It seems that most of the functions does not have unit tests.
Of course, I know that it is very difficult to write a lot of test cases. So whenever you add an algorithm,
how about writing a test case in the comments inside the function and checking it when PR is added use pydoctest?

I think it would be convenient if we let us know the time complexity and test results every time we add PR automatically.

I want to add this feature ;)