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Finned swordfish

 
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wapati



Joined: 10 Jun 2008
Posts: 472
Location: Brampton, Ontario, Canada.
PostPosted: Sat May 08, 2010 7:15 pm    Post subject: Finned swordfish Reply with quote
There are 2 finned-swordfish Very Happy and a bit of other stuff for this one.

Code:
. . .|. 8 .|. . .
. 4 6|7 . .|. . 5
1 . .|5 . 2|7 . .
-----+-----+-----
3 . 2|8 . .|9 . .
. . .|9 7 5|. . .
. . 5|. . 3|4 . 1
-----+-----+-----
. . 1|4 . 7|. . 9
5 . .|. . 8|6 1 .
. . .|. 3 .|. . .
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daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Sun May 09, 2010 11:34 am    Post subject: Reply with quote
Code:
 after basics:   <238> DP  =>  r5c8=6
 +--------------------------------------------------------------+
 |  279   5     79    |  3     8     4     |  1     269   26    |
 |  28    4     6     |  7     1     9     | *238  *238   5     |
 |  1     389   389   |  5     6     2     |  7     489   48    |
 |--------------------+--------------------+--------------------|
 |  3     67    2     |  8     4     1     |  9     5     67    |
 |  468   1     48    |  9     7     5     | *238  *238+6 2368  |
 |  789   789   5     |  6     2     3     |  4     78    1     |
 |--------------------+--------------------+--------------------|
 |  68    2368  1     |  4     5     7     | *238  *238   9     |
 |  5     37    347   |  2     9     8     |  6     1     347   |
 |  4789  2789  4789  |  1     3     6     |  5     2478  2478  |
 +--------------------------------------------------------------+
 # 64 eliminations remain
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arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
PostPosted: Sun May 09, 2010 12:03 pm    Post subject: Reply with quote
Another way to do the same thing.
Code:
 *-----------------------------------------------------------*
 | 279   5     79    | 3     8     4     | 1     269   26    |
 | 28    4     6     | 7     1     9     | 238   238   5     |
 | 1     389   389   | 5     6     2     | 7     489   48    |
 |-------------------+-------------------+-------------------|
 | 3     67    2     | 8     4     1     | 9     5     67    |
 | 468   1     48    | 9     7     5     | 238   2368  2368  |
 | 789   789   5     | 6     2     3     | 4     78    1     |
 |-------------------+-------------------+-------------------|
 | 68    2368  1     | 4     5     7     | 238   238   9     |
 | 5     37    347   | 2     9     8     | 6     1     347   |
 | 4789  2789  4789  | 1     3     6     | 5     2478  2478  |
 *-----------------------------------------------------------*
(8=7)r6c8-(7=6)r4c9-r1c9=(6-9)r1c8=(9-4)r3c8=r9c8-r9c1=r5c1-(4=8)r5c3; r5c789,r6c12<>8
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
PostPosted: Mon May 10, 2010 3:05 am    Post subject: Reply with quote
Danny, that is one tremendous DP find Exclamation Exclamation I have never seen one that had three identical digits in all cells.

Wapati, I finally found one finned swordfish, but could not find a second. I would appreciate specifics on both.

I complete the puzzle in three steps including an ALS_XZ that had two common values, which I have also never seen before.

ALS_A 267 in r14c9,
ALS_B 23678 in r2567c8
Exclusive=7
Common=2;
r1c8<>2, plus (2-6)r1c9 = r4c9 - r4c2 = r5c1 - (6=8)r7c1 - (8=23)r7c78; r9c8<>2
Common=6; r5c9<>6

NP(37)r8c23 = (4)r8c4 - (4=8)r5c3 - r5c789 = (8-7)r6c8 = (7)r4c9; r8c9<>7

(7=3)r8c2 - (3=4)r2c9 - (4=8)r3c9 - (8=39)r3c23 - (9=7)r1c3; r8c3<>7

Ted
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wapati



Joined: 10 Jun 2008
Posts: 472
Location: Brampton, Ontario, Canada.
PostPosted: Mon May 10, 2010 9:52 am    Post subject: Reply with quote
Code:
.------------------.------------------.------------------.
| 279   5     79   | 3     8     4    | 1     269   26   |
| 28    4     6    | 7     1     9    | 238   23    5    |
| 1    *389   39   | 5     6     2    | 7    *489  *48   |
:------------------+------------------+------------------:
| 3     67    2    | 8     4     1    | 9     5     67   |
| 468   1     48   | 9     7     5    | 238   2368  236  |
| 79   *789   5    | 6     2     3    | 4    *78    1    |
:------------------+------------------+------------------:
| 68    236-8 1    | 4     5     7    | 238   238   9    |
| 5     37    347  | 2     9     8    | 6     1     347  |
| 479  *289  #4789 | 1     3     6    | 5     247  *2478 |
'------------------'------------------'------------------'

This one is a Sahimi and was exposed by the first one.

.------------------.------------------.------------------.
| 279   5     79   | 3     8     4    | 1     269   26   |
| 28    4     6    | 7     1     9    | 238   23    5    |
| 1    *389   39   | 5     6     2    | 7     489  *48   |
:------------------+------------------+------------------:
| 3     67    2    | 8     4     1    | 9     5     67   |
| 46-8  1    *48   | 9     7     5    | 238   2368  236  |
| 79   *789   5    | 6     2     3    | 4     78    1    |
:------------------+------------------+------------------:
| 68    236   1    | 4     5     7    | 238   238   9    |
| 5     37    347  | 2     9     8    | 6     1     347  |
| 479  *289  *4789 | 1     3     6    | 5     247  *2478 |
'------------------'------------------'------------------'
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
PostPosted: Mon May 10, 2010 1:42 pm    Post subject: Reply with quote
Wapati,

Thanks for the info.

For the second time recently, I messed up basics. However, this time I failed to make basic deletions. I may have to resort to "Almost Basics" training. Wink

Ted
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peterj



Joined: 26 Mar 2010
Posts: 974
Location: London, UK
PostPosted: Mon May 10, 2010 3:57 pm    Post subject: Reply with quote
Ted
I think I mucked up too because I still had 8s in r3c3 and r69c1. Consequently struggled with this one!
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daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Mon May 10, 2010 4:21 pm    Post subject: Re: Finned swordfish Reply with quote
wapati wrote:
There are 2 finned-swordfish Very Happy and a bit of other stuff for this one.

If you compare wapati's grid above against my grid after basics, you'll see that some of the "other stuff" must have happened before the finned Swordfish on <8>. Actually, a lot of other stuff happened.

As for the finned Swordfish on <7>, it's present in my grid but there's a Kite that performs that elimination as well.
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peterj



Joined: 26 Mar 2010
Posts: 974
Location: London, UK
PostPosted: Mon May 10, 2010 6:22 pm    Post subject: Reply with quote
As you say quite a bit of stuff...!

xyz-wing(468); r6c1<>8
w-wing(48) (8=4)r3c9-r8c9=r8c2-(4=8)r5c3; r3c3<>8, r5c9<>8
finned x-wing(8) r36c28 fin r3c9; r2c8<>8 (or a skyscraper)
kite(8); r9c8<>8
kite(8); r9c1<>8 (not needed for the swordfish)

and then the finned swordfish on 8s! (I did the kite 7 earlier)

Danny, all in all your DP was a lot quicker!

Definitely a BBDB for me...
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wapati



Joined: 10 Jun 2008
Posts: 472
Location: Brampton, Ontario, Canada.
PostPosted: Mon May 10, 2010 7:36 pm    Post subject: Reply with quote
peterj wrote:


Danny, all in all your DP was a lot quicker!


It was brilliant! It took me back to when URs were new and they turned many a puzzle into "basics".
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daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Mon May 10, 2010 8:23 pm    Post subject: Reply with quote
Thanks everyone for the complements on the DP !!!

I was fortunate to spot it rather quickly. The tip-off was the completed stack #2 and so many candidates in the other two stacks.

But, since I'm an amateur at DPs, you won't believe how long it took for me to verify that the pattern was a true DP. My eyes crossed more than once. Whew!!!
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wapati



Joined: 10 Jun 2008
Posts: 472
Location: Brampton, Ontario, Canada.
PostPosted: Mon May 10, 2010 8:35 pm    Post subject: Reply with quote
This puzzle is so strange. All the hard steps are consecutive, with no clean-up between, and they all eliminate 8s.

Code:
W-wing on 48.
.------------------.------------------.------------------.
| 279   5     79   | 3     8     4    | 1     269   26   |
| 28    4     6    | 7     1     9    | 238   238   5    |
| 1     389   39-8 | 5     6     2    | 7     489  *48   |
:------------------+------------------+------------------:
| 3     67    2    | 8     4     1    | 9     5     67   |
| 468   1    *48   | 9     7     5    | 238   2368  236-8|
| 789   789   5    | 6     2     3    | 4     78    1    |
:------------------+------------------+------------------:
| 68    2368  1    | 4     5     7    | 238   238   9    |
| 5     37   #347  | 2     9     8    | 6     1    #347  |
| 4789  2789  4789 | 1     3     6    | 5     2478  2478 |
'------------------'------------------'------------------'

xyz-wing.
.------------------.------------------.------------------.
| 279   5     79   | 3     8     4    | 1     269   26   |
| 28    4     6    | 7     1     9    | 238   238   5    |
| 1     389   39   | 5     6     2    | 7     489   48   |
:------------------+------------------+------------------:
| 3     67    2    | 8     4     1    | 9     5     67   |
|*468   1    *48   | 9     7     5    | 238   2368  236  |
| 79-8  789   5    | 6     2     3    | 4     78    1    |
:------------------+------------------+------------------:
|*68    2368  1    | 4     5     7    | 238   238   9    |
| 5     37    347  | 2     9     8    | 6     1     347  |
| 4789  2789  4789 | 1     3     6    | 5     2478  2478 |
'------------------'------------------'------------------'

Finned swordfish.
.------------------.------------------.------------------.
| 279   5     79   | 3     8     4    | 1     269   26   |
| 28    4     6    | 7     1     9    | 238   238   5    |
| 1    *389   39   | 5     6     2    | 7    *489  *48   |
:------------------+------------------+------------------:
| 3     67    2    | 8     4     1    | 9     5     67   |
| 468   1     48   | 9     7     5    | 238   2368  236  |
| 79   *789   5    | 6     2     3    | 4    *78    1    |
:------------------+------------------+------------------:
| 68    236-8 1    | 4     5     7    | 238   238   9    |
| 5     37    347  | 2     9     8    | 6     1     347  |
|#4789 *2789 #4789 | 1     3     6    | 5    *2478 *2478 |
'------------------'------------------'------------------'

Sashimi sword.  See note below!
.------------------.------------------.------------------.
| 279   5     79   | 3     8     4    | 1     269   26   |
| 28    4     6    | 7     1     9    | 238   238   5    |
| 1    *389   39   | 5     6     2    | 7     489  *48   |
:------------------+------------------+------------------:
| 3     67    2    | 8     4     1    | 9     5     67   |
| 46-8  1    *48   | 9     7     5    | 238   2368  236  |
| 79   *789   5    | 6     2     3    | 4     78    1    |
:------------------+------------------+------------------:
| 68    236   1    | 4     5     7    | 238   238   9    |
| 5     37    347  | 2     9     8    | 6     1     347  |
| 4789 *2789 *4789 | 1     3     6    | 5     2478 *2478 |
'------------------'------------------'------------------'

xy-wing. After this it is all trivial.
.------------------.------------------.------------------.
| 279   5     79   | 3     8     4    | 1     269   26   |
| 28    4     6    | 7     1     9    | 238   238   5    |
| 1     389   39   | 5     6     2    | 7     489   48   |
:------------------+------------------+------------------:
| 3     67    2    | 8     4     1    | 9     5     67   |
|*46    1    *48   | 9     7     5    | 238   2368  236  |
| 79    789   5    | 6     2     3    | 4     78    1    |
:------------------+------------------+------------------:
|*68    236   1    | 4     5     7    | 238   238   9    |
| 5     37    347  | 2     9     8    | 6     1     347  |
| 4789  2789  479-8| 1     3     6    | 5     2478  2478 |
'------------------'------------------'------------------'



More 8s could have been eliminated, most people miss this.
Code:
.-------------------.------------------.-------------------.
| 279    5     79   | 3     8     4    | 1     269    26   |
| 28     4     6    | 7     1     9    | 238   238    5    |
| 1     *389   39   | 5     6     2    | 7     49-8  *48   |
:-------------------+------------------+-------------------:
| 3      67    2    | 8     4     1    | 9     5      67   |
| 46-8   1    *48   | 9     7     5    | 238   2368   236  |
| 79    *789   5    | 6     2     3    | 4     78     1    |
:-------------------+------------------+-------------------:
| 68     236   1    | 4     5     7    | 238   238    9    |
| 5      37    347  | 2     9     8    | 6     1      347  |
| 479-8 *2789 *4789 | 1     3     6    | 5     247-8 *2478 |
'-------------------'------------------'-------------------'


Last edited by wapati on Mon May 10, 2010 8:53 pm; edited 1 time in total
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peterj



Joined: 26 Mar 2010
Posts: 974
Location: London, UK
PostPosted: Mon May 10, 2010 8:43 pm    Post subject: Reply with quote
Wapati, where did this puzzle come from?
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wapati



Joined: 10 Jun 2008
Posts: 472
Location: Brampton, Ontario, Canada.
PostPosted: Mon May 10, 2010 8:57 pm    Post subject: Reply with quote
I generated it using Hoduko version 2.01.

I have changed many settings from the default.

If I like the look of a puzzle I put it in sudokucue and mess with it looking for odd things. If I find a way that I could solve it I print it and give it a try.

I rarely look at ones that don't have swordfish. Smile
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