dailysudoku.com

[nataraj]

CAUTION: LONG PUZZLE AHEAD; CONTAINS SQUIGGLIES

First I thought, I'd do this one on the plane. Found out 1 hour is not enough. Made a stupid mistake somewhere . Left the magazine in the plane

Then I thought, I'll do it late Saturday evening.
Went looking for the web version, found the puzzle. Fine

Found out 3 hours is not enough and a bottle of Bordeaux definitely too much for this puzzle .

Next day: (here's where the Aspirin comes in)

Finally I took my time.
Kept a few spare printouts handy.
Did a preliminary exercise
Took a walk after a few hours
Had lunch
Continued with the puzzle.
Finished it.

O.K. some minor details might be slightly exaggerated, but NOT MUCH!

Here goes:



(Enlarge to fit on 8 1/2x11 or better)

Note the shaded diagonals in the top left and bottom right sudokus.
They constitute one special house each (must contain all nubers 1-9 exactly once).

Enjoy!

Hints:

The classic and x-sudokus are of type "hard"
Be sure to use the shaded diagonals !

The most difficult part was the bottom left squiggly.
I strongly advise to do it separately (after having solved the top right box, which it shares with the center sudoku).

For you convenience, I include a separate image of that part:



*** S P O I L E R A L E R T ****

Special hints for the squiggly:

The start is straightforward enough:
Law of Leftovers (LoL) gives "4" in r6c8 (cut between cols 7 and 8:
9,4,7 in r123c7 must match r468c8)

single 4 box top left r4c1=4

single 6 row 8: r8c5=6 leads to
r5c4=6 (middle tower), r5c8=8 and col 8 is solved
single 6 in col 7: r6c7=6

box/line 5 in col 1: r3c2<>5

single r3c5=3. This opens a

swordfish (3) cols 4,6,7 (rows 6,7,9) and takes out 3 from r9c1.
I think this was the key move (also r6c3<>3)

triple 2,5,9 col 1: r3c2=1
NP 8,9 row 8: r8c2=4, r8c9=1, col 9 solved
cleanup: r5c1=9, r6c1=2, r3c1=5, r5c5=1,r5c3=3

single 1 in row 6: r6c3=1
NP 3,8 col 7: r4c7=1
single 1 col 6: r2c6=1

single 2 box (bottom center): r7c5=2
box/line 2 in col 6
single 2 col 4
triple 5,7,9 box "2" (top part of col 3)

NP 4,9 row 2 and the puzzle yields without further resistance