Comments on: My first Hitori puzzle (and a big one too!) http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/ Play your favorite type of Sudoku puzzles Mon, 30 Aug 2010 20:03:42 -0700 hourly 1 http://wordpress.org/?v=3.0.1 By: djape http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/comment-page-1/#comment-114521 djape Wed, 11 Feb 2009 18:13:20 +0000 http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/#comment-114521 Well, that is mentioned as the goal of Hitori puzzles. :) Well, that is mentioned as the goal of Hitori puzzles. :)

]]> By: zvifr http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/comment-page-1/#comment-114514 zvifr Wed, 11 Feb 2009 12:45:03 +0000 http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/#comment-114514 Shouldn't you mention in the rules that a number can't appear in a row or column more than once. Shouldn’t you mention in the rules that a number can’t appear in a row or column more than once.

]]> By: udosuk http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/comment-page-1/#comment-114497 udosuk Wed, 11 Feb 2009 01:16:02 +0000 http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/#comment-114497 Thank you very much for changing your puzzle/algorithm! :) Perhaps a big part of the "debate" is the interpretation of the word "duplicate". But the very fact that such an ambiguity can occur is enough reason for the change. Anyway, thanks again for the change, and hopefully you'll create/sell more great puzzles/books in the future! :mrgreen: Thank you very much for changing your puzzle/algorithm! :)

Perhaps a big part of the “debate” is the interpretation of the word “duplicate”. But the very fact that such an ambiguity can occur is enough reason for the change.

Anyway, thanks again for the change, and hopefully you’ll create/sell more great puzzles/books in the future! :mrgreen:

]]> By: djape http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/comment-page-1/#comment-114487 djape Tue, 10 Feb 2009 22:36:22 +0000 http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/#comment-114487 udosuk, even though I disagree that the solution was not unique (remember, the goal is only to eliminate duplicates, by shading DUPLICATE numbers black; once you fill in one duplicate, the second one is no longer duplicate), I decided to avoid any ambiguity and have changed my algorithm accordingly. I've uploaded a new version of the same puzzle. I believe this time there aren't any uncertainties - please let me know if you agree or not. udosuk, even though I disagree that the solution was not unique (remember, the goal is only to eliminate duplicates, by shading DUPLICATE numbers black; once you fill in one duplicate, the second one is no longer duplicate), I decided to avoid any ambiguity and have changed my algorithm accordingly.

I’ve uploaded a new version of the same puzzle. I believe this time there aren’t any uncertainties – please let me know if you agree or not.

]]> By: udosuk http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/comment-page-1/#comment-114485 udosuk Tue, 10 Feb 2009 20:56:02 +0000 http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/#comment-114485 For me, the focus is not whether "circling all cells is mandatory", but whether "the solution is unique". For all logic puzzles, uniqueness of solution is a very important aspect. It's obvious your given solution is not the unique solution for the given puzzle (under the rules you specified). Because if say, r6c10=5 is shaded black, we get another valid solution (note that it can be shaded black because originally we have two 5s on r6, so technically both of them are "duplicate numbers"). Take the example puzzle in the following page: http://en.wikipedia.org/wiki/Hitori In the solution grid, all white cells can't be shaded black, so the solution is "absolutely unique". I think it should be a desired standard for your puzzle too. :idea: So if possible, please change your software to adopt that "rule". Thanks! :mrgreen: For me, the focus is not whether “circling all cells is mandatory”, but whether “the solution is unique”. For all logic puzzles, uniqueness of solution is a very important aspect.

It’s obvious your given solution is not the unique solution for the given puzzle (under the rules you specified). Because if say, r6c10=5 is shaded black, we get another valid solution (note that it can be shaded black because originally we have two 5s on r6, so technically both of them are “duplicate numbers”).

Take the example puzzle in the following page:

http://en.wikipedia.org/wiki/Hitori

In the solution grid, all white cells can’t be shaded black, so the solution is “absolutely unique”. I think it should be a desired standard for your puzzle too. :idea:

So if possible, please change your software to adopt that “rule”. Thanks! :mrgreen:

]]> By: djape http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/comment-page-1/#comment-114474 djape Tue, 10 Feb 2009 10:47:23 +0000 http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/#comment-114474 I'm aware of that. When I was building my Hitori solver/generator it occurred to me that there is some ambiguity regarding the rules. Eventually I resolved it by adopting what seems to be a general consensus: the only goal is to eliminate duplicates by filling them black. And that's it. Circling white cells is only used to help you out while solving, it is actually not a mandatory part of the solution. Of course, if you convince me that the standard of Hitori is to also circle all cells that aren't black, I will easily change my software to adopt that rule. :) I’m aware of that. When I was building my Hitori solver/generator it occurred to me that there is some ambiguity regarding the rules. Eventually I resolved it by adopting what seems to be a general consensus: the only goal is to eliminate duplicates by filling them black. And that’s it. Circling white cells is only used to help you out while solving, it is actually not a mandatory part of the solution.

Of course, if you convince me that the standard of Hitori is to also circle all cells that aren’t black, I will easily change my software to adopt that rule. :)

]]> By: udosuk http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/comment-page-1/#comment-114460 udosuk Mon, 09 Feb 2009 12:29:42 +0000 http://www.djape.net/sudoku/wp/index.php/2009/02/07/my-first-hitori-puzzle-and-a-big-one-too/#comment-114460 I've finished this puzzle, but found that there are 5 cells which could be black or white. These include: r6c10=5 r9c7=2 r10c7=14 r10c8=10 r13c8=1 Of course, r9c7+r10c7 & r10c7+r10c8 can't be both black. But the fact that some of the cells in the solution grid can be either way gives me a sense of incompleteness. Is there a rule that says if a cell can be black or white then it must be white? :? I’ve finished this puzzle, but found that there are 5 cells which could be black or white.

These include:
r6c10=5
r9c7=2
r10c7=14
r10c8=10
r13c8=1

Of course, r9c7+r10c7 & r10c7+r10c8 can’t be both black. But the fact that some of the cells in the solution grid can be either way gives me a sense of incompleteness. Is there a rule that says if a cell can be black or white then it must be white? :?

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