Move all subroutines in star_coloring and acyclic_coloring

[amontoison]

For the paper, I explained star_coloring and acyclic_coloring as one algorithm without the subroutines.
Based on our modifications and the additional arguments passed to the subroutines, I am wondering if it might be more relevant to keep just two functions.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (10239ec) to head (60be001).
Report is 1 commits behind head on main.

Additional details and impacted files

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  Coverage   100.00%   100.00%           
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  Files           15        15           
  Lines         1785      1775   -10     
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- Hits          1785      1775   -10     

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[gdalle]

I disagree, there are two purposes to the subroutines:

• avoiding code duplication (treat! is called several times for instance)
• increasing clarity by separating the conceptual steps of the algorithm

Our code does not have to exactly mirror the paper. When I suggested presenting just one algorithm (the main loop), I meant we could keep the subroutines as subroutines, without recursing into them. I didn't mean they should be unrolled into a giant pseudocode, and thus I don't think we should unroll in our code either. Not to mention it mirrors the structure of the original paper.

[amontoison]

It's fine for me. It was just a suggestion.
I'm closing the PR.
I just changed one comment but I will open another PR for that.