| View previous topic :: View next topic |
| Author |
Message |
Earl
Joined: 30 May 2007
Posts: 677
Location: Victoria, KS
|
 Posted: Sun Dec 13, 2009 2:51 am Post subject: Dec 13 VH |
 |
|
Old reliable does it again.
A Solution: 239 xy-wing
Early Earl |
|
| Back to top |
|
 |
Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
|
| Posted: Sun Dec 13, 2009 4:25 am Post subject: |
|
|
| Alternatively, either an M-Wing or W-Wing on the 23 cells in boxes 14 will do it as well. |
|
| Back to top |
|
|
ondesmartenot
Joined: 06 Dec 2009
Posts: 3
Location: Philadelphia, PA
|
| Posted: Sun Dec 13, 2009 4:25 pm Post subject: Dec 13 VH |
|
|
| I found interconnecting pairs of 25's with an 8 to keep it unique. Anyone tell me if this is legit? |
|
| Back to top |
|
|
tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
|
| Posted: Sun Dec 13, 2009 4:42 pm Post subject: Re: Dec 13 VH |
|
|
| ondesmartenot wrote: | | I found interconnecting pairs of 25's with an 8 to keep it unique. Anyone tell me if this is legit? |
Hi onedesmartenot and welcome to our sudoku group.
A bit more info is needed to help with your request. Where are the pair of 25's located, where is the digit 8 that is involved, what did you delete, and finally what was the logic behind your deletion?
Ted |
|
| Back to top |
|
|
Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
|
| Posted: Sun Dec 13, 2009 5:12 pm Post subject: |
|
|
Ted, if it's of any help, this was my post-basic grid:
| Code: |
+------------+----------+----------+
| 4 12 23 | 8 5 9 | 136 7 16 |
| 39 6 7 | 1 2 4 | 39 8 5 |
| 5 18 89 | 7 6 3 | 19 2 4 |
+------------+----------+----------+
| 6 25 1 | 9 7 25 | 4 3 8 |
| 7 9 4 | 3 8 1 | 5 6 2 |
| 23 258 238 | 25 4 6 | 7 1 9 |
+------------+----------+----------+
| 29 7 259 | 6 1 258 | 28 4 3 |
| 8 3 26 | 4 9 7 | 126 5 16 |
| 1 4 256 | 25 3 258 | 268 9 7 |
+------------+----------+----------+
|
Play this puzzle online at the Daily Sudoku site |
|
| Back to top |
|
|
ondesmartenot
Joined: 06 Dec 2009
Posts: 3
Location: Philadelphia, PA
|
| Posted: Thu Dec 17, 2009 12:51 am Post subject: |
|
|
| Hi Ted, using Marty's post basic grid I was wondering if the pair of 25's in row 4 and the pair of 25's in column 4 would force R6C2 and R9C6 to be 8 in order to avoid a deadly pattern? |
|
| Back to top |
|
|
tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
|
| Posted: Thu Dec 17, 2009 3:13 am Post subject: |
|
|
| ondesmartenot wrote: | | Hi Ted, using Marty's post basic grid I was wondering if the pair of 25's in row 4 and the pair of 25's in column 4 would force R6C2 and R9C6 to be 8 in order to avoid a deadly pattern? |
Hi Again,
Here is the code with the four cells in question marked abcd.
| Code: | +------------+----------+----------+
| 4 12 23 | 8 5 9 | 136 7 16 |
| 39 6 7 | 1 2 4 | 39 8 5 |
| 5 18 89 | 7 6 3 | 19 2 4 |
+------------+----------+----------+
| 6 a25 1 | 9 7b25 | 4 3 8 |
| 7 9 4 | 3 8 1 | 5 6 2 |
| 23 258 238 |c25 4 6 | 7 1 9 |
+------------+----------+----------+
| 29 7 259 | 6 1 258 | 28 4 3 |
| 8 3 26 | 4 9 7 | 126 5 16 |
| 1 4 256 |d25 3 258 | 268 9 7 |
+------------+----------+----------+ |
The answer to your question is no; this is not a deadly pattern. However it is a pattern known as a remote pair that does provide deletions. Briefly, a remote pair is a sequence of an even number of four or more identical connected bivalue cells. In this case the sequence is marked abcd. The end cells of a remote pair act as pincers for the two digits of the bivalue cells. Thus, the two digits in the bivalue cells can be deleted from the two cells that see both ends of the remote pair sequence.
In this specific case, the two cells that see both end cells are r4c4 and r9c2. No deletions are possible since these two cells do not contain digit 2 or digit 5.
For a more complete and formal definition of remoter pairs, I suggest trying this site.
Ted |
|
| Back to top |
|
|
ondesmartenot
Joined: 06 Dec 2009
Posts: 3
Location: Philadelphia, PA
|
| Posted: Thu Dec 17, 2009 4:03 am Post subject: |
|
|
Hi Ted,
I have been thinking about this puzzle a lot and the remote pairs makes sense to me, but just for instance if R9C6 is an 8 than that leaves us with a pair of 25's in box 8 that would force R6C2 to be an 8, and also if R7C6 were an 8 the same would be true, if R6C2 is not an 8 than the six cells with 25 creates a deadly pattern?
-ondesmartenot |
|
| Back to top |
|
|
tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
|
| Posted: Thu Dec 17, 2009 4:47 am Post subject: |
|
|
| ondesmartenot wrote: | Hi Ted,
I have been thinking about this puzzle a lot and the remote pairs makes sense to me, but just for instance if R9C6 is an 8 than that leaves us with a pair of 25's in box 8 that would force R6C2 to be an 8, and also if R7C6 were an 8 the same would be true, if R6C2 is not an 8 than the six cells with 25 creates a deadly pattern?
-ondesmartenot |
Deadly Patterns are limited to restricted cell arrangements. I suggest that you go to the site previously provided and check out UR and BUG patterns.
Happy reading...
Ted |
|
| Back to top |
|
|
keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
|
| Posted: Thu Dec 17, 2009 4:48 am Post subject: |
|
|
| ondesmartenot wrote: | Hi Ted,
I have been thinking about this puzzle a lot and the remote pairs makes sense to me, but just for instance if R9C6 is an 8 than that leaves us with a pair of 25's in box 8 that would force R6C2 to be an 8, and also if R7C6 were an 8 the same would be true, if R6C2 is not an 8 than the six cells with 25 creates a deadly pattern?
-ondesmartenot |
Yes,
At least one of R6C2 and R9C6 must be 8. It so happens that in the solution both are 8, but only one is needed to avoid that particular DP. I do not see any eliminations.
R9C6 = 8 does not force R6C2 = 8.
Keith |
|
| Back to top |
|
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
