name = name;
	}

	public TreeMap<Integer, Student> getStudent() {
		return students;
	}

	public static void addStudent(int studieNr, Student student) {
		if (!students.containsKey(studieNr)) {
			students.put(student.getStudieNr(), student);
		}
	}

	public static void removeStudent(int studieNr) {
		if (students.containsKey(studieNr)) {
			students.remove(studieNr);
		}
	}

	public double average() {
		double sum = 0;
		int i = 0;
		double average = 0;
		for (i = 0; i < Student.getGrade().size(); i++) {
			sum = sum + Student.getGrade().get(i);
		}
		average = sum / i;
		return average;
	}

	public Student findStudent(int studieNr) {
		Student s = null;
		s = students.get(studieNr);
		return s;
	}

	public String toString() {
		return "" + name;
	}
}


----

package opgave3_3;

import java.util.ArrayList;

public class Student implements Comparable<Student>{
	private String name;
	private int studieNr;
	private static ArrayList<Integer> grades = new ArrayList<>();

	public Student(int studieNr, String name) {
		this.name = name;
		this.studieNr = studieNr;
	}

	public String getName() {
		return name;
	}

	public int getStudieNr() {
		return studieNr;
	}

	public static ArrayList<Integer> getGrade() {
		return grades;
	}

	public void setName(String name) {
		this.name = name;
	}

	public void addGrade(int grade) {
		Student.grades.add(grade);
	}

	public String toString() {
		return "" + name + ", " + studieNr;
	}

	@Override
	public int compareTo(Student o) {
		if (studieNr == o.studieNr) {
			return 0;
		} else if (studieNr > o.studieNr) {
			return 1;
		} else {
			return -1;
		}
	}
}