algo4: comprehensive: Iterator for inorder bst traversal
algo4: comprehensive: Iterator for inorder bst traversal with remove
algo4: tree: bst: New division for bst
    -- revisited convert_sorted_array_to_bst
    -- revisited validate_bst
    -- revisited recover_bst
algo4: tree: traversal: New division for tree traversal
    -- revisited all traversal problems
algo4: tree: Revisited maximum_depth and minimum_depth