6
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Contrary to the lazy puzzler, the creator of this masyu is too ambitious that he adds not only one but two extra stones, so the puzzle is unsolvable. Finish his job for him by removing those additional stones on the board so that the result is a uniquely solvable masyu.

Normal masyu rules apply.

enter image description here

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4
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By removing

The two stones in the third column

We can generate the following uniquely solvable solution

enter image description here

Reasoning

The three stones in the top left-hand corner are incompatible, hence one of them must be removed. Similarly, the stones in the bottom left-hand corner are incompatible, hence one of these must be removed. Developing the right hand side of the grid leads to the following.
enter image description here
From here, if the black stone in the third column remains, there must be a line emanating from it going up. Similarly, if the black stone in the second column remains, there must be a line emanating from it going right. These endpoints will necessarily need to be joined up and there will always be at least two ways to do this (thanks to jafe for pointing this out).
Hence, to get a unique solution, at least one of these black stones must be removed.

From there, there are just five combinations of stone removals to test for existence of a unique solution.

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  • $\begingroup$ @jafe Ah, yes, you're right sorry. $\endgroup$ – hexomino Aug 21 at 13:26
  • $\begingroup$ @jafe Altered the solution, based on your observation I was able to push the logic a bit more. $\endgroup$ – hexomino Aug 21 at 13:44
  • $\begingroup$ That's it, it's the correct answer! :D $\endgroup$ – athin Aug 21 at 14:46

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