.com.au puzzle, 9.0 SE

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.com.au puzzle, 9.0 SE

Postby storm_norm » Tue Nov 11, 2008 9:19 pm

I think this was 11/11's puzzle.

Code: Select all
.---------------------.---------------------.---------------------.
| 1379   36     17    | 4      2      35679 | 167    8      1567  |
| 3478   5      78    | 368    1      367   | 9      27     2467  |
| 14789  468    2     | 5689   678    5679  | 1467   157    3     |
:---------------------+---------------------+---------------------:
| 2      9      34    | 7      34     1     | 5      6      8     |
| 48     1      468   | 568    9      456   | 27     3      27    |
| 5      7      368   | 368    368    2     | 14     19     149   |
:---------------------+---------------------+---------------------:
| 6      34     157   | 1239   47     3479  | 8      12579  12579 |
| 137    38     9     | 1236   5      367   | 12367  4      1267  |
| 1347   2      1457  | 1369   3467   8     | 1367   1579   15679 |
'---------------------'---------------------'---------------------'

this is after two coloring moves and two AIC's.
what am I missing? it doesn't look as hard as it seems.
original
Code: Select all
. . .|4 . .|. 8 .
. 5 .|. 1 .|9 . .
. . 2|. . .|. . 3
-----+-----+-----
. . .|7 . .|. 6 8
. 1 .|. 9 .|. 3 .
5 7 .|. . 2|. . .
-----+-----+-----
6 . .|. . .|8 . .
. . 9|. 5 .|. 4 .
. 2 .|. . 8|. . .
storm_norm
 
Posts: 85
Joined: 27 February 2008

Re: .com.au puzzle, 9.0 SE

Postby re'born » Tue Nov 11, 2008 10:19 pm

I don't have an immediate solution, but I do immediately see a nice pair of moves (perhaps these were the AIC's you came up with) starting from just after SSTS.
Code: Select all
.---------------------.---------------------.---------------------.
| 1379   36     17    | 4      2      35679 | 167    8      1567  |
| 3478   5      78    | 368    1      367   | 9      27     2467  |
| 14789  468    2     | 5689   678    5679  | 1467   157    3     |
:---------------------+---------------------+---------------------:
| 2      9     3a4A   | 7      3A4*   1     | 5      6      8     |
| 4b8B   1      468   | 568    9      456   | 27     3      27    |
| 5      7      368   | 368    368    2     | 14     19     149   |
:---------------------+---------------------+---------------------:
| 6      3a4*   157   | 1239  -347    3479  | 8      12579  12579 |
| 137-8  3C8c   9     | 1236   5      367   | 12367  4      1267  |
| 1347&  2      1457& | 1369   3467&  8     | 1367   1579   15679 |
'---------------------'---------------------'---------------------'

There is a (grouped) w-wing. In my grid, it eliminates 3 from r7c5. You seem to have already made this deduction. But, you one needn't stop there. You can transport the ends of the w-wing (which gives the derived strong inference (3)r4c5=r7c2) to get the following:
(8=4)r5c2 - (4=3)r4c3 - (3)r4c5 = (3)r7c2 - (3=8)r8c2, => r8c1<>8.
Using colors, this works out to be c=C-a=A-b=B

In your grid, you've also made this deduction but seem to have missed the resulting hidden single, r8c2=8.
re'born
 
Posts: 551
Joined: 31 May 2007

Postby storm_norm » Wed Nov 12, 2008 5:42 pm

yep, found them. ohhh, how about a UR move over on the {2,7} ?
storm_norm
 
Posts: 85
Joined: 27 February 2008

Postby Glyn » Thu Nov 13, 2008 2:08 am

Well spotted storm_norm the one leading to r8c9<>7.

Code: Select all
(27)URr58c79
||
(7)r7c89,r9c789
||
(2)X-wing@r27c89-(2=7)r5c9
Glyn
 
Posts: 357
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Postby eleven » Thu Nov 13, 2008 5:17 am

But the puzzle is a biest.
Since i could not find something nice, i tried it forcibly. I noticed that a 4 in r5c1 would place all 4's. With a lot of following placements i got a contradiction. But r5c1=8 still did not solve it without haevy moves:(
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Joined: 10 February 2008

Postby daj95376 » Thu Nov 13, 2008 7:24 am

After the (27) UR, there are some eliminations in (6).

Code: Select all
 [r3c456]-6-[r2c46]=6=[r2c9]=4=[r2c1]-4-[r3c2]-6-[r3c456] => [r3c456]<>6
 +-----------------------------------------------------------------------+
 |  1379   36     17     |  4      2      35679  |  167    8      1567   |
 |  3478   5      78     |  368    1      367    |  9      27     2467   |
 |  14789  46     2      |  5689   678    5679   |  1467   157    3      |
 |-----------------------+-----------------------+-----------------------|
 |  2      9      34     |  7      34     1      |  5      6      8      |
 |  48     1      468    |  568    9      456    |  27     3      27     |
 |  5      7      368    |  368    368    2      |  14     19     149    |
 |-----------------------+-----------------------+-----------------------|
 |  6      34     157    |  1239   47     3479   |  8      12579  12579  |
 |  137    8      9      |  1236   5      367    |  12367  4      126    |
 |  1347   2      1457   |  1369   3467   8      |  1367   1579   15679  |
 +-----------------------------------------------------------------------+

Code: Select all
         [XY-Chain]             [r3c1]<>8
 r2  b1  Locked Candidate 1     [r2c4]<>8
 +-----------------------------------------------------------------------+
 |  1379   36     17     |  4      2      35679  |  167    8      1567   |
 |  3478   5      78     |  36     1      367    |  9      27     2467   |
 |  1479   46     2      |  589    78     579    |  1467   157    3      |
 |-----------------------+-----------------------+-----------------------|
 |  2      9      34     |  7      34     1      |  5      6      8      |
 |  48     1      468    |  568    9      456    |  27     3      27     |
 |  5      7      368    |  368    368    2      |  14     19     149    |
 |-----------------------+-----------------------+-----------------------|
 |  6      34     157    |  1239   47     3479   |  8      12579  12579  |
 |  137    8      9      |  1236   5      367    |  12367  4      126    |
 |  1347   2      1457   |  1369   3467   8      |  1367   1579   15679  |
 +-----------------------------------------------------------------------+
 # 113 eliminations remain
daj95376
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