Extra Regions

Thanks for these, Gareth. Loved all of them, particularly the Samurai. Hoping to see more Extra Regions in the future!

I agree with Marilyn. As someone who had put these on the forum wish list, I am especially delighted with the new variants. Greatly enjoyed.

Thank you, once again, Gareth. I never have a bored empty moment these days. Now what about those Mosaics you promised?!

And another vote from me too for more of these!

* SPOILER *

I was working on the Jigsaw Extra Regions Sudoku in the lower right on Page 25.

I believe that there is a BUG Formation in the puzzle which causes there to be 2 solutions. Doing the puzzle I got this far:

8  .  .  9  7  2  3  5  1
3  7  9  4  1  5  6  8  2
5  2  1  8  6  3  .  .  9
4  5  3  6  8  9  1  2  7
2  8  7  3  5  1  9  6  4
1  9  .  7  2  .  5  3  8
.  3  8  1  4  .  2  9  5
.  .  2  5  9  8  .  1  3
9  1  5  2  3  .  8  .  6

The BUG forms with all the empty spaces pairing up with 46,47, or 67. The extra regions do not make a difference. For those who don't know what I am talking about, check out the following:

Bivalue Universal Grave (BUG)

If you add the normal 3x3 sudoku region constraint, THEN you get the solution in the answers section.

An alternate solution is as follows:

8  4  6  9  7  2  3  5  1
3  7  9  4  1  5  6  8  2
5  2  1  8  6  3  7  4  9
4  5  3  6  8  9  1  2  7
2  8  7  3  5  1  9  6  4
1  9  4  7  2  6  5  3  8
6  3  8  1  4  7  2  9  5
7  6  2  5  9  8  4  1  3
9  1  5  2  3  4  8  7  6

(I hope that I didn't make a mistake typing that in...)

I could be wrong, but if you try those numbers out you find that it works as well.

I remember when doing this puzzle that I arrived at the same situation as Spittledung's first set of numbers. I just assumed the puzzle needed one of those fancy-named techniques that I don't really know, so I used trial and error to finish the puzzle. Fortunately my first try arrived at the solution in the answers section, so I didn't think anything more of it. Now I've tried the alternate route and Spittledung's right, they both work.

Hmm... I'll take a look at that. Doesn't sound good!

Ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh!!!

The problem here is that part of the instructions are missing... as well as the jigsaw shapes there are also the regular 3x3 boxes in the puzzle, but they're just not marked.

Clearly that is a big mistake on my behalf, and one I will need to take steps to make sure I don't do again.

Sorry - the puzzle is actually "correct" but it is not drawn correctly/the instructions are wrong. The same actually applies to both puzzles at the bottom of page 25.

My sincere apologies to anyone who got as far as Spittledung and then drove themselves crazy trying to resolve a unique solution!

How about having a few Hypersudoku puzzles in the mag?

Is Hyoersudoku a variant of "Extra Regions"?

Hi Jeff,

Yes, the Extra Regions ones in issues 2 and 3 are actually the same as Hypersudoku / Windoku - that is, four extra shaded 3x3 areas inside each 9x9 grid. There's a 5-grid Samurai version of this in both issues too.

In general I use 'Extra Regions' to refer to any layout of extra regions - back in Sudoku Pro I used to sometimes have different layouts of extra regions, although eventually I settled on just the 4 as above because I think it makes a more fun puzzle.