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Earl
Joined: 30 May 2007 Posts: 677 Location: Victoria, KS
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Posted: Sun Feb 07, 2010 4:06 pm Post subject: Feb 6 DB |
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The Feb 6 DB is, pradoxically, an easy tall order.
A Solution: skyscraper in 5
Earl
Code: |
+-------+-------+-------+
| 9 . . | 5 . . | . 1 . |
| 7 . . | . 1 3 | 6 . . |
| 6 . . | . . 2 | . . . |
+-------+-------+-------+
| . . 3 | . 8 . | . 2 5 |
| . 2 9 | . . . | 1 7 . |
| 8 7 . | . 5 . | 3 . . |
+-------+-------+-------+
| . . . | 3 . . | . . 4 |
| . . 7 | 1 4 . | . . 3 |
| . 4 . | . . 6 | . . 1 |
+-------+-------+-------+
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Play this puzzle online at the Daily Sudoku site |
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arkietech
Joined: 31 Jul 2008 Posts: 1834 Location: Northwest Arkansas USA
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Posted: Sun Feb 07, 2010 7:52 pm Post subject: |
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A different one stepper: |
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Louise56
Joined: 21 Sep 2005 Posts: 94 Location: El Cajon, California USA
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Posted: Mon Feb 08, 2010 12:23 am Post subject: |
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I can see the skyscraper but I don't understand the remote pair 58. I have lots of 58s but I'm not sure what to do with them. |
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arkietech
Joined: 31 Jul 2008 Posts: 1834 Location: Northwest Arkansas USA
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Posted: Mon Feb 08, 2010 1:32 am Post subject: |
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Louise56 wrote: | I can see the skyscraper but I don't understand the remote pair 58. I have lots of 58s but I'm not sure what to do with them. |
Code: | *--------------------------------------------------*
| 9 3 248 | 5 6 78 | 48 1 27 |
| 7 *58 24 | 49 1 3 | 6 *58 29 |
| 6 1 458 | 48 79 2 | 458 3 79 |
|----------------+----------------+----------------|
| 4 6 3 | 7 8 1 | 9 2 5 |
| 5 2 9 | 6 3 4 | 1 7 8 |
| 8 7 1 | 2 5 9 | 3 4 6 |
|----------------+----------------+----------------|
| 1 *58 6 | 3 279 578 | 27 589 4 |
| 2 9 7 | 1 4 58 | 58 6 3 |
| 3 4 *58 | 89 27 6 | 27 9-58 1 |
*--------------------------------------------------*
remote pair 58
if r9c3 is 8 then r2c8 is 5
if r9c3 is 5 then r2c8 is 8
so r9c8 <> 5 or 8
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Louise56
Joined: 21 Sep 2005 Posts: 94 Location: El Cajon, California USA
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Posted: Mon Feb 08, 2010 2:13 am Post subject: |
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Thank-you, that does make sense. Now when you see a lot of 58s for example, how do you know which one will be your pivot (not sure what the term is, but how would I know which 58 pair to use the logic on?) |
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arkietech
Joined: 31 Jul 2008 Posts: 1834 Location: Northwest Arkansas USA
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Posted: Mon Feb 08, 2010 3:03 am Post subject: |
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Louise56 wrote: | Thank-you, that does make sense. Now when you see a lot of 58s for example, how do you know which one will be your pivot (not sure what the term is, but how would I know which 58 pair to use the logic on?) |
You have to have 5 58's so one box has to have 2. Anyway that is what I look for. Four of them have to contain two candidates ( 58 ) the 5th (the target) has 58 plus other candidates. The 58 may be removed from the target.
Hope this helps. |
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keith
Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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Posted: Mon Feb 08, 2010 3:39 am Post subject: |
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Louise56 wrote: | Thank-you, that does make sense. Now when you see a lot of 58s for example, how do you know which one will be your pivot (not sure what the term is, but how would I know which 58 pair to use the logic on?) |
http://www.dailysudoku.com/sudoku/forums/viewtopic.php?t=2143
Keith |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Mon Feb 08, 2010 4:59 am Post subject: |
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Louise56 wrote: | Thank-you, that does make sense. Now when you see a lot of 58s for example, how do you know which one will be your pivot (not sure what the term is, but how would I know which 58 pair to use the logic on?) |
To an extent, I view it as trial and error. You see which of the pairs you can make a chain with. The chain itself needs to be an even number of cells.
I have to disagree with a statement that was made about the "target" cell having to contain a 58. Any cell that sees both ends of the chain can have a 5 and/or 8 removed. If it has both, all the better, but it only needs one or the other for an elimination to be made. |
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arkietech
Joined: 31 Jul 2008 Posts: 1834 Location: Northwest Arkansas USA
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Posted: Mon Feb 08, 2010 8:27 am Post subject: |
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Marty R. wrote: | Louise56 wrote: | Thank-you, that does make sense. Now when you see a lot of 58s for example, how do you know which one will be your pivot (not sure what the term is, but how would I know which 58 pair to use the logic on?) |
To an extent, I view it as trial and error. You see which of the pairs you can make a chain with. The chain itself needs to be an even number of cells.
I have to disagree with a statement that was made about the "target" cell having to contain a 58. Any cell that sees both ends of the chain can have a 5 and/or 8 removed. If it has both, all the better, but it only needs one or the other for an elimination to be made. |
Wouldn't this be a remote single rather than a remote pair?
Who dat did it! |
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Kdelle
Joined: 20 Mar 2008 Posts: 59 Location: Hudson, NH
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Posted: Mon Feb 08, 2010 3:26 pm Post subject: |
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arkietech wrote: | Louise56 wrote: | I can see the skyscraper but I don't understand the remote pair 58. I have lots of 58s but I'm not sure what to do with them. |
Code: | *--------------------------------------------------*
| 9 3 248 | 5 6 78 | 48 1 27 |
| 7 *58 24 | 49 1 3 | 6 *58 29 |
| 6 1 458 | 48 79 2 | 458 3 79 |
|----------------+----------------+----------------|
| 4 6 3 | 7 8 1 | 9 2 5 |
| 5 2 9 | 6 3 4 | 1 7 8 |
| 8 7 1 | 2 5 9 | 3 4 6 |
|----------------+----------------+----------------|
| 1 *58 6 | 3 279 578 | 27 589 4 |
| 2 9 7 | 1 4 58 | 58 6 3 |
| 3 4 *58 | 89 27 6 | 27 9-58 1 |
*--------------------------------------------------*
remote pair 58
if r9c3 is 8 then r2c8 is 5
if r9c3 is 5 then r2c8 is 8
so r9c8 <> 5 or 8
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Dan, is this also considered a kite?
Thanks,
Kathy |
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arkietech
Joined: 31 Jul 2008 Posts: 1834 Location: Northwest Arkansas USA
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Posted: Mon Feb 08, 2010 6:14 pm Post subject: |
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Kdelle wrote: | Dan, is this also considered a kite?
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No. There are many skyscrapers on 5 -- look in columns 3 and 7 for one and
in rows 3 and 9 for another.
I don't see any on 8's. |
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Louise56
Joined: 21 Sep 2005 Posts: 94 Location: El Cajon, California USA
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Posted: Mon Feb 08, 2010 7:14 pm Post subject: |
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Very helpful replies...thank-you |
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Asellus
Joined: 05 Jun 2007 Posts: 865 Location: Sonoma County, CA, USA
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Posted: Sat Feb 13, 2010 8:06 am Post subject: |
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Just to help (I hope) avoid confusion...
The eliminations in this puzzle CAN also be seen as BOTH a <5> Kite/Turbot Fish AND an <8> Kite/Turbot Fish that happen to occupy the same cells (in r2-c2-b7). But, most would would see it as the "more compact" special case it is, a Remote Naked Pair. As far as I can see, any 4-identical-cell RNP can also be seen as two superimposed Kites/Turbot Fish/Skyscrapers. |
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arkietech
Joined: 31 Jul 2008 Posts: 1834 Location: Northwest Arkansas USA
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Posted: Sat Feb 13, 2010 8:34 am Post subject: |
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Asellus wrote: | Just to help (I hope) avoid confusion...
The eliminations in this puzzle CAN also be seen as BOTH a <5> Kite/Turbot Fish AND an <8> Kite/Turbot Fish that happen to occupy the same cells (in r2-c2-b7). But, most would would see it as the "more compact" special case it is, a Remote Naked Pair. As far as I can see, any 4-identical-cell RNP can also be seen as two superimposed Kites/Turbot Fish/Skyscrapers. |
Thanks Asellus. I stand corrected. I could not see the trees for the forest. |
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