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| daj95376
| | Joined: 05 Feb 2006 | | Posts: 349 | | : | |
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 Posted: Fri Mar 31, 2006 5:23 pm Post subject: Simple Sudoku Solving Techniques and Order |
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I have Simple Sudoku and enjoy playing it at my limited skill level. However, I will never forgive angusj for removing bold highlighting from naked_single cells in version 4.1z. 
Anyway, I recently was stumped on a puzzle and the F7 hint said that eliminations could be performed based on a naked_quad. However, when I ran the same puzzle through QQwing, it reported a hidden_pair at the same step.
Obviously, the two programs apply solution techniques in a different order. That's okay, but now I'm curious as to the order SS applies its solution techniques. angusj? |
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| angusj
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 | | Joined: 18 Jun 2005 | | Posts: 406 | | : | |
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| Posted: Fri Mar 31, 2006 10:20 pm Post subject: Re: Simple Sudoku Solving Techniques and Order |
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| daj95376 wrote: | | That's okay, but now I'm curious as to the order SS applies its solution techniques. angusj? |
Naked Singles
Hidden Singles
Naked Pairs
Locked Candidates
Naked Triples
Naked Quads
Hidden Pairs
XWing
Swordfish
Colors
MultiColors
Hidden Triples
XYWing
Hidden Quads
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| daj95376
| | Joined: 05 Feb 2006 | | Posts: 349 | | : | |
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| Posted: Fri Mar 31, 2006 10:59 pm Post subject: |
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| Thank you for Simple Sudoku ... and your reply. |
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| angusj
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| | Joined: 18 Jun 2005 | | Posts: 406 | | : | |
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| Posted: Sat Apr 01, 2006 12:37 am Post subject: |
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| daj95376 wrote: | | Thank you for Simple Sudoku ... and your reply. |
It's a pleasure. Thanks for your thanks too . |
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| gypsy fly
| | Joined: 06 Mar 2006 | | Posts: 18 | | : | | Location: Portland OR USA |
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| Posted: Mon Apr 03, 2006 5:12 am Post subject: |
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| Does SS scan left to right, top to bottom? |
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| angusj
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| | Joined: 18 Jun 2005 | | Posts: 406 | | : | |
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| Posted: Mon Apr 03, 2006 5:50 am Post subject: |
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| gypsy fly wrote: | | Does SS scan left to right, top to bottom? |
Yes. |
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| evert
| | Joined: 30 Aug 2005 | | Posts: 68 | | : | | Location: Amsterdam |
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| Posted: Mon Apr 03, 2006 12:16 pm Post subject: |
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In some cases it's a pity that Simple Sudoku doesn't look at the number of elimination steps.
See the following puzzle:
| Code: |
*-----------*
|..1|4..|9.7|
|..2|..6|.58|
|.7.|...|...|
|---+---+---|
|.5.|.24|1..|
|...|...|.3.|
|7.9|5..|..4|
|---+---+---|
|29.|8..|..3|
|...|..1|...|
|.45|...|...|
*-----------*
*-----------*
|..1|43.|9.7|
|932|..6|458|
|.7.|...|3.1|
|---+---+---|
|.5.|.24|1..|
|...|...|.3.|
|7.9|5.3|.84|
|---+---+---|
|29.|84.|.13|
|...|..1|.4.|
|145|3..|8..|
*-----------*
*-----------------------------------------------------------*
| 568 68 1 | 4 3 258 | 9 26 7 |
| 9 3 2 | 17 17 6 | 4 5 8 |
| 4568 7 468 | 29 589 2589 | 3 26 1 |
|-------------------+-------------------+-------------------|
| 38 5 38 | 679 2 4 | 1 79 69 |
| 46 12 46 | 179 1789 789 | 257 3 259 |
| 7 12 9 | 5 16 3 | 26 8 4 |
|-------------------+-------------------+-------------------|
| 2 9 67 | 8 4 57 | 567 1 3 |
| 368 68 3678 | 2679 5679 1 | 2567 4 2569 |
| 1 4 5 | 3 679 279 | 8 79 269 |
*-----------------------------------------------------------*
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From this stadium Simple Sudoku applies 4 color steps.
However one multiple color step also solves it - see 6 R9C59 and 6 R6C57R4C9.
It was also easier for me to spot it.
Regards
Evert |
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| angusj
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| | Joined: 18 Jun 2005 | | Posts: 406 | | : | |
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| Posted: Mon Apr 03, 2006 1:08 pm Post subject: |
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| evert wrote: | | In some cases it's a pity that Simple Sudoku doesn't look at the number of elimination steps. |
Yes, it is a pity. However, it'd take about 10 times as long to write (and debug) such a programme and consequently would probably never see the light of day . |
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| rkral
| | Joined: 21 Oct 2005 | | Posts: 233 | | : | |
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| Posted: Mon Apr 03, 2006 2:49 pm Post subject: |
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| evert wrote: | From this stadium Simple Sudoku applies 4 color steps.
However one multiple color step also solves it - see 6 R9C59 and 6 R6C57R4C9.
It was also easier for me to spot it. |
I don't see that "one color step" at all. Would you please clarify?
TIA, Ron |
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| evert
| | Joined: 30 Aug 2005 | | Posts: 68 | | : | | Location: Amsterdam |
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| Posted: Mon Apr 03, 2006 3:25 pm Post subject: |
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Very helpful explanation of multiple colors:
http://www.setbb.com/sudoku/viewtopic.php?p=2575&mforum=sudoku#2575
There is a very short conjugate chain of 6s R9C5-R9C9 - let's lable them a and A.
There is also a conjugate chain R6C5-R6C7-R4C9 - let's lable them b and B and b.
R6C5 looks at R9C5 therefore b looks at a.
R4C9 looks at R9C9 therefore b looks at A.
If b looks at both a and A then b is false and therefore B is true.
--> R6C7 = 6. |
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| rkral
| | Joined: 21 Oct 2005 | | Posts: 233 | | : | |
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| Posted: Mon Apr 03, 2006 5:22 pm Post subject: |
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| evert wrote: | | If b looks at both a and A then b is false and therefore B is true. |
Of course, but the design philosophy of Simple Sudoku is to emulate a human solver. Therefore, it will find all simple coloring deductions -- those based on a single chain of conjugate links -- before it makes any multi-color deductions with two chains. |
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| Ruud
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 | | Joined: 17 Sep 2005 | | Posts: 708 | | : | | Location: Netherlands |
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| Posted: Mon Apr 03, 2006 6:14 pm Post subject: |
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| rkral wrote: | | the design philosophy of Simple Sudoku is to emulate a human solver. Therefore, it will find all simple coloring deductions before it makes any multi-color deductions with two chains. |
It is my experience - having published over a 100 nightmares - that human solvers shoot first and ask questions later. Many of the nightmares were immediately attacked with forcing chains after basic eliminations, despite my effort to select sudokus that do not require forcing chains.
The human solver is too diverse to be emulated by a single program.
Ruud.
_________________
Meet me at sudocue.net |
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| rkral
| | Joined: 21 Oct 2005 | | Posts: 233 | | : | |
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| Posted: Mon Apr 03, 2006 7:57 pm Post subject: |
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| Ruud wrote: | | The human solver is too diverse to be emulated by a single program. |
You are taking my statement too literally, I think.
If for any given puzzle, 51% or more of human solvers find a single chain of conjugates before they find two chains of conjugates, then I'd say a solver designed to make single chain deductions before multi-chain deductions is emulating a human solver.
Hmmm. Doesn't one *always* need to spot a 1st chain before one can spot a 2nd chain? |
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| Ruud
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| | Joined: 17 Sep 2005 | | Posts: 708 | | : | | Location: Netherlands |
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| Posted: Mon Apr 03, 2006 8:57 pm Post subject: |
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| rkral wrote: | | Hmmm. Doesn't one *always* need to spot a 1st chain before one can spot a 2nd chain? |
Not necessarily. I can spot a "skyscraper" or a "2-string-kite" as a single pattern, although I know there are multiple chains involved.
The human solver, unlike a computer program, will look at the complete picture and spot *anything* recognizable. How often will you not handle a set of locked candidates as a naked triple, rather than using the *easier* line-box interactions?
Are you really looking for singles first, then line-box, then naked pairs, then naked triples, then.... when an X-Wing is drawing your attention?
The use of programs like SudoCue and Simple Sudoku make it easier for a player to spot patterns than ever before. I can spot a finned fish even before I smell it. Yet many solvers prefer to apply coloring before any finned fish is reeled in.
Ruud.
_________________
Meet me at sudocue.net |
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| rkral
| | Joined: 21 Oct 2005 | | Posts: 233 | | : | |
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| Posted: Mon Apr 03, 2006 9:19 pm Post subject: |
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| Ruud wrote: | | Are you really looking for singles first, then line-box, then naked pairs, then naked triples, then.... when an X-Wing is drawing your attention? |
You use whatever "pops out" at you, of course ... so I think that's a silly question. I'm referring to a regimen one must fall back upon when nothing ... absolutely nothing ... pops out.
Anyway, I'm done with this topic. The relative priority of techniques is often a matter of personal preference and opinion, and I'm sure you know what people say about opinions. Besides, it's not even my solver. |
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