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prakash
Joined: 02 Jan 2008 Posts: 67 Location: New Jersey, USA
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Posted: Fri Jun 27, 2008 12:55 am Post subject: June 27, VH |
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I am sure I missed something simple. I had to jump through hoops to get his done. 2 XYZ wings, 1 X Wing and 1 XY Wing. Anybody spot something simpler?
XYZ Wing 13-143-43 removes 3 from R3C7
X Wing on 3 removes 3 from R2C5
XYZ Wing 49-479-79 removes 9 from R3C7
XY Wing 17-27-12 removes 1 from R1C5 |
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wapati
Joined: 10 Jun 2008 Posts: 472 Location: Brampton, Ontario, Canada.
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Posted: Fri Jun 27, 2008 4:40 am Post subject: Re: June 27, VH |
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prakash wrote: | Anybody spot something simpler?
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Shorter, yep. I find 2 string kites to be horribly hard to spot.
Code: | Simple stuff to here where a two string kite eliminates the 4 in r3c6.
.---------------------.---------------------.---------------------.
| 17 4 3 | 89 18 5 | 6 79 2 |
| 12 5 9 | 46 12346 7 | 134 8 13 |
| 6 27 8 | 49 1234 #12-4 | 1349 @479 5 |
:---------------------+---------------------+---------------------:
| 5 9 2 | 1 7 *48 |*34 6 38 |
| 478 678 46 | 2 5 3 | 149 @49 18 |
| 48 3 1 | 468 468 9 | 5 2 7 |
:---------------------+---------------------+---------------------:
| 248 268 46 | 5 12 126 | 7 3 9 |
| 9 1 7 | 3 48 468 | 2 5 46 |
| 3 26 5 | 7 9 246 | 8 1 46 |
'---------------------'---------------------'---------------------'
That sets up an xy wing that sets r1c5 to 8. The rest is simple.
.---------------------.---------------------.---------------------.
|*17 4 3 | 89 #8-1 5 | 6 79 2 |
| 12 5 9 | 46 12346 7 | 134 8 13 |
| 6 *27 8 | 49 1234 *12 | 1349 479 5 |
:---------------------+---------------------+---------------------:
| 5 9 2 | 1 7 48 | 34 6 38 |
| 478 678 46 | 2 5 3 | 149 49 18 |
| 48 3 1 | 468 468 9 | 5 2 7 |
:---------------------+---------------------+---------------------:
| 248 268 46 | 5 12 126 | 7 3 9 |
| 9 1 7 | 3 48 468 | 2 5 46 |
| 3 26 5 | 7 9 246 | 8 1 46 |
'---------------------'---------------------'---------------------' |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Fri Jun 27, 2008 4:41 am Post subject: |
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W-Wing, Type 4 UR, W-Wing. The UR probably wasn't needed. |
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wapati
Joined: 10 Jun 2008 Posts: 472 Location: Brampton, Ontario, Canada.
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Posted: Fri Jun 27, 2008 4:54 am Post subject: |
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I so like it that different paths are often easy to find.
Sudoku would be stale if there was only one path and order.
I confirm that the UR is not needed. |
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storm_norm
Joined: 18 Oct 2007 Posts: 1741
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Posted: Fri Jun 27, 2008 5:30 am Post subject: |
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Code: | .---------------------.---------------------.---------------------.
|*17 4 3 | 89 *18 5 | 6 79 2 |
|#12 5 9 | 46 1-2346 7 | 134 8 13 |
| 6 27 8 | 49 1234 124 | 1349 479 5 |
:---------------------+---------------------+---------------------:
| 5 9 2 | 1 7 48 | 34 6 38 |
| 478 678 46 | 2 5 3 | 149 49 18 |
| 48 3 1 | 468 468 9 | 5 2 7 |
:---------------------+---------------------+---------------------:
| 248 268 46 | 5 #12 126 | 7 3 9 |
| 9 1 7 | 3 48 468 | 2 5 46 |
| 3 26 5 | 7 9 246 | 8 1 46 |
'---------------------'---------------------'---------------------' |
w-wing {1,2} through the ones in the first row, removes 2 in r2c5
(2=1)r2c1-(1)r1c1=(1)r5c1-(1=2)r7c5; r2c5<>2 |
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nataraj
Joined: 03 Aug 2007 Posts: 1048 Location: near Vienna, Austria
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Posted: Fri Jun 27, 2008 5:55 am Post subject: |
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Something simple?
An xyz-wing very early on: 4,7,9 in row 3 + box 3, removes 9 from r3c7. From there, basic stuff for a while.
Near the end, either a UR (26 r79c26 with strong link 6 in r7) or an xy-wing pivot r3c2 (17-27-12) |
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Johan
Joined: 25 Jun 2007 Posts: 206 Location: Bornem Belgium
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Posted: Fri Jun 27, 2008 8:59 am Post subject: |
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I used the strong link* on <2> in C1, which eliminates <1> in R1C5 collapsing the whole puzzle. Either R2C1=2 or R7C1=2.
R2C1=2 => R1C1=1(a)
R7C1=2 => R7C5=1(b)
Code: | +-------------------------+-------------------------+-------------------------+
| 17 a 4 3 | 89 -[1]8 5 | 6 79 2 |
|*12 5 9 | 46 12346 7 | 134 8 13 |
| 6 27 8 | 49 1234 124 | 1349 479 5 |
+-------------------------+-------------------------+-------------------------+
| 5 9 2 | 1 7 48 | 34 6 38 |
| 478 678 46 | 2 5 3 | 149 49 18 |
| 48 3 1 | 468 468 9 | 5 2 7 |
+-------------------------+-------------------------+-------------------------+
|*248 268 46 | 5 12 b 126 | 7 3 9 |
| 9 1 7 | 3 48 468 | 2 5 46 |
| 3 26 5 | 7 9 246 | 8 1 46 |
+-------------------------+-------------------------+-------------------------+ |
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cgordon
Joined: 04 May 2007 Posts: 769 Location: ontario, canada
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Posted: Fri Jun 27, 2008 2:34 pm Post subject: |
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Remarkably easy really. I simply used the following:
x-wing on <6>
xyz-wing on <134>
x-wing on <2>
ER on <4>
xy-wing on <127>
A three coffee job at most. |
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Earl
Joined: 30 May 2007 Posts: 677 Location: Victoria, KS
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Posted: Fri Jun 27, 2008 4:31 pm Post subject: VH |
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An xyz-wing (479), then an xy-wing (127) (all in boxes 1-2-3) did it for me.
Earl |
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Clement
Joined: 24 Apr 2006 Posts: 1111 Location: Dar es Salaam Tanzania
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Posted: Sat Jun 28, 2008 5:25 pm Post subject: Daily Sudoku: Fri 27-Jun-2008 VH |
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I used the BUG Principle.Candidate 9 is the only one that appears three times in c8.Therefore, 9 must go in r3c8 which is the only three candidate cell in the column. That solves the puzzle. |
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nataraj
Joined: 03 Aug 2007 Posts: 1048 Location: near Vienna, Austria
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Posted: Sat Jun 28, 2008 6:02 pm Post subject: Re: Daily Sudoku: Fri 27-Jun-2008 VH |
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Clement wrote: | I used the BUG Principle.Candidate 9 is the only one that appears three times in c8.Therefore, 9 must go in r3c8 which is the only three candidate cell in the column. That solves the puzzle. |
"Careful with that axe, Eugene ..."
Clement, could you explain that a bit more? I do not have my grid available any more but I do remember that all essential steps in solving the puzzle occured at a time when I was still FAR AWAY from a "BUG" situation. The BUG+1 or BUG+n reasoning only comes into play, when almost all cells in the puzzle are either solved or have only two candidates left.
Looking at the posted grids here, I see a lot of three- four- and even five-candidate cells at the critical points.
Maybe you run that grid with the BUG+1 by us and also how you got there? |
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