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au 3/23/12 tough
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arkietech

Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

Posted: Fri Mar 23, 2012 6:06 am Post subject: au 3/23/12 tough

Code:

*-----------*
|..7|..3|...|
|..1|5..|.2.|
|..6|.8.|...|
|---+---+---|
|.7.|..9|.4.|
|8..|...|..5|
|.4.|2..|.9.|
|---+---+---|
|...|.3.|5..|
|.9.|..6|7..|
|...|4..|2..|
*-----------*

Play/print

SudoQ

Joined: 02 Aug 2011
Posts: 127

Posted: Fri Mar 23, 2012 10:20 am Post subject:

There is a short bi-cell solution. Followed by some non-singles.

Code:

r6c6=5 -> r7c6=8 ->
r9c6=5 ->

/SudoQ

arkietech

Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

Posted: Fri Mar 23, 2012 12:27 pm Post subject:

stte is "singles to the end"
What if it is basic moves to the end?

Code:

*--------------------------------------------------------------------*
| 249 58 7 | 169 12469 3 | 14689 1568 168 |
| 49 38 1 | 5 4679 47 | 34689 2 3678 |
| 249 35 6 | 179 8 1247 | 1349 1357 137 |
|----------------------+----------------------+----------------------|
| 16 7 35 | 1368 156 9 | 1368 4 2 |
| 8 2 9 | 1367 1467 147 | 136 1367 5 |
| 16 4 35 | 2 1567 b1578 | 1368 9 13678 |
|----------------------+----------------------+----------------------|
| 7 16 24 | 189 3 b128 | 5 168 14689 |
| 35 9 24 | 18 d12-5 6 | 7 138 1348 |
| 35 16 8 | 4 1579 a157 | 2 136 1369 |
*--------------------------------------------------------------------*
L-wing
(5)r9c6=(5-8)r6c6=(8-2)r7c6=(2)r8c5 => r8c5<>5
finish with basics

Play/print online

ronk

Joined: 07 May 2006
Posts: 398

Posted: Fri Mar 23, 2012 1:02 pm Post subject:

arkietech wrote:

What if it is basic moves to the end?

I've seen "sste", "Simple Sudoku to end", quite a bit on the Eureka! forum IIRC. If your basics are different, then ... ?

arkietech

Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

Posted: Fri Mar 23, 2012 2:11 pm Post subject:

ronk wrote:

If your basics are different, then ... ?

Basics on this site stop at quads or maybe quints. Simple Sudoku includes xy-wings, colors, and fish along with others. You're right. What is basic? Confused

I needed a couple of quads to finish this puzzle.

SudoQ

Joined: 02 Aug 2011
Posts: 127

Posted: Fri Mar 23, 2012 2:44 pm Post subject:

arkietech wrote:

I needed a couple of quads to finish this puzzle.

Quads are not needed in this puzzle:

Code:

r9c56=57
r1c157=249
r3c167=249
c4<>q2<>1

/SudoQ

JC Van Hay

Joined: 13 Jun 2010
Posts: 494
Location: Charleroi, Belgium

Posted: Fri Mar 23, 2012 2:49 pm Post subject:

arkietech wrote:

stte is "singles to the end"
What if it is basic moves to the end?
...
What is basic?

For most of the players : basics=SSTS.

From Sudopedia

SSTS : Simple Sudoku Technique Set : The set of techniques supported by the Angus Johnson "Simple Sudoku" program, that is LC, LS, XY Wing, some "simple" sdT, no DP.

But, as basics may vary from one player to another, I always list any sdT and Wing used. So if not stte, I now write LC and LS to the end if I don't give the details. Conjointly, in my mind, "after basics" would mean after LC and LS. In any case, it is not forbidden to list critical LC and LS, isn't ! Wink

arkietech

Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

Posted: Fri Mar 23, 2012 3:13 pm Post subject:

JC Van Hay wrote:

that is LC, LS, XY Wing, some "simple" sdT, no DP.

I'm guessing:
LC locked candidate
LS locked set

what is sdT and DP?

JC Van Hay

Joined: 13 Jun 2010
Posts: 494
Location: Charleroi, Belgium

Posted: Fri Mar 23, 2012 3:26 pm Post subject:

arkietech wrote:

JC Van Hay wrote:

that is LC, LS, XY Wing, some "simple" sdT, no DP.

I'm guessing:
LC locked candidate
LS locked set

what is sdT and DP?

LC Locked Candidates
LS Locked Set
sdT single-digit Technique
DP Deadly Pattern

arkietech

Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

Posted: Fri Mar 23, 2012 3:40 pm Post subject:

JC Van Hay wrote:

LC Locked Candidates
LS Locked Set
sdT single-digit Technique
DP Deadly Pattern

Thanks JC! I will start using stte with LS/LC where needed

Marty R.

Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

Posted: Fri Mar 23, 2012 4:00 pm Post subject:

Based on what I know, "basics" on this site has been understood to be subsets and locked candidates. I never knew what "singles" meant unless it was the same as basics. As far as I'm concerned, a statement such as "STTE" at the end is superfluous and confusing. It's implicit that after the last step listed, whether a one- or multi-stepper, only basics are needed to complete the puzzle. Last edited by Marty R. on Fri Mar 23, 2012 4:58 pm; edited 1 time in total

daj95376

Joined: 23 Aug 2008
Posts: 3854

Posted: Fri Mar 23, 2012 4:17 pm Post subject:

Code:

Basics: Naked/Hidden Single/Pair/Triple/Quad, Locked Candidates 1/2

SudoQ

Joined: 02 Aug 2011
Posts: 127

Posted: Fri Mar 23, 2012 5:29 pm Post subject:

daj95376 wrote:

Code:

Basics: Naked/Hidden Single/Pair/Triple/Quad, Locked Candidates 1/2

I agree, but some considers that there's a gap (a W-Wing) between triples and quads in an sample like this:

Code:

+------------------+-------------+------------------+
| 345 2378 16 | 267 9 27 | 158 127 13478 |
| 49 89 27 | 5 3 1 | 6 27 48 |
| 35 237 16 | 267 4 8 | 15 9 137 |
+------------------+-------------+------------------+
| 7 1 9 | 8 6 3 | 4 5 2 |
| 6 45 458 | 249 7 245 | 18 3 189 |
| 2 345 3458 | 49 1 45 | 7 6 89 |
+------------------+-------------+------------------+
| 1 3459 345 | 347 2 47 | 39 8 6 |
| 8 6 34 | 34 5 9 | 2 17 17 |
| 39 27 27 | 1 8 6 | 39 4 5 |
+------------------+-------------+------------------+

/SudoQ

ronk

Joined: 07 May 2006
Posts: 398

Posted: Fri Mar 23, 2012 5:50 pm Post subject:

Marty R. wrote:

As far as I'm concerned, a statement such as "STTE" at the end is superfluous and confusing. It's implicit that after the last step listed, whether a one- or multi-stepper, only basics are needed to complete the puzzle.

Surely there is difference between being able to finish with singles only or singles plus a naked quad, for example.

Marty R.

Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

Posted: Fri Mar 23, 2012 6:53 pm Post subject:

ronk wrote:

Marty R. wrote:

Surely there is difference between being able to finish with singles only or singles plus a naked quad, for example.

I don't know what "singles only" means, but as I said above, and as Danny listed, basics here are understood to be subsets and locked candidates. After a poster lists his advanced steps used, why is an acronym needed after that list?

arkietech

Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

Posted: Fri Mar 23, 2012 7:16 pm Post subject:

SudoQ wrote:

daj95376 wrote:

Code:

Basics: Naked/Hidden Single/Pair/Triple/Quad, Locked Candidates 1/2

I agree, but some considers that there's a gap (a W-Wing) between triples and quads in an sample like this:

Code:

/SudoQ

LS (quad r1 hidden pair b1)
xy-wing 385
stte

ronk

Joined: 07 May 2006
Posts: 398

Posted: Fri Mar 23, 2012 7:46 pm Post subject:

Marty R. wrote:

I don't know what "singles only" means ...

Starting at a given state, use of only naked single and hidden single moves will solve a puzzle.

Marty R.

Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

Posted: Fri Mar 23, 2012 11:23 pm Post subject:

Quote:

LS (quad r1 hidden pair b1)
xy-wing 385
stte

Dan, nothing personal, you just happen to be convenient. I mentioned above my opinion about the acronyms at the end of posts. What does that "stte" tell the reader? What if there were only basics remaining but something other than singles? What would've been there instead of stte? I just don't understand. You've posted countless solutions without ending acronyms. What changed? How can I use those to my advantage? What about readers even less advanced than me?

DonM

Joined: 15 Sep 2009
Posts: 51

Posted: Fri Mar 30, 2012 3:23 am Post subject:

Marty R. wrote:

Quote:

LS (quad r1 hidden pair b1)
xy-wing 385
stte

I'll give it a try- at least as far as stte (singles to the end) is concerned. The latter has been used to indicate the end of the 'main' solution for some time by those manually solving fairly difficult puzzles so there must be a good reason. And there is: Since singles to the end means that starting with the final exclusion or placement of the solver's last move, the puzzle falls apart with nothing but a cascade of singles, there is no other move to be made, either basic or advanced and the stte assures the reader that the final move shown is, indeed, the final move.

This is quite different from basics-to-the-end or sste (simple sudoku to the end) or comparable. Personally, I have an issue with the solver not showing all moves including any final basic moves up to the 'singles to the end (stte) point, for two reasons:
1) I don't see why I have to search out those basic moves of someone else's solution- sometimes a so-called simple xy-wing doesn't jump out at you. And I don't want to have to enter the other person's solution through Simple Sudoku to find out what those final moves are either.
2) The elegance of a solution (IMO) is often somewhat dependent on how many total moves are required to solve the puzzle. One person's solution may have 3 advanced moves followed by 2 basic moves to solve a puzzle. Another person's may have a different set of 3 advanced moves followed by 1 basic move to solve the same puzzle. I would likely find the latter, the more elegant. But how would I know the difference if both solver's didn't show all the moves.

Edit: For those newer solvers who might be confused by the various acronyms, don't confuse the above with ssts (simple sudoku technique set) which is often used by more advanced solvers at the beginning of the 'main' solution and indicates the starting point as being after basic moves. That I am totally in favor of because most of us don't want to bother with opening basic moves and the ssts point is the same for everybody.

daj95376

Joined: 23 Aug 2008
Posts: 3854

Posted: Fri Mar 30, 2012 4:32 pm Post subject:

Fully Qualified Enough ???

Code:

+-----------------------+
| . . 7 | . . 3 | . . . |
| . . 1 | 5 . . | . 2 . |
| . . 6 | . 8 . | . . . |
|-------+-------+-------|
| . 7 . | . . 9 | . 4 . |
| 8 . . | . . . | . . 5 |
| . 4 . | 2 . . | . 9 . |
|-------+-------+-------|
| . . . | . 3 . | 5 . . |
| . 9 . | . . 6 | 7 . . |
| . . . | 4 . . | 2 . . |
+-----------------------+

start Givens:
Naked Single = 1 r2c3
Naked Single = 2 r2c8,r6c4,r9c7
Naked Single = 3 r1c6,r7c5
Naked Single = 4 r4c8,r6c2,r9c4
Naked Single = 5 r2c4,r5c9,r7c7
Naked Single = 6 r3c3,r8c6
Naked Single = 7 r1c3,r4c2,r8c7
Naked Single = 8 r3c5,r5c1
Naked Single = 9 r4c6,r6c8,r8c2
end Givens:

after Clues/Givens
*-----------------------------------------------------------------------------*
| 2459 258 7 | 169 12469 3 | 14689 1568 14689 |
| 349 38 1 | 5 4679 47 | 34689 2 346789 |
| 23459 235 6 | 179 8 1247 | 1349 1357 13479 |
|-------------------------+-------------------------+-------------------------|
| 12356 7 235 | 1368 156 9 | 1368 4 12368 |
| 8 1236 239 | 1367 1467 147 | 136 1367 5 |
| 1356 4 35 | 2 1567 1578 | 1368 9 13678 |
|-------------------------+-------------------------+-------------------------|
| 12467 1268 248 | 1789 3 1278 | 5 168 14689 |
| 12345 9 23458 | 18 125 6 | 7 138 1348 |
| 13567 13568 358 | 4 1579 1578 | 2 1368 13689 |
*-----------------------------------------------------------------------------*

Code:

Hidden Single = 2 r4c9
Hidden Single = 9 r5c3

Hidden Single = 2 r5c2

after initial Singles
*-----------------------------------------------------------------------------*
| 2459 58 7 | 169 12469 3 | 14689 1568 14689 |
| 349 38 1 | 5 4679 47 | 34689 2 346789 |
| 23459 35 6 | 179 8 1247 | 1349 1357 13479 |
|-------------------------+-------------------------+-------------------------|
| 1356 7 35 | 1368 156 9 | 1368 4 2 |
| 8 2 9 | 1367 1467 147 | 136 1367 5 |
| 1356 4 35 | 2 1567 1578 | 1368 9 13678 |
|-------------------------+-------------------------+-------------------------|
| 12467 168 248 | 1789 3 1278 | 5 168 14689 |
| 12345 9 23458 | 18 125 6 | 7 138 1348 |
| 13567 13568 358 | 4 1579 1578 | 2 1368 13689 |
*-----------------------------------------------------------------------------*

Code:

c3b4 Locked Pair <> 35 r46c1,r89c3

Naked Single = 8 r9c3

c1b4 Naked Pair <> 16 r789c1
c3b7 Naked Pair <> 24 r78c1

Naked Single = 7 r7c1

c1b7 Locked Pair <> 35 r123c1,r9c2

c9b9 Locked Candidate 1 <> 4 r123c9
c9b9 Locked Candidate 1 <> 9 r123c9

after Basics
*--------------------------------------------------------------------*
| 249 58 7 | 169 12469 3 | 14689 1568 168 |
| 49 38 1 | 5 4679 47 | 34689 2 3678 |
| 249 35 6 | 179 8 1247 | 1349 1357 137 |
|----------------------+----------------------+----------------------|
| 16 7 35 | 1368 156 9 | 1368 4 2 |
| 8 2 9 | 1367 1467 147 | 136 1367 5 |
| 16 4 35 | 2 1567 1578 | 1368 9 13678 |
|----------------------+----------------------+----------------------|
| 7 16 24 | 189 3 128 | 5 168 14689 |
| 35 9 24 | 18 125 6 | 7 138 1348 |
| 35 16 8 | 4 1579 157 | 2 136 1369 |
*--------------------------------------------------------------------*

Code:

c48 X-Wing <> 7 r3c69,r5c56

after SSTS
*--------------------------------------------------------------------*
| 249 58 7 | 169 12469 3 | 14689 1568 168 |
| 49 38 1 | 5 4679 47 | 34689 2 3678 |
| 249 35 6 | 179 8 124 | 1349 1357 13 |
|----------------------+----------------------+----------------------|
| 16 7 35 | 1368 156 9 | 1368 4 2 |
| 8 2 9 | 1367 146 14 | 136 1367 5 |
| 16 4 35 | 2 1567 1578 | 1368 9 13678 |
|----------------------+----------------------+----------------------|
| 7 16 24 | 189 3 128 | 5 168 14689 |
| 35 9 24 | 18 125 6 | 7 138 1348 |
| 35 16 8 | 4 1579 157 | 2 136 1369 |
*--------------------------------------------------------------------*

Code:

L3-Wing: (2)r8c5 = (2-8)r7c6 = (8-5)r6c6 = (5)r9c6 => r8c5<>5

Hidden Single = 5 r8c1

Naked Single = 3 r9c1

r9 Naked Pair <> 16 r9c569

Naked Single = 9 r9c9

Hidden Single = 9 r7c4

r1 Naked Quad <> 1568 r1c57
r3 Naked Quad <> 1357 r3c67

c7b3 Naked Pair <> 49 r2c7

c4b2 Locked Candidate 1 <> 1 r458c4

after advanced step and additional Basics; STE/STTE
*--------------------------------------------------------------------*
| 249 58 7 | 16 249 3 | 49 1568 168 |
| 49 38 1 | 5 4679 47 | 368 2 3678 |
| 249 35 6 | 17 8 24 | 49 1357 13 |
|----------------------+----------------------+----------------------|
| 16 7 35 | 368 156 9 | 1368 4 2 |
| 8 2 9 | 367 146 14 | 136 1367 5 |
| 16 4 35 | 2 1567 1578 | 1368 9 13678 |
|----------------------+----------------------+----------------------|
| 7 16 24 | 9 3 128 | 5 168 1468 |
| 5 9 24 | 8 12 6 | 7 138 1348 |
| 3 16 8 | 4 57 57 | 2 16 9 |
*--------------------------------------------------------------------*

Code:

Naked Single = 8 r8c4

Hidden Single = 8 r4c7,r6c6

Hidden Single = 5 r9c6

Naked Single = 7 r9c5

Hidden Single = 7 r2c6,r5c4,r6c9

Naked Single = 1 r3c4

Naked Single = 3 r3c9
Naked Single = 6 r1c4

Naked Single = 3 r4c4
Naked Single = 5 r3c2
Naked Single = 6 r2c7

Naked Single = 5 r4c3
Naked Single = 7 r3c8
Naked Single = 8 r1c2,r2c9

Naked Single = 1 r1c9
Naked Single = 3 r2c2,r6c3

Naked Single = 1 r6c7
Naked Single = 4 r8c9
Naked Single = 5 r1c8

Naked Single = 2 r8c3
Naked Single = 3 r5c7
Naked Single = 6 r6c1,r7c9

Naked Single = 1 r4c1,r7c2,r8c5,r9c8
Naked Single = 4 r7c3
Naked Single = 5 r6c5
Naked Single = 6 r5c8

Naked Single = 2 r7c6
Naked Single = 3 r8c8
Naked Single = 4 r5c5
Naked Single = 6 r4c5,r9c2
Naked Single = 8 r7c8

Naked Single = 1 r5c6
Naked Single = 4 r3c6
Naked Single = 9 r2c5

Naked Single = 2 r1c5
Naked Single = 4 r2c1
Naked Single = 9 r3c7

Naked Single = 2 r3c1
Naked Single = 4 r1c7
Naked Single = 9 r1c1

Solution:
987623451431597628256184973175369842829741365643258197714932586592816734368475219

DonM wrote:

I don't see why I have to search out those basic moves of someone else's solution- sometimes a so-called simple xy-wing doesn't jump out at you.

From your explanation, it appears that you consider an XY-Wing to be a Basics move. I, on the other hand, consider it an SSTS move. Hmmm!!!

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