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daj95376
Joined: 23 Aug 2008
Posts: 3854
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 Posted: Wed Jul 21, 2010 3:43 pm Post subject: Puzzle 10/07/21: A |
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| Code: | +-----------------------+
| . . . | 6 2 4 | . . . |
| . 2 . | 3 . 8 | 7 1 . |
| . . 3 | 5 . . | . . . |
|-------+-------+-------|
| 2 9 7 | . 8 . | . . . |
| 8 . . | 4 5 2 | 3 . . |
| 5 3 . | . 6 7 | . 2 8 |
|-------+-------+-------|
| . 7 . | . 3 . | 2 . . |
| . 5 . | . . 6 | . 7 . |
| . . . | . . 5 | . . 3 |
+-----------------------+
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Play this puzzle online at the Daily Sudoku site |
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Thu Jul 22, 2010 4:27 am Post subject: Petronas Towers |
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Originally started this looking at ANP (14=5) in row 7 and just went up to create the Petronas Towers.
A={1,4,6,9} Orange
B = {1,4,5,6,9} Green
x=1
z=9 so r1c3 <> 9 solves puzzle.
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peterj
Joined: 26 Mar 2010
Posts: 974
Location: London, UK
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| Posted: Thu Jul 22, 2010 3:53 pm Post subject: |
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Looking at mm's ALS I noticed a different take on it with an interesting looking pattern - like a sort of chain of m-wings. Does it have a name?
Both c1 and c9 have an m-wing type pattern of (1)=(1-9)=(9). The start of the pattern (1) in both column is in r7 (the restricted common of the ALS) and the discontinuity is r1c3 eliminating the 9.
I suppose as an AIC it's
| Code: | | (9)r3c1=(9-1)r9c1=(1)r7c1 - (1)r7c9=(1-9)r8c9=(9)r1c9; r1c3<>9 |
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Thu Jul 22, 2010 4:21 pm Post subject: |
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Thanks Peter.
I had never noticed that this was a large discontinuous loop. Or indeed a conjoined pair of M Wings. Puts me in mind of Volkswagen's W12 engine which was two V6s strapped together !
Last edited by Mogulmeister on Thu Jul 22, 2010 6:32 pm; edited 1 time in total |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Thu Jul 22, 2010 4:47 pm Post subject: |
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W-Wing (14), flightless with pincer transport
X-Wing (9)
W-Wing (48) |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Thu Jul 22, 2010 5:53 pm Post subject: |
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| Code: | +--------------------------------------------------------------+
| 7 1 89 | 6 2 4 | 589 3 59 |
| 46 2 5 | 3 9 8 | 7 1 46 |
| 469 48 3 | 5 7 1 | 4689 468 2 |
|--------------------+--------------------+--------------------|
| 2 9 7 | 1 8 3 | 456 456 456 |
| 8 6 1 | 4 5 2 | 3 9 7 |
| 5 3 4 | 9 6 7 | 1 2 8 |
|--------------------+--------------------+--------------------|
| *14 7 6 | 8 3 9 | 2 45 *14+5 |
| 3 5 89 | 2 *14 6 | 489 7 *14+9 |
| *14+9 48 2 | 7 *14 5 | 4689 468 3 |
+--------------------------------------------------------------+
# 39 eliminations remain
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| Code: | DP(14): ???
(5-1)r7c9 = (1)r7c1
(9-1)r9c1 = (1)r7c1
(9)r8c9 - r9c7 = (9-1)r9c1 = (1)r7c1
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Thu Jul 22, 2010 6:43 pm Post subject: |
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| Mogulmeister wrote: | Thanks Peter.
I had never noticed that this was a large discontinuous loop. Or indeed a conjoined pair of M Wings. Puts me in mind of Volkswagen's W12 engine which was two V6s strapped together ! |
Ed - The only difference (cosmetic) I'd make to your AIC Peter would be to start and end with the 9 in r1c3. |
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Luke451
Joined: 20 Apr 2008
Posts: 310
Location: Southern Northern California
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| Posted: Thu Jul 22, 2010 8:51 pm Post subject: |
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Nice, Dan.
Thinking out loud:
I suppose it's generally safe to say that if any deadly pattern is comprised of nothing but bivalues it's a BUG-Lite. (So a UR would also be a BUG-Lite.)
If at least one cell in a DP has more than two values, then it's a MUG. |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Thu Jul 22, 2010 9:50 pm Post subject: |
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| Luke451 wrote: | Nice, Dan.
Thinking out loud:
I suppose it's generally safe to say that if any deadly pattern is comprised of nothing but bivalues it's a BUG-Lite. (So a UR would also be a BUG-Lite.)
If at least one cell in a DP has more than two values, then it's a MUG. |
I'm jumping in here without knowing much of what I'm talking about, including ignorance of terms such as MUG and Bug Lite. However, if this is true, "that if any deadly pattern is comprised of nothing but bivalues it's a BUG-Lite", I thought that was the actual dreaded BUG. Thus, such terms as BUG+1, BUG+2, etc. to describe patterns with one or two trivalues. |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Thu Jul 22, 2010 10:53 pm Post subject: |
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| Luke451 wrote: | Thinking out loud:
I suppose it's generally safe to say that if any deadly pattern is comprised of nothing but bivalues it's a BUG-Lite. (So a UR would also be a BUG-Lite.)
If at least one cell in a DP has more than two values, then it's a MUG. |
I would start with ...
| Sudopedia wrote: | A Bivalue Universal Grave or BUG is a state of the grid in which every unsolved cell has 2 candidates, without the presence of Hidden Singles.
This is one of the Deadly Patterns that do not occur in a valid Sudoku. For some people, it is also a solving technique.
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Note: every candidate value could conceivably be present in a BUG.
| Sudopedia wrote: | BUG Lite is a solving technique that fills the gap between Uniqueness Test and BUG. It deals with isolated Deadly Patterns which are not Unique Rectangles.
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I take "isolated" to mean a subset of the unsolved cells. I suspect that a substantially large BUG-Lite could conceivably be based on a DP with every candidate value.
In both cases, I believe the "almost", that should be preceeding BUG/BUG-Lite in solutions, is replaced with a trailing "+n" to indicate the number of cells inside the DP that contain candidate values outside the DP.
As for MUG, I don't have a working definition.
In any event, I only use non-BUG/non-UR DPs based on 2/3 candidate values, and I do not assign a "name". |
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Luke451
Joined: 20 Apr 2008
Posts: 310
Location: Southern Northern California
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| Posted: Thu Jul 22, 2010 11:42 pm Post subject: |
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Maybe I could pose this a different way; BUG+n is not where I'm going w/this.
Look at the all the entries under "Deadly Patterns" in Sudopedia. I'm wondering if all of them are BUG-Lites.
There are many other types of DPs, but all of the ones in the DP article are comprised of bivalue cells. They all look like "BUG-Lites" to me, if one was going to name them. |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Fri Jul 23, 2010 1:20 am Post subject: |
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| Luke451 wrote: | Maybe I could pose this a different way; BUG+n is not where I'm going w/this.
Look at the all the entries under "Deadly Patterns" in Sudopedia. I'm wondering if all of them are BUG-Lites.
There are many other types of DPs, but all of the ones in the DP article are comprised of bivalue cells. They all look like "BUG-Lites" to me, if one was going to name them. |
Okay. It appears that the information on deadly patterns in Sudopedia is dated. It includes the following statement.
| Sudopedia wrote: | all deadly patterns of size less than about 30 cells consist entirely of bivalue cells
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This would explain why all of their examples are BUG-Lites.
Since MUGs aren't identified in Sudopedia, the existence of DPs with multi-value cells containing less than 30 cells appears to be unknown. A recent ronk link shows MUGs that involve considerably fewer than 30 cells. |
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Luke451
Joined: 20 Apr 2008
Posts: 310
Location: Southern Northern California
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| Posted: Fri Jul 23, 2010 7:33 pm Post subject: |
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Just for fun, more on the difference between a BUG-Lite and a MUG:
| daj95376 wrote: | | Code: | +--------------------------------------------------------------+
| 7 1 89 | 6 2 4 | 589 3 59 |
| 46 2 5 | 3 9 8 | 7 1 46 |
| 469 48 3 | 5 7 1 | 4689 468 2 |
|--------------------+--------------------+--------------------|
| 2 9 7 | 1 8 3 | 456 456 456 |
| 8 6 1 | 4 5 2 | 3 9 7 |
| 5 3 4 | 9 6 7 | 1 2 8 |
|--------------------+--------------------+--------------------|
| *14 7 6 | 8 3 9 | 2 45 *14+5 |
| 3 5 89 | 2 *14 6 | 489 7 *14+9 |
| *14+9 48 2 | 7 *14 5 | 4689 468 3 |
+--------------------------------------------------------------+
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The DP has all bivalues (14); it's a BUG-Lite. At least one of the "+" candidates must be true.
This next one I failed to note the origin, sorry:
| Code: | *--------------------------------------------------------------------*
| 5 4 23 | 9 1 23 | 6 8 7 |
| 8 23 1 | 7 6 23 | 49 5 49 |
| 7 9 6 | 58 58 4 |*123 *123 *13 |
|----------------------+----------------------+----------------------|
| 6 25 245 | 3 28 1 | 7 9 -48 |
| 3 1 29 | 4 7 89 | 28 6 5 |
| 29-4 8 7 | 6 29 5 |*123+4 *123 *13+4 |
|----------------------+----------------------+----------------------|
| 14 35 345 | 2 589 89 | 1358 7 6 |
| 129 7 2359 | 158 4 6 | 13589 13 1389 |
| 19 6 8 | 15 3 7 | 159 4 2 |
*--------------------------------------------------------------------* |
The DP has multiple candidate cells, as it's a composite of bivalue DPs; it's a MUG. At least one of the "+" candidates must be true. (r6c1<>4)
Here's a Myth Jellies MUG using this same pattern. |
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Sun Jul 25, 2010 2:59 pm Post subject: |
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I finally got around to working on this puzzle and used the ADP 14.
As part of the analysis I also found an independent but related solution.
r8c9<>9 because (9)r8c9-(9=8)r8c3-(8=4)r9c2-(4=1)r7c1-r7c9=(1)r8c9,
or continuing the chain posted by Danny, (9)r8c9 - r9c7 = (9-1)r9c1 = (1)r7c1 - (1)r7c9 = (1) r8c9
Ted |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Sun Jul 25, 2010 3:24 pm Post subject: |
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| tlanglet wrote: | or continuing the chain posted by Danny, (9)r8c9 - r9c7 = (9-1)r9c1 = (1)r7c1 - (1)r7c9 = (1) r8c9
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Ted: I noticed that chain as I was trying to resolve the DP, but it didn't occur to me that it might be sufficient to crack the puzzle. Nice find! |
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Sun Jul 25, 2010 10:00 pm Post subject: |
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| Nice discontinuity Ted. |
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