Question about commented code and strategies

[Joxter]

Hey, thank you for the project, it implements many human strategies and is very handy for learning and defining difficulties.

I'm just curious about the commented code, mostly dealing with different strategies. Why? What's wrong with them?

I also heard about several more advanced strategies (XWing, Swordfish, Jellyfish, XYWing, XYZWing). What about them?

Thank you

[Joxter]

hi again, I have another question!:)

Could you please explain how removeCandidatesFromMultipleCells works?

        //-1 because candidate '1' is at index 0 etc.
        if (candidate && cellCandidates[candidate - 1] !== null) {
          cellCandidates[candidate - 1] = null; //NOTE: also deletes them from board variable

As far as I understand: the cellCandidates is an array of candidates and the candidate index has nothing to do with its value. So cellCandidates[candidate - 1] !== null looks confusing.

It must be something like cellCandidates.contains(candidate). But it breaks several "solve method" tests. I'm totally confused.