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Free Press Jan 22, 2010
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keith



Joined: 19 Sep 2005
Posts: 3150
Location: near Detroit, Michigan, USA

PostPosted: Fri Jan 22, 2010 6:03 pm    Post subject: Free Press Jan 22, 2010 Reply with quote

Not yet completed, but it seems to be in my "unreasonable" category.
Code:
Puzzle: FP012210
+-------+-------+-------+
| . 2 . | . 9 . | . . 1 |
| . 5 . | . 6 . | . . . |
| . . 4 | . . 3 | . . 8 |
+-------+-------+-------+
| . . . | . . . | . 8 7 |
| 8 . . | . . . | . . . |
| 6 4 7 | . . . | . . 9 |
+-------+-------+-------+
| 7 . . | 5 . . | 9 . . |
| . . . | . 7 . | . 6 . |
| . 6 . | . 4 . | . 2 . |
+-------+-------+-------+
Keith
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Earl



Joined: 30 May 2007
Posts: 546
Location: St Louis MO

PostPosted: Fri Jan 22, 2010 6:24 pm    Post subject: Free Press Reply with quote

A one-stepper.

A Solution: Coloring in 5


Earl
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cgordon



Joined: 04 May 2007
Posts: 769
Location: ontario, canada

PostPosted: Fri Jan 22, 2010 9:10 pm    Post subject: Reply with quote

Earl: I can't see the colouring on 5. These are my 5's after finding the quad in box 5.
Cheers, Craig

Code:
            
+-------+-------+-------+   
| . . . | . . 5 | 5 5 . |   
| . . . | . . . | . . . |   
| . . . | . 5 . | 5 5 . |   
+-------+-------+-------+   
| 5 . 5 | . 5 . | 5 . . |   
| . . 5 | . 5 . | 5 5 . |   
| . . . | . . 5 | 5 5 . |   
+-------+-------+-------+   
| . . . | . . . | . . . |   
| 5 . 5 | . . . | . . 5 |   
| 5 . 5 | . . . | . . 5 |
+-------+-------+-------+
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keith



Joined: 19 Sep 2005
Posts: 3150
Location: near Detroit, Michigan, USA

PostPosted: Fri Jan 22, 2010 9:30 pm    Post subject: Reply with quote

Craig,

R4C1 can be solved as 2. Then, there is a kite on 5 that solves R6C8 as 3.

Keith
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Marty R.



Joined: 12 Feb 2006
Posts: 5123
Location: Rochester, NY, USA

PostPosted: Fri Jan 22, 2010 11:05 pm    Post subject: Reply with quote

Quote:
Then, there is a kite on 5 that solves R6C8 as 3.

Obviously, 5 was the key. I solved r6c8=3, except I used an ER on 5 to do that. After that it depended only on finding a quad in c6.
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Earl



Joined: 30 May 2007
Posts: 546
Location: St Louis MO

PostPosted: Sat Jan 23, 2010 1:40 am    Post subject: Free Reply with quote

Craig,

The coloring in 5 consists of the strong pairs in R3-C6 with pincers R3C8, R6C6 eliminating 5 in R6C8, solving the puzzle. Some might call this a kite.

Earl
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keith



Joined: 19 Sep 2005
Posts: 3150
Location: near Detroit, Michigan, USA

PostPosted: Sat Jan 23, 2010 2:37 am    Post subject: Reply with quote

Just to be sure we're on the same page. After basics, including a quad (hidden triple 479) in B5:
Code:
+-------------------+-------------------+-------------------+
| 3     2     6     | 478   9     4578  | 45    457   1     |
| 19    5     8     | 147   6     147   | 34    3479  2     |
| 19    7     4     | 12    125   3     | 6     59    8     |
+-------------------+-------------------+-------------------+
| 2     139   1359  | 6     135   49    | 1345  8     7     |
| 8     139   1359  | 479   1235  479   | 12345 345   6     |
| 6     4     7     | 123   8     125   | 1235  35    9     |
+-------------------+-------------------+-------------------+
| 7     8     23    | 5     23    6     | 9     1     4     |
| 4     139   1239  | 1239  7     129   | 8     6     5     |
| 5     6     19    | 189   4     189   | 7     2     3     |
+-------------------+-------------------+-------------------+
Keith
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Marty R.



Joined: 12 Feb 2006
Posts: 5123
Location: Rochester, NY, USA

PostPosted: Sat Jan 23, 2010 4:46 am    Post subject: Re: Free Reply with quote

Earl wrote:
Craig,

The coloring in 5 consists of the strong pairs in R3-C6 with pincers R3C8, R6C6 eliminating 5 in R6C8, solving the puzzle. Some might call this a kite.

Earl

Earl,

To me, what you have is a simple coloring chain on 5, going from r3c8-->r3c5-->r1c6-->r6c6. My understanding of a Kite is two strong links emanating from a box with at least three of the candidates present and the paths of the two strong links being at right angles. My comments are based on Keith's grid, just above my post.
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Sat Jan 23, 2010 5:10 am    Post subject: Reply with quote

Code:
 candidate <5> from Keith's grid with Earl's r3c6 cells marked:
 2-String Kite => r6c8<>5
 +-----------------------------------+
 |  .  .  .  |  .  . *5  |  5  5  .  |
 |  .  5  .  |  .  .  .  |  .  .  .  |
 |  .  .  .  |  . *5  .  |  . *5  .  |
 |-----------+-----------+-----------|
 |  .  .  5  |  .  5  .  |  5  .  .  |
 |  .  .  5  |  .  5  .  |  5  5  .  |
 |  .  .  .  |  .  . *5  |  5 -5  .  |
 |-----------+-----------+-----------|
 |  .  .  .  |  5  .  .  |  .  .  .  |
 |  .  .  .  |  .  .  .  |  .  .  5  |
 |  5  .  .  |  .  .  .  |  .  .  .  |
 +-----------------------------------+
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cgordon



Joined: 04 May 2007
Posts: 769
Location: ontario, canada

PostPosted: Sat Jan 23, 2010 3:41 pm    Post subject: Reply with quote

Quote:
To me, what you have is a simple coloring chain on 5, going from r3c8-->r3c5-->r1c6-->r6c6.

That makes perfect sense. However - where I usually have problems is in the simple basics - can't see the woods for the trees, or whatever. I still have a 5 in R3C7. How did you get the 6???
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keith



Joined: 19 Sep 2005
Posts: 3150
Location: near Detroit, Michigan, USA

PostPosted: Sat Jan 23, 2010 4:09 pm    Post subject: Reply with quote

cgordon wrote:
I still have a 5 in R3C7. How did you get the 6???

In the starting grid:

R3C7 is the only square in row 3 that can be <6>.

Keith
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keith



Joined: 19 Sep 2005
Posts: 3150
Location: near Detroit, Michigan, USA

PostPosted: Sat Jan 23, 2010 4:25 pm    Post subject: Reply with quote

Let's split a few hairs:
Code:
 +-----------------------------------+
 |  .  .  .  |  .  . *5  |  5  5  .  |
 |  .  5  .  |  .  .  .  |  .  .  .  |
 |  .  .  .  |  . *5  .  |  . *5p .  |
 |-----------+-----------+-----------|
 |  .  .  5  |  .  5  .  |  5  .  .  |
 |  .  .  5  |  .  5  .  |  5  5  .  |
 |  .  .  .  |  .  . *5p |  5 -5  .  |
 |-----------+-----------+-----------|
 |  .  .  .  |  5  .  .  |  .  .  .  |
 |  .  .  .  |  .  .  .  |  .  .  5  |
 |  5  .  .  |  .  .  .  |  .  .  .  |
 +-----------------------------------+

This is simple coloring. One of the pincer cells p is 5, the other is not.

Code:
 +-----------------------------------+
 |  .  .  .  |  .  5 @5  |  5  5  .  |
 |  .  5  .  |  .  .  .  |  .  .  .  |
 |  .  .  .  |  . *5  .  |  . *5p .  |
 |-----------+-----------+-----------|
 |  .  .  5  |  .  5  .  |  5  .  .  |
 |  .  .  5  |  .  5  .  |  5  5  .  |
 |  .  .  .  |  .  . @5p |  5 -5  .  |
 |-----------+-----------+-----------|
 |  .  .  .  |  5  .  .  |  .  .  .  |
 |  .  .  .  |  .  .  .  |  .  .  5  |
 |  5  .  .  |  .  .  .  |  .  .  .  |
 +-----------------------------------+

Note the pattern of 5 in B2.

This is a kite / turbot / skyscraper. One OR BOTH of the pincer cells p is 5.

Keith
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cgordon



Joined: 04 May 2007
Posts: 769
Location: ontario, canada

PostPosted: Sat Jan 23, 2010 4:54 pm    Post subject: Reply with quote

Quote:
R3C7 is the only square in row 3 that can be <6>.

I've got four <6>s - but don't worry about it - clearly I erred somewhere.
Code:
            
+-------+-------+-------+   
| . . 6 | . . . | 6 . . |   
| . . . | . . . | . . . |   
| . . 6 | . . . | 6 . . |   
+-------+-------+-------+   
| . . . | . . . | . . . |   
| . . . | . . . | . . . |   
| . . . | . . . | . . . |   
+-------+-------+-------+   
| . . . | . . . | . . . |   
| . . . | . . . | . . . |   
| . . . | . . . | . . . |
+-------+-------+-------+
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keith



Joined: 19 Sep 2005
Posts: 3150
Location: near Detroit, Michigan, USA

PostPosted: Sat Jan 23, 2010 6:06 pm    Post subject: Reply with quote

R3C3 is 4. Did you transcribe the puzzle incorrectly?

Starting grid, with pencil marks:
Code:
+-------------------------+-------------------------+-------------------------+
| 3       2       368     | 478     9       4578    | 34567   3457    1       |
| 139     5       1389    | 12478   6       12478   | 2347    3479    234     |
| 19      179     4       | 127     125     3       | 2567    579     8       |
+-------------------------+-------------------------+-------------------------+
| 12359   139     12359   | 123469  1235    124569  | 123456  8       7       |
| 8       139     12359   | 1234679 1235    1245679 | 123456  1345    23456   |
| 6       4       7       | 1238    12358   1258    | 1235    135     9       |
+-------------------------+-------------------------+-------------------------+
| 7       138     1238    | 5       1238    1268    | 9       134     34      |
| 123459  1389    123589  | 12389   7       1289    | 13458   6       345     |
| 1359    6       13589   | 1389    4       189     | 13578   2       35      |
+-------------------------+-------------------------+-------------------------+

Keith
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cgordon



Joined: 04 May 2007
Posts: 769
Location: ontario, canada

PostPosted: Sat Jan 23, 2010 6:49 pm    Post subject: Reply with quote

Quote:
R3C3 is 4. Did you transcribe the puzzle incorrectly?

Awfully sorry - I did. Embarassed
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Sat Jan 23, 2010 6:53 pm    Post subject: Reply with quote

Let's split a few more hairs. Sashimi X-Wing, finned X-Wing, Skyscraper, 2-String Kite, turbot fish, and Empty Rectangle are all simple coloring ... if ... you allow coloring on grouped strong links.
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keith



Joined: 19 Sep 2005
Posts: 3150
Location: near Detroit, Michigan, USA

PostPosted: Sat Jan 23, 2010 7:11 pm    Post subject: Reply with quote

daj95376 wrote:
Let's split a few more hairs. Sashimi X-Wing, finned X-Wing, Skyscraper, 2-String Kite, turbot fish, and Empty Rectangle are all simple coloring ... if ... you allow coloring on grouped strong links.
Really? I'll have to think about it.

Does this include both ER cases, where the hinge pin cell does / does not contain the candidate?

The reason I hesitate is because I don't think grouped coloring is bi-directional. For example in simple coloring I might be able to say: If cell A is true then cell B is false.

The reverse statement is valid: ... and then if B is false A is true.

In grouped coloring I am not sure the reverse statement can, in general, be made. Even so, does that matter in the patterns you have named?

Keith
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Sat Jan 23, 2010 7:20 pm    Post subject: Reply with quote

keith wrote:
daj95376 wrote:
Let's split a few more hairs. Sashimi X-Wing, finned X-Wing, Skyscraper, 2-String Kite, turbot fish, and Empty Rectangle are all simple coloring ... if ... you allow coloring on grouped strong links.
Really? I'll have to think about it.

Does this include both ER cases, where the hinge pin cell does / does not contain the candidate?

The reason I hesitate is because I don't think grouped coloring is bi-directional. For example in simple coloring I might be able to say: If cell A is true then cell B is false.

The reverse statement is valid: ... and then if B is false A is true.

In grouped coloring I am not sure the reverse statement can, in general, be made. Even so, does that matter in the patterns you have named?

Yes on ERs. However, there are other techniques besides the Empty Rectangle -- like the 2-String Kite -- when the hinge cell must be empty.

I went through a very painful discussion on ERIs in the Players' Forums awhile back. They introduced me to a concept on bi-directional links that still smarts (and I don't completely accept). I'll show how it works ... if you realllllly insist.

Grouped coloring doesn't have to be bidirectional. All that matters is the color of the cells at the endpoints of the chain ... and any cell that sees them. Grouped coloring has been around for a long time in the form of X-Colors and other coloring techniques based on grouped coloring.

Regards, Danny
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keith



Joined: 19 Sep 2005
Posts: 3150
Location: near Detroit, Michigan, USA

PostPosted: Sat Jan 23, 2010 9:06 pm    Post subject: Reply with quote

Quote:
I went through a very painful discussion on ERIs in the Players' Forums

I stay away from that forum. For some of the participants, the size of their egos is far larger than the substance of their discussion.

Directionality of a link is my own idea which I have not discussed with anyone else. I have no idea if they mean the same thing that I do.

Since I am not a programmer, and I argue the logic each time, the precise names, rules and formulas do not matter to me. The example of directionality I like is that of the half M-wing.

In the regular M-wing you start with two bivalue cells that have the same candidates.
A ..... B
XY .... XY

Suppose you can prove they have the same value: If either one is X, so is the other. They are a complementary pair. Then, you can build the M-wing by adding a strong link in Y at either end.

The half-wing occurs when you can only say that if A is X then B is X. (You cannot say that if B is X, A is X.) Then, you can only add the strong link in Y at B.

Keith
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cgordon



Joined: 04 May 2007
Posts: 769
Location: ontario, canada

PostPosted: Sat Jan 23, 2010 11:16 pm    Post subject: Reply with quote

Hey: Even though I can't even copy a Sudoku correctly - at least my screw-up generated a discussion. And at least I am the only one who can spell colouring.
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