* [mypy] fix type annotations for problem003/sol1 and problem003/sol3
* [mypy] fix type annotations for project euler problem007/sol2
* [mypy] fix type annotations for project euler problem008/sol2
* [mypy] fix type annotations for project euler problem009/sol1
* [mypy] fix type annotations for project euler problem014/sol1
* [mypy] fix type annotations for project euler problem 025/sol2
* [mypy] fix type annotations for project euler problem026/sol1.py
* [mypy] fix type annotations for project euler problem037/sol1
* [mypy] fix type annotations for project euler problem044/sol1
* [mypy] fix type annotations for project euler problem046/sol1
* [mypy] fix type annotations for project euler problem051/sol1
* [mypy] fix type annotations for project euler problem074/sol2
* [mypy] fix type annotations for project euler problem080/sol1
* [mypy] fix type annotations for project euler problem099/sol1
* [mypy] fix type annotations for project euler problem101/sol1
* [mypy] fix type annotations for project euler problem188/sol1
* [mypy] fix type annotations for project euler problem191/sol1
* [mypy] fix type annotations for project euler problem207/sol1
* [mypy] fix type annotations for project euler problem551/sol1
* Project Euler problem 191 solution
* Add type hints and reference links
* Address requested changes
- update documentation
- split out helper function but mark it with an underscore
- remove redundant comments or make them more explicit/helpful
* Address requested changes