The New Sudoku Players' Forum

[BakyX]

Hi again. Has this puzzle exactly one solution ? If yes, how to solve that ?

[JasonLion]

Yes, that is a valid puzzle.

One possible solution is a finned X-Wing on 1, and then singles to the end.

[Leren]

Code: Select all

*--------------------------------------------------------------*
| 23459 23489 4578   | 6     789   2347   | 249   1     478    |
| 249   2489  6      | 147   1789  1247   | 5     3     478    |
| 2349  1     478    | 347   789   5      | 249   278   6      |
|--------------------+--------------------+--------------------|
| 7     34    45     | 345   2     9      | 8     6     1      |
| 1359  3689 a158    | 135   16    3-1    | 7     4     2      |
| 14    46    2      | 8     167   147    | 3     9     5      |
|--------------------+--------------------+--------------------|
| 6     7    b14     | 12    3     8      | 124   5     9      |
| 8     5     9      | 127   4     6      | 12    27    3      |
|c124   24    3      | 9     5    d17     | 6     78    478    |
*--------------------------------------------------------------*

Another solution is a 2 Stringed Kite : (1) r5c3 = r7c3 - r9c1 = (1) r9c6 => - 1 r5c6; stte

Leren

[BakyX]

JasonLion: Thank you. I'm still not enough good at finding finned X-wings.

Leren: Thank you too. I think I understand what do you mean. We've got string "abcd" and now a=1 or d=1. But I don't understand your notation:

2 Stringed Kite : (1) r5c3 - r7c3 = r9c1 = (1) r9c6 => - 1 r5c6; stte

[Leren]

There were typos in my notation, which I've now corrected to: (1) r5c3 = r7c3 - r9c1 = (1) r9c6

What this means in words, when read from left to right, is : If r5c3 is not 1, then r7c3 is 1, so r9c1 is not 1, so r9c6 is 1

When read from right to left it says : if r9c6 is not 1, then r9c1 is 1, so r7c3 is not 1, so r5c3 is 1.

Note that the 1's are placed in brackets to indicate that whether they are assumed to be True or False depends on which direction you are reading the chain.

Also, the second and third terms do not include 1's. it's customary to only include the number when it changes from the previous term, which de-clutters the notation a bit.

Leren

[BakyX]

Thank you, Leren