February 23, 2017

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February 23, 2017

Postby ArkieTech » Thu Feb 23, 2017 12:28 am

Code: Select all
 *-----------*
 |...|..2|564|
 |...|.31|..8|
 |.9.|...|..1|
 |---+---+---|
 |2.6|9..|...|
 |...|1.5|...|
 |...|..6|8.7|
 |---+---+---|
 |6..|...|.2.|
 |3..|51.|...|
 |719|2..|...|
 *-----------*


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Re: February 23, 2017

Postby Leren » Thu Feb 23, 2017 12:45 am

Code: Select all
*--------------------------------------------------------------*
| 18    378   1378   | 78    9     2      | 5     6     4      |
| 5     6     2      | 4     3     1      | 9     7     8      |
| 48    9     478    | 6     5     78     | 2     3     1      |
|--------------------+--------------------+--------------------|
| 2    b4578D 6      | 9    b478  b478    |b34B   1     35C    |
| 489   3478  3478   | 1     478   5      | 6     49    2      |
| 149  c45E   145    | 3     2     6      | 8     459   7      |
|--------------------+--------------------+--------------------|
| 6    c458E  458    | 7-8   47-8  3      | 1     2     9      |
| 3     2     48     | 5     1     9      | 7     48    6      |
| 7     1     9      | 2     6    a48A    |a34A   458   35     |
*--------------------------------------------------------------*

ALS XY Wing: (8=3) r9c67 - (3=5) r4c2567 - (5=8) r67c2 => - 8 r7c45; stte

or (8=3) r9c67 - r4c6 = (3-5) r4c9 = r4c2 - (5=8) r67c2 => - 8 r7c45; stte

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Last edited by Leren on Thu Feb 23, 2017 1:22 am, edited 1 time in total.
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Re: February 23, 2017

Postby SteveG48 » Thu Feb 23, 2017 1:04 am

Code: Select all
 *-----------------------------------------------------------*
 | 18    378   1378  | 78    9     2     | 5     6     4     |
 | 5     6     2     | 4     3     1     | 9     7     8     |
 | 48    9     478   | 6     5     78    | 2     3     1     |
 *-------------------+-------------------+-------------------|
 | 2     4578  6     | 9     478   478   | 34    1    b35    |
 | 489   3478  3478  | 1     478   5     | 6     49    2     |
 | 149 de45   d145   | 3     2     6     | 8    c459   7     |
 *-------------------+-------------------+-------------------|
 | 6    f458  e458   |g78   g478   3     | 1     2     9     |
 | 3     2     48    | 5     1     9     | 7     48    6     |
 | 7     1     9     | 2     6     8-4   |a34    458  a35    |
 *-----------------------------------------------------------*


(4=35)r9c79 - 5r4c9 = r6c8 - 5r6c23 = (4r6c2)&(5r7c3) - (4|5=8)r7c2 - (8=47)r7c45 => -4 r9c6 ; stte
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Re: February 23, 2017

Postby bat999 » Thu Feb 23, 2017 11:45 am

Code: Select all
.-------------------.-----------------.---------------.
| 18    378    1378 |  78   9     2   |  5   6     4  |
| 5     6      2    |  4    3     1   |  9   7     8  |
| 48    9      478  |  6    5     78  |  2   3     1  |
:-------------------+-----------------+---------------:
| 2     478-5  6    |  9   c478  d478 | d34  1    d35 |
| 489   3478   3478 |  1   c478   5   |  6   49    2  |
| 149  a45     145  |  3    2     6   |  8   459   7  |
:-------------------+-----------------+---------------:
| 6    a458    458  | b78  b478   3   |  1   2     9  |
| 3     2      48   |  5    1     9   |  7   48    6  |
| 7     1      9    |  2    6     48  |  34  458   35 |
'-------------------'-----------------'---------------'
(5=8)r67c2 - (8=4)r7c45 - (4=78)r45c5 - (7|8=5)r4c679 => -5 r4c2; stte
8-)
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Re: February 23, 2017

Postby Cenoman » Thu Feb 23, 2017 4:18 pm

Code: Select all
 +---------------------+-------------------+-----------------+
 | 18    378    1378   | 78*  9      2     | 5    6     4    |
 | 5     6      2      | 4    3      1     | 9    7     8    |
 | 48    9      478    | 6    5      78*   | 2    3     1    |
 +---------------------+-------------------+-----------------+
 | 2     4578   6      | 9   a478* ad478*  | 3-4  1     35   |
 | 489   3478   3478   | 1    478    5     | 6    49    2    |
 | 149   45     145    | 3    2      6     | 8    459   7    |
 +---------------------+-------------------+-----------------+
 | 6     458    458    | 78* b478*   3     | 1    2     9    |
 | 3     2      48     | 5    1      9     | 7    48    6    |
 | 7     1      9      | 2    6     c48    | 34   458   35   |
 +---------------------+-------------------+-----------------+

DP (78) b2p19, r4c56, r7c45 using internals
(4)r4c56 == r7c5 - r9c6 = (4)r4c6 => -4 r4c7; stte

Edit: the above DP is incomplete (cf. JC Van Hay's and eleven's post below) The complete DP (78) b2p19, r4c56, r7c45, r13c3 is not efficient (not found a chain between 3r1c3 and 4r4c7 using internals or between 7r1c2 and 4r4c7 using externals)

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Last edited by Cenoman on Fri Feb 24, 2017 9:33 am, edited 1 time in total.
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Re: February 23, 2017

Postby eleven » Thu Feb 23, 2017 7:29 pm

no dp without 78r13c3
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Re: February 23, 2017

Postby JC Van Hay » Thu Feb 23, 2017 7:35 pm

Hi Cenoman,

Have a look at http://sudopedia.enjoysudoku.com/Deadly_Pattern.html

Best regards, JC.
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Re: February 23, 2017

Postby eleven » Thu Feb 23, 2017 9:05 pm

Cenoman,

deadly (uniqueness) patterns have 2 properties:
- there are at least 2 "inner" pattern solutions
- candidates outside cannot kill all but exactly one of these solutions

In your incomplete pattern any 7 or 8 in r13 would kill one of the pattern solutions.
With 78r13c3 all 78's are pairs in all units, so there cannot be 7 or 8 outside in these units.
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Re: February 23, 2017

Postby Cenoman » Fri Feb 24, 2017 9:34 am

Since I read JC's and eleven's posts the chorus "Shame, shame, shame on you..." plays in continuous loop on my stereo.
I'am ripe for tarring and feathering...

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