The New Sudoku Players' Forum

[NoClue]

Hi, all,

here is another VERY EASY (!!!) Sudoku, which I tried to solve (# 649807 - very hard):

Code: Select all

+-----+-----+-----+
|. . 7|2 . 6|8 . .|
|. 9 .|. 8 .|. 2 .|
|. . 2|3 . 5|9 . .|
+-----+-----+-----+
|7 . .|. 5 .|. . 4|
|. 4 .|. 6 .|. 8 .|
|2 . .|. 1 .|. . 6|
+-----+-----+-----+
|. . 4|5 . 7|6 . .|
|. 1 .|. 4 .|. 5 .|
|. . 5|1 . 8|4 . .|
+-----+-----+-----+

again I could hardly find ANY hidden singles (only 36) - so I had to pencilmark 14 cells:

Code: Select all

+-------+------+---------+
|1. 35 7|2 9 6.|8.. 4 35.|
|35 9. 6|4 8 1.|357 2 357|
|4. 8. 2|3 7 5.|9.. 6 1..|
+-------+------+---------+
|7. 6. 1|8 5 23|23. 9 4..|
|35 4. 9|7 6 23|1.. 8 235|
|2. 35 8|9 1 4.|35. 7 6..|
+-------+------+---------+
|9. 2. 4|5 3 7.|6.. 1 8..|
|8. 1. 3|6 4 9.|27. 5 27.|
|6. 7. 5|1 2 8.|4.. 3 9..|
+-------+------+---------+

Any tipps and hints are appreciated. Thanks in advance

[coloin]

Try sudoku explainer.

http://diuf.unifr.ch/people/juillera/Sudoku/Sudoku.html

but

Code: Select all

+-------------------+-------------------+-------------------+
| 1     35    7     | 2     9     6     | 8     4     35    |
| 35@   9     6     | 4     8     1     | 357*  2     357   |
| 4     8     2     | 3     7     5     | 9     6     1     |
+-------------------+-------------------+-------------------+
| 7     6     189   | 89    5     23    | 123   39    4     |
| 35@   4     19    | 7     6     23    | 1235  8     2359  |
| 2     35@   89    | 89    1     4     | 35@   7     6     |
+-------------------+-------------------+-------------------+
| 9     2     4     | 5     3     7     | 6     1     8     |
| 8     1     3     | 6     4     9     | 27    5     27    |
| 6     7     5     | 1     2     8     | 4     39    39    |
+-------------------+-------------------+-------------------+

xy chain -
there are 4 positions with 35@
so the 357* on row2col7 cant be a 3 or a 5
C

[NoClue]

@ coloin

thanks for the tip with XY-chain and the link of Sudoku-Explainer...