| View previous topic :: View next topic | 
	
	
		| Author | Message | 
	
		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
 | 
			
				|  Posted: Fri Mar 18, 2011 4:35 pm    Post subject: Free Press March 18, 2011 |   |  
				| 
 |  
				| Not yet done.  Does require advanced moves. 
  	  | Code: |  	  | Puzzle: FP031811 +-------+-------+-------+
 | . . . | . 3 9 | . 4 . |
 | . . 7 | 8 . . | 3 6 . |
 | . . . | . . . | . 7 . |
 +-------+-------+-------+
 | 5 . . | 4 . 1 | . . . |
 | 4 . . | . 5 . | . . 2 |
 | . . . | 9 . 8 | . . 7 |
 +-------+-------+-------+
 | . 1 . | . . . | . . . |
 | . 3 . | . . 7 | 9 . . |
 | . 2 . | 3 1 . | . . 4 |
 +-------+-------+-------+
 
 | 
 Play this puzzle online at the Daily Sudoku site
 
 Keith
 |  | 
	
		| Back to top |  | 
	
		|  | 
	
		| Marty R. 
 
 
 Joined: 12 Feb 2006
 Posts: 5770
 Location: Rochester, NY, USA
 
 | 
			
				|  Posted: Fri Mar 18, 2011 6:46 pm    Post subject: |   |  
				| 
 |  
				|  	  | Quote: |  	  | XY-Chain. The 9 in r5c8 proves a 1 in r8c9; r8c8<>1 | 
 |  | 
	
		| Back to top |  | 
	
		|  | 
	
		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
 | 
			
				|  Posted: Fri Mar 18, 2011 8:17 pm    Post subject: |   |  
				| 
 |  
				| After basics:  	  | Code: |  	  | +-------------+-------------+-------------+ |-12  58  6   | 7   3   9   |125f 4   158 |
 | 12d 59  7   | 8   4   25  | 3   6  -159c|
 | 89  4   3   | 1   6   25  | 25  7   89  |
 +-------------+-------------+-------------+
 | 5   89b 2   | 4   7   1   | 68  39  36  |
 | 4   7   89  | 6   5   3   | 18e 19a 2   |
 | 3   6   1   | 9   2   8   | 4   5   7   |
 +-------------+-------------+-------------+
 | 78  1   58  | 25  9   4   | 567 23  36  |
 | 6   3   4   | 25  8   7   | 9   12  15  |
 | 79  2   59  | 3   1   6   | 57  8   4   |
 +-------------+-------------+-------------+
 | 
 M-wing:  9 in a forces 9 in c (coloring via b).  a and d are pincers on 1.  Transport a through e to f, making the eliminations shown.  Bringing us here:
 Which is a BUG+2 - one or both of the cells marked @ is 5. 	  | Code: |  	  | +-------------+-------------+-------------+ | 2   58  6   | 7   3   9   | 1-5 4   158@|
 | 1   59  7   | 8   4   2   | 3   6   59  |
 | 89  4   3   | 1   6   5   | 2   7   89  |
 +-------------+-------------+-------------+
 | 5   89  2   | 4   7   1   | 68  39  36  |
 | 4   7   89  | 6   5   3   | 18  19  2   |
 | 3   6   1   | 9   2   8   | 4   5   7   |
 +-------------+-------------+-------------+
 | 78  1   58  | 25  9   4   |567@ 23  36  |
 | 6   3   4   | 25  8   7   | 9   12  1-5 |
 | 79  2   59  | 3   1   6   | 57  8   4   |
 +-------------+-------------+-------------+
 | 
 
 Keith
 |  | 
	
		| Back to top |  | 
	
		|  | 
	
		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
 | 
			
				|  Posted: Fri Mar 18, 2011 9:40 pm    Post subject: |   |  
				| 
 |  
				| In the second grid above, there are other ways to make the same eliminations: 
 
 a and b are M-wing pincers on 5, since 9 in a forces 9 in c. 	  | Code: |  	  | +-------------+-------------+-------------+ | 2   58  6   | 7   3   9   | 1-5 4   158 |
 | 1   59d 7   | 8   4   2   | 3   6   59a |
 | 89  4   3   | 1   6   5   | 2   7   89  |
 +-------------+-------------+-------------+
 | 5   89  2   | 4   7   1   | 68  39  36  |
 | 4   7   89  | 6   5   3   | 18  19  2   |
 | 3   6   1   | 9   2   8   | 4   5   7   |
 +-------------+-------------+-------------+
 | 78  1   58  | 25  9   4   | 567 23  36  |
 | 6   3   4   | 25  8   7   | 9   12  1-5 |
 | 79  2   59c | 3   1   6   | 57b 8   4   |
 +-------------+-------------+-------------+
 | 
 
 Another way to look at it is c and d are not just a W-wing - they are a remote pair since they are connected by strong links on 9.  Then, make the one-link extension of both ends, d to a and c to b, to establish the pincers on 5 at a and b.
 
 Keith
 |  | 
	
		| Back to top |  | 
	
		|  | 
	
		| tlanglet 
 
 
 Joined: 17 Oct 2007
 Posts: 2468
 Location: Northern California Foothills
 
 | 
			
				|  Posted: Sat Mar 19, 2011 1:31 am    Post subject: |   |  
				| 
 |  
				| I initially found three different anp() moves that reduced the puzzle to the BUG+2 posted by Keith, but then I spotted a flightless w-wing(58)r1c2|r7c3 with SL (8)b4 (The w-wing (59)r2c2/r9c3 with SL b4 provides the same pincers on 5)
 
 I could not find a transport that provided a deletion on (5), but with  two pincer transports; r7c8,r8c4<>2
 (5)r1c2-(8)r1c2=r4c2-(8=9)r5c3-(9=1)r5c8-(1=2)r8c8
 ||
 (5)r7c3-(5=2)r7c4
 
 Fun puzzle.......
 
 Ted
 |  | 
	
		| Back to top |  | 
	
		|  | 
	
		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
 | 
			
				|  Posted: Sat Mar 19, 2011 2:23 am    Post subject: |   |  
				| 
 |  
				|  	  | tlanglet wrote: |  	  | Fun puzzle....... Ted
 | 
 I thought so too.  Had to break out the Sonoma juice.
 
 It's too bad that these Friday Freep puzzles are so variable, when some of them are quite good.
 
 Keith
 |  | 
	
		| Back to top |  | 
	
		|  | 
	
		| tlanglet 
 
 
 Joined: 17 Oct 2007
 Posts: 2468
 Location: Northern California Foothills
 
 | 
			
				|  Posted: Sat Mar 19, 2011 2:39 am    Post subject: |   |  
				| 
 |  
				|  	  | keith wrote: |  	  |  	  | tlanglet wrote: |  	  | Fun puzzle....... Ted
 | 
 I thought so too.  Had to break out the Sonoma juice
 Keith
 | 
 
 I agree about breaking out the juice, but I prefer the Zinfandels from the Northern Foothills of California where I live.
 
 Ted
 |  | 
	
		| Back to top |  | 
	
		|  | 
	
		| daj95376 
 
 
 Joined: 23 Aug 2008
 Posts: 3854
 
 
 | 
			
				|  Posted: Sat Mar 19, 2011 3:52 am    Post subject: |   |  
				| 
 |  
				|  	  | Code: |  	  | after basics +-----------------------------------------------------+
 |  12   58   6    |  7    3    9    | #125  4   *158  |
 |  12   59   7    |  8    4    25   |  3    6   #159  |
 |  89   4    3    |  1    6    25   |  2-5  7    89   |
 |-----------------+-----------------+-----------------|
 |  5    89   2    |  4    7    1    |  68   39   36   |
 |  4    7    89   |  6    5    3    |  18   19   2    |
 |  3    6    1    |  9    2    8    |  4    5    7    |
 |-----------------+-----------------+-----------------|
 |  78   1    58   |  25   9    4    | #567  23   36   |
 |  6    3    4    |  25   8    7    |  9    12   15   |
 |  79   2    59   |  3    1    6    |  57   8    4    |
 +-----------------------------------------------------+
 # 35 eliminations remain
 
 BUG+4:
 
 (=5)r1c7|r2c9|r7c7  =>  r3c7<>5   -or-
 
 (=1)r1c9 - (1=2)r1c1 - r2c2 = r2c6 - (2=5)r3c6  =>  r3c7<>5
 
 | 
 Now, where did I put the Skyy vodka and Bloody Mary mix?
 |  | 
	
		| Back to top |  | 
	
		|  | 
	
		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
 | 
			
				|  Posted: Sat Mar 19, 2011 12:11 pm    Post subject: |   |  
				| 
 |  
				| Danny, 
 That is amazing, I would never have thought to look for it.
 
 Your second chain is a little simpler if you note that in R1, 1 in R1C8 forces 5 in R1C7, and then the first chain applies.
 
 And, this takes us to the BUG+2, right?
 
 Keith
 |  | 
	
		| Back to top |  | 
	
		|  | 
	
		| daj95376 
 
 
 Joined: 23 Aug 2008
 Posts: 3854
 
 
 | 
			
				|  Posted: Sat Mar 19, 2011 4:17 pm    Post subject: |   |  
				| 
 |  
				|  	  | keith wrote: |  	  | Your second chain is a little simpler if you note that in R1, 1 in R1C9 forces 5 in R1C7, and then the first chain applies. 
 And, this takes us to the BUG+2, right?
 
 | 
 It was late and I was tired. However, I didn't use any of the 5s from the BUG+4 in the second chain because they were presumed false from the "-or-" condition. What I should have done is show: (5=12)r1c71 - (1)r1c9 to exclude that possibility. Essentially, if the 5s are false, then r1c9=1 is also false. Maybe this is really a BUG+3 scenario?
 
 There were so many XY-Chains that crack the puzzle, I was sure that any elimination in a bivalue cell would crack the puzzle. My oversight!
 
 Thanks for cleaning up my sloppiness!!!
 
 Regards, Danny
 |  | 
	
		| Back to top |  | 
	
		|  | 
	
		|  |