added a faster solution to project euler problem 14

[crazazy]

Describe your change:

Adds a new algorithm for project euler problem 14. This algorithm is quite a bit faster than the 2 existing algorithms, as it avoids computing the same collatz chain twice

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms have a URL in its comments that points to Wikipedia or other similar explanation.
• If this pull request resolves one or more open issues then the commit message contains Fixes: #{$ISSUE_NO}.

[TravisBuddy]

Hey @crazazy,
Something went wrong with the build.

TravisCI finished with status errored, which means the build failed because of something unrelated to the tests, such as a problem with a dependency or the build process itself.

View build log

TravisBuddy Request Identifier: 24d1cf70-c9cd-11ea-994d-63e86313f42e

[TravisBuddy]

Hey @crazazy,
Something went wrong with the build.

TravisCI finished with status errored, which means the build failed because of something unrelated to the tests, such as a problem with a dependency or the build process itself.

View build log

TravisBuddy Request Identifier: d52a9dc0-c9cd-11ea-994d-63e86313f42e

[ruppysuppy]

Don't use nested functions, move the functions out of the solution function body. Add type hints to all functions and doctests too

[TravisBuddy]

Travis tests have failed

Hey @crazazy,
Please read the following log in order to understand the failure reason.
It'll be awesome if you fix what's wrong and commit the changes.

TravisBuddy Request Identifier: 811b5c80-caca-11ea-84bb-258f0278865c

[crazazy]

Added docstrings on all helper functions and doctests wherever possible. Sadly, it turns out that I can't view the side effects on calculate_chain, so that function cannot have doctests

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

Please reopen this issue once you commit the changes requested or make improvements on the code. Thank you for your contributions.