public class DropOutStakSingleLinkedList<E> implements Stak<E> {
    private Node head = null;
    private int size = 0;
    private int maxSize;

    public DropOutStakSingleLinkedList(int maxSize) {
        if (maxSize < 0) maxSize = 1;
        this.maxSize = maxSize;
    }

    public void push(E object) {
        Node node = new Node(object, head);

        if (size == maxSize) {
            if (maxSize == 1) {
                node.next = head.next;
            } else {
                Node cursor = head;
                while (cursor.next.next != null) {
                    cursor = cursor.next;
                }
                cursor.next = null;
            }
            size--;
        }

        head = node;
        size++;
    }

    public E pop() {
        if (isEmpty()) throw new StakTomException("Stakken er tom");
        Node temp = head;
        head = head.next;
        size--;
        return temp.element;
    }

    public E top() {
        if (isEmpty()) throw new StakTomException("Stakken er tom");
        return head.element;
    }

    public int size() {
        return size;
    }

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

    public String toString() {
        if (isEmpty()) return "[]";

        StringBuilder b = new StringBuilder(3 * size);
        b.append('[');
        Node cursor = head;
        for (int i = 0;; i++) {
            b.append(cursor.element);
            if (i == size - 1) return b.append(']').toString();
            b.append(", ");
            cursor = cursor.next;
        }
    }

    private class Node {
        E element;
        Node next;

        Node(E element, Node next) {
            this.element = element;
            this.next = next;
        }
    }

    public static void main(String[] args) {
        DropOutStakSingleLinkedList<Integer> ints = new DropOutStakSingleLinkedList<Integer>(3);

        ints.push(1); System.out.println(ints);
        ints.push(2); System.out.println(ints);
        ints.push(3); System.out.println(ints);
        ints.push(4); System.out.println(ints);
        ints.pop(); System.out.println(ints);
    }
}