iphone sudoku2 expert difficulty

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iphone sudoku2 expert difficulty

Postby dennisolvany » Sat Jul 07, 2012 9:08 pm

I just started playing expert level. Apparently this one requires a technique that I am unfamiliar with. Screenshot attached.
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Re: iphone sudoku2 expert difficulty

Postby daj95376 » Sat Jul 07, 2012 11:56 pm

You missed an X-Wing on <4>, but it's extraneous. There's also "Simple Coloring" on <4> and <8>.

Cells a-b-c-d form a Simple Coloring pattern on <8> that's called a "turbot fish". It justifies r8c2<>8.

Code: Select all
 +--------------------------------------------------------------+
 |  5     478   1478  |  3     148   2     |  9     6     48    |
 |  6     9     148   |  5     7     48    |  148   3     2     |
 |  3     2     148   |  9     148   6     |  148   5     7     |
 |--------------------+--------------------+--------------------|
 |  78    6     478   |  1     48    9     |  5     2     3     |
 |  1     3     5     |  2     6     48    |  7    c48    9     |
 |  2    a48    9     |  7     5     3     |  6     1    b48    |
 |--------------------+--------------------+--------------------|
 |  47    1     2     |  8     9     5     |  3     47    6     |
 |  9     7-8   6     |  4     3     1     |  2    d78    5     |
 |  48    5     3     |  6     2     7     |  48    9     1     |
 +--------------------------------------------------------------+
 # 33 eliminations remain
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