dailysudoku.com Forum Index dailysudoku.com
Discussion of Daily Sudoku puzzles
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Puzzle 11/07/25: A XY

 
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Puzzles by daj
View previous topic :: View next topic  
Author Message
daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Mon Jul 25, 2011 3:47 pm    Post subject: Puzzle 11/07/25: A XY Reply with quote

A tight-knit solution when restricted to XY steps.

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

Play this puzzle online at the Daily Sudoku site
Back to top
View user's profile Send private message
Luke451



Joined: 20 Apr 2008
Posts: 310
Location: Southern Northern California

PostPosted: Mon Jul 25, 2011 4:43 pm    Post subject: Reply with quote

How about just XY-"ish?"
Quote:
aur(12)r23c69[(8=5)r23c9]-r5c9=(5-1)r5c2=(1-8)r3c2=(8)r1c3 =>r1c9<>8
Back to top
View user's profile Send private message
Marty R.



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

PostPosted: Wed Jul 27, 2011 1:11 am    Post subject: Reply with quote

Four steps for me.

Type 4 UR (12); r23c9<>1
Type 4 UR (16); r4c39<>1
Potential DP boxes 23, 38-12-13-28; common outcome; r23c6=12
M-Wing (15); r4c3, r5c9<>5
Back to top
View user's profile Send private message
tlanglet



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

PostPosted: Wed Jul 27, 2011 1:30 pm    Post subject: Reply with quote

Danny, I worked on a "A tight-knit solution when restricted to XY steps' type solution but had no luck. However, I did find the same one-stepper as posted by Luke but with a different POV.

(1)r46c3=(1-5)r5c2=r5c9-aur(12)r23c69[(5)r3c9=(8)r23c9]-r1c9=(8-1)r1c3; r1c3<>1

Ted
Back to top
View user's profile Send private message
daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Wed Jul 27, 2011 3:12 pm    Post subject: Reply with quote

tlanglet wrote:
I worked on a "tight-knit solution" when restricted to XY steps' type solution but had no luck.

A 5-cell XY-Chain is present after basics. However, it doesn't proceed very far without the finned X-Wing. Together, they perform enough eliminations in r3c9 to expose the game-winning XY-Wing.

Code:
 after basics
 +--------------------------------------------------------------+
 |  2     3     18    |  5     7     6     |  14    9     148   |
 |  5     4     7     |  9     38    12    |  13    6     128   |
 |  6     18    9     |  34    348   12    |  135   7     1258  |
 |--------------------+--------------------+--------------------|
 |  8     7     156   |  2     14    9     |  145   3     1456  |
 |  3     15    2     |  14    6     7     |  9     8     145   |
 |  4     9     16    |  8     5     3     |  7     2     16    |
 |--------------------+--------------------+--------------------|
 |  7     56    35    |  36    2     4     |  8     1     9     |
 |  1     2     4     |  7     9     8     |  6     5     3     |
 |  9     68    38    |  136   13    5     |  2     4     7     |
 +--------------------------------------------------------------+
 # 41 eliminations remain

 r16\c39 finned  X-Wing                  <> 1    r23c9

XY-Chain: (8=3)r2c5 (=1)r2c7 (=2)r2c6 (=1)r3c6 (=8)r3c2  =>  r3c5<>8

 <18+5>  XY-Wing  r3c2/r3c9+r5c2         <> 5    r5c9


Note: a UR Type 4 is present ... but extraneous.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Puzzles by daj All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group