| View previous topic :: View next topic   | 
	
	
	
		| Author | 
		Message | 
	
	
		tlanglet
 
 
  Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
  | 
		
			
				 Posted: Thu Oct 15, 2009 10:09 pm    Post subject: Decabit Insane October 15 | 
				     | 
			 
			
				
  | 
			 
			
				For me, the first move was the hardest.
 
 
 	  | Code: | 	 		  
 
+-------+-------+-------+
 
| . . 7 | 3 . . | . . . |
 
| . . . | . 8 4 | . 5 . |
 
| 4 . 5 | . . . | 7 8 . |
 
+-------+-------+-------+
 
| . 8 . | . . 5 | 2 . . |
 
| . . 3 | 4 . 8 | . . . |
 
| 2 . . | . . . | . . . |
 
+-------+-------+-------+
 
| . . . | . . 6 | . 4 2 |
 
| . . . | . . . | 1 . 7 |
 
| . 1 . | . . 3 | . 6 5 |
 
+-------+-------+-------+
 
 | 	  
 
Play this puzzle online at the Daily Sudoku site
 
Ted | 
			 
		  | 
	
	
		| Back to top | 
		 | 
	
	
		  | 
	
	
		storm_norm
 
 
  Joined: 18 Oct 2007 Posts: 1741
 
  | 
		
			
				 Posted: Thu Oct 15, 2009 11:49 pm    Post subject:  | 
				     | 
			 
			
				
  | 
			 
			
				 	  | Code: | 	 		  .------------------------.------------------------.------------------------.
 
| 8       69      7      | 3       5       19     | 469     2       1469   |
 
| 1369    2369    1269   | 7       8       4      | 369     5       369    |
 
| 4       39      5      | 269     69      129    | 7       8       139    |
 
:------------------------+------------------------+------------------------:
 
| 1679    8       1469   | 169     1369    5      | 2       1379    3469   |
 
| 15679   5679    3      | 4       2       8      | 569     179     69     |
 
| 2       4569    1469   | 169     1369    7      | 34569   139     8      |
 
:------------------------+------------------------+------------------------:
 
| 3579    3579    89     | 1589    179     6      | 389     4       2      |
 
| 3569    234569  24689  | 2589    49     *29     | 1       39      7      |
 
| 79      1       2489   |*289     479     3      |*89      6       5      |
 
'------------------------'------------------------'------------------------' | 	  
 
xyz-wing removes 9 from r9c5
 
 
 	  | Code: | 	 		  +-----------------------+-------------------+-------------------+
 
| 8      69      7      | 3       5     19  | 469    2     1469 |
 
| 1369   2369    1269   | 7       8     4   | 369    5     369  |
 
| 4      39      5      | 269     69    129 | 7      8     139  |
 
+-----------------------+-------------------+-------------------+
 
| 1679   8       1469   | 169     1369  5   | 2      1379  3469 |
 
| 15679  5679    3      | 4       2     8   | 569    179   69   |
 
| 2      4569    1469   | 169     1369  7   | 34569  139   8    |
 
+-----------------------+-------------------+-------------------+
 
| 3579   3579    89     | 1589    179   6   | 389    4     2    |
 
| 3569   234569  24689  | 2589    (49)  29  | 1      39    7    |
 
| 79     1       89(24) | 8-9(2)  7(4)  3   | 89     6     5    |
 
+-----------------------+-------------------+-------------------+ | 	  
 
(9=4)r8c5 - (4)r9c5 = (4-2)r9c3 = (2)r9c4; r9c4 <> 9
 
 
 	  | Code: | 	 		  +----------------------+------------------+-------------------+
 
| 8      69      7     | 3     5     19   | 469    2     1469 |
 
| 1369   2369    1269  | 7     8     4    | 369    5     369  |
 
| 4      39      5     | 269   69    129  | 7      8     139  |
 
+----------------------+------------------+-------------------+
 
| 1679   8       1469  | 169   1369  5    | 2      1379  3469 |
 
| 15679  5679    3     | 4     2     8    | 569    179   69   |
 
| 2      4569    1469  | 169   1369  7    | 34569  139   8    |
 
+----------------------+------------------+-------------------+
 
| 3579   3579    89    | 1589  179   6    | 389    4     2    |
 
| 3569   234569  24689 | 2589  49    (29) | 1      3-9   7    |
 
| 79     1       2489  | (28)  47    3    | (89)   6     5    |
 
+----------------------+------------------+-------------------+ | 	  
 
xy-wing finishes {2,8,9} | 
			 
		  | 
	
	
		| Back to top | 
		 | 
	
	
		  | 
	
	
		tlanglet
 
 
  Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
  | 
		
			
				 Posted: Fri Oct 16, 2009 11:36 am    Post subject:  | 
				     | 
			 
			
				
  | 
			 
			
				I also had three moves to complete this puzzle.
 
 
The first move was the xyz-wing noted by Norm; it took me a while to spot it and I did not find any other VH type moves. This step deleted the 9 from r9c5, which opened up a
 
xy-wing 47-9 with vertex 47 in r9c5 and pincers in r8c5 & r9c1 which deleted the 9 in r9c4, which was the same as Norm's short chain, plus the 9s in r8c123. This move then opened up a
 
xy-wing 28-9, which again was identical to the move by Norm.
 
 
I wonder if this puzzle has other VH solutions   
 
 
Ted | 
			 
		  | 
	
	
		| Back to top | 
		 | 
	
	
		  | 
	
	
		Earl
 
 
  Joined: 30 May 2007 Posts: 677 Location: Victoria, KS
  | 
		
			
				 Posted: Fri Oct 16, 2009 2:56 pm    Post subject: insane | 
				     | 
			 
			
				
  | 
			 
			
				If you use the 479 xyz-wing to remove 9 from R9C4, it opens a 289 xy-wing, solving the puzzle in two steps.
 
 
Earl | 
			 
		  | 
	
	
		| Back to top | 
		 | 
	
	
		  | 
	
	
		tlanglet
 
 
  Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
  | 
		
			
				 Posted: Fri Oct 16, 2009 5:08 pm    Post subject: Re: insane | 
				     | 
			 
			
				
  | 
			 
			
				 	  | Earl wrote: | 	 		  If you use the 479 xyz-wing to remove 9 from R9C4, it opens a 289 xy-wing, solving the puzzle in two steps.
 
 
Earl | 	  
 
 
Very nice Earl   | 
			 
		  | 
	
	
		| Back to top | 
		 | 
	
	
		  | 
	
	
		keith
 
 
  Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
  | 
		
			
				 Posted: Fri Oct 16, 2009 9:00 pm    Post subject:  | 
				     | 
			 
			
				
  | 
			 
			
				Did you notice that, after basics, EVERY unsolved cell could be 9?  In other words, no solved cells are 9.
 
 
Keith | 
			 
		  | 
	
	
		| Back to top | 
		 | 
	
	
		  | 
	
	
		Marty R.
 
 
  Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
  | 
		
			
				 Posted: Sat Oct 17, 2009 4:24 am    Post subject:  | 
				     | 
			 
			
				
  | 
			 
			
				I noticed that with the 9s. I also used eight moves. Then I noticed a triple which may have been there before the moves, but, what the heck, I finished it.        | 
			 
		  | 
	
	
		| Back to top | 
		 | 
	
	
		  | 
	
	
		tlanglet
 
 
  Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
  | 
		
			
				 Posted: Sat Oct 17, 2009 4:45 am    Post subject:  | 
				     | 
			 
			
				
  | 
			 
			
				 	  | Marty R. wrote: | 	 		  I noticed that with the 9s. I also used eight moves. Then I noticed a triple which may have been there before the moves, but, what the heck, I finished it.        | 	  
 
 
Well Marty, you answered my question: Yes this puzzle has multiple VH solutions.
 
 
Ted | 
			 
		  | 
	
	
		| Back to top | 
		 | 
	
	
		  | 
	
	
		wapati
 
 
  Joined: 10 Jun 2008 Posts: 472 Location: Brampton, Ontario, Canada.
  | 
		
			
				 Posted: Sat Oct 17, 2009 7:04 am    Post subject:  | 
				     | 
			 
			
				
  | 
			 
			
				 	  | tlanglet wrote: | 	 		  
 
I wonder if this puzzle has other VH solutions   
 
Ted | 	  
 
What are the VH methods?
 
 
Is there a listing on-site?
 
 
Thanks. | 
			 
		  | 
	
	
		| Back to top | 
		 | 
	
	
		  | 
	
	
		nataraj
 
 
  Joined: 03 Aug 2007 Posts: 1048 Location: near Vienna, Austria
  | 
		
			
				 Posted: Sat Oct 17, 2009 11:38 am    Post subject:  | 
				     | 
			 
			
				
  | 
			 
			
				 	  | wapati wrote: | 	 		  What are the VH methods?
 
 
Is there a listing on-site?
 
 
Thanks. | 	  
 
 
Don't know about a listing. Also, I think what is meant by "VH methods" is really "methods to solve this site's VH puzzles". And to that question, the answer (from my experience)  is:
 
 
 
To solve "Very Hard" puzzles from dailysudoku.com, you need nothing more than x-wing, xy-wing and xyz-wing | 
			 
		  | 
	
	
		| Back to top | 
		 | 
	
	
		  | 
	
	
		wapati
 
 
  Joined: 10 Jun 2008 Posts: 472 Location: Brampton, Ontario, Canada.
  | 
		
			
				 Posted: Sat Oct 17, 2009 10:56 pm    Post subject:  | 
				     | 
			 
			
				
  | 
			 
			
				 	  | nataraj wrote: | 	 		   	  | wapati wrote: | 	 		  What are the VH methods?
 
 
Is there a listing on-site?
 
 
Thanks. | 	  
 
 
Don't know about a listing. Also, I think what is meant by "VH methods" is really "methods to solve this site's VH puzzles". And to that question, the answer (from my experience)  is:
 
 
 
To solve "Very Hard" puzzles from dailysudoku.com, you need nothing more than x-wing, xy-wing and xyz-wing | 	  
 
 
Thanks. | 
			 
		  | 
	
	
		| Back to top | 
		 | 
	
	
		  | 
	
	
		 |