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May 11 VH

 
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Earl



Joined: 30 May 2007
Posts: 677
Location: Victoria, KS

PostPosted: Mon May 11, 2009 2:19 am    Post subject: May 11 VH Reply with quote

This one offers alternate routes.

Solution: x-wing (3), then xy-wing (269); or an xy-chain beginning at R8C2 to R4C6, extended to R3C5 eliminates the <6> in R3C2 for a single step solution.


Early Earl
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Mon May 11, 2009 4:16 am    Post subject: Reply with quote

I used what I'll call a 1-1/2 step solution.

Quote:
XY-Wing on 239 and then a pincer transport
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crunched



Joined: 05 Feb 2008
Posts: 168

PostPosted: Mon May 11, 2009 5:37 am    Post subject: Reply with quote

I think below shows the grid after basics are removed.

Code:

+----------+-------------+----------+
| 5 4  69  | 169 3   169 | 2  7   8 |
| 8 2  39  | 7   49  459 | 1  345 6 |
| 1 36 7   | 256 246 8   | 35 345 9 |
+----------+-------------+----------+
| 2 7  5   | 8   69  69  | 4  1   3 |
| 6 1  8   | 23  24  234 | 59 59  7 |
| 3 9  4   | 15  7   15  | 8  6   2 |
+----------+-------------+----------+
| 7 5  23  | 4   8   29  | 6  39  1 |
| 4 36 236 | 129 129 7   | 39 8   5 |
| 9 8  1   | 36  5   36  | 7  2   4 |
+----------+-------------+----------+

Play this puzzle online at the Daily Sudoku site


Last edited by crunched on Mon May 11, 2009 5:56 am; edited 1 time in total
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crunched



Joined: 05 Feb 2008
Posts: 168

PostPosted: Mon May 11, 2009 5:50 am    Post subject: Reply with quote

I also found an x wing on 1s (rows 1 & 6). That opened up a 239 xy wing. But I did not see the xy wing that Earl found. Nor did I solve the puzzle. LOL

Marty R. wrote:
I used what I'll call a 1-1/2 step solution.

Quote:
XY-Wing on 239 and then a pincer transport
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George Woods



Joined: 28 Mar 2006
Posts: 304
Location: Dorset UK

PostPosted: Mon May 11, 2009 9:22 am    Post subject: a not v elegant solution! Reply with quote

Using the grid given by crunched , I found the XY wing(239) that eliminates the 9 from r2c6. But so What?. Looked hard at the 45 at r2c6 and realised that a 4 kills the 9 at r1c4so r8c4 is9, and a 5 at releases the triplet 236 in col 4 that makes r8c4 9. So r8c4 is 9. Now look again and see that the XY wing wasn't needed for this logic . Use the ALS? set 36 23 and 256 in col 4 . If r3c4 is not 5 then r8c4 is 9, and if it is 5 the the 49 pair in Box2 mean that r8c4 is 9.

So having done all that I went to draw/play and used the hints to see how the "official" solution went- Wow a 9 at r8c4! So something close to my barbaric solution is the "official" one!
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arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

PostPosted: Mon May 11, 2009 12:06 pm    Post subject: Reply with quote

Needed two steps:
Quote:
x-wing 3
xy-wing 269
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

PostPosted: Mon May 11, 2009 1:57 pm    Post subject: Reply with quote

Marty R. wrote:
I used what I'll call a 1-1/2 step solution.

Quote:
XY-Wing on 239 and then a pincer transport

Marty, I like your new definition! I also solved the puzzle in 1-1/2 steps but used a pincer pseudo-cell. Should my move be called a 1-1/2 + 1/4 = 1-3/4?

xy-wing 369 with pivot 36 in r3c2 and pseudo-cell 69 in row8; transport 9 r8c7 to r1c4 via r8c4 to complete the puzzle.

Ted
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Ema Nymton



Joined: 17 Apr 2009
Posts: 89

PostPosted: Mon May 11, 2009 5:56 pm    Post subject: Re: a not v elegant solution! Reply with quote

.

The recent spate of VH Sudoku seem to be exercises in minutiae.

George Woods wrote:
Using the grid given by crunched , I found the XY wing(239) that eliminates the 9 from r2c6. But so What?. Looked hard at the 45 at r2c6 and realised that a 4 kills the 9 at r1c4so r8c4 is9, and a 5 at releases the triplet 236 in col 4 that makes r8c4 9. So r8c4 is 9. Now look again and see that the XY wing wasn't needed for this logic . Use the ALS? set 36 23 and 256 in col 4 . If r3c4 is not 5 then r8c4 is 9, and if it is 5 the the 49 pair in Box2 mean that r8c4 is 9.

So having done all that I went to draw/play and used the hints to see how the "official" solution went- Wow a 9 at r8c4! So something close to my barbaric solution is the "official" one!


Is this not a fancy way of saying you guessed? ...

Much of the bragging going on here seems to be being done in an absence of reason/logic. As posted, after being crunched,

The basic puzzle has no visible "239" in and cell.
The basic puzzle has no visible triplet 236 in col 4

I am sorry for raining on any one's parade. I have not solved this one and am frustrated.

~@:o?
.
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Kdelle



Joined: 20 Mar 2008
Posts: 59
Location: Hudson, NH

PostPosted: Mon May 11, 2009 7:10 pm    Post subject: Reply with quote

Never mind......Brain cramp!
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Mon May 11, 2009 7:22 pm    Post subject: Reply with quote

George Woods wrote:
Quote:
Use the ALS? set 36 23 and 256 in col 4 . If r3c4 is not 5 then r8c4 is 9, and if it is 5 the the 49 pair in Box2 mean that r8c4 is 9.


George,
I like your logic.
can I assume that you found the hidden single 1 at r8c5 which makes r8c4 {2,9}?
if this is the case then, if you don't mind, I can translate into a chain.

Code:
.---------------.---------------.---------------.
| 5    4    69  |16-9  3    169 | 2    7    8   |
| 8    2    39  | 7   *49  *459 | 1    345  6   |
| 1    36   7   |*256  246  8   | 35   345  9   |
:---------------+---------------+---------------:
| 2    7    5   | 8    69   69  | 4    1    3   |
| 6    1    8   |*23   24   234 | 59   59   7   |
| 3    9    4   | 15   7    15  | 8    6    2   |
:---------------+---------------+---------------:
| 7    5    23  | 4    8    29  | 6    39   1   |
| 4    36   236 |*29   1    7   | 39   8    5   |
| 9    8    1   |*36   5    36  | 7    2    4   |
'---------------'---------------'---------------'

np = naked pair
nt = naked tripe

np(49)r2c56 = (5)r2c6 - (5)r3c4 = nt(236)r359c4 - (2)r8c4 = (9)r8c4; r1c4 <> 9
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Mon May 11, 2009 9:14 pm    Post subject: Reply with quote

Quote:
Much of the bragging going on here seems to be being done in an absence of reason/logic. As posted, after being crunched,

The basic puzzle has no visible "239" in and cell.
The basic puzzle has no visible triplet 236 in col 4

I am sorry for raining on any one's parade. I have not solved this one and am frustrated.


Ema,

If you are referring to my and other references to a 239 XY-Wing, it is indeed present in Crunched's grid.

The 239 designation does not mean a cell with those three numbers. It is a standard method of describing an XY-Wing that consists of three cells, 23-29-39. In the grid above it can be found in r7c3, r7c6 and r2c3. The pincers of 9 remove the 9 from r2c6, after which the 9 from r2c3 can be transported to r4c5 (via r2c5) and the new pincers remove the 9 from r4c6.
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swando



Joined: 09 Mar 2009
Posts: 17
Location: Surrey, BC. Canada

PostPosted: Tue May 12, 2009 7:42 am    Post subject: Reply with quote

This were I got with the basics and then used a 269 to eliminate the 9 in R 1 C4 and that did it.

[code]
+---------+-------------+----------+
| 5 4 69 | 169 3 169 | 2 7 8 |
| 8 2 39 | 7 49 459 | 1 345 6 |
| 1 36 7 | 256 246 8 | 35 45 9 |
+---------+-------------+----------+
| 2 7 5 | 8 69 69 | 4 1 3 |
| 6 1 8 | 23 24 234 | 59 59 7 |
| 3 9 4 | 15 7 15 | 8 6 2 |
+---------+-------------+----------+
| 7 5 23 | 4 8 29 | 6 39 1 |
| 4 36 26 | 29 1 7 | 39 8 5 |
| 9 8 1 | 36 5 36 | 7 2 4 |
+---------+-------------+----------+
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Ema Nymton



Joined: 17 Apr 2009
Posts: 89

PostPosted: Tue May 12, 2009 12:00 pm    Post subject: Reply with quote

.

Thank you for the help. It is very helpful.

Marty R. wrote:
Quote:
Much of the bragging going on here seems to be being done in an absence of reason/logic. As posted, after being crunched,

The basic puzzle has no visible "239" in and cell.
The basic puzzle has no visible triplet 236 in col 4

I am sorry for raining on any one's parade. I have not solved this one and am frustrated.


Ema,

If you are referring to my and other references to a 239 XY-Wing, it is indeed present in Crunched's grid.

The 239 designation does not mean a cell with those three numbers. It is a standard method of describing an XY-Wing that consists of three cells, 23-29-39. In the grid above it can be found in r7c3, r7c6 and r2c3. The pincers of 9 remove the 9 from r2c6, after which the 9 from r2c3 can be transported to r4c5 (via r2c5) and the new pincers remove the 9 from r4c6.



~@:o?
.
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