The New Sudoku Players' Forum

[dokudude]

Totally lost on Fourteen by Lepton, and I would like the smallest hint possible.

Rules: Draw nine non-overlapping 3x3 boxes, and place the digits 1-9 once each in every box. Digits cannot repeat in any row or column. Cells outside boxes do not contain digits.

Here's what I have so far.

I got this from the Cracking the Cryptic YouTube channel, but I don't want to watch the video for fear of spoiling too much. Have I gotten something wrong? (If so, you don't need to tell me what.)

[eleven]

Didn't know this variant, as a vanilla solver one has to be careful, e.g. not to "see" a 28 pair in box one, because there is no 8 in the rest of the column.

It took me some time to solve it, maybe not the best way:

First step was to eliminate 9 from r4c8:
- 9r4c9 -> 9r89c7 -> 9r23c5 -> 8r2c4
- 9r4c9 -> 28r23c7, then the unique rectangle 28 with cells r23c1 forces 8 to be in r13c2.
These 8's kill all 8's in box 7, so r3c8 can't be 9.

The rest seemed to be easier.

[Edit:] corrected typos
You can see that as a hint to find a more elegant way.

[marek stefanik]

This should be a bit simpler.

Small hint: focus on r2c4.

Detailed explanation: Show

c567 each need to contain 9 digits, so each digit must appear in each of them.
The 8|9 in r2c4 must appear in c56, taking up magenta and light green, then in c7 it is forced into r3c7, which forces it into r1c2 in blue.
Finally it is left with r89c3 in grey, so it cannot be 8.
The puzzle is easy afterwards.

Marek

[Hajime]

Still puzzling. Why is the arrangement of the nine boxes (dokudude interim puzzle) the right way to go? Very nice puzzle

[eleven]

This should be a bit simpler.

Yes, last night it was too late for me to get it simpler. Probably you need some practice with those puzzles to find such moves directly.

Still puzzling. Why is the arrangement of the nine boxes (dokudude interim puzzle) the right way to go? Very nice puzzle

I found the youtube link now, where it schould be explained - too long for me. That only 14 givens are needed, is remarkable.