dailysudoku.com

[mm01090]

I have done most of the Very Hard Squigglies, but I am stuck on a few.

After basics and LOL, here is what I have:

+-------------+------------+---------------+
| 9 15 3 | 2 4 7 | 156 16 8 |
| 4 2 7 | 8 6 9 | 15 3 15 |
| 156 156 8 | 15 7 4 | 3 9 2 |
+-------------+------------+---------------+
| 2 8 16 | 167 5 3 | 9 47 146 |
| 3 156 2 | 4 9 156 | 8 16 7 |
| 156 3 9 | 1567 8 156 | 2 47 1456 |
+-------------+------------+---------------+
| 8 4 56 | 3 1 56 | 7 2 9 |
| 7 9 4 | 16 2 8 | 16 5 3 |
| 56 7 156 | 9 3 2 | 4 8 16 |
+-------------+------------+---------------+

The hint puts a '6' in R5C8. Can someone explain why?

[Steve R]

I think I can.

If you run your eye along row 5 you will find it intersects five boxes. Let’s call them A, B, C, D and E from left to right.

Now, your diagram makes it clear that 1 occupies row 5 or row 6 in boxes A and D. Accordingly it can be excluded from row 5 in box E.

Steve

[mm01090]

Thanks. That did the trick.

Is there a name for that type of logic or technique?

[Steve R]

It's usually called "box-line interaction," just as in classical SuDoku.

Steve