MM 1365 4/5/09 diabolical

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MM 1365 4/5/09 diabolical

Postby storm_norm » Sun Apr 12, 2009 8:37 pm

this is a daily puzzle from the sudokulist site.
it was posted over on the daily site here...
http://www.dailysudoku.com/sudoku/forums/viewtopic.php?t=3447&sid=6fa7a077f311b276cca6cb6d3b2ecb26

Code: Select all
.---------------------.---------------------.---------------------.
| 1      589    4     | 5689   7      69    | 2      56     3     |
| 358    3589   35    | 2      1568   169   | 7      156    4     |
| 6      2      7     | 4      15     3     | 9      15     8     |
:---------------------+---------------------+---------------------:
| 35     4      8     | 13     9      7     | 15     2      6     |
| 9      135    1356  | 1368   12368  126   | 158    4      7     |
| 2      7      16    | 168    4      5     | 18     3      9     |
:---------------------+---------------------+---------------------:
| 45     56     9     | 7      256    246   | 3      8      1     |
| 37     136    2     | 1369   136    8     | 4      79     5     |
| 34578  1358   135   | 1359   135    149   | 6      79     2     |
'---------------------'---------------------'---------------------'


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

one of the hardest daily diabolicals. usually not this challenging.
enjoy,

Norm
Last edited by storm_norm on Sun Apr 12, 2009 5:02 pm, edited 1 time in total.
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Postby daj95376 » Sun Apr 12, 2009 8:51 pm

[Withdrawn:]
Last edited by daj95376 on Sun Apr 12, 2009 9:21 pm, edited 1 time in total.
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Postby storm_norm » Sun Apr 12, 2009 9:01 pm

Danny,
I hit the submit button prematurely.:(

I meant to add the link to the daily sudoku site. which I will edit into the original posting.
I felt this puzzle would be a good candidate as a >8.0 SE type puzzle for the posters to consider on this forum.
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Postby ttt » Mon Apr 13, 2009 7:25 am

Code: Select all
 *--------------------------------------------------------------------*
 | 1      589    4      | 5689   7      69     | 2      56     3      |
 | 358    3589   35     | 2      1568   169    | 7      156    4      |
 | 6      2      7      | 4      15     3      | 9      15     8      |
 |----------------------+----------------------+----------------------|
 | 35     4      8      | 13     9      7      | 15     2      6      |
 | 9      135    1356   | 1368   12368  126    | 158    4      7      |
 | 2      7      16     | 168    4      5      | 18     3      9      |
 |----------------------+----------------------+----------------------|
 | 45     56     9      | 7      256    246    | 3      8      1      |
 | 37     136    2      | 1369   136    8      | 4      79     5      |
 | 34578  1358   135    | 1359   135    149    | 6      79     2      |
 *--------------------------------------------------------------------*


My path for this one
01: -als:r9c168-9-r9c4=5=r1c4=8=r1c2-8-r2c1=8=r9c1-
(ht479)r9c168=(9-5)r9c4=(5-8)r1c4=(8)r1c2-(8)r2c1=(8)r9c1 => Loop: r9c1<>35, r9c6<>1, r9c4<>13, r1c4<>69, r2c2<>8, some singles

02: Coloring 5’s r7c2=r7c5-r9c4=r1c4 => r1c2<>5

03: XYZ-wing (169)r2c6, (16)r2c8, (69)r1c6 => r2c5<>6, singles to the end

Please correct me for NL notation, thanks
Edit: Oh…, reading solutions on the daily site and see that my solution is very similar to them:(

ttt
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Postby ttt » Mon Apr 13, 2009 11:52 am

Code: Select all
 *--------------------------------------------------------------------*
 | 1      589    4      | 5689   7      69     | 2      56     3      |
 | 358    3589   35     | 2      1568   169    | 7      156    4      |
 | 6      2      7      | 4      15     3      | 9      15     8      |
 |----------------------+----------------------+----------------------|
 | 35     4      8      | 13     9      7      | 15     2      6      |
 | 9      135    1356   | 1368   12368  126    | 158    4      7      |
 | 2      7      16     | 168    4      5      | 18     3      9      |
 |----------------------+----------------------+----------------------|
 | 45     56     9      | 7      256    246    | 3      8      1      |
 | 37     136    2      | 1369   136    8      | 4      79     5      |
 | 34578  1358   135    | 1359   135    149    | 6      79     2      |
 *--------------------------------------------------------------------*

Something out of the solution – I’m not sure for the name but maybe “almost patterns”:D

01: On using UR(15)r23c58 => r2c5<>5
02: “Almost Coloring”, if r9c246<>1 => coloring 1’s r2c6=r5c6-r5c2=r8c2-r9c3=r9c5 => r2c5<>1

(1=5)r3c5-(5)r1c4=(5)r9c4-(5=np13)r9c35-(1)r9c246=(1)[r2c6=r5c6-r5c2=r8c2-r9c3=r9c5] => r2c5<>1

03: “Almost XYZ-wing”

(5)r2c8=[XYZ-wing: (169)r2c68/r1c6]-(6=8)r2c5-(8)r1c4=(8)r1c2-(8=np135)r9c235-(5)r9c4=(5)r1c4 => r1c8<>5

ttt
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Re: MM 1365 4/5/09 diabolical

Postby aran » Tue Apr 14, 2009 4:12 am

Code: Select all
.---------------------.---------------------.---------------------.
| 1      589    4     | 5689   7      69    | 2      56     3     |
| 358    3589   35    | 2      1568   169   | 7      156    4     |
| 6      2      7     | 4      15     3     | 9      15     8     |
:---------------------+---------------------+---------------------:
| 35     4      8     | 13     9      7     | 15     2      6     |
| 9      135    1356  | 1368   12368  126   | 158    4      7     |
| 2      7      16    | 168    4      5     | 18     3      9     |
:---------------------+---------------------+---------------------:
| 45     56     9     | 7      256    246   | 3      8      1     |
| 37     136    2     | 1369   136    8     | 4      79     5     |
| 34578  1358   135   | 1359   135    149   | 6      79     2     |
'---------------------'---------------------'---------------------'

1. hidden quad c2 : 1356r5789c2=8r9c2-8r9c1=8r2c1-8r2c5=(8-5)r1c4=(5-9)r9c4=9r8c4-(9=7)r8c8
A. -7r9c8=(7-8)r9c1=8r9c2 : loop=><8>r2c2 <6>r1c4 <13>r9c4 <345>r9c1
B. -(7=3)r8c1-(35=1)r9c3-(13=6)r8c2-(6=5)r7c2 :=><5>r12c2 :=>pointing 5s b1r2 : =><5>r2c58
2. hidden quad b7 : substitute 135r9c3 for 135r5c2 : same chain as 1B...=5r7c2 : =><5>=4r7c1 :=><4>r7c6
3. hidden triple c5 : 135r389c5=6r8c5-(6=2)r7c6-(26=5)r7c5-(5=1)r3c5 : =><1>r2c5
4. Xwing9 r12c26 :=><9>r1c4
5 xy chain : (6=8)r2c5-(8=5)r1c4-(5=6)r1c8 : =><6>=9r1c6
singles
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