public static String find(BinaryTree<String>.Node<String> root, String character, String pattern) {
        if(root.data.compareTo(character)==0) {
            return pattern;
        }

        if(root.data.contains(character)){
            if(root.left!=null && root.left.data.contains(character)){
                return find(root.left, character,pattern+"0");
            }

            if(root.right!=null && root.right.data.contains(character)){
                return find(root.right, character,pattern+"1");
            }
        }

        return null;
    }