* [mypy] fix type annotations for graphs/a_star.py #4052
* updating DIRECTORY.md
* Add from __future__ import anotations
* rename delta by DIRECTIONS
Co-authored-by: John Law <johnlaw.po@gmail.com>
* Rename delta by DIRECTIONS in all code
* Enclose script in __main__ code block
* Refactor DIRECTIONS with comments for readibility
* Delete heuristic example comment
* Do not print, return all values
* Fix multilines
* fix black
* Update a_star.py
Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Co-authored-by: John Law <johnlaw.po@gmail.com>
* organized graph algorithms
* all graph algorithms in Graphs/ folder
* all graph algorithms are in one folder
* Rename number theory/factorial_python.py to maths/factorial_python.py