Interesting puzzle

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Interesting puzzle

Postby Eioru » Thu Sep 28, 2006 3:47 pm

Code: Select all
...1..2..
.........
..3..4..5
6..2..7..
.7.....3.
..8..5..9
1..7..6..
.5.....1.
..9..3..4


When you analysis it, the result is crazy....many"2"
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interesting puzzle

Postby gurth » Mon Oct 02, 2006 8:11 am

re: interesting puzzle

Eioru,

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


Nice puzzle! It foxed me. I found a solution, but not the crazy "2" !

Solution:
(1) SSTS (tricks using the Simple Sudoku Technique Set).

(2) ? 3a9, 3b4, 3h7, 9g8, 5g5 ?? leave no place for 5 in box 2.
So -3a9, 3a5, SSTS.

(3) ? -5e3, singles, ??(=contradiction found) 5e3, SSTS.

(4) ? -1c7, singles, ?? 1c7, singles to END.

Trivalue cell c7 turns out to be a good garnet, needing only singles for contradiction of -1c7 and verification of 1c7 to end.

It looks as if such garnets will frequently be met.
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Re: interesting puzzle

Postby tarek » Mon Oct 02, 2006 8:15 am

gurth wrote:Trivalue cell c7 turns out to be a good garnet

Could you provide a link to the precious stone guidebook gurth ???

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Postby daj95376 » Mon Oct 02, 2006 4:15 pm

After SSTS,

Code: Select all
 *--------------------------------------------------------------------*
 | 4589   4689   4567   | 1      35689  6789   | 2      4689   3678   |
 | 24589  24689  12467  | 35689  25689  26789  | 3489   4689   1678   |
 | 2789   12689  3      | 689    2689   4      | 189    6789   5      |
 |----------------------+----------------------+----------------------|
 | 6      349    145    | 2      3489   189    | 7      458    18     |
 | 2459   7      1245   | 4689   4689   1689   | 458    3      26     |
 | 234    124    8      | 346    7      5      | 14     26     9      |
 |----------------------+----------------------+----------------------|
 | 1      2348   24     | 7      24589  289    | 6      2589   238    |
 | 2348   5      2467   | 4689   24689  2689   | 389    1      278    |
 | 278    268    9      | 568    1      3      | 58     2578   4      |
 *--------------------------------------------------------------------*

At this point, setting [r2c4]=6 easily leads to a contradiction in [r1/b13] using just 6s. However, deducing [r2c4]<>6 isn't obvious using just 6s. Here's what I derived. Is there a simpler way, using just 6s, to get this elimination?

Code: Select all
[r9c4]=6                                                    => [r2c4]<>6
[r9c2]=6 => { XY-Wing [r12c39] | ( [r5c9]=6 => [r6c4]=6 ) } => [r2c4]<>6
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Postby ronk » Mon Oct 02, 2006 5:31 pm

daj95376 wrote:Here's what I derived. Is there a simpler way, using just 6s, to get this elimination?

Code: Select all
[r9c4]=6                                                    => [r2c4]<>6
[r9c2]=6 => { XY-Wing [r12c39] | ( [r5c9]=6 => [r6c4]=6 ) } => [r2c4]<>6

I don't know about simpler, but here's a slightly different view ...
Code: Select all

  .  6 *6  |  .  6  6  |  .  6 *6 
  .  6 *6  | -6  6  6  |  .  6 *6 
  .  6  .  |  6  6  .  |  .  6  . 
 ----------+-----------+----------
  .  .  .  |  .  .  .  |  .  .  . 
  .  .  .  |  6  6  6  |  .  . #6 
  .  .  .  |  6  .  .  |  .  6  . 
 ----------+-----------+----------
  .  .  .  |  .  .  .  |  .  .  . 
  .  . #6  |  6  6  6  |  .  .  . 
  .  6  .  |  6  .  .  |  .  .  . 

If both r5c9<>6 and r8c3<>6, then your r12c39 x-wing implies r2c4<>6
If r5c9=6, the empty rectangle in b5 implies r2c4<>6
If r8c3=6, the empty rectangle in b8 implies r2c4<>6
For all three possibilities, r2c4<>6

I won't try to write an expression.:)
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Postby RW » Mon Oct 02, 2006 5:49 pm

I'm not a fisherman, but isn't this a finned Jellyfish?

Code: Select all
  .  6 *6  |  . *6 *6  |  .  6 *6 
  .  6 *6  | -6 *6 *6  |  .  6 *6 
  .  6  .  |  6 #6  .  |  .  6  . 
 ----------+-----------+----------
  .  .  .  |  .  .  .  |  .  .  . 
  .  .  .  |  6 *6 *6  |  .  . *6 
  .  .  .  |  6  .  .  |  .  6  . 
 ----------+-----------+----------
  .  .  .  |  .  .  .  |  .  .  . 
  .  . *6  |  6 *6 *6  |  .  .  . 
  .  6  .  |  6  .  .  |  .  .  . 


and it's finned Swordfish counterpart:

Code: Select all
  .  6  6  |  .  6  6  |  .  6  6 
  .  6  6  | -6  6  6  |  .  6  6 
  . *6  .  | *6 #6  .  |  . *6  . 
 ----------+-----------+----------
  .  .  .  |  .  .  .  |  .  .  . 
  .  .  .  |  6  6  6  |  .  .  6 
  .  .  .  | *6  .  .  |  . *6  . 
 ----------+-----------+----------
  .  .  .  |  .  .  .  |  .  .  . 
  .  .  6  |  6  6  6  |  .  .  . 
  . *6  .  | *6  .  .  |  .  .  . 


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Postby ronk » Mon Oct 02, 2006 5:57 pm

RW, you're now a fisherman!:D
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Postby tarek » Mon Oct 02, 2006 9:33 pm

RW wrote:and it's finned Swordfish counterpart:

Code: Select all
  .  6  6  |  .  6  6  |  .  6  6 
  .  6  6  | -6  6  6  |  .  6  6 
  . *6  .  | *6 #6  .  |  . *6  . 
 ----------+-----------+----------
  .  .  .  |  .  .  .  |  .  .  . 
  .  .  .  |  6  6  6  |  .  .  6 
  .  .  .  | *6  .  .  |  . *6  . 
 ----------+-----------+----------
  .  .  .  |  .  .  .  |  .  .  . 
  .  .  6  |  6  6  6  |  .  .  . 
  . *6  .  | *6  .  .  |  .  .  . 

Nice. I guess this is a bit tricky to spot without pencilmarks:D

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Postby daj95376 » Mon Oct 02, 2006 11:02 pm

Thanks ronk and RW !!! Too bad the remainder of the solution isn't this interesting.
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Precioius Stones Guidebook

Postby gurth » Wed Oct 04, 2006 11:26 am

re: Precious Stones Guidebook

Tarek,
I have opened a topic "PEARLS, RUBIES, GARNETS, EMERALDS, ETC." giving definitions of these terms, for which I am responsible.

DIAMONDS are not my province, but rather udosuk's I think. Refer to him regarding diamonds, please.

udosuk,
and anyone else, please feel free to use the new topic to add your own jewelry definitions. Then everything will stay together for ready reference.

For that matter, why confine yourself to gemstones? Anything goes! Maybe flowers... Or else proper names such as "Mona Lisa" ?
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Postby RW » Wed Oct 04, 2006 2:23 pm

tarek wrote:Nice. I guess this is a bit tricky to spot without pencilmarks:D


It's tricky to see it's a finned swordfish, but as a Nishio elimination it's not very hard to find (assuming r2c4=6, you can't place the rest of the 6s). But I must admit that in this case I never even looked at the puzzle, only ronks diagram of 6s.

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