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competition #1020 plus

 
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Sun Apr 27, 2008 7:52 am    Post subject: competition #1020 plus Reply with quote

I hope the bonus puzzle provides a good challenge because the other three puzzles are "one-steppers."

competition # 1020

Code:
. . .|. . .|. . .
. . .|4 6 .|3 . .
8 . .|. . .|. 7 1
-----+-----+-----
. . 7|3 . .|. 1 9
. . 8|. . .|7 . .
. 6 .|. . 9|4 3 .
-----+-----+-----
3 5 .|. . .|. 2 4
. . 6|. 3 1|. . .
. . .|. . .|. . .

-------

competition # 1022

Code:
. . .|9 6 .|3 . .
. 6 .|. . .|. 4 .
. 1 8|. 7 .|9 . 6
-----+-----+-----
. . 1|. . 7|. . .
. 3 .|. 4 .|. 8 .
. . .|5 . .|2 . .
-----+-----+-----
6 . 5|. 8 .|4 9 .
. 7 .|. . .|. 3 .
. . 3|. 2 6|. . .

-------

daily telegraph 4/25

Code:
9 2 .|. . .|. 7 4
. 6 .|5 . 3|2 . .
. . .|9 . .|. . .
-----+-----+-----
2 . .|. . .|. . .
. . 8|. 4 .|. . .
. . .|3 . .|. . 5
-----+-----+-----
7 . .|. . 6|. . .
. . 1|2 . 7|. 3 .
4 5 .|. . .|. 8 6

-------

bonus

Code:
8 . .|. 5 .|3 . .
. . 6|8 . .|5 2 .
. . 7|. . 4|. 9 .
-----+-----+-----
. . .|. 3 1|. . .
. 9 .|. . .|. 1 .
. . .|5 2 .|. . .
-----+-----+-----
. 1 .|2 . .|7 . .
. 6 5|. . 8|4 . .
. . 3|. 4 .|. . 2
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Asellus



Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA

PostPosted: Mon Apr 28, 2008 12:40 am    Post subject: Reply with quote

I used 10 steps on that bonus puzzle. Don't know if they were all necessary.

[1] Finned X-Wing
[2] Finned Swordfish (or Color Wing, or Kite with transported pincer)
[3] X-Wing
[4] An interesting 48 UR involving a grouped strong link
[5] XY Chain
[6] XY Chain
[7] X-Wing
[8] XY Chain
[9] X-Wing
[10] Skyscraper
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Victor



Joined: 29 Sep 2005
Posts: 207
Location: NI

PostPosted: Mon Apr 28, 2008 7:35 am    Post subject: Reply with quote

Quote:
Don't know if they were all necessary.
Accurate as ever!
Code:

+-------------+-------------+----------------+
| 8    4  19  | 169  5   2  | 3    67   167  |
| 19   3  6   | 8    179 79 | 5    2    4    |
| 5    2  7   | 3    16  4  | 168  9    168  |
+-------------+-------------+----------------+
| 467  5  248 | 4679 3   1  | 2689 4678 6789 |
| 3    9  24  | 47   8   67 | 26   1    5    |
| 1467 78 148 | 5    2   69 | 689  4678 3    |
+-------------+-------------+----------------+
| 49   1  489 | 2    69  3  | 7    5    689  |
| 2    6  5   | 179  179 8  | 4    3    19   |
| 79   78 3   | 169  4   5  | 1689 68   2    |
+-------------+-------------+----------------+

Simple colouring, or an ER, kills the 6 in r1c9. That exposes an XY-chain 9r1c3 = 9r9c1. When the dust has settled, another ER / colouring kills the 1 in r1c9, and that about does it.
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Asellus



Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA

PostPosted: Mon Apr 28, 2008 8:04 am    Post subject: Reply with quote

Victor,

Glad to see you found a shorter route! Your first step is probably the same as mine (I didn't keep detailed notes this time) since it can also be seen as a Finned X-Wing in r37. I generally don't look for chains (XY or otherwise) until I've been stymied trying to find various Fish, the usual Wings, and the more straightforward DPs.

In any case, it was an agreeable puzzle: one that succumbs to moderately advanced techniques, but not without a bit of work.
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ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Mon Apr 28, 2008 8:07 am    Post subject: Reply with quote

Asellus wrote:
[4] An interesting 48 UR involving a grouped strong link
I noticed that, it eliminated 4 from r6c3:
Code:
 *------------------------------------------------*
 | 8    4   19   | 169  5    2   | 3    67   17   |
 | 19   3   6    | 8    179  79  | 5    2    4    |
 | 5    2   7    | 3    16   4   | 18   9    168  |
 |---------------+---------------+----------------|
 | 6    5  #248  | 49   3    1   |*289 #478 *789  |
 | 3    9   24   | 47   8    67  | 26   1    5    |
 | 147  78 #148  | 5    2    69  | 69  #48   3    |
 |---------------+---------------+----------------|
 | 49   1   489  | 2    69   3   | 7    5    689  |
 | 2    6   5    | 179  179  8   | 4    3    19   |
 | 79   78  3    | 169  4    5   | 189  68   2    |
 *------------------------------------------------*

r6c3=4 => r6c8=8 => (r4c8=4 and r4c3=8)

This opened an xy-chain, r6c3=1 or
r6c3=8 => r6c2=7 => r9c2=8 => r9c8=6 => r1c8=7 => r1c9=1
==> r1c3<>1

Code:
 *------------------------------------------*
 | 8   4   9    | 16  5   2   | 3   67  17  |
 | 1   3   6    | 8   79  79  | 5   2   4   |
 | 5   2   7    | 3   16  4   | 8   9   16  |
 |--------------+-------------+-------------|
 | 6   5   248  |#49  3   1   | 29  47  78  |
 | 3   9  *24   |*47  8   67  | 26  1   5   |
 |-47  78  1    | 5   2   69  | 69  48  3   |
 |--------------+-------------+-------------|
 |#49  1  -48   | 2   69  3   | 7   5   68  |
 | 2   6   5    | 17  17  8   | 4   3   9   |
 |@79  78  3    |@69  4   5   | 1   68  2   |
 *------------------------------------------*

A w-wing with pincer coloring then solves it. Strong link for 9 in row 9, r4c4=4 transported to r5c3=4.
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Asellus



Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA

PostPosted: Mon Apr 28, 2008 7:45 pm    Post subject: Reply with quote

ravel,

Glad you saw it, too; I knew you'd like it. I actually saw it the other way around, focussing on the grouped strong link on <8>s in b4. If r4c8 is <4>, r6c8 and r4c3 are <8> and r6c3 cannot be <4>. But, if r4c8 is not <4>, r6c8 is <4>.
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