The New Sudoku Players' Forum

[steves48]

Here is image of expert puzzle. This was an iphone screenshot. Please let me know if there is a better way to pust puzzles.

[JasonLion]

The best format to use is something like this:

Code: Select all

1349  8     349   | 134   5     2     | 7     136   36   
2     13    7     | 138   6     9     | 4     5     38   
134   6     5     | 13478 347   134   | 138   9     2   
------------------+-------------------+------------------
6     34    1     | 34    2     8     | 9     7     5   
7     9     8     | 5     34    6     | 2     34    1   
34    5     2     | 9     1     7     | 36    8     346 
------------------+-------------------+------------------
1349  1347  6     | 2     8     1345  | 135   134   3479
8     12347 349   | 13467 347   1345  | 1356  12346 34679
5     12347 34    | 13467 9     134   | 1368  12346 34678

Though:
.8..527..2.7.6945..65....926.1.289757985.62.1.52917.8...628....8........5...9....
is also acceptable.

This is a rather involved puzzle. It took me about 20 medium complex techniques to solve it. The first was

(3=4)R6C1 - (4)R13C1 = (4)R1C3 - (4=3)R9C3 => R7C1<>3

That doesn't really get you very far however.

There may well be something that solves it more quickly, but I didn't notice it.

[steves48]

This is my first time on this forum. Please explain your notation in the solution you provided. I have no idea how to interpret it. Thank you. Is there a typo in the solution? R13 ?

Also, in the format for upload, is that something I could type in a text editor like notepad and then upload?

Thank you.

[JasonLion]

The notation is an Alternating Inference Chain, or AIC. You can read more about it at the Sudopedia AIC page. AIC notation is by far the most common form of notation here on the Forum. At it's basic level it is well standardized. However there isn't complete agreement on how to notate some of the more complex techniques.

R13C1 is not a typo, it indicates a grouped link, i.e. the 4s that appear in both R1C1 and R3C1 taken together as a group.

Many of us use programs to produce the upload format with pencil marks, though I've gotten fairly good at typing it free hand. They are easiest to create by hand in editors that support fixed width fonts, but can be done without that as long as you keep track of the max number of pencil marks in each column. You can also use the preview feature on the forum to see if you got all the spacing right.

[JC Van Hay]

Most straightforward next moves : analysis of the puzzle from R4 or 8R3 or R2C2.