The New Sudoku Players' Forum

[Yogi]

5..624831.2.78.5....859..277...162.54.2.35.7..5..723..3..16..52...25.7.32.534....
The map suggested possible Skyscrapers & Kites for candidates 14689.
No skys found in any of these, but the 4Kite r2c389 / r37c7 in Box3 => r7c3<>4.
This creates the 4-candidate XWing r37c27 which now excludes 4 from r89c2.
Does this solve the puzzle? Possibly, but r7c3 is now 79, a Pair with r1c3 => 3r4c3 stte.

Interestingly, SadMan solved this puzzle from here by a completely different route.
It found an XY chain which eliminates 9 from r7c3 and another which eliminates 4 from r7c7.

[Leren]

Code: Select all

*--------------------------------------------------------------*
| 5     79    79     | 6     2     4      | 8     3     1      |
| 16    2     34     | 7     8     13     | 5     69-4  469    |
| 16   b34    8      | 5     9     13     |a46    2     7      |
|--------------------+--------------------+--------------------|
| 7     389   39     | 489   1     6      | 2     489   5      |
| 4     16    2      | 89    3     5      | 169   7     689    |
| 89    5     16     | 489   7     2      | 3     14689 4689   |
|--------------------+--------------------+--------------------|
| 3     4789  479    | 1     6     789    | 9-4   5     2      |
| 89   c146   16     | 2     5     89     | 7    d146   3      |
| 2     1679  5      | 3     4     79     | 169   1689  689    |
*--------------------------------------------------------------*

Skyscraper (4) r3c7 = r3c2 - r8c2 = (4) r8c8 => - 4 r2c8, r7c7; stte

SadMan has a very limited set of solving techniques, which does not include Skycrapers, Kites or ERs. Try Hodoku here, which is much better.

Leren