class TreeTest {
    public static void main(String[] args) {
        // let's encode 1 - 2 ^ 4 x 2
        // (- (1 ε ε) (x (^ (2 ε ε) (4 ε ε)) (4 ε ε)))
        // we use strings to represent values (operations or data)
        BinaryTreeNode<String> root = new BinaryTreeNode<>("-");
        root.setLeft(new BinaryTreeNode<>("1"));
        root.setRight(new BinaryTreeNode<>("x"));
        root.getRight().setLeft(new BinaryTreeNode<>("^"));
        root.getRight().setRight(new BinaryTreeNode<>("4"));
        root.getRight().getLeft().setLeft(new BinaryTreeNode<>("2"));
        root.getRight().getLeft().setRight(new BinaryTreeNode<>("4"));

        System.out.println(root.size());

        System.out.println(root);

        System.out.println("height: " + BinaryTreeNode.getHeight(root));
        System.out.println("height: " + BinaryTreeNode.getHeight(null));
    }
}