uni/inf1010/hw5/LenkeListe.java

import java.util.Iterator;

class LenkeListe<E extends Comparable<E>> implements Iterable<E> {
	public Node first;
	public Node last;

	public class Node<T extends Comparable<T>> {
		public Node next;
		public Node prev;
		public E val;

		Node(E val) {
			this.val = val;
		}
	}

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

	public void leggTil(E val) {
		Node<E> n = new Node<>(val);

		if (first == null)
			first = n;

		if (last == null) {
			last = n;
		} else {
			n.prev = last;
			last.next = n;
			last = n;
		}
	}

	public void fjernMinste() {
		Node smallest = first;
		Node n = first;

		while (n != null) {
			if (n.val.compareTo(smallest.val) < 0) {
				smallest = n;
			}
			n = n.next;
		}

		fjern(smallest);
	}

	public boolean inneholder(E val) {
		for (E e: this) {
			if (e.compareTo(val) == 0)
				return true;
		}

		return false;
	}

	public void fjern(Node n) {
		n.prev.next = n.next;
		n.next.prev = n.prev;
		if (n == first) {
			first = n.next;
		}
		if (n == last) {
			last = n.prev;
		}
	}

	private class ListIterator<T extends Comparable<T>> implements Iterator<T> {
		private Node nextNode = first;

		@Override
		public boolean hasNext() {
			return nextNode != null;
		}

		@Override
		public T next() {
			Node n = nextNode;
			nextNode = n.next;
			return (T)n.val;
		}

		@Override
		public void remove() {
			throw new UnsupportedOperationException();
		}
	}

	//Iterator, foreach loops
	@Override
	public Iterator<E> iterator() {
		return new ListIterator<E>();
	}
}