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| daj95376
| Joined: 05 Feb 2006 | Posts: 349 | : | | Items |
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Posted: Sun Apr 16, 2006 6:30 pm Post subject: Partially Solved Puzzle |
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I'm in the process of trying to develop a puzzle generator that generates a filled grid and then produces a difficult puzzle from it. Speed is not a factor!
I'm still early in the development process and keep changing my (un-scientific) methodology. Until today, I haven't been able to generate anything that Simple Sudoku couldn't handle easily. Imagine my surprise when the following puzzle popped out during a test run. It's most likely just an anomaly where my generator stumbled onto a difficult puzzle. In any event, Simple Sudoku partially solves it (using F11) and then said "no hint available".
If someone has a free moment, I'd sure like to know the next technique needed to crack this puzzle. My own experience is limited. Thanks!
Code: | from Simple Sudoku:
*-----------* "Original"
|...|.5.|9.6|
|...|68.|.2.|
|76.|..4|.5.|
|---+---+---|
|..3|..8|..2|
|1..|...|..9|
|8..|4..|6..|
|---+---+---|
|.2.|7..|.95|
|.5.|.42|...|
|9.7|.3.|...|
*-----------*
*-----------* "Partially Solved"
|28.|.5.|9.6|
|53.|68.|.2.|
|76.|2.4|853|
|---+---+---|
|6.3|..8|..2|
|1.2|...|.89|
|8.5|42.|63.|
|---+---+---|
|428|7..|395|
|356|942|..8|
|917|835|264|
*-----------*
*-----------------------------------------------------------*
| 2 8 14 | 13 5 137 | 9 147 6 |
| 5 3 149 | 6 8 179 | 147 2 17 |
| 7 6 19 | 2 19 4 | 8 5 3 |
|-------------------+-------------------+-------------------|
| 6 479 3 | 15 179 8 | 1457 147 2 |
| 1 47 2 | 35 67 36 | 457 8 9 |
| 8 79 5 | 4 2 19 | 6 3 17 |
|-------------------+-------------------+-------------------|
| 4 2 8 | 7 16 16 | 3 9 5 |
| 3 5 6 | 9 4 2 | 17 17 8 |
| 9 1 7 | 8 3 5 | 2 6 4 |
*-----------------------------------------------------------*
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| vidarino
| Joined: 10 Feb 2006 | Posts: 38 | : | Location: Haugesund, Norway | Items |
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Posted: Sun Apr 16, 2006 7:31 pm Post subject: |
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There aren't any trivial techniques that cracks this one, it seems, but the following nice loop does it;
Code: | R2C6-7-R2C9-1-R6C9=1=R6C6=9=R2C6
-> R2C6 <> 7 |
The notation is thoroughly explained in a post on the Players' forum. (I can look up the direct link if need be.)
Quick and dirty explanation; if R2C6 were 7 it would wipe out all the 9s from column 6. |
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| Carcul
| Joined: 29 Dec 2005 | Posts: 50 | : | Location: Coimbra, Portugal | Items |
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Posted: Fri Jun 16, 2006 6:35 pm Post subject: Another Solution |
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[r5c5](-7-[r4c5|r5c7])-7-[r5c2]-4-[r5c7]-5-[r5c4]-3-[r1c4](-1-[r2c6])-1-
-[r1c3]-4-[r2c3]-{TILA(1): r2c3|r3c3|r3c5|r4c5|r6c6|r6c9|r2c9|},
=> r5c5<>7 and the puzzle is solved.
Carcul |
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| daj95376
| Joined: 05 Feb 2006 | Posts: 349 | : | | Items |
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Posted: Fri Jun 16, 2006 9:07 pm Post subject: |
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Carcul, Thank You for your solution!
Code: | *-----------------------------------------------------------*
| 2 8 14 | 13 5 137 | 9 147 6 |
| 5 3 149 | 6 8 179 | 147 2 17 |
| 7 6 19 | 2 19 4 | 8 5 3 |
|-------------------+-------------------+-------------------|
| 6 479 3 | 15 179 8 | 1457 147 2 |
| 1 47 2 | 35 67 36 | 457 8 9 |
| 8 79 5 | 4 2 19 | 6 3 17 |
|-------------------+-------------------+-------------------|
| 4 2 8 | 7 16 16 | 3 9 5 |
| 3 5 6 | 9 4 2 | 17 17 8 |
| 9 1 7 | 8 3 5 | 2 6 4 |
*-----------------------------------------------------------*
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Since my original posting, I've advanced my solving techniques a little.
Code: | [r3c5]=1 => [r7c5]=6
=> [r1c4]=3 => [r1c6]=7 => [r2c6]=9 => [r6c6]=1 => [r7c6]=6
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Results in [r3c5]=9 and the puzzle is solved with a cascade of singles.
Last edited by daj95376 on Wed Sep 13, 2006 9:23 am; edited 1 time in total |
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| Perry
| Joined: 13 Jul 2006 | Posts: 3 | : | Location: Geneva | Items |
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Posted: Fri Jul 14, 2006 4:29 pm Post subject: Partially Solved Puzzle |
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Hi,
My program found XY-Chain: r3c5-r1c4-r5c4-r4c4-r6c6
must contain 9 at head or tail, so 9 can be crossed out of
r2c6 and r3c5
Perry |
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| fermat
| Joined: 05 Feb 2006 | Posts: 25 | : | Location: Melbourne | Items |
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Posted: Sat Jul 15, 2006 12:51 am Post subject: Re: Partially Solved Puzzle |
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Perry wrote: | Hi,
My program found XY-Chain: r3c5-r1c4-r5c4-r4c4-r6c6
must contain 9 at head or tail, so 9 can be crossed out of
r2c6 and r3c5
Perry |
That should read "r4c5", r3c5 is 9. |
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| Perry
| Joined: 13 Jul 2006 | Posts: 3 | : | Location: Geneva | Items |
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Posted: Mon Jul 17, 2006 3:13 pm Post subject: Re: Partially Solved Puzzle |
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You're right, thanks for dorrecting, my apologies for the typo.
Perry |
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