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wings again

 
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ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Thu Mar 06, 2008 4:04 pm    Post subject: wings again Reply with quote

Code:
 +-------+-------+-------+
 | 1 . . | 2 . . | 3 . . |
 | . . . | . 8 . | . 5 . |
 | . . 3 | . . 4 | . . 1 |
 +-------+-------+-------+
 | 5 . . | . . . | 6 . . |
 | . 1 . | . 6 . | . 2 . |
 | . . 2 | . . . | . . 7 |
 +-------+-------+-------+
 | 2 . . | 4 . . | 7 . . |
 | . 7 . | . 5 . | . . . |
 | . . 4 | . . 6 | . . 9 |
 +-------+-------+-------+ gsf
>>> play online
Slow puzzle, but i had a x-,xy-,xyz-,w- and M-wing (and the UR) - not in this order.
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Thu Mar 06, 2008 10:05 pm    Post subject: Reply with quote

after basics you get this pattern on 8

Code:
. . G | . . . | . o o
. . . | . o . | . . .
R . . | . . . | . G .
---------------------
. o . | o . . | . o o
o . R | o . . | r . .
o o . | . . o | . o .
---------------------
. . . | . . o | . X o
. . . | o . o | g X .
o o . | . . . | . . .



the coloring eliminates 8 from r78c8

Code:
   |---c1--|---c2--|---c3--||---c4--|---c5--|---c6--||---c7--|---c8--|---c9--
-----------------------------------------------------------------------------
r1 |     1 |     4 |   689 ||     2 |    79 |     5 ||     3 |  6789 |    68
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r2 |     7 |     2 |    69 ||    13 |     8 |    13 ||    49 |     5 |    46
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r3 |    89 |     5 |     3 ||     6 |    79 |     4 ||     2 |   789 |     1
===========================||=======================||=======================
r4 |     5 |   389 |     7 ||  1389 |   134 |     2 ||     6 |  3489 |   348
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r5 |  3489 |     1 |    89 ||   389 |     6 |     7 ||   489 |     2 |     5
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r6 | 34689 |  3689 |     2 ||     5 |    34 |   389 ||     1 |  3489 |     7
===========================||=======================||=======================
r7 |     2 |    69 |     5 ||     4 |    13 |  1389 ||     7 |   36  |   368
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r8 |    69 |     7 |     1 ||   389 |     5 |   389 ||    48 |  346  |     2
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r9 |    38 |    38 |     4 ||     7 |     2 |     6 ||     5 |     1 |     9
.............................................................................


then the UR 79 in r13c9 eliminates the 9 in r13c8?? and that is a type 4?

xyz-wing {389} in box 4 eiminates 8 in r6c2

still working...
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Marty R.



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

PostPosted: Thu Mar 06, 2008 10:18 pm    Post subject: Reply with quote

My first two steps were Norm's Type 4 and the XYZ. After that I needed Medusa to open things up for a W-Wing on 34 to finish it off.

There were no freebies at the start and lots of polyvalued cells, so a fair amount of grunt work was needed before I could start looking for the usual techniques.
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Johan



Joined: 25 Jun 2007
Posts: 206
Location: Bornem Belgium

PostPosted: Thu Mar 06, 2008 10:34 pm    Post subject: Reply with quote

The grid after basics:
Code:
+-------------------------+------------------------+------------------------+
| 1        4         689  | 2      *79       5     | 3       *6789     68   |
| 7        2         69   | 13      8        13    | 49       5        46   |
| 89       5         3    | 6      *79       4     | 2       *789      1    |
+-------------------------+------------------------+------------------------+
| 5        389       7    | 1389    134      2     | 6        3489     348  |
| 3489     1         89   | 389     6        7     | 489      2        5    |
| 34689    3689      2    | 5       34       389   | 1        3489     7    |
+-------------------------+------------------------+------------------------+
| 2        69        5    | 4       13       1389  | 7        368      368  |
| 69       7         1    | 389     5        389   | 48       3468     2    |
| 38       38        4    | 7       2        6     | 5        1        9    |
+-------------------------+------------------------+------------------------+


UR [79]* in R13C58 eliminates both <9>'s in R13C8. The grid after UR [79]:
Code:
+-------------------------+------------------------+------------------------+
| 1        4         89   | 2       79       5     | 3        678      68   |
| 7        2         6    | 13      8        13    | 9        5        4    |
| 89       5         3    | 6       79       4     | 2        78       1    |
+-------------------------+------------------------+------------------------+
| 5        389       7    | 1389    134      2     | 6        3489     38   |
| 3489     1         89   | 389     6        7     | 48       2        5    |
| 34689    3689      2    | 5       34       389   | 1        3489     7    |
+-------------------------+------------------------+------------------------+
| 2        69        5    | 4       13       1389  | 7        368      368  |
| 69       7         1    | 389     5        389   | 48       3468     2    |
| 38       38        4    | 7       2        6     | 5        1        9    |
+-------------------------+------------------------+------------------------+


UR [38]* in R47C89 takes out <9> in R4C2. Either R4C8=4 => R5C7=8 => R5C3=9(a) or R4C8=9 => R67C2=69(b) or R7C89=6 => R7C2=9(c)
The <9> in R4C2 can see abc
Code:
+-------------------------+------------------------+------------------------+
| 1        4         89   | 2       79       5     | 3        678      68   |
| 7        2         6    | 13      8        13    | 9        5        4    |
| 89       5         3    | 6       79       4     | 2        78       1    |
+-------------------------+------------------------+------------------------+
| 5        38-[9]    7    | 1389    134      2     | 6       *3489    *38   |
| 3489     1       a 89   | 389     6        7     | 48       2        5    |
| 34689  b 3689      2    | 5       34       389   | 1        3489     7    |
+-------------------------+------------------------+------------------------+
| 2      b 69 c      5    | 4       13       1389  | 7       *368     *368  |
| 69       7         1    | 389     5        389   | 48       3468     2    |
| 38       38        4    | 7       2        6     | 5        1        9    |
+-------------------------+------------------------+------------------------+


After UR [38] there is a Finned X-wing* for digit <3> in R67C58 with the Fin(F) in R8C8 that takes out <3> in R7C9, that solves the puzzle.
Code:
+-------------------------+------------------------+------------------------+
| 1        4         89   | 2       79       5     | 3        678      68   |
| 7        2         6    | 13      8        13    | 9        5        4    |
| 89       5         3    | 6       79       4     | 2        78       1    |
+-------------------------+------------------------+------------------------+
| 5        38        7    | 19      14       2     | 6        49       38   |
| 3489     1         89   | 389     6        7     | 48       2        5    |
| 34689    69        2    | 5      *34       389   | 1       *3489     7    |
+-------------------------+------------------------+------------------------+
| 2        69        5    | 4      *13       1389  | 7       *368    -[3]68 |
| 69       7         1    | 389     5        389   | 48      F3468     2    |
| 38       38        4    | 7       2        6     | 5        1        9    |
+-------------------------+------------------------+------------------------+
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nataraj



Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria

PostPosted: Fri Mar 07, 2008 6:52 am    Post subject: Reply with quote

After coloring on 8 and xyz-wing and UR 79, this where I started looking at the left part of the grid:

Code:

+--------------------------+--------------------------+--------------------------+
| 1       4       89       | 2       79      5        | 3       678     68       |
| 7       2       6        | 13      8       13       | 9       5       4        |
| 89      5       3        | 6       79      4        | 2       78      1        |
+--------------------------+--------------------------+--------------------------+
| 5       389     7        | 1389    134     2        | 6       3489    38       |
| 3489    1       89       | 389     6       7        | 48      2       5        |
| 34689   369     2        | 5       34      389      | 1       3489    7        |
+--------------------------+--------------------------+--------------------------+
| 2       69      5        | 4       13      1389     | 7       36      368      |
| 69      7       1        | 389     5       389      | 48      346     2        |
| 38      38      4        | 7       2       6        | 5       1       9        |
+--------------------------+--------------------------+--------------------------+

So many bi-values with 3,6,8,9

Look at r8c1. If r8c1=9 then the first column is
r3c1=8 (transport to r1c3=9, r5c3=8)
r9c1=3
r5c1=4

and that is impossible, because r5c7 is left without candidates (since we have r5c1=4,r5c3=8)
Hence r8c1=6

The puzzle needs some coloring on 3 and/or an x-wing on 8 a bit later, but that's it.
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Earl



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

PostPosted: Fri Mar 07, 2008 4:03 pm    Post subject: wings Reply with quote

[UR [79]* in R13C58 eliminates both <9>'s in R13C8]

How?

Earl
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Steve R



Joined: 24 Oct 2005
Posts: 289
Location: Birmingham, England

PostPosted: Fri Mar 07, 2008 4:45 pm    Post subject: Reply with quote

Code:
-----------------------------------------------------------------------
|     1 |    4 | 689 ||     2 |   79+ |     5 ||     3 |  79+68 |    68
+-------+------+-----||-------+-------+-------||-------+--------+------
|     7 |    2 |  69 ||    13 |    8  |    13 ||    49 |     5  |    46
+-------+------+-----||-------+-------+-------||-------+--------+------
|    89 |    5 |   3 ||     6 |   79+ |     4 ||     2 |  79+8  |     1
=====================||======================||========================
|     5 |  389 |   7 ||  1389 |  134  |     2 ||     6 |  3489  |   348
+-------+------+-----||-------+-------+-------||-------+--------+------
|  3489 |    1 |  89 ||   389 |    6  |     7 ||   489 |     2  |     5
+-------+------+-----||-------+-------+-------||-------+--------+------
| 34689 | 3689 |   2 ||     5 |   34  |   389 ||     1 |  3489  |     7
=====================||=======================||=======================
|     2 |   69 |   5 ||     4 |   13  |  1389 ||     7 |    36  |   368
+-------+------+-----||-------+-------+-------||-------+--------+------
|    69 |    7 |   1 ||   389 |    5  |   389 ||    48 |   346  |     2
+-------+------+-----||-------+-------+-------||-------+--------+------
|    38 |   38 |   4 ||     7 |    2  |     6 ||     5 |     1  |     9
......................................................................


Quote:
… then the UR 79 in r13c58 eliminates the 9 in r13c8?? …

Quote:
How?

Because r1c5 is conjugate to r1c8 with respect to 7 and r3c5 is conjugate to r3c8 with respect to 7. One of the rectangle cells in column 8 must therefore contain a 7: if the deadly pattern is to be avoided, the other cannot contain 9.

Steve
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ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Sun Mar 09, 2008 10:53 am    Post subject: Reply with quote

Another way to see the type 4 UR is: If you dont have a 7 or 9 in the rest of column 8, you would have a 79 pair in r13c8 and thus the deadly pattern. Because there is no 7 outside, the 9 must be outside and can be removed from the UR cells.

Nice solutions, Johan and nataraj, thats what i like with sudokus, so many different ways to solve them.
That was mine, after the UR and the xyz-wing:
Code:
 *--------------------------------------------------------------------*
 | 1      4      89     | 2      79     5      | 3      678    68     |
 | 7      2      6      |@13     8     #13     | 9      5      4      |
 | 89     5      3      | 6      79     4      | 2      78     1      |
 |----------------------+----------------------+----------------------|
 | 5      389    7      | 1389   134    2      | 6      3489   38     |
 | 3489   1      89     | 389    6      7      | 48     2      5      |
 | 34689  369    2      | 5      34     389    | 1      3489   7      |
 |----------------------+----------------------+----------------------|
 | 2      69     5      | 4     #13    @1389   | 7      368    368    |
 | 69     7      1      |-389    5      389    | 48     3468   2      |
 | 38     38     4      | 7      2      6      | 5      1      9      |
 *--------------------------------------------------------------------*
M-wing 13, the pairs connected with strong links for 1 via r7c6, strong link for 3 in row 2.
This eliminates 3 from r8c4 and opens a w-wing 89 (SL for 8 in column 7), that takes out 9 from r5c4.

Then 9 is locked to row 5 in box 4 and pinned to r7c2.

Later an x-wing on 8, followed by an xy-wing solved it.
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