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Vanhegan Fiendish 11/15

 
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

PostPosted: Sat Nov 15, 2008 3:41 pm    Post subject: Vanhegan Fiendish 11/15 Reply with quote

Here is another Vahegan that I enjoyed very much; it has many different VH possibilities. I finally got it down to two steps using a variation of xy-wing based on several recent discussion on this forum.
Code:

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

Play this puzzle online at the Daily Sudoku site[/code]

Ted

ps: This is my first attempt to format the code for Draw/Play; hope it works.
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nataraj



Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria

PostPosted: Sat Nov 15, 2008 4:44 pm    Post subject: Reply with quote

More than two steps for me...

After basics,
Code:


+--------------------------+--------------------------+--------------------------+
| 467     9       8        | 57      2       3        | 4567    1       457      |
| 2       14      1567     | 8       45      9        | 4567    457     3        |
| 47      3       57       | 157     6       147      | 8       2       9        |
+--------------------------+--------------------------+--------------------------+
| 8       6       13       | 123     45      12       | 457     9       457      |
| 5       2       4        | 67      9       67       | 3       8       1        |
| 19      7       139      | 135     8       14       | 45      6       2        |
+--------------------------+--------------------------+--------------------------+
| 3       5       27       | 26      1       8        | 9       47      467      |
| 146     14      16       | 9       7       5        | 2       3       8        |
| 79      8       279      | 4       3       26       | 1       57      567      |
+--------------------------+--------------------------+--------------------------+


an extended xy-wing (4) r3c1=r6c6 (via r69c1) removes 4 from r3c6.
Some cleanup and 2 URs (13 and 47) later, a BUG+3
Code:

+--------------------------+--------------------------+--------------------------+
| 67      9       8        | 57      2       3        | 46      1       45       |
| 2       1       56       | 8       4       9        | 67      57      3        |
| 4       3       57       | 157     6       17       | 8       2       9        |
+--------------------------+--------------------------+--------------------------+
| 8       6       3        | 12      5       12       | 47      9       47       |
| 5       2       4        | 67      9       67       | 3       8       1        |
| 19      7       19       | 3       8       4        | 5       6       2        |
+--------------------------+--------------------------+--------------------------+
| 3       5       27       | 26      1       8        | 9       4       67       |
| 16      4       16       | 9       7       5        | 2       3       8        |
| 79      8       279      | 4       3       26       | 1       57      567      |
+--------------------------+--------------------------+--------------------------+

At least one of the three cells r3c4,r9c39 must be 7, in all cases r9c1=9.
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Sat Nov 15, 2008 6:01 pm    Post subject: Reply with quote

nataraj wrote:
After basics ...
an extended xy-wing (4) r3c1=r6c6 (via r69c1) removes 4 from r3c6.

FWIW: This is a 4-cell XY-Chain.

===== ===== ===== ===== =====

After basics, I found:

Code:
(13) UR [r46c34] => [r6c4]<>1

general Remote Pair [r2c5]:[r6c7] => [r2c7]<>45

The UR isn't necessary, but I had to resort to a chain/loop to crack the puzzle in two steps.


Last edited by daj95376 on Sat Nov 15, 2008 7:17 pm; edited 1 time in total
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nataraj



Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria

PostPosted: Sat Nov 15, 2008 7:11 pm    Post subject: Reply with quote

daj95376 wrote:
nataraj wrote:
After basics ...
an extended xy-wing (4) r3c1=r6c6 (via r69c1) removes 4 from r3c6.

FWIW: This is a 4-cell XY-Chain.


Wow!
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Sat Nov 15, 2008 7:41 pm    Post subject: Reply with quote

nataraj wrote:
daj95376 wrote:
nataraj wrote:
After basics ...
an extended xy-wing (4) r3c1=r6c6 (via r69c1) removes 4 from r3c6.

FWIW: This is a 4-cell XY-Chain.

Wow!

Right! But why stop at one XY-Chain.

Code:
 nataraj's XY-Chain a-b-c-d  =>  [r3c6]<>4
 +--------------------------------------------------------------+
 |  467   9     8     |  57    2     3     |  4567  1     457   |
 |  2     14    1567  |  8     45    9     |  4567  457   3     |
 | a47    3     57    |  157   6     17-4  |  8     2     9     |
 |--------------------+--------------------+--------------------|
 |  8     6     13    |  123   45    12    |  457   9     457   |
 |  5     2     4     |  67    9     67    |  3     8     1     |
 | c19    7     139   |  135   8    d14    |  45    6     2     |
 |--------------------+--------------------+--------------------|
 |  3     5     27    |  26    1     8     |  9     47    467   |
 |  146   14    16    |  9     7     5     |  2     3     8     |
 | b79    8     279   |  4     3     26    |  1     57    567   |
 +--------------------------------------------------------------+

After further basics:

Code:
 XY-Chain a-b-c-d-e  =>  [r3c4]<>5
 *--------------------------------------------------*
 | 67   9    8    |a57   2    3    | 467  1    457  |
 | 2    1    567  | 8    4    9    | 67   57   3    |
 | 4    3   e57   | 17-5 6    17   | 8    2    9    |
 |----------------+----------------+----------------|
 | 8    6    13   | 123  5    12   | 47   9    47   |
 | 5    2    4    |b67   9    67   | 3    8    1    |
 | 19   7    139  | 13   8    4    | 5    6    2    |
 |----------------+----------------+----------------|
 | 3    5   d27   |c26   1    8    | 9    4    67   |
 | 16   4    16   | 9    7    5    | 2    3    8    |
 | 79   8    279  | 4    3    26   | 1    57   567  |
 *--------------------------------------------------*

And the puzzle is cracked.
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Marty R.



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

PostPosted: Sat Nov 15, 2008 10:58 pm    Post subject: Reply with quote

I also used the W-Wing, which Danny calls "General remote pair."

Code:
+--------------------------+--------------------------+--------------------------+
| 67      9       8        | 57      2       3        | 46      1       45       |
| 2       1       56       | 8       4       9        | 67      57      3        |
| 4       3       57       | 157     6       17       | 8       2       9        |
+--------------------------+--------------------------+--------------------------+
| 8       6       3        | 12      5       12       | 47      9       47       |
| 5       2       4        | 67      9       67       | 3       8       1        |
| 19      7       19       | 3       8       4        | 5       6       2        |
+--------------------------+--------------------------+--------------------------+
| 3       5       27       | 26      1       8        | 9       4       67       |
| 16      4       16       | 9       7       5        | 2       3       8        |
| 79      8       279      | 4       3       26       | 1       57      567      |
+--------------------------+--------------------------+--------------------------+

Nobody mentioned the XY-Wing pivoted in r7c4 which, with pincer transport, zaps the 7 from r3c3. But I still had to use Medusa to finish it off.
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Sun Nov 16, 2008 10:44 am    Post subject: Reply with quote

nataraj wrote:
After basics,
Code:
+--------------------------+--------------------------+--------------------------+
| 467     9       8        | 57      2       3        | 4567    1       457      |
| 2       14      1567     | 8       45      9        | 4567    457     3        |
| 47      3       57       | 157     6       147      | 8       2       9        |
+--------------------------+--------------------------+--------------------------+
| 8       6       13       | 123     45      12       | 457     9       457      |
| 5       2       4        | 67      9       67       | 3       8       1        |
| 19      7       139      | 135     8       14       | 45      6       2        |
+--------------------------+--------------------------+--------------------------+
| 3       5       27       | 26      1       8        | 9       47      467      |
| 146     14      16       | 9       7       5        | 2       3       8        |
| 79      8       279      | 4       3       26       | 1       57      567      |
+--------------------------+--------------------------+--------------------------+

an extended xy-wing (4) r3c1=r6c6 (via r69c1) removes 4 from r3c6.

Wait a minute. Where's the XY-Wing that's being extended?

If it's through using the 9s in [r69c1], then this is a new way (to me) of extending an XY-Wing.

This makes three ways that I've seen to extend an XY-Wing. Just how many ways are there?
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ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Sun Nov 16, 2008 1:08 pm    Post subject: Reply with quote

daj95376 wrote:
This makes three ways that I've seen to extend an XY-Wing. Just how many ways are there?
At least on one forum it would be helpful, when people use the same terms. If a grid is there, its no problem for me, but when only a solution path is given, people might look for another thing in vain.
I have seen 3 names for this 4-cell xy-chain, "generalized xy-wing", "extended xy-wing" and "grouped xy-wing". And i think "extended xy-wing" was also used for an xy-wing with pincer transport (what was the 3rd meaning ?)
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

PostPosted: Sun Nov 16, 2008 3:01 pm    Post subject: Reply with quote

My two step solution was the combination of the "extended" xy-wing149 with pivot <19> at r6c1 as noted by Nataraj, and the xy-wing267 with pivot <26> in r7c4 which, with the <7> in the pincer at r5c4 transport to r3c6 via r5c6, deletes <7> at r3c3 as noted my Marty.

I would also encourage acceptance of a set of common terms as noted by Ravel. On many occasions, I have spent time trying to analyze a posted solution only to determine later that I did not understand the terminology.

Ted
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Sun Nov 16, 2008 5:33 pm    Post subject: Reply with quote

Ted wrote:
... and the xy-wing267 with pivot <26> in r7c4 which, with the <7> in the pincer at r5c4 transport to r3c6 via r5c6, deletes <7> at r3c3 as noted my Marty.

Oops, I forgot this one. Make that four ways!

ravel wrote:
I have seen 3 names for this 4-cell xy-chain, "generalized xy-wing", "extended xy-wing" and "grouped xy-wing". And i think "extended xy-wing" was also used for an xy-wing with pincer transport (what was the 3rd meaning ?)

3-cell XY-Chain

Code:
             ** ** **
XY-Wing:     ZX-XY-YZ                            =>  eliminations in Z

4-cell XY-Chain

Code:
             ** *   * **
Ext. #1:     ZX-XV-VY-YZ                         =>  eliminations in Z

5-cell XY-Chain

Code:
             ** ** **
Ext. #2:     ZX-XY-YZ-ZW-WZ                      =>  eliminations in Z
Ext. #3:  WZ-ZX-XY-YZ-ZW                         =>  eliminations in W

XY-Chain w/ Strong Link

Code:
             ** ** **
Ext. #4:     ZX-XY-YZ-ZW-VZ (strong link ZW-VZ)  =>  eliminations in Z
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ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Sun Nov 16, 2008 9:57 pm    Post subject: Reply with quote

For me its up to Keith to name them for this forum.
I think, more names for the same are no problem, neither overlapping names like skyscraper, turbot fish, ER, finned x-wing and coloring.
But the same name for 2 different methods is irritating.


Last edited by ravel on Sun Nov 16, 2008 10:01 pm; edited 1 time in total
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keith



Joined: 19 Sep 2005
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Location: near Detroit, Michigan, USA

PostPosted: Sun Nov 16, 2008 10:01 pm    Post subject: Reply with quote

"XY Chain" is my vote. I prefer to say N links rather than N+1 cells.

So, an XY-wing is a two-link chain (of three cells). "XY-wing" is fine.

Personally, I think terms like "extended XY-wing" and "XY-wing with pincer transport" are not (or should not be) names of patterns. Rather, they help to describe how you found the chain.

Keith

For Marty: 0 and 10. Could this be a perfect season?
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ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Sun Nov 16, 2008 10:06 pm    Post subject: Reply with quote

keith wrote:
Rather, they help to describe how you found the chain.
Thats why like a name for them. I find them looking at the 2 bivalue cells with a common number. But i fiind xy-chains, when looking for pincers or just "where does that go to ?"
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Marty R.



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PostPosted: Sun Nov 16, 2008 10:17 pm    Post subject: Reply with quote

Quote:
For Marty: 0 and 10. Could this be a perfect season?

There's excellent potential there, but if Daunte shows flashes of his one-time brilliance, who knows, maybe they could eke one out. I'm not a particular fan of theirs, but I really hope they win something. I don't wish that type of perfection on anybody.
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Sun Nov 16, 2008 10:40 pm    Post subject: Reply with quote

Marty R. wrote:
Quote:
For Marty: 0 and 10. Could this be a perfect season?

There's excellent potential there, but if Daunte shows flashes of his one-time brilliance, who knows, maybe they could eke one out. I'm not a particular fan of theirs, but I really hope they win something. I don't wish that type of perfection on anybody.


i always scratch my head when people argue about which is harder: either going 16-0 or 0-16. to me, its a no brainer. it doesn't require anything hard at all to lose every game. unless, of course, the other team is trying harder to lose?? Very Happy I hear over and over about how NBA teams will try to be bad in order to gain a higher drafting order.
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

PostPosted: Mon Nov 17, 2008 3:43 pm    Post subject: Reply with quote

keith wrote:


Personally, I think terms like "extended XY-wing" and "XY-wing with pincer transport" are not (or should not be) names of patterns. Rather, they help to describe how you found the chain.

Keith

I support the idea on having basic pattern names with additional comments to describe any modifications or extensions. I view these modifications or extensions as just blending of additional basic patterns; thus transporting a pincer is simply applying the basic coloring technique starting at a pincer cell identified by another basic pattern.

As a student of Sudoku, I also greatly appreciate having some detailed info regarding any modifications or extensions.

Ted
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Mon Nov 17, 2008 10:44 pm    Post subject: Reply with quote

keith wrote:
"XY Chain" is my vote. I prefer to say N links rather than N+1 cells.

So, an XY-wing is a two-link chain (of three cells). "XY-wing" is fine.

Hmmmm!

XY-Wing as an XY-Chain:

Code:
Z-[cell_1]-X-[cell_2]-Y-[cell_3]-Z  =>  [peers of cell_1 & cell_3]<>Z

Strong Inference in cell_1
Weak   Inference to cell_2
Strong Inference in cell_2
Weak   Inference to cell_3
Strong Inference in cell_3

I count five inferences in an XY-Wing. I'm guessing that you are only counting the weak inferences . I'll stick with number of cells Exclamation

[Edit: changed link to inference.]


Last edited by daj95376 on Tue Nov 18, 2008 4:42 am; edited 2 times in total
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA

PostPosted: Tue Nov 18, 2008 2:19 am    Post subject: Reply with quote

Quote:
i always scratch my head when people argue about which is harder: either going 16-0 or 0-16. to me, its a no brainer. it doesn't require anything hard at all to lose every game. unless, of course, the other team is trying harder to lose?? Very Happy I hear over and over about how NBA teams will try to be bad in order to gain a higher drafting order.


The point is, where is the business case? Now that the Lions are 0-10, I think their business case is to be the worst team in the league. They will have the first pick, and may get another Billy Sims or Barry Sanders.

If they win all the rest of their games (to be 6-10) they will just be a bad team. They will not make the playoffs, they will not get a great draft pick.

Being very bad can be so good! (Not only for sports teams!)

Keith


Last edited by keith on Tue Nov 18, 2008 2:39 am; edited 1 time in total
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA

PostPosted: Tue Nov 18, 2008 2:30 am    Post subject: Reply with quote

daj95376 wrote:
keith wrote:
"XY Chain" is my vote. I prefer to say N links rather than N+1 cells.

So, an XY-wing is a two-link chain (of three cells). "XY-wing" is fine.

Hmmmm!

XY-Wing as an XY-Chain:

Code:
Z-[cell_1]-X-[cell_2]-Y-[cell_3]-Z  =>  [peers of cell_1 & cell_3]<>Z

Strong Link in cell_1
Weak   Link to cell_2
Strong Link in cell_2
Weak   Link to cell_3
Strong Link in cell_3

I count five links in an XY-Wing. I'm guessing that you are only counting the weak links. I'll stick with number of cells Exclamation

Danny,

I did not intend to count links "in" a cell. I was only counting the links between cells, and I don't agree they are necessarily "weak links".

Keith
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