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 

Serpentine

 
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Other puzzles
View previous topic :: View next topic  
Author Message
Earl



Joined: 30 May 2007
Posts: 677
Location: Victoria, KS
PostPosted: Fri Feb 22, 2008 10:22 pm    Post subject: Serpentine Reply with quote
I needed complex xy-chains and then careful coloring. Maybe you medussa fans can offer a more direct solution.

Earl

Code:

+-------------+-------------+-------------+
| 39  8   23  | 1   5   69  | 7    4   26 |
| 5   4   1   | 36  236 7   | 8    9   26 |
| 6   7   29  | 4   29  8   | 15   15  3  |
+-------------+-------------+-------------+
| 2   369 8   | 7   369 45  | 1459 156 59 |
| 379 1   567 | 2   369 345 | 459  56  8  |
| 4   69  56  | 569 8   1   | 3    2   7  |
+-------------+-------------+-------------+
| 379 369 67  | 35  1   2   | 59   8   4  |
| 8   5   4   | 69  7   69  | 2    3   1  |
| 1   2   39  | 8   4   35  | 6    7   59 |
+-------------+-------------+-------------+

Play this puzzle online at the Daily Sudoku site


PS I later found that if you color all the strong linked 9's, the 9 in R4C9 is eliminated and the puzzle melts.

Last edited by Earl on Sat Feb 23, 2008 1:28 am; edited 1 time in total
Back to top
View user's profile Send private message Send e-mail
Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
PostPosted: Sat Feb 23, 2008 1:16 am    Post subject: Reply with quote
Code:

+-------------+-------------+-------------+
| 39  8   23  | 1   5   69  | 7    4   26 |
| 5   4   1   | 36  236 7   | 8    9   26 |
| 6   7   29  | 4   29  8   | 15   15  3  |
+-------------+-------------+-------------+
| 2   369 8   | 7   369 45  | 1459 156 59 |
| 37  1   567 | 2   369 345 | 459  56  8  |
| 4   69  56  | 569 8   1   | 3    2   7  |
+-------------+-------------+-------------+
| 379 36  67  | 35  1   2   | 59   8   4  |
| 8   5   4   | 69  7   69  | 2    3   1  |
| 1   2   39  | 8   4   35  | 6    7   59 |
+-------------+-------------+-------------+

Play this puzzle online at the Daily Sudoku site

I haven't taken this too far. Start a 6-cell coloring chain on 9, starting at r6c2 to r6c4 and ending at r1c1. That takes out the 9 from r5c1. Then locked 9s in box 4 take out the 9 in r7c2, leaving the above. Note the 36-69-39 XY-Wing pivoted in r7c2. Color the 9 pincer from r9c3-->r9c9-->r4c9 which takes out the 9 from r4c2. That should make a pretty decent dent.

P.S. I just played with it some more and that finished it off.
Back to top
View user's profile Send private message
Asellus



Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
PostPosted: Sat Feb 23, 2008 2:58 am    Post subject: Reply with quote
<9> coloring eliminates three <9>s: r5c1 and r47c2. This fixes <9> in b4 and leads to an X-Wing that removes <9> from r4c9, though this X-Wing isn't necessary to the solution. (I can't see a way for the coloring to eliminate the <9> at r4c9 directly.)

An interesting alternative with URs: First, the Type 4 {15} UR at r34c78 together with the Type "6" {45} UR at r45c67 remove <5> from r4c78 and from r5c7. This creates an X-Wing in r49 that removes <5> from r5c6. (This X-Wing step isn't necessary, but makes the solution easier.) The UR eliminations reveal an XY Wing with r4c9 pivot that removes <4> from both r4c7 and r5c6 and solves the puzzle.
Back to top
View user's profile Send private message Visit poster's website
storm_norm



Joined: 18 Oct 2007
Posts: 1741
PostPosted: Sun Feb 24, 2008 5:49 am    Post subject: Reply with quote
Code:
   |---c1--|---c2--|---c3--||---c4--|---c5--|---c6--||---c7--|---c8--|---c9--
-----------------------------------------------------------------------------
r1 |    39 |     8 |   239 ||     1 |     5 |    69 ||     7 |     4 |    26
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r2 |     5 |     4 |     1 ||    36 |   236 |     7 ||     8 |     9 |    26
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r3 |     6 |     7 |    29 ||     4 |    29 |     8 ||    15 |    15 |     3
===========================||=======================||=======================
r4 |     2 |   369 |     8 ||     7 |   369 |   345 ||  1459 |   156 |    59
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r5 |   379 |     1 |   567 ||     2 |   369 |   345 ||   459 |    56 |     8
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r6 |     4 |    69 |    56 ||   569 |     8 |     1 ||     3 |     2 |     7
===========================||=======================||=======================
r7 |   379 |   369 |    67 ||    35 |     1 |     2 ||    59 |     8 |     4
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r8 |     8 |     5 |     4 ||    69 |     7 |    69 ||     2 |     3 |     1
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r9 |     1 |     2 |    39 ||     8 |     4 |    35 ||     6 |     7 |    59
.............................................................................


I see multicoloring on 3
and
multicoloring on 9.

both are very tricky if not done right.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Other puzzles 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