Untitled

Selection sort Doubly linked list java
public class LinkedList {
        public Node first;
        public Node last;

        public LinkedList() {
            first = null;
            last = null;
        }

        public boolean isEmpty() {
            return first == null;
        }

        public void addFirst(Student student) {
            Node newNode = new Node(student);
            if (isEmpty())
                last = newNode;
            else
                first.previous = newNode;
            newNode.next = first;
            first = newNode;
        }

        public void addLast(Student student) {
            Node newNode = new Node(student);
            if (isEmpty())
                first = newNode;
            else
                last.next = newNode;
            newNode.previous = last;
            last = newNode;
        }

        public void display() {
            Node current = last;
            while (current != null) {
                System.out.print(current.student.name + "b");
                System.out.print(current.student.surname + "b");
                System.out.println(current.student.educationType);
                current = current.previous;
            }
        }

public void Sort() {
            LinkedList list = new LinkedList();
            Node toStart = last;
            while (toStart!=null){
                list.addLast(findSmallest(toStart).student);
                toStart = toStart.previous;
            }


        }

public Node findSmallest(Node toStartFrom) {
            Node current = toStartFrom;
            Node smallest = toStartFrom; //if i put here `last` it will work correctly
            while(current != null) {
                if (smallest.student.name.compareToIgnoreCase(current.student.name) > 0) smallest = current;
                current = current.previous;
            }
            return smallest;
        }

    }

  public class Node {
        public Student student;

        public Node next;
        public Node previous;

        public Node(Student student) {
            this.student = student;
        }
    }


    public class Student {
        public String name;
        public String surname;
        public String educationType;

        static public Student createStudent() {
         ....
            return student;
        }
    }