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Set J Puzzle 47 -- busy VH+

 
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Sat Feb 07, 2009 10:26 pm    Post subject: Set J Puzzle 47 -- busy VH+ Reply with quote

Bonus points given if you find (grouped) 2-String Kite.

Code:
 +-----------------------+
 | 2 . . | . . 6 | . . . |
 | . 6 . | 3 . 9 | . . . |
 | . . 7 | 4 2 . | . 6 . |
 |-------+-------+-------|
 | . 1 3 | . 4 5 | 2 . . |
 | . . 2 | 6 1 . | 4 . . |
 | 6 7 . | 2 . 3 | . 9 . |
 |-------+-------+-------|
 | . . . | 7 6 . | . . . |
 | . . 9 | . . 2 | . . 1 |
 | . . . | . . . | . 3 7 |
 +-----------------------+

Play this puzzle online at the Daily Sudoku site

===== ===== ===== ===== ===== ===== ===== ===== ===== Ratings are Accumulative

Basics: Naked/Hidden Single, Naked Pair/Triple, Locked Candidate 1/2

Basics+: Naked Quad, Hidden Pair/Triple/Quad

VH: BUG+1, UR Type 1, X-Wing, XY-Wing, XYZ-Wing

VH+: 2-String Kite, Empty Rectangle, Remote Pair, Skyscraper, Colors, UR Type 2

Advanced: finned X-Wing, Multiple Colors, Swordfish, M-Wing, W-Wing, XY-Chain

Extreme: Jellyfish, (but mostly) Chain
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Mon Feb 09, 2009 2:43 am    Post subject: Reply with quote

Twisted Evil
here we go.
three steps.
ER on 1 is present below

Code:
.---------------------.---------------------.---------------------.
| 2      34589  158   | 18     57     6     | 35789  145    489   |
| 145    6      158   | 3      57     9     | 578    1245   248   |
|E1359   3589   7     | 4      2     E18    | 3589   6      89    |
:---------------------+---------------------+---------------------:
| 8      1      3     | 9      4      5     | 2      7      6     |
| 59     59     2     | 6      1      7     | 4      8      3     |
| 6      7      4     | 2      8      3     | 1      9      5     |
:---------------------+---------------------+---------------------:
|E1345   3458  E158   | 7      6     -148   | 589    245    2489  |
| 7      458    9     | 58     3      2     | 6      45     1     |
|E145    2      6     | 158    9      148   | 58     3      7     |
'---------------------'---------------------'---------------------'

------------------
then...
Code:
.---------------------.---------------------.---------------------.
| 2     *34589  158   | 18     57     6     |*35789  145   *489   |
|*145    6      158   | 3      57     9     | 578    1245   248   |
|U1359  U3589   7     | 4      2      18    |*3589   6     *89    |
:---------------------+---------------------+---------------------:
| 8      1      3     | 9      4      5     | 2      7      6     |
|U59    U59     2     | 6      1      7     | 4      8      3     |
| 6      7      4     | 2      8      3     | 1      9      5     |
:---------------------+---------------------+---------------------:
| 1345   3458   158   | 7      6      48    | 589    245    2489  |
| 7      458    9     | 58     3      2     | 6      45     1     |
|*45     2      6     | 158    9      148   |-58     3      7     |
'---------------------'---------------------'---------------------'

notice the UR cells marked on {5,9}. the UR says that in order to avoid the deadly pattern, both the 5 in r3c7 and the 9's in r3c79 can't all be false.
in other words, UR59[(5)r3c7 = (9)r3c79]... which can be extended to eliminate the 5 in r9c7...
UR59[(5)r3c7 = (9)r3c79] - (9)r1c79 = (9-4)r1c2 = (4)r2c1 - (4=5)r9c1; r9c7 <> 5
---------------------
Code:
.---------------------.---------------------.---------------------.
| 2      34589  158   | 18     57     6     | 3579   145    489   |
| 14     6      18    | 3      57     9     | 57     124    248   |
| 1359   3589   7     | 4      2      18    | 359    6      89    |
:---------------------+---------------------+---------------------:
| 8      1      3     | 9      4      5     | 2      7      6     |
| 59     59     2     | 6      1      7     | 4      8      3     |
| 6      7      4     | 2      8      3     | 1      9      5     |
:---------------------+---------------------+---------------------:
| 1345   3458   158   | 7      6      48    | 59     245    249   |
| 7     -458    9     |W58     3      2     | 6     W45     1     |
|W45     2      6     |W15     9      14    | 8      3      7     |
'---------------------'---------------------'---------------------'

the above marked W-wing on {4,5} removes 4 from r8c2 and finishes it.
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