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Set G Puzzle 82

 
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Sat Dec 20, 2008 10:51 pm    Post subject: Set G Puzzle 82 Reply with quote

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

Play this puzzle online at the Daily Sudoku site
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Sun Dec 21, 2008 1:30 am    Post subject: Reply with quote

Code:
.---------------------.---------------------.---------------------.
| 1      9      28    | 6      4      3     | 5      7      28    |
| 5      38     368   | 2      7      1     | 468    48     9     |
| 26     4      7     | 8      9      5     | 126    3      126   |
:---------------------+---------------------+---------------------:
| 234    6      9     | 7      128    248   | 12348  5      12348 |
| 234    7      2345  | 35     128    248   | 9      6      12348 |
| 8      1      2345  | 35     6      9     | 234    24     7     |
:---------------------+---------------------+---------------------:
| 9      38     3468  | 1      28     7     | 23468  248    5     |
| 7      5      1     | 4      3      268   | 268    9      268   |
| 346    2      3468  | 9      5      68    | 7      1      3468  |
'---------------------'---------------------'---------------------'

Quote:
1. x-wing 8
2. UR24 r45c16 means r9c1 <> 3, and r56c3 <> 3
3. xy-wing {3,4,8}... (3=8)r7c2 - (8=4)r7c8 - (4=3)r9c9; r9c13 <> 3
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Marty R.



Joined: 12 Feb 2006
Posts: 5164
Location: Rochester, NY, USA

PostPosted: Sun Dec 21, 2008 2:29 am    Post subject: Reply with quote

I used eight steps, but probably would've used fewer if I looked for X-Wings earlier. I had URs, an ER, XY-Wing, W-Wing, two X-Wings and an XY-Wing with pincer transport as the finisher.
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cgordon



Joined: 04 May 2007
Posts: 769
Location: ontario, canada

PostPosted: Sun Dec 21, 2008 4:28 pm    Post subject: Reply with quote

Whoa that was a struggle. Started with a couple of Type 4 URs and a couple of ERs - but then I whittled away at so many xy wings -I lost count. But I finally slayed the beast.
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tlanglet



Joined: 17 Oct 2007
Posts: 2461
Location: Northern California Foothills

PostPosted: Sun Dec 21, 2008 8:07 pm    Post subject: Reply with quote

After reviewing the previous posts, I find that I used the most steps: NINE Exclamation I had a similar mix of techniques as already noted.

But I did come across another interesting circumstance as follows.
Code:


 *-----------------------------------------------------------*
 | 1     9     28    | 6     4     3     | 5     7     28    |
 | 5     38    36    | 2     7     1     | 46    48    9     |
 | 26    4     7     | 8     9     5     | 12    3     126   |
 |-------------------+-------------------+-------------------|
 | 234   6     9     | 7     18    248   | 1348  5     134   |
 | 234   7     245   | 35    18    248   | 9     6     1348  |
 | 8     1     45    | 35    6     9     | 34    2     7     |
 |-------------------+-------------------+-------------------|
 | 9     38    346   | 1     2     7     | 346   48    5     |
 | 7     5     1     | 4     3     68    | 28    9     268   |
 | 346   2     348   | 9     5     68    | 7     1     346   |
 *-----------------------------------------------------------*

I was searching the code above looking for an extended xy-wing and I found one: pivot <48> in r7c8, pincer <28> in r8c7 and pseudo-cells <48> and <28> in b3. This provides deletion of <2>s in r3c7 & r8c9.

Now look at the W-wing <28> in r1c9 & r8c7 with strong ling <8> in c8. It is the extended xy-wing Exclamation

So what do we call this situation Question

And Danny, it was a great puzzle.

Ted
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Sun Dec 21, 2008 10:19 pm    Post subject: Reply with quote

tlanglet wrote:
Now look at the W-wing <28> in r1c9 & r8c7 with strong ling <8> in c8. It is the extended xy-wing Exclamation

So what do we call this situation Question

A W-Wing that coincides to a 4-cell XY-Chain having identical endpoint cells. Impressive!

Quote:
And Danny, it was a great puzzle.

Thanks, this makes searching through a stack of potential puzzles worth it!


Last edited by daj95376 on Sun Dec 21, 2008 10:37 pm; edited 2 times in total
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tlanglet



Joined: 17 Oct 2007
Posts: 2461
Location: Northern California Foothills

PostPosted: Sun Dec 21, 2008 10:26 pm    Post subject: Reply with quote

daj95376 wrote:
tlanglet wrote:
Now look at the W-wing <28> in r1c9 & r8c7 with strong ling <8> in c8. It is the extended xy-wing Exclamation

So what do we call this situation Question

A W-Wing that coincides with a 4-cell XY-Chain having identical endpoint cells and identical body cells. Impressive!


I have worked on two more puzzles since my prior post and found two more instances of the same circumstances. Maybe this is not all that uncommon.

Ted
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Sun Dec 21, 2008 10:47 pm    Post subject: Reply with quote

tlanglet wrote:
I have worked on two more puzzles since my prior post and found two more instances of the same circumstances. Maybe this is not all that uncommon.

A 4-cell XY-Chain seems common to me. I don't have a feel for how common they are with identical endpoint cells. I think this forces the body cells to be identical as well.

Code:
XY - YZ - ZY - YX

This will always correspond to the general W-Wing

Code:
XY - Y = Y - YX
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Mon Dec 22, 2008 2:58 am    Post subject: Reply with quote

FWIW, there really isn't anything we can discuss about seeing two different techniques that are absolutely correct for the cells they use.

its a coincedence that is... umm...

step right up
step right up

choose your path through the maze and don't get stuck
that's right, each path has its ending, each path has its twists

but you will still end up at the same place...

step right up
step right up.
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