Stuck

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Stuck

Postby hrcjcr » Sun Apr 22, 2007 5:59 pm

I have reduced the puzzle as much as I can using all tools I'm familiar with.
Are my eyes just missing something?
Code:
[code]
2 6 7 | 8 134 34 | 345 9 15
3 18 9 | 17 1467 5 | 2468 248 16
18 4 5 | 2 136 9 | 368 38 7

9 7 1 | 3 2 46 | 4568 48 56
6 28 28 | 5 47 1 | 347 347 9
45 35 34 | 9 8 67 | 67 1 2

7 389 348 | 6 39 2 | 1 5 48
15 125 6 | 4 157 8 | 9 27 3
458 123589 2348 | 17 13579 37 | 27 6 48[/code]
hrcjcr
 
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Re: Stuck

Postby re'born » Sun Apr 22, 2007 6:41 pm

hrcjcr wrote:I have reduced the puzzle as much as I can using all tools I'm familiar with.
Are my eyes just missing something?
Code:
Code: Select all
.---------------------.---------------------.---------------------.
| 2      6      7     | 8      134    34    | 345    9      15    |
| 3      18     9     | 17     1467   5     | 2468   248    16    |
| 18     4      5     | 2      136    9     | 368    38     7     |
:---------------------+---------------------+---------------------:
| 9      7      1     | 3      2      46    | 4568   48     56    |
| 6      28     28    | 5      47     1     | 347    347    9     |
| 45     35     34    | 9      8      67    | 67     1      2     |
:---------------------+---------------------+---------------------:
| 7      389    348   | 6      39     2     | 1      5      48    |
| 15     125    6     | 4      157    8     | 9      27     3     |
| 458    123589 2348  | 17     13579  37    | 27     6      48    |
'---------------------'---------------------'---------------------'


I don't see a really easy solution, but here is a solution:

[r3c5]-1-[r1c5]=1=[r1c9]-1-[r2c9]-6-[r2c5]=6=[r3c5]

implying r3c5<>1, solving the puzzle.
re'born
 
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Joined: 31 May 2007

Postby udosuk » Sun Apr 22, 2007 7:14 pm

Another approach:
Code: Select all
 *-----------------------------------------------------------------------------*
 | 2       6       7       | 8       134     34      | 345     9       15      |
 | 3      *18      9       | 17      1467    5       |-2468   -248    *16      |
 |-18      4       5       | 2       136     9       |#368    #38      7       |
 |-------------------------+-------------------------+-------------------------|
 | 9       7       1       | 3       2       46      | 4568    48      56      |
 | 6       28      28      | 5       47      1       | 347     347     9       |
 | 45      35      34      | 9       8       67      | 67      1       2       |
 |-------------------------+-------------------------+-------------------------|
 | 7       389     348     | 6       39      2       | 1       5       48      |
 | 15      125     6       | 4       157     8       | 9       27      3       |
 | 458     123589  2348    | 17      13579   37      | 27      6       48      |
 *-----------------------------------------------------------------------------*

ALS-xz rule:
ALS A(*): r2c29={168}
ALS B(#): r3c78={368}
restricted common: x=6
common: z=8

Therefore r2c78 & r3c1 cannot be 8.

(Alternative reasoning:
If r2c78 or r3c1=8, then r2c29=[16] & r3c78=[63], and we'll have two 6s in b3.)

:idea:
udosuk
 
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Postby re'born » Sun Apr 22, 2007 11:41 pm

Here is a more 'elementary' approach. The potential deadly pattern in r79c39[48] implies r9c3<>4,8 (the first uses r6c3 in addition, while second follows from the strong link on 4 in row 7). This reduces the puzzle to an x-wing and 2 xy-wings.
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Postby hrcjcr » Wed Apr 25, 2007 2:27 pm

Thanks for the suggestions.
hrcjcr
 
Posts: 19
Joined: 19 November 2005


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