## Halloween Sudoku

For fans of Killer Sudoku, Samurai Sudoku and other variants

### Halloween Sudoku

The 2 eyes form 2 blocks containing the digits 1 to 9 only one time. The same goes for the mouth which is also an extra block containing the digits 1 to 9 only once.
I already solved it half with logic and trial and error for the other part because i didn't found the way to start. Any advice?
Attachments
121642142_10158900859554923_2059651658671508700_n.jpg (12.93 KiB) Viewed 178 times
urhegyi

Posts: 243
Joined: 13 April 2020

### Re: Halloween Sudoku

I solved the puzzle and it seemed quite straightforward, so it's difficult to guess where you might be stuck. Could you post the exact point in the puzzle that you are stuck on? It will be easier for us to help then.
SCLT

Posts: 167
Joined: 06 August 2013

### Re: Halloween Sudoku

halloween-part.png (15.42 KiB) Viewed 166 times
SCLT wrote:I solved the puzzle and it seemed quite straightforward, so it's difficult to guess where you might be stuck. Could you post the exact point in the puzzle that you are stuck on? It will be easier for us to help then.

I redid my steps from the notes I took, and actually the second time it's much easier. At this point it seemed already been solved:
urhegyi

Posts: 243
Joined: 13 April 2020

### Re: Halloween Sudoku

Singles only, most hidden singles, some naked singles, easy but a pretty nice puzzle !
A possible solution path:
Hidden Text: Show
Code: Select all
`Grid Step Cell Row Col Value Why   1   1   1   7   1   3   HS in row         1   1   2   3   3   3   HS in row         1   1   3   1   4   3   HS in row         1   1   4   6   6   3   HS in row         1   1   5   1   5   4   HS in col         1   1   6   4   9   8   HS in box         1   1   7   2   4   8   HS in jigsaw         1   1   8   7   3   1   HS in jigsaw         1   1   9   6   3   8   HS in jigsaw         1   1   10   2   7   1   HS in jigsaw         1   2   11   7   2   8   HS in row         1   2   12   5   3   4   HS in row         1   2   13   4   3   5   HS in row         1   2   14   4   5   1   HS in row         1   2   15   1   6   1   HS in row         1   2   16   9   6   8   HS in row         1   2   17   8   8   1   HS in row         1   2   18   1   8   8   HS in row         1   2   19   2   8   2   HS in col         1   2   20   2   6   5   HS in col         1   2   21   5   1   1   HS in col         1   2   22   8   4   4   HS in col         1   2   23   8   9   5   HS in col         1   2   24   9   5   7   HS in col         1   2   25   7   4   5   HS in box         1   2   26   4   4   7   HS in jigsaw         1   3   27   3   6   7   HS in row         1   3   28   2   1   7   HS in col         1   3   29   2   3   9   HS in box         1   3   30   6   2   7   HS in box         1   3   31   8   1   9   HS in box         1   3   32   3   4   9   HS in box         1   3   33   5   6   9   HS in box         1   3   34   7   5   9   HS in box         1   3   35   1   7   7   HS in box         1   3   36   1   9   9   HS in box         1   3   37   5   8   7   HS in box         1   3   38   2   5   6   HS in jigsaw         1   3   39   3   8   5   HS in jigsaw         1   4   40   1   2   6   Naked Single         1   4   41   8   2   2   Naked Single         1   4   42   9   3   6   Naked Single         1   4   43   6   4   6   Naked Single         1   4   44   8   6   6   Naked Single         1   4   45   3   7   6   Naked Single         1   4   46   9   9   2   Naked Single         1   4   47   4   1   6   HS in row         1   4   48   5   4   2   HS in row         1   4   49   7   6   2   HS in row         1   4   50   5   7   5   HS in row         1   4   51   7   8   6   HS in row         1   4   52   5   9   6   HS in row         1   4   53   4   7   2   HS in col         1   4   54   4   8   3   HS in col         1   4   55   6   1   2   HS in col         1   4   56   7   7   4   HS in col         1   4   57   9   7   3   HS in col         1   4   58   9   8   9   HS in col         1   4   59   6   8   4   HS in box         1   4   60   6   7   9   HS in box      `

Hajime

Posts: 280
Joined: 20 April 2018
Location: Netherlands

### Re: Halloween Sudoku

I set it up on Hodoku - first color the cells for the eyes and mouth, File -> Modify Givens to set givens, File -> Play Game when ready.
The eyes and mouth regions have to be manually checked for candidates eliminations.

As noted in a previous post, the puzzle solves with singles only, ED=1.5/1.2/1.2.
1to9only

Posts: 2267
Joined: 04 April 2018

### Re: Halloween Sudoku

I generated a few of the halloween sudokus to keep busy before halloween day!
Code: Select all
`........9..8...4.5.....8..........7.3...82.....7..42.........1...93.....5.....8.. ED=1.5/1.2/1.2.....7.12.6.....3..24.9......8..1..........5..4...6.2........4.......7.....2..... ED=1.5/1.2/1.2.........69......2.....5.1.4.3.86.............1....7.......32.....5....3..5...... ED=1.5/1.2/1.2.9..82...7..6.....2....1............9..1...........8.4..3....2.......18..5......6 ED=1.5/1.5/1.5...7.......3..5..281...6.5.......37496........................6.....8.35......... ED=2.0/1.2/1.29.......3..2...14.........2..........3............9.7..8.195.............2.46..1. ED=3.4/1.2/1.2..7...........3..7....6.8..1.3.........5.4....4........2.3..75.5.86.............. ED=3.8/1.2/1.2..4.6..........26...79.....3.........1...784.............61.4.........58.......3. ED=4.2/1.2/1.2.......9..5..1.42....8.....3..7.1..8..2....5........6....5..28............3...... ED=4.4/1.2/1.2......2.........6...45...91...6.2..8...1...5...6.87.......2.9...1......3......... ED=4.4/1.2/1.2`

[Edit 22/10] Solutions - the ED ratings may be slightly different as I've now added Intersections for this variant!
Hidden Text: Show
Code: Select all
`165243789728916435934578162482659371391782546657134298243865917819327654576491823 ED=1.5/1.2/1.2583467912769125834124398675258741396691832457347956128815673249432589761976214583 ED=1.5/1.2/1.2578912634691348572234675819453786921782159346916234758167493285849527163325861497 ED=1.5/1.2/1.2396482715781635942245971368834257691967148253512396874673814529429563187158729436 ED=1.5/1.5/1.5645782913793145682812396457251869374967453128384271569139527846476918235528634791 ED=2.0/1.2/1.2915624783872953146346817592697281435431576829258349671783195264164732958529468317 ED=2.8/1.2/1.2657891234819423567234765891163982475982574316745136982426319758598647123371258649 ED=3.8/1.2/1.2234561789159478263867923514346852197512397846798146325983615472671234958425789631 ED=4.2/1.2/1.2671234895958617423234859671365721948412968357897345162149573286586192734723486519 ED=4.4/1.2/1.2568719234391248567724563891479652318283194756156387429637421985812975643945836172 ED=1.7/1.2/1.2`
Last edited by 1to9only on Thu Oct 22, 2020 8:41 am, edited 1 time in total.
1to9only

Posts: 2267
Joined: 04 April 2018

### Re: Halloween Sudoku

Nice job creating 10 more Halloween sudokus. I read about windoku last week with 9 possible blocks:
9 5 5 5 9 6 6 6 9
7 1 1 1 7 2 2 2 7
7 1 1 1 7 2 2 2 7
7 1 1 1 7 2 2 2 7
9 5 5 5 9 6 6 6 9
8 3 3 3 8 4 4 4 8
8 3 3 3 8 4 4 4 8
8 3 3 3 8 4 4 4 8
9 5 5 5 9 6 6 6 9
Is there some similarity when defining Halloween sudokus?
urhegyi

Posts: 243
Joined: 13 April 2020

### Re: Halloween Sudoku

Only a very small similarity: the bottom 3 blocks contain the mouth, so there must be exactly 2 digits 1to9 in the white.

Hajime

Posts: 280
Joined: 20 April 2018
Location: Netherlands

### Re: Halloween Sudoku

urhegyi wrote:Nice job creating 10 more Halloween sudokus. I read about windoku last week with 9 possible blocks:
9 5 5 5 9 6 6 6 9
7 1 1 1 7 2 2 2 7
7 1 1 1 7 2 2 2 7
7 1 1 1 7 2 2 2 7
9 5 5 5 9 6 6 6 9
8 3 3 3 8 4 4 4 8
8 3 3 3 8 4 4 4 8
8 3 3 3 8 4 4 4 8
9 5 5 5 9 6 6 6 9
Is there some similarity when defining Halloween sudokus?

Yes there are (29 easy) hidden constraints but usefulness is always limited.
Can sometimes skip complicated steps in special designed puzzles. Not as useful compared with windoku.
creint

Posts: 231
Joined: 20 January 2018

### Latin Square + Halloween

This has no 3x3 blocks - difficulty: easy
Code: Select all
`.7.5..4..4.9..5.2..9......1.52...........43..3..........1....45.6.28.......4.8.9. ED=2.0/1.5/1.5`

Solution:
Hidden Text: Show
Code: Select all
`178523469489635127294357681652749813726194358345812976831976245967281534513468792 ED=2.0/1.5/1.5`
1to9only

Posts: 2267
Joined: 04 April 2018