Pointers please...

Post the puzzle or solving technique that's causing you trouble and someone will help

Pointers please...

Postby Josh » Tue Feb 07, 2006 4:24 pm

Not sure if this is tricky or if I'm missing something obvious (again!) but any pointers you could give me towards techniques that might help me progress would be appreciated...

The start:

Code: Select all
..6|.83|...
.9.|.6.|...
.21|4..|6..
---+---+---
18.|...|.7.
..2|.7.|5..
.6.|...|.34
---+---+---
..3|..5|48.
...|.3.|.9.
...|82.|7..



Where I've got to:

Code: Select all
..6|.83|...
.9.|.6.|3..
321|497|658
---+---+---
185|34.|.7.
432|.78|5..
.6.|.5.|834
---+---+---
.73|.15|48.
...|73.|.95
...|82.|7.3


My candidates:

Code: Select all
57  45  6   | 125 8 3   | 19 24 179
578 9   478 | 125 6 12  | 3  24 17
3   2   1   | 4   9 7   | 6  5  8
------------+-----------+----------
1   8   5   | 3   4 69  | 29 7  269
4   6   2   | 69  7 8   | 5  16 169
79  6   79  | 12  5 12  | 8  3  4
------------+-----------+----------
269 7   3   | 69  1 5   | 4  8  26
268 14  48  | 7   3 46  | 12 9  5
569 145 49  | 8   2 469 | 7  16 3



TIA,

Cheers!

Josh.
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Posts: 6
Joined: 02 February 2006

Postby Carcul » Tue Feb 07, 2006 4:36 pm

Hi Josh.

You have a Turbot Fish on cells r7c9/r7c4/r5c4/r4c6/r4c9 that eliminates the "6" from r7c9, solving the puzzle.

Regards, Carcul
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Postby tarek » Tue Feb 07, 2006 4:40 pm

Code: Select all
*-----------------------------------------------*
| 57   45   6   | 125  8    3   | 19   24   179 |
| 578  9    478 | 125  6    12  | 3    24   17  |
| 3    2    1   | 4    9    7   | 6    5    8   |
|---------------+---------------+---------------|
| 1    8    5   | 3    4    69  | 29   7    269 |
| 4    3    2   |*69   7    8   | 5   *16   169 |
| 79   6    79  | 12   5    12  | 8    3    4   |
|---------------+---------------+---------------|
| 269  7    3   |*69   1    5   | 4   *8   -26  |
| 268  14   48  | 7    3    46  | 12   9    5   |
| 569  145  49  | 8    2    469 | 7   #16   3   |
*-----------------------------------------------*
Eliminating 6 From r7c9 (Almost Finned XWing in Columns 4 & 8)


Solves the puzzle
User avatar
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Postby Josh » Tue Feb 07, 2006 5:15 pm

Cool!

That's a new one - I shall mostly be reading up on Turbot Fishes...

Cheers!

Josh.
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Joined: 02 February 2006

Postby CathyW » Tue Feb 07, 2006 5:20 pm

The "easy" way is to use the uniqueness test on r2c4,6 and r6c4,6 which indicates that r2c4 must be 5 otherwise you'd have at least 2 solutions to the puzzle. The rest solves with singles.:)
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Postby Carcul » Tue Feb 07, 2006 6:50 pm

Hi CathyW.

CathyW wrote:The "easy" way is to use the uniqueness test on r2c4,6 and r6c4,6 which indicates that r2c4 must be 5 otherwise you'd have at least 2 solutions to the puzzle. The rest solves with singles.


I have also spoted the unique rectangle, but after using uniqueness to make r2c4=5 the rest does not solve with singles. Using directly the Turbot Fish (or other advanced technique) does lead to only singles.

Regards, Carcul
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Postby TKiel » Tue Feb 07, 2006 8:13 pm

Also, coloring on 6's using two conjugate chains reveals r9c8=6.

Interesting: one puzzle-- 4 people--four different solution methods.

Tracy
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Postby CathyW » Tue Feb 07, 2006 10:29 pm

Carcul wrote:I have also spoted the unique rectangle, but after using uniqueness to make r2c4=5 the rest does not solve with singles. Using directly the Turbot Fish (or other advanced technique) does lead to only singles.


Apologies - a few more eliminations were required before getting to the point of singles only. But after the the uniqueness making r2c4=5, the eliminations were fairly straightforward xy-chains.
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Posts: 316
Joined: 20 June 2005

Postby QBasicMac » Tue Feb 07, 2006 10:51 pm

TKiel wrote:Interesting: one puzzle-- 4 people--four different solution methods.


And a fifth way (heh)

After reaching this
Code: Select all
+---------------+-------------+-------------+
| 57   45   6   | 125  8  3   | 19  24  179 |
| 578  9    478 | 125  6  12  | 3   24  17  |
| 3    2    1   | 4    9  7   | 6   5   8   |
+---------------+-------------+-------------+
| 1    8    5   | 3    4  69  | 29  7   269 |
| 4    3    2   | 69   7  8   | 5   16  169 |
| 79   6    79  | 12   5  12  | 8   3   4   |
+---------------+-------------+-------------+
| 269  7    3   | 69   1  5   | 4   8   26  |
| 268  14   48  | 7    3  46  | 12  9   5   |
| 569  145  49  | 8    2  469 | 7   16  3   |
+---------------+-------------+-------------+


note that r5c8 is 1 or 6.

Make copy of puzzle and place 1 in one copy and 6 in the other.

The copy with 6 fails.

The copy with 1 solves.

Hence the puzzle is valid and we have found the only solution.

Mac
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