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Set NNP Puzzle 45

 
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Fri Jan 23, 2009 2:02 am    Post subject: Set NNP Puzzle 45 Reply with quote

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

Play this puzzle online at the Daily Sudoku site

===== ===== ===== ===== ===== ===== ===== ===== ===== New Ratings

Can be solved using steps from ...

Basics: Naked/Hidden Single, Naked Pair/Triple, Locked Candidate 1/2

Basics+: Naked Quad, Hidden Pair/Triple/Quad

VH: BUG+1, UR Type 1, X-Wing, XY-Wing, XYZ-Wing

VH+: 2-String Kite, Empty Rectangle, Remote Pair, Skyscraper, Colors, UR Type 2

Advanced: finned/Sashimi X-Wing, Multiple Colors, Swordfish, M-Wing, W-Wing, XY-Chain

Extreme: Jellyfish, (but mostly) Chain
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Fri Jan 23, 2009 7:02 pm    Post subject: Reply with quote

Code:
.------------------------.------------------------.------------------------.
| 1       25      2357   | 345     6       57     | 279     479     8      |
| 37      8       4      | 39      2       79     | 1       5       6      |
| 257     6       9      | 45      8       1      | 27      47      3      |
:------------------------+------------------------+------------------------:
| 256789  245     2578   | 569     3       59     | 579     1       24     |
| 59      3       1      | 2       7       4      | 6       8       59     |
| 25679   245     257    | 569     1       8      | 3       79      24     |
:------------------------+------------------------+------------------------:
| 4       9       6      | 1       5       2      | 8       3       7      |
| 28      1       28     | 7       4       3      | 59      6       59     |
| 35      7       35     | 8       9       6      | 4       2       1      |
'------------------------'------------------------'------------------------'

UR {2,4}
xy-wing
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Marty R.



Joined: 12 Feb 2006
Posts: 5160
Location: Rochester, NY, USA

PostPosted: Sun Jan 25, 2009 4:15 pm    Post subject: Reply with quote

I used an assortment of moves including XY-Wings, W-Wing and ER before finishing off with a Type 2 UR on 24. However, I think the UR was there all along so some of my previous moves were probably not necessary.
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keith



Joined: 19 Sep 2005
Posts: 3173
Location: near Detroit, Michigan, USA

PostPosted: Sun Jan 25, 2009 5:45 pm    Post subject: Reply with quote

The UR alone does not solve it.

The most effective way to look at the UR is that <5> in C2 must be in B4. That solves R1C2 and R5C1.

The XY-wing 45-7 is in R13.

Keith
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tlanglet



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

PostPosted: Sun Jan 25, 2009 10:03 pm    Post subject: Reply with quote

I used the Type 2 UR 24 plus a w-wing with what I believe is termed a "grouped link". The w-wing is shown in the following code which results after taking the eliminations due to the Type 2 UR24.
Code:

 *--------------------------------------------------------------------*
 | 1      2      357    | 345    6      W57    | 79     479    8      |
 | 37     8      4      | 39     2      79     | 1      5      6      |
 | W57    6      9      | 45     8      1      | 2      47     3      |
 |----------------------+----------------------+----------------------|
 | 26789  45     278    | 569    3      59     | 579    1      24     |
 | 59     3      1      | 2      7      4      | 6      8      59     |
 | 2679   45     27     | 569    1      8      | 3      79     24     |
 |----------------------+----------------------+----------------------|
 | 4      9      6      | 1      5      2      | 8      3      7      |
 | 28     1      28     | 7      4      3      | 59     6      59     |
 | 35     7      35     | 8      9      6      | 4      2      1      |
 *--------------------------------------------------------------------*


The w-wing57 is in r1c6 & r3c1(marked with a W) and the "grouped link on <7>" is in box3. A <7> will be placed in either r1 or r3 within box3 thereby forcing one of the w-wing pincers to be a <5>, which deletes <5> from r1c3 to complete the puzzle.

Is this form of a strong link termed a "grouped link"?

Ted
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keith



Joined: 19 Sep 2005
Posts: 3173
Location: near Detroit, Michigan, USA

PostPosted: Sun Jan 25, 2009 10:57 pm    Post subject: Reply with quote

Ted,

Your elimination certainly is correct. The W-wing logic is, in this case, <7> in either W-cell forces <5> in the other. I think "grouped link" is an adequately descriptive name. (I would know what to look for.)

By the way, you have missed that the UR (also) takes out <5> in R5C1.

Keith
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