Did I do this right?

Advanced methods and approaches for solving Sudoku puzzles

Postby udosuk » Sat Mar 14, 2009 7:30 pm

PIsaacson wrote:I think you miss my point. I was asking for the full PM to confirm the exact conformation of the candidate in question at positions {x,A,F,W} as given in the example.

In that case you need the following PM grid:
Code: Select all
  23456789  23456789  23456789 | 123456789 123456789  23456789 | 123456789  23456789  23456789
  23456789 123456789 123456789 |  23456789  23456789  23456789 |  23456789  23456789  23456789
  23456789  23456789  23456789 |  23456789 123456789  23456789 | 123456789  23456789 123456789
-------------------------------+-------------------------------+-------------------------------
 123456789  23456789  23456789 | 123456789 123456789  23456789 |  23456789  23456789 123456789
  23456789  23456789  23456789 |  23456789 123456789  23456789 | 123456789  23456789  23456789
 123456789  23456789  23456789 | 123456789 123456789  23456789 | 123456789  23456789 123456789
-------------------------------+-------------------------------+-------------------------------
  23456789 123456789 123456789 |  23456789  23456789 123456789 |  23456789 123456789  23456789
  23456789 123456789 123456789 |  23456789  23456789 123456789 |  23456789 123456789  23456789
  23456789 123456789 123456789 |  23456789  23456789 123456789 |  23456789 123456789  23456789

Just make sure you use a solver which can handle Sukaku grids (and those with multiple solutions). JSudoku is one of them.

According to my solver, the grid above only produces 2 eliminations: r1c7<>1, r3c5<>1.:idea:
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Postby daj95376 » Sat Mar 14, 2009 7:56 pm

PIsaacson wrote:
udosuk wrote:That's true but for the purpose of the discussion here it's making use of a different set of cells

I think you miss my point. I was asking for the full PM to confirm the exact conformation of the candidate in question at positions {x,A,F,W} as given in the example. Even ER depends upon the absence of x in box 3, which is what I assumed the '.'s represent.

Various single digit methods, such as ER, Skyscraper, 2-String Kite, Turbot Fish, X-cycles, simple coloring, multiple fish patterns and POM can all be used to analyze the example position. I don't disagree with that and I fully understand how to produce the 2 eliminations that I found, using X-coloring with all the stated candidates.

I was merely questioning whether or not all the possible eliminations have been located, again assuming that all the candidates are represented in the example. I would like to submit the PM to templates to see if there is anything else, but my solver can't accept such single digit exemplar positions and I can't perform POM analysis accurately by hand.

Unfortunately, the full puzzle seems to no longer be available, so the question is moot. Meanwhile, I've been running benchmarks to compare the various single digit methods. I'll open a thread in the programming forum when I have all the data.

See you there if you're interested in continuing a single digit analysis discussion.

Unless I'm mistaken, EnterGT answered your question ... vaguely.

EnterGT wrote:Actually, I can't, sorry. It's a daily puzzle site, and I don't have access to previous puzzles. I assure you, however, that all possible cells for this candidate are marked.

This could be interpreted to mean that all of the candidate cells are shown, and that the unspecified boxes/columns/rows are where the value is solved. Here's one scenario.

Code: Select all
. . . | x x . | A . .
. X . | . . . | . . .
. . . | . F . | F . W
------+-------+------
x . . | x x . | . . x
. . . | . F . | F . .
x . . | x x . | x . x
------+-------+------
. . X | . . . | . . .
. . . | . . X | . . .
. . . | . . . | . X .
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Postby EnderGT » Sat Mar 14, 2009 10:09 pm

daj95376 wrote:Unless I'm mistaken, EnterGT answered your question ... vaguely.

I apologize for my answer being vague, it was not intentionally so.

daj95376 wrote:This could be interpreted to mean that all of the candidate cells are shown, and that the unspecified boxes/columns/rows are where the value is solved.

This is correct. Boxes with no candidates have been solved. Only unsolved candidate positions were shown.
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Postby ronk » Sun Mar 15, 2009 5:34 pm

PIsaacson wrote:I was merely questioning whether or not all the possible eliminations have been located, again assuming that all the candidates are represented in the example. I would like to submit the PM to templates to see if there is anything else, but my solver can't accept such single digit exemplar positions and I can't perform POM analysis accurately by hand.

According to [ed: my implementation of] templates, the only possible exclusions are at r1c7 and r3c5 -- as already posted by others.
Code: Select all
. . . | x  x . |-A . .
. . . | .  . . | . . .
. . . | . -F . | F . W
------+--------+------
x . . | x  x . | . . x
. . . | .  F . | F . .
x . . | x  x . | x . x
------+--------+------
. . . | .  . . | . . .
. . . | .  . . | . . .
. . . | .  . . | . . .
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Postby daj95376 » Sun Mar 15, 2009 10:09 pm

ronk wrote:According to [ed: my implementation of] templates, the only possible exclusions are at r1c7 and r3c5 -- as already posted by others.

Interesting. My implementation of templates eliminates all of the candidates because the missing assignments result in all templates being unacceptable. That's why I created the example scenario above. I'll give templates some more thought with regard to incomplete grids like this one.
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Postby ronk » Sun Mar 15, 2009 11:27 pm

daj95376 wrote:
ronk wrote:According to [ed: my implementation of] templates, the only possible exclusions are at r1c7 and r3c5 -- as already posted by others.

Interesting. My implementation of templates eliminates all of the candidates because the missing assignments result in all templates being unacceptable. That's why I created the example scenario above. I'll give templates some more thought with regard to incomplete grids like this one.

Sorry, didn't mean to imply that I've automated the addition of missing assignments; still doing so manually, much like you did in your example above.
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