void bToDLL(Node *root, Node **head_ref)
{
	stack<Node*> s;
	if (root == NULL) *head_ref = NULL;
	*head_ref = NULL;
	Node* prev = NULL;
	Node* curr;
	Node* trav = root->left;
	s.push(root);
	while (!s.empty())
	{
		while (trav!=NULL)
		{
			s.push(trav);
			trav = trav->left;
		}
		curr = s.top();
		if (*head_ref == NULL)
		{
			*head_ref = curr;
			prev = curr;
		}
		else
		{
			curr->left = prev;
			prev->right = curr;
			prev = curr;
		}
		trav = (s.top())->right;
		s.pop();
	}

	Node* helper = NULL;
	if (*head_ref == NULL) cout << " " << endl << " " << endl;
	else
	{
		while ((*head_ref) != NULL)
		{
			cout << (*head_ref)->data << ' ';
			helper = (*head_ref);
			*head_ref = (*head_ref)->right;
		}

		cout << endl;
		*head_ref = helper;
		while ((*head_ref) != NULL)
		{
			cout << (*head_ref)->data << ' ';
			(*head_ref) = (*head_ref)->left;
		}
		cout << endl;

	}


}