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Almost Naked Sudoku (Posted on 2009-02-12) Difficulty: 3 of 5
A Sudoku with NO numbers provided whatsoever? Devious and/or fiendishly clever? One solution from millions? Yes!

The rules here are really very simple!
It's a basic Sudoku with 1 to 9 appearing in every row, column and each of the nine blocks, although not diagonally (no large 'X'). All numbers that are higher than their abutting non-diagonal cell neighbours in the same block are in the pink cells. All numbers that are lower than their abutting (non-diagonal) cell neighbours in each block are in the blue cells. (The colour relationships do not apply between adjacent blocks!!)

That's it! Definitely enough to get any self-respecting hard-core Sudoku fanatic started with a combination of some logical thinking and standard Sudoku techniques.

Note: Graphic is a "jpg", xhtml generated by brianjn.

  Submitted by rod hines    
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Solution: (Hide)
Well, try as I might, 'One solution from millions'? Not quite, it would appear!!!

The solution presented by Eigenray is actually the one I had, however some of the 5's and 6's (as bolded) are indeed interchangeable, resulting in two valid solutions here that weren't initially apparent (to me) without such computer testing. While I wipe the egg off my face, let me say 'Great detective work there, Eigenray'!

And kudo's as well to Jyqm, who determined the unstated second key assumption regarding 2's and 8's needed to keep moving toward the solution.

Comments: ( You must be logged in to post comments.)
  Subject Author Date
Solutionuh ohEigenray2009-02-13 08:44:29
re: assumingJyqm2009-02-12 22:39:12
Hints/TipsassumingCharlie2009-02-12 18:28:53
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