Vanhegan extreme December 13, 2012

Post puzzles for others to solve here.

Vanhegan extreme December 13, 2012

Postby ArkieTech » Thu Dec 13, 2012 8:14 am

Code: Select all
 *-----------*
 |...|.2.|48.|
 |..5|.6.|..2|
 |...|93.|7..|
 |---+---+---|
 |...|...|1.8|
 |.54|...|63.|
 |7.3|...|...|
 |---+---+---|
 |..9|.42|...|
 |4..|.9.|5..|
 |.87|.1.|...|
 *-----------*


Play/Print this puzzle online
dan
User avatar
ArkieTech
 
Posts: 2715
Joined: 29 May 2006
Location: NW Arkansas USA

Re: Vanhegan extreme December 13, 2012

Postby Leren » Thu Dec 13, 2012 11:05 am

Code: Select all
*--------------------------------------------------------------------------------*
| 39      379     6        | 1       2       57       | 4       8       35       |
| 13      47      5        | 478     6       478      | 39      19      2        |
| 12      24      8        | 9       3       45       | 7      d156    c16-5     |
|--------------------------+--------------------------+--------------------------|
| 69      69      2        | 34      5       34       | 1       7       8        |
| 8       5       4        | 2       7       1        | 6       3       9        |
| 7       1       3        | 6       8       9        | 2       45      45       |
|--------------------------+--------------------------+--------------------------|
| 356     36      9        | 357     4       2        | 8      a16     b1367     |
| 4       236     1        | 378     9       3678     | 5       2-6     367      |
| 2356    8       7        | 35      1       36       | 39      249-6   346      |
*--------------------------------------------------------------------------------*


M Ring: (6=1) r7c8 - r7c9 =(1-6) r3c9 = r3c8 - r7c8 Loop => r89c8 <6>, r3c9 <5>

Leren
Leren
 
Posts: 2968
Joined: 03 June 2012

Re: Vanhegan extreme December 13, 2012

Postby storm_norm22 » Thu Dec 13, 2012 11:39 am

Code: Select all
+------------------+---------------+-------------------+
| 39      379    6 | 1    2  57    | 4     8      35   |
| (13)    47     5 | 478  6  478   | 9(3)  19     2    |
| (12)    24     8 | 9    3  45    | 7     156    156  |
+------------------+---------------+-------------------+
| 69      69     2 | 34   5  34    | 1     7      8    |
| 8       5      4 | 2    7  1     | 6     3      9    |
| 7       1      3 | 6    8  9     | 2     45     45   |
+------------------+---------------+-------------------+
| 356     36     9 | 357  4  2     | 8     16     1367 |
| 4       36(2)  1 | 378  9  378-6 | 5     (26)   367  |
| 356(2)  8      7 | 35   1  (36)  | 9(3)  249-6  34-6 |
+------------------+---------------+-------------------+

(3=6)r9c6 - (3)r9c7 = (3)r2c7 - (3=1)r2c1 - (2=1)r3c1 - (2)r9c1 = (2)r8c2 - (2=6)r8c8; r8c6 <> 6 and r9c89 <> 6
Norm
storm_norm22
 
Posts: 59
Joined: 21 November 2012

Re: Vanhegan extreme December 13, 2012

Postby ArkieTech » Thu Dec 13, 2012 12:48 pm

Leren wrote:
Code: Select all
*--------------------------------------------------------------------------------*
| 39      379     6        | 1       2       57       | 4       8       35       |
| 13      47      5        | 478     6       478      | 39      19      2        |
| 12      24      8        | 9       3       45       | 7      d156    c16-5     |
|--------------------------+--------------------------+--------------------------|
| 69      69      2        | 34      5       34       | 1       7       8        |
| 8       5       4        | 2       7       1        | 6       3       9        |
| 7       1       3        | 6       8       9        | 2       45      45       |
|--------------------------+--------------------------+--------------------------|
| 356     36      9        | 357     4       2        | 8      a16     b1367     |
| 4       236     1        | 378     9       3678     | 5       2-6     367      |
| 2356    8       7        | 35      1       36       | 39      249-6   346      |
*--------------------------------------------------------------------------------*


M Ring: (6=1) r7c8 - r7c9 =(1-6) r3c9 = r3c8 - r7c8 Loop => r89c8 <6>, r3c9 <5>

Leren


:D

I have always called this a "loop" or "continous loop". What is an m-ring? :?
dan
User avatar
ArkieTech
 
Posts: 2715
Joined: 29 May 2006
Location: NW Arkansas USA

Re: Vanhegan extreme December 13, 2012

Postby tlanglet » Thu Dec 13, 2012 1:08 pm

I started this puzzle by noticing a couple of BUG-Lite patterns including this one step solution

BUG-Lite+4(456)r369c89[6r9c16=(5-4)r3c6]=(4-2)r3c2=r8c2-(2=6)r8c8 => r9c89<>6

Ted
tlanglet
2010 Supporter
 
Posts: 538
Joined: 29 May 2010

Re: Vanhegan extreme December 13, 2012

Postby Marty R. » Thu Dec 13, 2012 6:01 pm

Nice Ted. I looked at a bunch of those URs/BUG lites and didn't see anything I could do.

Code: Select all
+------------+------------+--------------+
| 39   379 6 | 1   2 57   | 4  8    35   |
| 13   47  5 | 478 6 478  | 39 19   2    |
| 12   24  8 | 9   3 45   | 7  156  156  |
+------------+------------+--------------+
| 69   69  2 | 34  5 34   | 1  7    8    |
| 8    5   4 | 2   7 1    | 6  3    9    |
| 7    1   3 | 6   8 9    | 2  45   45   |
+------------+------------+--------------+
| 356  36  9 | 357 4 2    | 8  16   1367 |
| 4    236 1 | 378 9 3678 | 5  26   367  |
| 2356 8   7 | 35  1 36   | 39 2469 346  |
+------------+------------+--------------+

Play this puzzle online at the Daily Sudoku site

Some kind of nameless (to me) loop.

(6=2)r8c8-r8c2=r9c1-(2=1)r3c1-r3c89=r2c8-(1=6)r3c8=>r3c8<>16
Marty R.
 
Posts: 1455
Joined: 23 October 2012
Location: Rochester, New York, USA

Re: Vanhegan extreme December 13, 2012

Postby daj95376 » Thu Dec 13, 2012 6:43 pm

I've lost count of the number of times my solver has found this particular UR pattern in puzzles.

Code: Select all
--- UR+3U/2SL: the strong links are disjoint with different labels => "a" can be removed from "abY"

 ab-----abX
     a

     b
abY-----abZ

Code: Select all
 after basics
 +--------------------------------------------------------------+
 |  39    379   6     |  1     2     57    |  4     8     35    |
 |  13    47    5     |  478   6     478   |  39    19    2     |
 |  12    24    8     |  9     3     45    |  7    *16+5 *16+5  | <- SL on "6"
 |--------------------+--------------------+--------------------|
 |  69    69    2     |  34    5     34    |  1     7     8     |
 |  8     5     4     |  2     7     1     |  6     3     9     |
 |  7     1     3     |  6     8     9     |  2     45    45    |
 |--------------------+--------------------+--------------------|
 |  356   36    9     |  357   4     2     |  8    *16   *16+37 | <- SL on "1"
 |  4     236   1     |  378   9     3678  |  5     26    367   |
 |  2356  8     7     |  35    1     36    |  39    2469  346   |
 +--------------------------------------------------------------+
 # 56 eliminations remain

 r37c89  <16> UR+3U/2SL                             r3c8<>1

 (2=4)r3c2 - (4=5)r3c6 - (5=6)r3c8 - (6=2)r8c8  =>  r8c2<>2
daj95376
2014 Supporter
 
Posts: 2624
Joined: 15 May 2006

Re: Vanhegan extreme December 13, 2012

Postby Leren » Thu Dec 13, 2012 8:57 pm

ArkieTech Wrote : What is an m-ring?


Some M Wing and M Ring discussion has been removed from this forum

The following is an external link that retains some of this information.

https://www.speedsudoku.com/forum/viewtopic.php?f=58&t=695

The M Ring I found in this puzzle is a Type A as described in this link.

Leren
Last edited by Leren on Thu Dec 13, 2012 9:58 pm, edited 1 time in total.
Leren
 
Posts: 2968
Joined: 03 June 2012

Re: Vanhegan extreme December 13, 2012

Postby Luke » Thu Dec 13, 2012 9:27 pm

tlanglet wrote:I started this puzzle by noticing a couple of BUG-Lite patterns including this one step solution

BUG-Lite+4(456)r369c89[6r9c16=(5-4)r3c6]=(4-2)r3c2=r8c2-(2=6)r8c8 => r9c89<>6

Nice, Ted. A DP with only two outs is always fun to look at. The (369) BUG-Lite in chute 1 has only two as well, but not as much fun if one is looking for a one-stepper.
User avatar
Luke
2015 Supporter
 
Posts: 435
Joined: 06 August 2006
Location: Southern Northern California

Re: Vanhegan extreme December 13, 2012

Postby pjb » Thu Dec 13, 2012 10:13 pm

Starting from Leren's grid, another one step solution uses the ALS XZ technique:

ALS 1 of 13569 at r1c9, r2c78, r3c8
ALS 2 of 16 at r7c8
X value 1, Z value 6
eliminates 6 from r89c8

pjb
pjb
2014 Supporter
 
Posts: 1762
Joined: 11 September 2011
Location: Sydney, Australia

Re: Vanhegan extreme December 13, 2012

Postby storm_norm22 » Thu Dec 13, 2012 10:30 pm

the m-ring is simply an m-wing in which the first and last nodes reside in the same box, same row or same column.

when this happens all eliminations happen along the houses that contain the weak links. hence why there are more eliminations in the chain.
Norm
storm_norm22
 
Posts: 59
Joined: 21 November 2012

Re: Vanhegan extreme December 13, 2012

Postby ArkieTech » Thu Dec 13, 2012 10:45 pm

storm_norm22 wrote:the m-ring is simply an m-wing in which the first and last nodes reside in the same box, same row or same column.

when this happens all eliminations happen along the houses that contain the weak links. hence why there are more eliminations in the chain.



Thanks Norm,

Are all rings loops? I assume all loops are not rings.
dan
User avatar
ArkieTech
 
Posts: 2715
Joined: 29 May 2006
Location: NW Arkansas USA

Re: Vanhegan extreme December 13, 2012

Postby pjb » Thu Dec 13, 2012 10:56 pm

I might be a bit old fashioned, but isn't Leren's M-ring also called a 'nice' loop?
pjb
pjb
2014 Supporter
 
Posts: 1762
Joined: 11 September 2011
Location: Sydney, Australia

Re: Vanhegan extreme December 13, 2012

Postby Leren » Thu Dec 13, 2012 10:57 pm

daj 95376 wrote: r37c89 <16> UR+3U/2SL r3c8<>1


There's also a third SL (on 1 in column 9) in this UR which also => r7c9 <6>

Also, in your diagram woudn't it be better to write it as

Code: Select all
 ab-----aX
     a

     b
abY-----bZ


ie b doesn't have to be in the top right hand cell and a doesn't have to be in the bottom right hand cell

Leren
Last edited by Leren on Fri Dec 14, 2012 2:07 am, edited 1 time in total.
Leren
 
Posts: 2968
Joined: 03 June 2012

Re: Vanhegan extreme December 13, 2012

Postby storm_norm22 » Thu Dec 13, 2012 11:00 pm

I am not sure how many patterns get the name "ring" but regardless of whether the pattern is called a ring, all loops perform exactly the same. the issue isn't whether the pattern gets a name... the issue is recognizing why a pattern forms a loop. its something that can be missed and/or misunderstood.

for example. the discussion in the daily forums about the "half m-wing"... Ravel's example... this pattern is a m-wing that starts and ends in the same box which forms a loop... and in that example there is another elimination which has not been pointed out. this is a good example of how all of the chain's logic is sometimes overlooked in our mind's eye.
Norm
storm_norm22
 
Posts: 59
Joined: 21 November 2012

Next

Return to Puzzles