
* fix mypy: data_structures:binary_tree * mypy --strict for binary_trees in data_structures * fix pre-commit Co-authored-by: LiHao <leo_how@163.com>
* fix mypy: data_structures:binary_tree * mypy --strict for binary_trees in data_structures * fix pre-commit Co-authored-by: LiHao <leo_how@163.com>