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Earl
Joined: 30 May 2007 Posts: 677 Location: Victoria, KS
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Posted: Sun Jul 29, 2007 5:16 pm Post subject: July 29 VH |
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I got his far and I know that R3C6 should be a 5, but I dont know why?
Code: |
+------------+-------------+------------+
| 8 6 24 | 2459 3 1 | 7 25 249 |
| 1 235 7 | 2459 29 8 | 45 6 2349 |
| 245 35 9 | 6 7 25 | 1 8 234 |
+------------+-------------+------------+
| 69 29 8 | 7 5 4 | 3 1 26 |
| 3 4 5 | 1 26 26 | 8 9 7 |
| 67 27 1 | 3 8 9 | 45 25 246 |
+------------+-------------+------------+
| 25 1 6 | 25 4 7 | 9 3 8 |
| 45 8 34 | 59 69 356 | 2 7 1 |
| 79 79 23 | 8 1 23 | 6 4 5 |
+------------+-------------+------------+
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Play this puzzle online at the Daily Sudoku site |
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Johan
Joined: 25 Jun 2007 Posts: 206 Location: Bornem Belgium
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Posted: Sun Jul 29, 2007 5:51 pm Post subject: 29 JYLY VH |
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Earl,
There is a naked triple in C2, that takes you further on the track for solving the puzzle. |
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Earl
Joined: 30 May 2007 Posts: 677 Location: Victoria, KS
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Posted: Sun Jul 29, 2007 9:54 pm Post subject: VH July 29 |
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Johan,
Thanks. I must have had a senior moment to miss the naked pair in box 1. After that, an x-y wing, centered in box 1, eliminates the 5 in R8C6, making R3C6 5, and the puzzle opens up.
Not really a VH, if I had been alert.
Thanks
Earl |
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cgordon
Joined: 04 May 2007 Posts: 769 Location: ontario, canada
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Posted: Mon Jul 30, 2007 1:39 pm Post subject: |
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I needed two xy wings: 1) 25 pivot R7C1 and 2) 42 pivot R3C1. Plus a slew of naked triples and pairs and x-wings (particularly on 6's). Maybe there was an easier way. In any event, I enjoyed this one. |
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George Woods
Joined: 28 Mar 2006 Posts: 304 Location: Dorset UK
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Posted: Tue Jul 31, 2007 3:07 pm Post subject: an intersting (to me) XY chain |
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Although there are a couple of XY wings that open up the puzzle, I found an alternative route via the pair of 24 in Box 1 along with the pair of 23 in row 9. Usually these simple pairs seem sterile, and hardly worth considering BUT they form a neat XY chain 24 42 23 32 that eliminates the 2 in r3c6 and so to an easy solution |
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Jeff
Joined: 06 May 2007 Posts: 46
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Posted: Tue Jul 31, 2007 8:04 pm Post subject: July 29 VH |
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I have read all the various notes above on this puzzle. I cannot seem to find out how to get down to the numbers that appeared in the diagram at the start of the discussion, mainly the pair of 35's in Box 4 and the 3,5's in Box 7. I would appreciate some good input. Many thanks,
Code: |
+------------+-------------+------------+
| 8 6 23 | 459 3 1 | 7 25 249 |
| 1 35 7 | 2459 29 8 | 45 6 2349 |
| 24 35 9 | 6 7 25 | 1 8 234 |
+------------+-------------+------------+
| 69 29 8 | 7 5 4 | 3 1 26 |
| 35 4 35 | 1 26 26 | 8 9 7 |
| 67 27 1 | 3 8 9 | 45 25 246 |
+------------+-------------+------------+
| 25 1 6 | 25 4 7 | 9 3 8 |
| 345 8 345 | 59 69 356 | 2 7 1 |
| 79 79 23 | 8 1 23 | 6 4 5 |
+------------+-------------+------------+
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cgordon
Joined: 04 May 2007 Posts: 769 Location: ontario, canada
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Posted: Tue Jul 31, 2007 8:42 pm Post subject: |
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Quote: | I cannot seem to find out how to get down to the numbers that appeared in the diagram at the start of the discussion, mainly the pair of 35's in Box 4 |
I used an xy wing. The 25 in R7C1 is the pivot cell that "sees" 2 wing cells - the 35 in R5C1 and the 23 in R9C3. The leftover digit in the wing cells (the one not shared with the pivot cell) is a 3. Any cell that "sees" both wing cells cannot contain a 3. Therefore in this case the 3 in R5C3 can be eliminated. |
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Johan
Joined: 25 Jun 2007 Posts: 206 Location: Bornem Belgium
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Posted: Tue Jul 31, 2007 9:18 pm Post subject: Pair of 35's |
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Jeff,
I've used an XY-chain length 5 to clear up the [35] pair in box 4.
Starting with number 2[A] in R7C1 => [B]R3C1=4 => [C]R1C3=2 => [D]R9C3=3 => [E]R5C3=5, which eliminates <5> in R5C1 and R8C3.
Code: |
[code]
+---------+-------+-------+
| . . C24| . . . | . . . |
| . . . | . . . | . . . |
|B24 . . | . . . | . . . |
+---------+-------+-------+
| . . . | . . . | . . . |
| 3-5. E35| . . . | . . . |
| . . . | . . . | . . . |
+---------+-------+-------+
|A25 . . | . . . | . . . |
| . .34-5| . . . | . . . |
| . . D23| . . . | . . . |
+---------+-------+-------+
[/code]
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Jeff
Joined: 06 May 2007 Posts: 46
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Posted: Tue Jul 31, 2007 9:55 pm Post subject: July 29 VH |
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Thanks for the info on cleaning up the 35's in Columns 1 and 3. Now I am looking at Johon's note early in this thread. He indicates that there is an x-y wing "centered in Box 1". I can't figure out which xy wing eliminates the 5 from R8C6. Could you tell me which specific 3 cells are involved. Many thanks, |
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Johan
Joined: 25 Jun 2007 Posts: 206 Location: Bornem Belgium
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Posted: Tue Jul 31, 2007 10:56 pm Post subject: |
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Jeff,
Like Earl first replied, there is an xy-wing centered in box1.
The pivot cell [24] is in R3C1. The pincer cells are R3C6[25] and R8C1[45]
Code: |
+--------+---------+-------+
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| 24 . . | . . 25 | . . . |
+--------+---------+-------+
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| . . . | . . . | . . . |
+--------+---------+-------+
| . . . | . . . | . . . |
| 45 . . | . . 3-56| . . . |
| . . . | . . . | . . . |
+--------+---------+-------+
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Jeff
Joined: 06 May 2007 Posts: 46
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Posted: Tue Jul 31, 2007 11:55 pm Post subject: July 29 VH |
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Johan,
Many thanks. I was under the impression that with those 3 cells, one would call the (45) in C1R8 the Pincer. Is that correct?
Jeff |
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Jeff
Joined: 06 May 2007 Posts: 46
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Posted: Tue Jul 31, 2007 11:56 pm Post subject: July 29 VH |
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Whoops. I meant to say that I thought the (45) would be the pivot.
Jeff |
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TKiel
Joined: 22 Feb 2006 Posts: 292 Location: Kalamazoo, MI
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Posted: Wed Aug 01, 2007 11:40 am Post subject: |
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The pivot has to share a row/box/column with each pincer. |
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