Puzzle 52

Complain about the difficulty levels or show off your solving skills.
nj3h
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Puzzle 52

Post by nj3h »

Please look at Jigsaw Number 52 from May 2. I am at the position listed below.

.-------.-------.-------.-------.-------.-------.-------.-------.-------.
| 2 | 1 | 3 | 5689 | 5689 | 7 | 569 | 469 | 49 |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 1 | 578 | 56 | 4 | 569 | 3 | 569 | 2789 | 279 |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 3 | 4 | 9 | 2 | 7 | 8 | 1 | 5 | 6 |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 4578 | 69 | 5678 | 5678 | 2 | 1 | 4789 | 3 | 479 |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 457 | 269 | 1 | 567 | 3 | 46 | 479 | 2679 | 8 |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 478 | 269 | 278 | 78 | 468 | 5 | 24679 | 1 | 3 |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 78 | 3 | 4 | 1 | 68 | 9 | 2678 | 267 | 5 |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 9 | 578 | 2578 | 3 | 1 | 46 | 24678 | 24678 | 247 |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 6 | 578 | 578 | 5789 | 4589 | 2 | 3 | 48 | 1 |
'-------'-------'-------'-------'-------'-------'-------'-------'-------'

SumoCue provides a hint that says LoL elimination on Rows 12. The elimination is the 5 in r2c2. Is this the correct LoL logic for this elimination?

1. Innies: r1c2345678 + r2c34567

2. Outies: r3c23789 + r4c3478 + r5c457

3. The 5s for Nonets 2 and 3 must occur in r12 (one in each, of course)

4. There is a 5 in r3c8, therefore another 5 must occur in r4c34 + r5c4.

5. This eliminates the 5 in r2c2

For the last week I have been studying this technique. I believe I am implementing it correctly. If not, please let me know.

Thanks for the help.

George
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Post by sudokuEd »

Code: Select all

.-------.-------.-------.-------.-------.-------.-------.-------.-------.
| 2     | 1     | 3     | 5689  | 5689  | 7     | 569   | 469   | 49    |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 1     | 578   | 56    | 4     | 569   | 3     | 569   | 2789  | 279   |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 3     | 4     | 9     | 2     | 7     | 8     | 1     | 5     | 6     |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 4578  | 69    | 5678  | 5678  | 2     | 1     | 4789  | 3     | 479   |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 457   | 269   | 1     | 567   | 3     | 46    | 479   | 2679  | 8     |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 478   | 269   | 278   | 78    | 468   | 5     | 24679 | 1     | 3     |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 78    | 3     | 4     | 1     | 68    | 9     | 2678  | 267   | 5     |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 9     | 578   | 2578  | 3     | 1     | 46    | 24678 | 24678 | 247   |
:-------+-------+-------+-------+-------+-------+-------+-------+-------:
| 6     | 578   | 578   | 5789  | 4589  | 2     | 3     | 48    | 1     |
'-------'-------'-------'-------'-------'-------'-------'-------'-------'
Hi George,

The LoL eliminations I can see for r12 are 5 from r2c2 & 6 from r5c6. I see these in a different way to how you are looking at it.

Outies r12 (ie outies n2&3) = r3c456 + r4c56 + r5c6 (6 cells)
Innies r12 (ie innies n1&4) = r1c19 + r2c1289 (6 cells)
The leftover outies & innies each have 6 cells -> they must have the same digits.

The outies don't have a 5 -> the innies cannot have a 5 -> no 5 r2c2
The innies don't have a 6 -> the outies cannot have a 6-> no 6 r5c6.

BTW: A much simpler way (for me) to make these same eliminations is really a jigsaw X-wing. If you put your steps 3 and 5 together you can make the same elimination without having to worry about LoL.
nj3h wrote:3. The 5s for Nonets 2 and 3 must occur in r12 (one in each, of course)
5. This eliminates the 5 in r2c2
And with the 6's
6. 6 in r12 only in n23-> 6 locked for n23
6a. no 6 r5c6

Hope this helps.

Cheers
Ed
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Post by Glyn »

Hi George


Looking at the eliminations Sumocue did I see that Ed missed the 9's in R1C9 and R2C89 all from N4.
From the same groupings as Ed used, Outties R12 (N23) don't contain 9 -> Innies (N14) cannot contain 9 -> R1C9 and R2C89<>9.

Here the alternate way of looking at this is 9's in N2 and N3 must come from R1 and R2. No Nonet 4 can have no 9's in R12.

In effect the LOL description here breaks down into Generalized X-Wings in 5,6 and 9.

I guess Ed and I find it easier to pick them off one at time and leave counting the sets until later when the grid is a bit clearer of candidates.

All the best

Glyn
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nj3h
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Post by nj3h »

Ed and Glyn,

Thanks for the feedback. I really appreciate seeing better ways to get at the answer. Both of your shined your light to make that happen.

I never thought of a "Jigsaw x-wing" until I read the responses. Does SumoCue identify that technique? Since that seems "easier" to spot than a LoL technique, I would have thought that the "Jigsaw x-wing" would have been the hint instead of the LoL R12 hint. I don't think the order that solving techniques are applied can be adjusted by the user in SumoCue like they can in SudoCue. So the "Jigsaw x-wing" technique may be there, but just wasn't the hint presented.

Again thanks for the help.

Regards,
George
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Post by Glyn »

Hi George

I don't think that Sumocue uses X-wing at all as a hint on the Jigsaws. JC's program does identify many of these patterns as X-wings, so it picks them off one at a time.

Ruuds' LOL implementation is pretty thorough but for a human solver it can be a little bit obscure sometimes.

If you start looking at the Jigsaws from later in the week, you'll hit the dreaded hint Pattern Matching. JC identifies some of these reductions as Turbot Fish (short chains in one candidate) others it can't find. Ruud uses a template to find all of them so think of it as being brute force on one digit.

There is no guarantee that analysing one candidate at a time, even with templates, can crack everything though. So there is still room for the human solver to look for more multidigit combinations.

All the best,

Glyn
I have 81 brain cells left, I think.
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Post by Jean-Christophe »

Please note that JSudoku does not search for LoL.

You can define / create LoL yourself with Solve : Law of Leftovers. It will then synchonize automatically the set of candidates for innies & outies whenever some side/half change. Still some nasty bug in there though. :oops: Working on it...

You may also view the innies & outies with Highlight : Law of Leftovers.

This explains why JSudoku uses a lot of Intersections, Grouped X-Wing & Turbots whereas the same could be deduced with simpler techniques like LoL.
nj3h
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Post by nj3h »

What is the website for JSudoku? I saw one with that name (version 1.85). Is this the same program that JC mentioned in this thread?

Will this program allow the user to generate jigsaw puzzles?

Regards,
George
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Post by Jean-Christophe »

It's not the same program.
My program can be downloaded here:
http://jcbonsai.free.fr/sudoku/?cat=7

See also my post in this forum:
http://www.sudocue.net/forum/viewtopic.php?t=674

PS Yes, it does allow generating jigsaw.
nj3h
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Post by nj3h »

Hi JC,

I look forward to trying your program this evening. I am looking at it at work, but cannot take the time to get into in detail.

Is it possible to take a particular jigsaw template in SumoCue and use it in JSudoku? I added some of my own designs to SumoCue and would like to be able to use one of those layouts to generate a puzzle.

In the list of solving techniques, I presume the grayed out techniques (like Law of Leftovers) are for future implementation?

What does "renban" refer to?

Thanks for sharing your software with me.

Regards,
George
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Post by Jean-Christophe »

Yes you can use a particular jigsaw template to generate a grid.
You may also generate JigSaw & Killer templates if you like.

The "Law of Leftovers Sets" technique is already implemented. It will become available whenever you define/create LoL by hand with Solve : Law of Leftovers.

Still a bug in there. Buddies of some givens or solved cell could have invalid candidates. It should be fixed in the next release. In the meantime, "Solve : Reset possibilities" may fix the conflict.

For Renban see
http://jcbonsai.free.fr/sudoku/JSudokuU ... nban_group
And also
http://www.sachsentext.de/en/renban2.htm

Kind regards,
Glyn
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Post by Glyn »

Hi everyone

Just tried todays Daily and 'Reset Possibilities' at the first warning enables the solution process to complete, also gets Ultra Hard (56) a lot further.

All the best,

Glyn
I have 81 brain cells left, I think.
nj3h
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Post by nj3h »

Hi JC,

Thanks for the information in your last message. You mention that I can use JSudoku to generate a puzzle for a jigsaw pattern I created.

I presume I enter the pattern through the design menu option. Can I then save that pattern to load it up again without having to re-draw it? If you have a few extra moments, could you please give me the steps to follow to enter my own jigsaw template and how to save it for future use?


Regards,
George
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Post by Jean-Christophe »

If you have some SumoCue data for the jigsaw pattern, it's easier to paste it in JSudoku. It will then use that jigsaw pattern to generate a grid. It choose some other pattern for the givens.

Otherwize, RTFM :twisted: :roll:

As I see some interest in Jigsaw, I've implemented automatic search of LoL. Will be avail in the next version which will be released as soon as I've made some more tests.
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Post by Jean-Christophe »

Glyn wrote:Just tried todays Daily and 'Reset Possibilities' at the first warning enables the solution process to complete, also gets Ultra Hard (56) a lot further.
I've tried to solve with the new version. Still can't solve #56. :cry:
Had more success with #55 (Ultra Hard) :) :

Code: Select all

Stats&#58;
30 Naked Singles
23 Hidden Singles
2 Naked Pairs
14 Law of Leftovers
2 LoL Synchronization
4 Intersections
1 Pointing Pairs
3 Turbot Fishes
1 Grouped X-Wing
1 Grouped Turbot Fishes
1 Generalized Swordfish &#40;222&#41;
1 Turbot Chain with 5 links
nj3h
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Post by nj3h »

Hi JC,

Thanks for the replies. A question about the solvers.

I wasn't clear in the manual about one point. Does the selection of the solvers remove that particular technique from being used in the generation of a puzzle?

What I would like to do, is to generate a jigsaw puzzle with all techniques from X-wing and easier and LoL as possible techniques required to solve the puzzle. How do I go about doing this, with just the techniques that I want the generator to consider when a new puzzle is created?

If the above is possible, is there a way to save just the techniques in the solver that I want check marked each time I load up JSudoku?

Regards,
George
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