I saw someone post a ying-yang puzzle on here recently and I thought I might challenge people here with another one!

Rules of Yin-Yang:

Fill each empty cell with either a black circle or a white circle.

All white circles should be orthogonally connected, so do all black circles.

There may not be any 2x2 cell region consisting of the same circle color.

enter image description here

  • 6
    $\begingroup$ Sorry to downvote, but grid-deduction puzzles should have a unique solution and be solvable by logic. $\endgroup$
    – Bubbler
    Nov 19, 2020 at 9:57
  • 2
    $\begingroup$ I was a little disapointed when I found this out. $\endgroup$ Nov 19, 2020 at 10:06
  • $\begingroup$ Otherwise it was fun! $\endgroup$ Nov 19, 2020 at 10:06

2 Answers 2


Black tiles and black circles and yellow tiles are white circles...

First of all some simple deductions:

enter image description here

Next if R4C8 is B then it will lead to opposite pairs and so it must be W and then some more deductions:

enter image description here

Next if R8C5 is both B and W then it leads to these overlapping deductions so this must be the configurations...

enter image description here

Then if R4C4 is W then it will lead R3C5 to become isolated. So it must be black. Then a few deductions later we have:

enter image description here

Then using the edge rule and hypothetically say R1C8 is W then it will lead to this:

enter image description here

And if we say it is black it will lead to this. Notice how similar they are since alot of the deductions overlap meaning that most of this will be in the final answer.

enter image description here

So lets say R1C8 is W then the puzzle is unsolvable because R10C3 needs to connect to R7C5, R7C7, R6C9. And doing so will isolate a group of White circles. Therefore R1C8 must be black.

So assuming 10C4 is white and using the edge connection rule and a few deductions we have this. The finished result.

enter image description here

  • 1
    $\begingroup$ As I said in the comments I am sure that there are multiple solutions $\endgroup$ Nov 19, 2020 at 8:05

This has many solutions. I believe this is the furthest you can go. Everything else is ambiguous.

enter image description here

  • $\begingroup$ Yeah it is an easy one. $\endgroup$
    – J.Spencer
    Nov 19, 2020 at 9:49
  • 9
    $\begingroup$ @J.Spencer not if you are using logic. Then it's impossible. $\endgroup$
    – Kruga
    Nov 19, 2020 at 9:52

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