The New Sudoku Players' Forum

[ronk]

You are twisting words. My presentation was an analogy, not an "approach".

Good heavens, if that is important to you, I withdraw "approach" forthwith.

Good heavens, this is not Eureka!

[DonM]

Code: Select all

Ruud's Sunday Nightmare, 1/6/08
.27....3.94...35..1...2........9...3..93.46..3...6........1...4..28...75.5....98.
 *--------------------------------------------------------------------*
 | 58     2      7      | 49     58     16     | 14     3      169    |
 | 9      4      68     | 167    78     3      | 5      126    12678  |
 | 1      368    3568   | 49     2      5678   | 478    469    6789   |
 |----------------------+----------------------+----------------------|
 | 2458  *1678   14568  | 1257   9      12578  | 12478  1245   3      |
 | 258   *178    9      | 3      578    4      | 6      125    1278   |
 | 3     *178    1458   | 1257   6      12578  | 12478  12459  12789  |
 |----------------------+----------------------+----------------------|
 | 78     9      38     | 2567   1      2567   | 23     26     4      |
 | 6     *13     2      | 8      4      9      | 13     7      5      |
 | 47     5      14     | 267    3      267    | 9      8      126    |
 *--------------------------------------------------------------------*


The hidden set of (1678) seems promising because it "targets" all the extra 8's in box 4 or column 2. One doesn't have to do many pushups to find:
(1678)r4568c2=(3)r8c2-(3=8)r7c3 => r46c3 <> 8. If a short chain is more "elegant" then that's gotta be pretty slick .

Just for the heckuvit, as another Joe solver , this would be my first move targeting another hidden set:
ht(145)r469c3=(5)r3c3-r3c6=r1c5-(5=8)r1c1-(8=6)r2c3 => r4c3<>6 -> r4c2=6

Since this puzzle caught my interest from the point of view of good initial moves, here's another (but would actually better serve as a 2nd move to the above):
(2)r5c1=(2-4)r4c1=r9c1-(4=1)r9c3-r8c2=(1-3)r8c7=(3-2)r7c7=grp(2)r46c7 => r5c89<>2 -> r5c1=2

[aran]

Code: Select all

Ruud's Sunday Nightmare, 1/6/08
.27....3.94...35..1...2........9...3..93.46..3...6........1...4..28...75.5....98.
 *--------------------------------------------------------------------*
 | 58     2      7      | 49     58     16     | 14     3      169    |
 | 9      4      68     | 167    78     3      | 5      126    12678  |
 | 1      368    3568   | 49     2      5678   | 478    469    6789   |
 |----------------------+----------------------+----------------------|
 | 2458  *1678   14568  | 1257   9      12578  | 12478  1245   3      |
 | 258   *178    9      | 3      578    4      | 6      125    1278   |
 | 3     *178    1458   | 1257   6      12578  | 12478  12459  12789  |
 |----------------------+----------------------+----------------------|
 | 78     9      38     | 2567   1      2567   | 23     26     4      |
 | 6     *13     2      | 8      4      9      | 13     7      5      |
 | 47     5      14     | 267    3      267    | 9      8      126    |
 *--------------------------------------------------------------------*


An alternative of equivalent effect to daj's discontinuous loop posted earlier :
68(r2c3,r3c2)=3r3c2-3r8c2=(3-8)r7c3=8r7c1-(8=5)r1c1-(35=68)r3c3
(ie either 68 pair in r2c3,r3c2 or in r23c3)
=><8>=5 r1c1