July 5, 2020

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July 5, 2020

Postby tarek » Sun Jul 05, 2020 7:30 am

Code: Select all
+-------+-------+-------+
| . . 1 | 3 . . | . . 5 |
| . . . | . . 5 | 7 2 . |
| 8 . . | . . . | . 1 . |
+-------+-------+-------+
| 3 . . | . 7 . | 9 . . |
| . . . | 5 8 . | 2 7 . |
| . 9 . | . . . | . . 4 |
+-------+-------+-------+
| . 3 . | 8 1 . | . . . |
| . 1 7 | . 4 . | . . . |
| 2 . . | . . 6 | . . . |
+-------+-------+-------+
..13....5.....572.8......1.3...7.9.....58.27..9......4.3.81.....17.4....2....6...

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Re: July 5, 2020

Postby Cenoman » Sun Jul 05, 2020 8:33 am

Code: Select all
 +-------------------+-------------------+----------------------+
 | a69    7    1     |  3     2    8     |Bb46     469    5     |
 |  469*  46*  3     |  1     69   5     |  7      2      8     |
 |  8     25   25    |  47    69   47    |  3      1      69    |
 +-------------------+-------------------+----------------------+
 |  3     25   258   |  246   7    124   |  9      568    16    |
 |  1     46*  46*   |  5     8    9     |  2      7      3     |
 |  7     9    258   |  26    3    12    |  1568   568    4     |
 +-------------------+-------------------+----------------------+
 | A456*  3   y469*  |  8     1    27    | B456    4569   27    |
 |  56    1    7     |  29    4    3     |  568    5689   269   |
 |  2     8   z49    |  79    5    6     |  1-4    3      179   |
 +-------------------+-------------------+----------------------+

DP(46)r257c123 using mixed external-internals
(6)r1c1 - (6=4)r1c7
(5)r7c1 - (5=64)r17c7
(9)r7c3 - (9=4)r9c3
=> -4 r9c7; ste
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Re: July 5, 2020

Postby SpAce » Sun Jul 05, 2020 1:44 pm

Code: Select all
.--------------.---------------.--------------------.
| 69   7   1   | 3    2   8    | 46     469    5    |
| 469  46  3   | 1    69  5    | 7      2      8    |
| 8    25  25  | 47   69  47   | 3      1      69   |
:--------------+---------------+--------------------:
| 3    25  258 | 246  7   24-1 | 9      568   b1"6  |
| 1    46  46  | 5    8   9    | 2      7      3    |
| 7    9   258 | 26   3  a1'2  | 568-1  568    4    |
:--------------+---------------+--------------------:
| 456  3   469 | 8    1  a2'7  | 456    4569  b2"7  |
| 56   1   7   | 29   4   3    | 568    5689   269  |
| 2    8   49  | 79   5   6    | 14     3     b17"9 |
'--------------'---------------'--------------------'

(12)r67c6 = (271)r794c9 => -1 r4c6,r6c7; stte

uncompressed: Show
(1=2)r6c6 - r7c6 = (2-7)r7c9 = (7-1)r9c9 = (1)r4c9 => -1 r4c6,r6c7; stte
-SpAce-: Show
Code: Select all
   *             |    |               |    |    *
        *        |=()=|    /  _  \    |=()=|               *
            *    |    |   |-=( )=-|   |    |      *
     *                     \  ¯  /                   *   

"If one is to understand the great mystery, one must study all its aspects, not just the dogmatic narrow view of the Jedi."
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Re: July 5, 2020

Postby SpAce » Sun Jul 05, 2020 2:02 pm

Hi Cenoman,

Cenoman wrote:DP(46)r257c123 using mixed external-internals
(6)r1c1 - (6=4)r1c7
(5)r7c1 - (5=64)r17c7
(9)r7c3 - (9=4)r9c3
=> -4 r9c7; ste

A Deadly Death Blossom? :) That's very nice! My first solution used the same DP and the same guardians but a different elimination. After seeing yours there was no point in posting that, because it was both too similar and not nearly as nice (6x6 vs 4x4 in matrix form).

Btw, I think that DP type should have its own name, because it's so simple and distinctive. In fact, it's the closest thing to a UR having just two digits and being located in a single chute. I think it falls under the definitions of BUG-Lite and Unique Loop, but they're much more generic allowing different shapes and multiple digits. The Extended UR (SudokuWiki) is probably the closest in shape, but even that can have multiple digits.
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Re: July 5, 2020

Postby yzfwsf » Sun Jul 05, 2020 2:19 pm

Code: Select all
.--------------.--------------.-----------------.
| 69   7   1   | 3    2   8   | 46    469   5   |
| 469  46  3   | 1    69  5   | 7     2     8   |
| 8    25  25  | 47   69  47  | 3     1     69  |
:--------------+--------------+-----------------:
| 3    25  258 | 246  7   124 | 9     568   c16 |
| 1    46  46  | 5    8   9   | 2     7     3   |
| 7    9   258 | 26   3   a12 | b1568 568   4   |
:--------------+--------------+-----------------:
| 456  3   469 | 8    1   f27 | 456   4569  e27 |
| 56   1   7   | 29   4   3   | 568   5689  269 |
| 2    8   49  | 79   5   6   | 14    3     d179|
'--------------'--------------'-----------------'

1r6c6=r6c7-r4c9=(1-7)r9c9=(7-2)r7c9=2r7c6 => -2r6c6;stte
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Re: July 5, 2020

Postby yzfwsf » Sun Jul 05, 2020 2:27 pm

Cenoman wrote:(6)r1c1 - (6=4)r1c7
(5)r7c1 - (5=64)r17c7
(9)r7c3 - (9=4)r9c3
=> -4 r9c7; ste

r1c1 should be r2c1?
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Re: July 5, 2020

Postby SpAce » Sun Jul 05, 2020 2:37 pm

yzfwsf wrote:
Cenoman wrote:(6)r1c1 - (6=4)r1c7
(5)r7c1 - (5=64)r17c7
(9)r7c3 - (9=4)r9c3
=> -4 r9c7; ste

r1c1 should be r2c1?

If you mean 6r1c1, it's correct as an external guardian to the DP. The corresponding internal guardian in box 1 would be 9r2c1. It would work too, but with a slightly longer route: (9)r2c1 - (9=6)r1c1 - (6=4)r1c7.
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Re: July 5, 2020

Postby SteveG48 » Sun Jul 05, 2020 3:50 pm

Code: Select all
 *-----------------------------------------------------------*
 | 69    7     1     | 3     2     8     | 46    469   5     |
 | 469   46    3     | 1     69    5     | 7     2     8     |
 | 8     25    25    | 47    69    47    | 3     1    a69    |
 *-------------------+-------------------+-------------------|
 | 3     25    258   | 246   7     124   | 9    d568   1-6   |
 | 1     46    46    | 5     8     9     | 2     7     3     |
 | 7     9     258   | 26    3    c12    |d1568 d568   4     |
 *-------------------+-------------------+-------------------|
 | 456   3     469   | 8     1    c27    | 456   4569  27    |
 | 56    1     7     |b29    4     3     | 568   5689 a269   |
 | 2     8     49    | 79    5     6     | 14    3     179   |
 *-----------------------------------------------------------*


(6=92)r38c9 - 2r9c4 = (21)r67c6 - (1=586)b6p278 => -6 r4c9 ; stte
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Re: July 5, 2020

Postby Ngisa » Sun Jul 05, 2020 6:17 pm

Code: Select all
+-------------------+------------------+----------------------+
|e69      7     1   | 3      2     8   | 46      f469     5   |
| 469    46     3   | 1      69    5   | 7        2       8   |
| 8      25     25  | 47     69    47  | 3        1      g69  |
+-------------------+------------------+----------------------+
| 3      25     258 | 246    7     124 | 9        568     16  |
| 1      46     46  | 5      8     9   | 2        7       3   |
| 7      9      258 | 26     3    a12  |b1568     568     4   |
+-------------------+------------------+----------------------+
|d456    3     d469 | 8      1     7-2 | 456     e4569    27  |
|d56     1      7   |j29     4     3   | 568     i5689   h269 |
| 2      8     d49  | 79     5     6   |c14       3      h179 |
+-------------------+------------------+----------------------+

(2=1)r6c6 - r6c7 = (1-4)r9c7 = (4569)b7p9143 - (9)r7c8&(6=9)r1c1 - r1c8 = r3c9 - r89c9 = r8c8 - (9=2)r8c4 => - 2r7c6; stte

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Re: July 5, 2020

Postby Cenoman » Sun Jul 05, 2020 10:26 pm

SpAce wrote:A Deadly Death Blossom?
Why not ? But a bit pleonastic, though...
Btw, I think that DP type should have its own name,

Sudopedia recommmends to name it BUG-lite. Extended UR could fit with other 6-cell DP's but not with the L-shaped one.

PS: thanks for your quick answer to ysfwsf.
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Re: July 5, 2020

Postby pjb » Sun Jul 05, 2020 11:43 pm

Code: Select all
 69      7       1      | 3      2      8      | 46     469    5     
 469     46      3      | 1      69     5      | 7      2      8     
 8       25      25     | 47     69     47     | 3      1     b69     
------------------------+----------------------+---------------------
 3       25      258    | 246    7      24-1   | 9      568   b16     
 1       46      46     | 5      8      9      | 2      7      3     
 7       9       258    | 26     3     a12     | 568-1  568    4     
------------------------+----------------------+---------------------
 456     3       469    | 8      1     a27     | 456    4569  b27     
 56      1       7      | 29     4      3      | 568    5689  b269   
 2       8       49     | 79     5      6      | 14     3      179   

(1=7)r67c6 - (7=1269)r3478c9 => -1 r4c6, r6c7; stte

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