Sudoku Players' Forum (clone)

here is the puzzle:
5 7 9 | 8 . 4 | . 6 3
4 8 . | 3 7 6 | 5 . 9
. 6 3 | 9 . 5 | 7 8 4
-------+-------+------
3 9 7 | 1 5 2 | 8 4 6
8 . 5 | 4 6 9 | . . 7
6 . 4 | 7 3 8 | 9 5 .
-------+-------+------
9 4 . | 6 8 . | . 7 5
. 3 8 | 5 4 . | 6 9 .
. 5 6 | 2 9 . | 4 . 8

Code: Select all

5798.4.6348.3765.9.639.57843971528468.5469..76.473895.94.68..75.3854.69..5629.4.8

Code: Select all

*-------------------------------------*
| 5   7   9  | 8 12 4   | 1-2  6   3  |
| 4   8  b12 | 3 7  6   | 5   a12  9  |
| 12  6   3  | 9 12 5   | 7    8   4  |
|------------+----------+-------------|
| 3   9   7  | 1 5  2   | 8    4   6  |
| 8   12  5  | 4 6  9   | 123  123 7  |
| 6   12  4  | 7 3  8   | 9    5   12 |
|------------+----------+-------------|
| 9   4  c12 | 6 8  13  |d123  7   5  |
| 127 3   8  | 5 4  17  | 6    9   12 |
| 17  5   6  | 2 9  137 | 4    13  8  |
*-------------------------------------*

There is a Skyscraper of 2's in cells marked a-b-c-d which removes the 2 from r1c7. If you don't know about Skyscrapers you can read about them here.

Leren