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 

Vanhegan extreme

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



Joined: 12 Feb 2006
Posts: 5179
Location: Rochester, NY, USA

PostPosted: Fri Aug 17, 2012 3:43 pm    Post subject: Vanhegan extreme Reply with quote

Puzzle # 6-644191, rated 1.0.0.1.1. I've played a half-dozen moves and they just eliminate a candidate or two without opening anything up.

Code:

+----------------+--------------+-------------+
| 6   79    4    | 3    279 5   | 8   279  1  |
| 189 13789 357  | 29   6   19  | 4   279  25 |
| 19  2     157  | 8    179 4   | 579 3    6  |
+----------------+--------------+-------------+
| 7   136   1236 | 1269 5   139 | 12  8    4  |
| 128 18    9    | 4    12  7   | 6   5    3  |
| 5   4     1236 | 126  8   13  | 127 127  9  |
+----------------+--------------+-------------+
| 129 5     12   | 7    3   6   | 19  4    8  |
| 3   679   67   | 19   4   8   | 125 1269 25 |
| 4   169   8    | 5    19  2   | 3   16   7  |
+----------------+--------------+-------------+

Play this puzzle online at the Daily Sudoku site
Back to top
View user's profile Send private message
daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Fri Aug 17, 2012 4:26 pm    Post subject: Reply with quote

Marty,

There is an Empty Rectangle for r1c2<>9, but it doesn't contribute much until after you find the chain for r1c5<>7. Even so, there's still several steps remaining.

Code:
 ER -> r1c2<>9
 +-----------------------------------------------------------------------+
 |  6      79     4      |  3     *279    5      |  8      279    1      |
 |  189    1378-9 357    | *29     6     *19     |  4      279    25     |
 |  19     2      157    |  8     *179    4      |  579    3      6      |
 |-----------------------+-----------------------+-----------------------|
 |  7      136    1236   |  1269   5      139    |  12     8      4      |
 |  128    18     9      |  4      12     7      |  6      5      3      |
 |  5      4      1236   |  126    8      13     |  127    127    9      |
 |-----------------------+-----------------------+-----------------------|
 |  129    5      12     |  7      3      6      |  19     4      8      |
 |  3      679    67     |  19     4      8      |  125    1269   25     |
 |  4     *169    8      |  5     *19     2      |  3      16     7      |
 +-----------------------------------------------------------------------+
 # 68 eliminations remain

 (7=9)r1c2 - r23c1 = (9-2)r7c1 = r5c1 - r5c5 = (2)r1c5  =>  r1c5<>7
Back to top
View user's profile Send private message
Marty R.



Joined: 12 Feb 2006
Posts: 5179
Location: Rochester, NY, USA

PostPosted: Fri Aug 17, 2012 10:16 pm    Post subject: Reply with quote

Thanks Danny. Chains are a mixed blessing for me. They're effective, but the only way I can find them is with trial and error.

At any rate, after r1c5<>7, I used an XY-Wing (259), pivoted in r2c8 which made a direct elimination and more after a transport. I thought that would finish it off, but no, I then needed simple coloring on 1.

I know ratings don't always mean a lot, but this puzzle was more difficult than numerous others I've seen with more difficult ratings.
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