Profundidade e largura recursivas

        public Stack<Node<T>> PRO (Node<T> node, System.Predicate<Node<T>> match)
        {
            var fila = new Stack<Node<T>> ();

            Node<T> recursivo (Node<T> ESTADO)
            {
                if (match (node)) return node;
                else
                {
                    //REMOVER_DA_PILHA (esTADO);
                    fila.Pop ();
                    foreach (Node<T> child in node.Children)
                    {
                        fila.Push (child);
                    }
                }
                while (fila.Count > 0)
                {
#if DEBUG
                    System.Diagnostics.Debug.WriteLine (node.ToString ());
#endif
                    if (match (fila.First ()))
                    {
                        return fila.First ();
                    }
                    fila.Pop ();
                }
                return null;
            }
            recursivo (node);
            return fila;
        }

        public Node<T> LARGURA (Node<T> node, System.Predicate<Node<T>> match)
        {
            var fila = new Stack<Node<T>> ();
            var current = node;

            do
            {
#if DEBUG
                System.Diagnostics.Debug.WriteLine (current.ToString ());
#endif

                if (match (current)) return current;

                else
                {
                    foreach (Node<T> child in current.Children)
                        fila.Push (child);
                }

                if (fila.Count == 0) return default (Node<T>);
                current = fila.Pop ();
            } while (true);
        }

        public class ItsAlmostAStack<T>
        {
            private List<T> items = new List<T> ();

            public void Push (T item)
            {
                items.Add (item);
            }
            public T Pop ()
            {
                if (items.Count > 0)
                {
                    T temp = items[items.Count - 1];
                    items.RemoveAt (items.Count - 1);
                    return temp;
                }
                else
                    return default (T);
            }
            public void Remove (int itemAtPosition)
            {
                items.RemoveAt (itemAtPosition);
            }
        }