Stuck on 32x32 sudoku

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Stuck on 32x32 sudoku

Postby Submachine » Fri Mar 26, 2021 4:54 pm

Hi everyone,

Hopefully I can get help here with bigger sudokus than 9x9. I tried my luck with a 32x32 sudoku in a newspaper, but it stumped me.

I made a copy in Microsoft Excel to allow adding multiple pencilmarks, but this is as far as I got. (See the attachment.)

[Pencilmark explanation: - green cells contain values I filled in
- small texts are pencilmarks. For example, 2/A/D means the cell can only have those values
- lowercase pencilmarks: h means horizontally linked, v means vertically linked, b means box linked. For example, if a row can only contain three '2'-s, they are all marked as 2h. Combinations can exist, for example: 4vbh.]


I am not looking for the final solution (the solution is accessible at the end of the newspaper anyway), instead I want to know what the next step is and why. And in case I would get stuck again later, a step-by-step solution would be helpful for reference, but that may be too much to ask for.

Alternatively, if someone manages to solve it, I would glady hear about solving techniques that make solving giant sudokus easier.


NOTE: If necessary, I can manually re-type the puzzle with a different format to input it easier into solving tools. Just please clarify what the format should look like.
Attachments
32x32 Sudoku.xlsx
Partially solved sudoku with chaotic pencilmarks
(19.39 KiB) Downloaded 9 times
Submachine
 
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Re: Stuck on 32x32 sudoku

Postby 1to9only » Fri Mar 26, 2021 6:50 pm

Code: Select all
 G Q . . E B . . . K . 7 . . . I O . 3 . 2 . . T . . . 0 9 4 . .
 F D . 1 . O . . . . 9 . E . 8 . . R . P S . . U G 7 3 Q . . K N
 P . U . . . . . 4 . . . . L 7 . 8 H . E . G . N J 9 . . R . . .
 4 . O E . . F 8 I Q 2 U J S . . 9 B 5 . D . V C H 6 T . . . 1 7
 3 R C . . 2 Q 6 G . . A H . . 0 M 4 U 7 . . 8 5 . . . . . . . D
 7 . . T . K U H . S V C O . F . . . . . 3 6 J . L . E . Q . . 8
 . . 8 . J . T . . E . F . M 1 V . . . C K O . . . . U 4 2 H . A
 H B V 9 . L . . M . 3 8 . 2 U Q S 1 F . 7 E . . . D I N . . . .
 . . Q U A F K . . 9 . R . . 5 . . E B V 1 3 . D M . G 2 H . 4 6
 C . . . . 9 L Q 3 1 . . R . B M P G . 5 A T . . . . 6 . . . O F
 R G D H . 4 O . . L N . . . 2 . . 8 . . . J . E 0 V 7 . . 3 . .
 A J 9 . . . . M 2 . . . I . E S 4 U . . . C F . D . . . . . N 1
 2 O 5 6 . I S P V C . 0 G 3 D 7 . . K R N 4 . . E 1 L . M B 8 J
 E T . F 2 D 1 . . G . P . . 9 . 3 . . N . 0 . . B . C . . . . R
 B V K . N E 0 . T . 8 . 1 4 H C L 6 . . . . . . Q I J . D . . .
 1 . . 4 . J B G E . . I T F . O H . S . . . 6 K P 3 . . . . 0 C
 L P . . . . 2 K 5 8 . . . I . H E . 4 S U . . 3 V R F J G . . .
 Q . . O . . H . . . . . . . 3 G J 9 . 8 . D . 4 . A . K . 1 M .
 D . . . . . . E . . R . 2 . 4 . . . . . G . T . . U 9 L . . C .
 V 1 R C . G 4 I . . M E 5 P . . F . 6 U O . S 8 7 . H . J D . K
 U . . . . . D A . J Q . . . K F G 7 . L . . . 6 T . . . . S E 9
 K 9 F . . U V N 6 . I 4 . . A . . . . . . M C . . G . . 8 R . 3
 T 5 G . . 3 . . . . F L Q . S N D M . O . . K A I 0 4 . . . . H
 M E . J F 8 . S A . G K U 1 L . R 3 . . 9 . 7 . O Q D C 4 N . .
 . . . D K 0 7 . . . E M . 9 I 1 V S R . . B . F . . P . 6 8 5 L
 0 . 3 V I 5 . . . . P 9 7 . . . 1 C N . 6 . E . . J . T . F . 4
 6 . . M Q V C 4 . R T G . . O . U D E 3 P 7 H . N 8 1 . S . . 0
 8 . 1 . . . . . Q O . . 4 . 6 D 7 . . G I . . 2 9 E M . . C H V
 S F E G 1 A 9 B 7 4 . V . H P U . . 8 I 5 N D M 3 C 0 6 T . R O
 . . . N . . 8 J L . S . . . Q 2 . . H . . . . 1 . . V 7 . U . E
 9 K . . D S E U 8 . . 6 N . J . . 0 . 4 . V . . . L Q . 1 . 7 .
 . 7 L Q 3 H . . B . . 1 S C V E 6 . . . T 8 O . . . R D . . P G

I've extracted the current state of the 32x32 sudoku, including solved cells, but excluding pencilmarks.
I'm assuming 0-9,A-V map to the numbers 1-32.

Grid in 1-32 format:
Code: Select all
 17 27  .  . 15 12  .  .  . 21  .  8  .  .  . 19 25  .  4  .  3  .  . 30  .  .  .  1 10  5  .  .
 16 14  .  2  . 25  .  .  .  . 10  . 15  .  9  .  . 28  . 26 29  .  . 31 17  8  4 27  .  . 21 24
 26  . 31  .  .  .  .  .  5  .  .  .  . 22  8  .  9 18  . 15  . 17  . 24 20 10  .  . 28  .  .  .
  5  . 25 15  .  . 16  9 19 27  3 31 20 29  .  . 10 12  6  . 14  . 32 13 18  7 30  .  .  .  2  8
  4 28 13  .  .  3 27  7 17  .  . 11 18  .  .  1 23  5 31  8  .  .  9  6  .  .  .  .  .  .  . 14
  8  .  . 30  . 21 31 18  . 29 32 13 25  . 16  .  .  .  .  .  4  7 20  . 22  . 15  . 27  .  .  9
  .  .  9  . 20  . 30  .  . 15  . 16  . 23  2 32  .  .  . 13 21 25  .  .  .  . 31  5  3 18  . 11
 18 12 32 10  . 22  .  . 23  .  4  9  .  3 31 27 29  2 16  .  8 15  .  .  . 14 19 24  .  .  .  .
  .  . 27 31 11 16 21  .  . 10  . 28  .  .  6  .  . 15 12 32  2  4  . 14 23  . 17  3 18  .  5  7
 13  .  .  .  . 10 22 27  4  2  .  . 28  . 12 23 26 17  .  6 11 30  .  .  .  .  7  .  .  . 25 16
 28 17 14 18  .  5 25  .  . 22 24  .  .  .  3  .  .  9  .  .  . 20  . 15  1 32  8  .  .  4  .  .
 11 20 10  .  .  .  . 23  3  .  .  . 19  . 15 29  5 31  .  .  . 13 16  . 14  .  .  .  .  . 24  2
  3 25  6  7  . 19 29 26 32 13  .  1 17  4 14  8  .  . 21 28 24  5  .  . 15  2 22  . 23 12  9 20
 15 30  . 16  3 14  2  .  . 17  . 26  .  . 10  .  4  .  . 24  .  1  .  . 12  . 13  .  .  .  . 28
 12 32 21  . 24 15  1  . 30  .  9  .  2  5 18 13 22  7  .  .  .  .  .  . 27 19 20  . 14  .  .  .
  2  .  .  5  . 20 12 17 15  .  . 19 30 16  . 25 18  . 29  .  .  .  7 21 26  4  .  .  .  .  1 13
 22 26  .  .  .  .  3 21  6  9  .  .  . 19  . 18 15  .  5 29 31  .  .  4 32 28 16 20 17  .  .  .
 27  .  . 25  .  . 18  .  .  .  .  .  .  .  4 17 20 10  .  9  . 14  .  5  . 11  . 21  .  2 23  .
 14  .  .  .  .  .  . 15  .  . 28  .  3  .  5  .  .  .  .  . 17  . 30  .  . 31 10 22  .  . 13  .
 32  2 28 13  . 17  5 19  .  . 23 15  6 26  .  . 16  .  7 31 25  . 29  9  8  . 18  . 20 14  . 21
 31  .  .  .  .  . 14 11  . 20 27  .  .  . 21 16 17  8  . 22  .  .  .  7 30  .  .  .  . 29 15 10
 21 10 16  .  . 31 32 24  7  . 19  5  .  . 11  .  .  .  .  .  . 23 13  .  . 17  .  .  9 28  .  4
 30  6 17  .  .  4  .  .  .  . 16 22 27  . 29 24 14 23  . 25  .  . 21 11 19  1  5  .  .  .  . 18
 23 15  . 20 16  9  . 29 11  . 17 21 31  2 22  . 28  4  .  . 10  .  8  . 25 27 14 13  5 24  .  .
  .  .  . 14 21  1  8  .  .  . 15 23  . 10 19  2 32 29 28  .  . 12  . 16  .  . 26  .  7  9  6 22
  1  .  4 32 19  6  .  .  .  . 26 10  8  .  .  .  2 13 24  .  7  . 15  .  . 20  . 30  . 16  .  5
  7  .  . 23 27 32 13  5  . 28 30 17  .  . 25  . 31 14 15  4 26  8 18  . 24  9  2  . 29  .  .  1
  9  .  2  .  .  .  .  . 27 25  .  .  5  .  7 14  8  .  . 17 19  .  .  3 10 15 23  .  . 13 18 32
 29 16 15 17  2 11 10 12  8  5  . 32  . 18 26 31  .  .  9 19  6 24 14 23  4 13  1  7 30  . 28 25
  .  .  . 24  .  .  9 20 22  . 29  .  .  . 27  3  .  . 18  .  .  .  .  2  .  . 32  8  . 31  . 15
 10 21  .  . 14 29 15 31  9  .  .  7 24  . 20  .  .  1  .  5  . 32  .  .  . 22 27  .  2  .  8  .
  .  8 22 27  4 18  .  . 12  .  .  2 29 13 32 15  7  .  .  . 30  9 25  .  .  . 28 14  .  . 26 17

Now I just need a 32x32 sudoku solver!

[Edit] Fixed missing dots (empty cells) at end of a couple of lines. Thx to creint for pointing this out.
Last edited by 1to9only on Fri Mar 26, 2021 11:23 pm, edited 1 time in total.
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Re: Stuck on 32x32 sudoku

Postby 1to9only » Fri Mar 26, 2021 8:12 pm

Next Steps:: Show
Naked Single: R16C15: 24
Naked Single: R5C15: 30
Naked Single: R20C15: 1
I'm using 1-32 number format, so you'll have to convert 1-32 to 0-9,A-V.

Afterwards:: Show
There is a quite a bunch of Pointing and Claiming that follows after above.
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Re: Stuck on 32x32 sudoku

Postby creint » Fri Mar 26, 2021 10:57 pm

1to9only: you were missing one last . in your format, 31 items on one line.
Code: Select all
 12 32 21  . 24 15  1  . 30  .  9  .  2  5 18 13 22  7  .  .  .  .  .  . 27 19 20  . 14  .  .

Code: Select all
 27  .  . 25  .  . 18  .  .  .  .  .  .  .  4 17 20 10  .  9  . 14  .  5  . 11  . 21  .  2 23


It needs some rounds of locked singles, if you don't use the naked singles you may need many rounds of sets.
Easiest advise is just to solve it with a solver, it saves a lot of time.

It is not about needing more techniques to solve those, because most of them just use the basics. It's more about looking in the right places to save time. Looking randomly is very ineffective.

Scan the whole grid once for singles + locked singles. Not applying your result. Yes this takes a lot of time and it feels like you don't make progress. Finding naked singles without pencilmarks is hard, but if you don't create pencilmarks than you still need them in this puzzle for sets if you don't use them.

If find a single you write down your excluded pencilmark locations.
Make sure you never miss anything or else you need to start scanning the whole puzzle again for something if your affected constraints dry up.

Apply your results and repeat but this time look only in your affected constraints.
You only need to scan affected cells for naked singles.
And scan affected digits in constraints for hidden single/locked singles.
Example: -1r1c1 -> scan r1c1, 1r1, 1c1, 1b1; you don't need to scan other digits in row 1.
r1c1 only 1 pencilmark left in cell?
1r1 only 1 pencilmark left or is the group pencilmarks of digit 1 contained in another constraint?

You can skip delays scanning for locked singles but you should resume scanning where you left off, maybe in reverse gives faster results.
On larger puzzles the chance of finding something at random decreases.

Example layout
Step 1
-1r1c1
-2r1c2
Scanlist 1
[constraint, hidden single, naked single, locked single]
r1c1, x, x, x
r1c2, x, x
1r1
1c1
1b1
2r1
2c1
2b1

You could keep seperate tables to index pencilmarks, but more bookkeeping can give errors.
For this puzzle you need ~160+ steps. 2500 initial pencilmarks / 160 = ~15 pencilmarks each step, 450 initial empty cells / 160 = ~3 filled cell each step.
I could generate one that only takes ~6 steps where the chance of finding something is much higher.

Let me know if this method works for manual solving.
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Re: Stuck on 32x32 sudoku

Postby Submachine » Sat Mar 27, 2021 10:17 pm

Thanks for the responses! I must have been really tired to not notice that single. Especially ironic if you see my pencilmark for that cell.

I already scanned the entire grid for naked singles, that was the only one I missed.

I would like to use a solver, but most online tools I found were for 9x9 grids. And I do use pencilmarks, though I may be thinking of something different. Most of the time when I finish all basic techniques I know of and don't find anything, I am left with looking randomly, which - as you said - is indeed very ineffective.

Today I started creating an even bigger grid, where each cell is a 6x6 grid containing all possible values. In this bigger grid, I can keep track of ruled out values easier, but it will be a lot of time to make. (And it will all be manual, so errors can happen, as already proved by the missed single.)
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Re: Stuck on 32x32 sudoku

Postby creint » Sun Mar 28, 2021 9:13 pm

Submachine wrote:Today I started creating an even bigger grid, where each cell is a 6x6 grid containing all possible values. In this bigger grid, I can keep track of ruled out values easier, but it will be a lot of time to make. (And it will all be manual, so errors can happen, as already proved by the missed single.)


You want to create manually a large grid instead of solving one?
My solver can do all those things. If you cannot paste it then you need to do manual designing, cells+constraint. Probably complex for other users.
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Re: Stuck on 32x32 sudoku

Postby 1to9only » Mon Mar 29, 2021 2:43 pm

See: http://forum.enjoysudoku.com/giant-sudoku-s-16x16-25x25-36x36-100x100-t6578.html
Near the end of the thread, the 25x25 and 36x36 sudokus posted are solvable with singles only.
The last post has a link to a github repo that contains some pascal source code.
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Re: Stuck on 32x32 sudoku

Postby Submachine » Tue Mar 30, 2021 6:29 am

1to9only wrote:See: http://forum.enjoysudoku.com/giant-sudoku-s-16x16-25x25-36x36-100x100-t6578.html
Near the end of the thread, the 25x25 and 36x36 sudokus posted are solvable with singles only.
The last post has a link to a github repo that contains some pascal source code.

Thank you, though I am still trying to solve my current puzzle first. :) And the size of this puzzle is 32x32, which does not fit the description.

creint wrote:You want to create manually a large grid instead of solving one? My solver can do all those things.

No no, I still intend to solve it. But you said I need more pencilmarks to solve this puzzle, and creating a larger grid is my only way to keep track of 2-to-32 pencilmarks per cell.

There may be a confusion, because I did not receive a solver (you said your solver can do it, but I don't have it). But I would be happy to receive one. I just don't know much about github and pascal source codes, so I would prefer something with a user-friendly interface.

Should I create a new post in a different subtopic to look for a solver?
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Re: Stuck on 32x32 sudoku

Postby 1to9only » Tue Mar 30, 2021 10:23 am

For the partially solved 32x32 sudoku in post #1:
Solution Path:: Show
Code: Select all
Naked Single: R16C15: 24
Naked Single: R5C15: 30
Naked Single: R20C15: 1
Pointing: Cells R1C3,R2C3: 20 in block and column: -20r25c3, -20r27c3
Pointing: Cells R4C20,R8C20: 21 in block and column: -21r32c20, -21r26c20, -21r19c20, -21r30c20
Pointing: Cells R1C22,R2C22: 18 in block and column: -18r19c22, -18r24c22, -18r21c22
Pointing: Cells R2C23,R8C23: 5 in block and column: -5r30c23, -5r25c23
Pointing: Cells R12C4,R15C4: 4 in block and column: -4r19c4, -4r21c4
Pointing: Cells R12C4,R15C4: 26 in block and column: -26r28c4, -26r31c4
Pointing: Cells R9C26,R10C26: 24 in block and column: -24r20c26, -24r21c26
Pointing: Cells R11C28,R13C28,R15C28: 16 in block and column: -16r3c28, -16r5c28, -16r28c28, -16r31c28, -16r27c28
Pointing: Cells R12C28,R15C28,R16C28: 28 in block and column: -28r4c28, -28r6c28
Pointing: Cells R17C5,R19C5,R21C5,R22C5: 25 in block and column: -25r30c5
Pointing: Cells R18C14,R21C14,R23C14: 28 in block and column: -28r26c14, -28r31c14, -28r6c14, -28r30c14, -28r1c14, -28r28c14
Pointing: Cells R18C19,R21C19,R23C19: 13 in block and column: -13r11c19
Pointing: Cells R18C29,R19C29: 16 in block and column: -16r5c29
Pointing: Cells R25C10,R26C10,R31C10,R32C10: 3 in block and column: -3r18c10, -3r20c10, -3r24c10, -3r22c10, -3r23c10
Pointing: Cells R21C26,R21C28: 23 in block and row: -23r21c13, -23r21c6, -23r21c5
Pointing: Cells R17C13,R17C15: 23 in block and row: -23r17c6, -23r17c5
Claiming: Cells R8C29,R8C30: 25 in row and block: -25r5c30, -25r5c29, -25r3c30
Claiming: Cells R25C9,R25C10: 24 in row and block: -24r32c10, -24r28c12
Claiming: Cells R17C12,R18C12,R19C12,R21C12: 24 in column and block: -24r18c10, -24r20c10, -24r20c9, -24r19c9, -24r19c10, -24r21c9, -24r18c9
Hidden Single: R20C18: 24 in row
Hidden Single: R20C31: 11 in row
Hidden Single: R20C22: 27 in row
Hidden Single: R20C26: 3 in row
Hidden Single: R3C27: 3 in block
Hidden Single: R20C5: 22 in row
Naked Single: R17C22: 2
Naked Single: R20C9: 10
Hidden Single: R17C13: 10 in block
Hidden Single: R6C16: 10 in block
Hidden Single: R2C16: 5 in block
Hidden Single: R8C23: 5 in block
Hidden Single: R6C5: 5 in block
Hidden Single: R17C15: 23 in block
Hidden Single: R30C13: 23 in block
Hidden Single: R27C13: 16 in block
Hidden Single: R11C9: 16 in column
Hidden Single: R9C13: 1 in column
Hidden Single: R1C15: 13 in column
Hidden Single: R8C25: 13 in block
Hidden Single: R2C29: 13 in block
Pointing: Cells R19C9,R21C9,R23C9: 2 in block and column: -2r6c9, -2r1c9
Hidden Single: R6C28: 2 in row
Hidden Single: R5C11: 2 in row
Pointing: Cells R26C7,R32C7: 23 in block and column: -23r1c7, -23r2c7, -23r19c7, -23r3c7
Pointing: Cells R3C11,R3C12: 25 in block and row: -25r3c28
Pointing: Cells R4C15,R4C16: 28 in block and row: -28r4c22, -28r4c6, -28r4c5
Pointing: Cells R5C25,R5C26,R5C27: 21 in block and row: -21r5c14, -21r5c4
Hidden Single: R3C4: 21 in block
Pointing: Cells R22C13,R22C14: 14 in block and row: -14r22c10
Claiming: Cells R5C30,R5C31: 20 in row and block: -20r1c31, -20r8c31, -20r2c30, -20r8c30
Hidden Single: R8C20: 20 in row
Hidden Single: R1C20: 7 in block
Hidden Single: R4C20: 21 in block
Hidden Single: R8C13: 21 in block
Hidden Single: R8C7: 11 in row
Hidden Single: R26C7: 17 in column
Hidden Single: R32C7: 23 in block
Hidden Single: R4C15: 17 in column
Hidden Single: R26C15: 28 in column
Hidden Single: R8C5: 17 in block
Hidden Single: R4C16: 28 in block
Hidden Single: R4C29: 4 in row
Hidden Single: R30C31: 4 in block
Hidden Single: R26C31: 14 in block
Hidden Single: R29C30: 27 in block
Hidden Single: R26C20: 23 in row
Hidden Single: R25C20: 27 in block
Hidden Single: R26C24: 27 in block
Hidden Single: R32C29: 24 in row
Naked Single: R29C13: 22
Hidden Single: R27C24: 22 in row
Hidden Single: R26C8: 22 in row
Hidden Single: R25C8: 25 in block
Hidden Single: R30C1: 25 in block
Hidden Single: R32C8: 3 in block
Hidden Single: R28C8: 16 in block
Hidden Single: R31C19: 25 in block
Hidden Single: R14C18: 25 in block
Hidden Single: R26C27: 25 in block
Hidden Single: R25C3: 30 in row
Hidden Single: R31C3: 26 in row
Naked Single: R25C1: 20
Hidden Single: R32C24: 20 in block
Pointing: Cells R1C13,R7C13: 26 in block and column: -26r11c13
Pointing: Cells R10C19,R14C19: 20 in block and column: -20r28c19
Pointing: Cells R25C2,R26C2: 18 in block and column: -18r19c2, -18r21c2
Pointing: Cells R26C22,R28C22: 29 in block and column: -29r15c22
Pointing: Cells R30C22,R30C23: 10 in block and row: -10r30c20
Pointing: Cells R32C19,R32C20: 10 in block and row: -10r32c30
Pointing: Cells R27C30,R27C31: 20 in block and row: -20r27c9
Naked Single: R27C9: 21
Naked Single: R29C11: 20
Hidden Single: R28C18: 20 in block
Hidden Single: R28C19: 22 in block
Hidden Single: R30C18: 26 in block
Claiming: Cells R1C9,R6C9,R7C9: 14 in column and block: -14r3c12, -14r7c11, -14r3c10, -14r3c11, -14r1c11
Claiming: Cells R29C17,R29C18: 3 in row and block: -3r31c17
Claiming: Cells R29C17,R29C18: 21 in row and block: -21r32c18, -21r30c17
Claiming: Cells R32C10,R32C11: 1 in row and block: -1r28c11, -1r30c10
Claiming: Cells R32C25,R32C26: 5 in row and block: -5r30c25, -5r25c25, -5r30c26, -5r25c26
Naked Single: R25C26: 18
Hidden Single: R26C2: 18 in block
Naked Single: R26C9: 31
Hidden Single: R32C25: 31 in row
Hidden Single: R32C26: 5 in block
Hidden Single: R10C25: 5 in block
Hidden Single: R14C11: 5 in block
Hidden Single: R32C30: 21 in row
Pointing: Cells R12C10,R12C11: 7 in block and row: -7r12c6, -7r12c7, -7r12c5, -7r12c14
Hidden Single: R11C5: 7 in block
Hidden Single: R30C6: 7 in block
Naked Single: R11C13: 11
Naked Single: R25C13: 4
Hidden Single: R3C16: 4 in block
Hidden Single: R7C8: 4 in block
Hidden Single: R7C6: 8 in block
Hidden Single: R5C5: 10 in block
Hidden Single: R3C5: 29 in block
Hidden Single: R12C7: 4 in block
Hidden Single: R15C4: 4 in block
Hidden Single: R12C4: 26 in block
Hidden Single: R23C8: 10 in block
Pointing: Cells R1C14,R2C14,R6C14: 6 in block and column: -6r31c14, -6r30c14, -6r27c14, -6r28c14
Pointing: Cells R1C14,R2C14,R6C14: 11 in block and column: -11r26c14, -11r31c14, -11r30c14, -11r27c14, -11r28c14
Naked Single: R27C14: 12
Hidden Single: R26C29: 12 in row
Naked Single: R5C14: 24
Hidden Single: R25C10: 24 in column
Naked Single: R25C9: 13
Hidden Single: R30C2: 13 in block
Hidden Single: R31C21: 13 in block
Naked Single: R25C21: 5
Hidden Single: R30C3: 5 in block
Hidden Single: R21C2: 5 in block
Hidden Single: R19C2: 4 in block
Naked Single: R28C29: 11
Naked Single: R28C2: 31
Hidden Single: R25C23: 31 in block
Hidden Single: R25C28: 17 in row
Naked Single: R28C11: 6
Naked Single: R28C12: 4
Hidden Single: R20C10: 4 in block
Hidden Single: R21C28: 4 in block
Hidden Single: R21C26: 23 in block
Hidden Single: R31C23: 4 in block
Hidden Single: R20C16: 30 in row
Hidden Single: R20C28: 12 in row
Hidden Single: R30C26: 12 in block
Hidden Single: R5C27: 12 in block
Hidden Single: R31C17: 12 in block
Hidden Single: R28C4: 12 in block
Hidden Single: R31C4: 28 in block
Hidden Single: R32C1: 6 in block
Hidden Single: R30C17: 6 in block
Hidden Single: R30C20: 30 in block
Hidden Single: R12C27: 21 in column
Hidden Single: R10C11: 21 in block
Hidden Single: R5C26: 21 in column
Hidden Single: R5C28: 25 in block
Hidden Single: R3C28: 32 in block
Hidden Single: R4C28: 23 in block
Hidden Single: R1C26: 16 in column
Hidden Single: R31C14: 30 in row
Hidden Single: R30C14: 17 in block
Hidden Single: R28C14: 1 in block
Hidden Single: R31C24: 17 in block
Hidden Single: R15C23: 17 in block
Hidden Single: R12C30: 17 in block
Hidden Single: R28C22: 21 in row
Hidden Single: R26C22: 29 in block
Hidden Single: R28C28: 29 in block
Hidden Single: R30C25: 21 in row
Hidden Single: R31C25: 16 in block
Hidden Single: R30C10: 16 in row
Hidden Single: R30C12: 14 in block
Hidden Single: R17C11: 14 in block
Hidden Single: R16C10: 14 in block
Hidden Single: R15C10: 23 in block
Hidden Single: R10C19: 14 in block
Hidden Single: R6C20: 14 in block
Hidden Single: R14C19: 20 in block
Hidden Single: R11C19: 23 in block
Hidden Single: R11C20: 2 in block
Hidden Single: R18C11: 13 in block
Hidden Single: R21C13: 13 in block
Hidden Single: R23C19: 13 in block
Hidden Single: R17C5: 13 in column
Hidden Single: R3C6: 13 in column
Hidden Single: R2C5: 23 in block
Hidden Single: R19C6: 23 in block
Hidden Single: R21C6: 2 in block
Hidden Single: R17C6: 27 in block
Hidden Single: R14C13: 9 in column
Hidden Single: R18C13: 32 in column
Hidden Single: R9C2: 9 in row
Hidden Single: R16C2: 22 in block
Hidden Single: R23C9: 2 in row
Hidden Single: R30C29: 19 in row
Hidden Single: R32C10: 19 in row
Hidden Single: R32C11: 1 in block
Hidden Single: R31C28: 19 in row
Hidden Single: R27C28: 6 in block
Hidden Single: R31C16: 6 in block
Naked Single: R5C10: 26
Naked Single: R5C25: 29
Naked Single: R9C14: 20
Hidden Single: R10C12: 20 in block
Naked Single: R12C20: 1
Naked Single: R15C21: 28
Naked Single: R27C16: 11
Hidden Single: R25C2: 11 in block
Hidden Single: R25C25: 3 in row
Hidden Single: R26C25: 11 in block
Hidden Single: R1C27: 11 in block
Hidden Single: R1C25: 9 in block
Hidden Single: R7C25: 28 in block
Hidden Single: R31C10: 11 in column
Hidden Single: R26C10: 3 in block
Hidden Single: R31C11: 18 in block
Hidden Single: R4C22: 11 in row
Hidden Single: R30C23: 11 in block
Hidden Single: R30C21: 1 in block
Hidden Single: R30C22: 10 in block
Hidden Single: R28C23: 28 in block
Hidden Single: R30C5: 28 in row
Hidden Single: R12C6: 28 in block
Hidden Single: R16C28: 28 in block
Hidden Single: R3C19: 11 in row
Hidden Single: R4C30: 22 in row
Naked Single: R1C11: 22
Hidden Single: R7C18: 22 in block
Hidden Single: R5C4: 22 in block
Hidden Single: R2C22: 22 in column
Hidden Single: R1C22: 18 in block
Naked Single: R1C18: 32
Hidden Single: R2C8: 32 in block
Naked Single: R5C21: 16
Hidden Single: R3C31: 16 in block
Hidden Single: R19C22: 16 in block
Hidden Single: R18C29: 16 in block
Hidden Single: R22C31: 22 in block
Hidden Single: R19C32: 27 in block
Naked Single: R5C22: 19
Naked Single: R32C19: 10
Pointing: Cells R2C3,R6C3: 11 in block and column: -11r17c3, -11r19c3
Pointing: Cells R3C13,R7C13: 12 in block and column: -12r22c13
Naked Single: R22C13: 14
Hidden Single: R1C14: 14 in block
Hidden Single: R3C8: 14 in block
Hidden Single: R1C8: 2 in block
Hidden Single: R7C9: 14 in block
Hidden Single: R3C23: 2 in block
Hidden Single: R3C21: 27 in row
Hidden Single: R1C23: 23 in block
Hidden Single: R16C18: 27 in row
Hidden Single: R13C23: 27 in row
Naked Single: R1C13: 26
Naked Single: R11C21: 12
Pointing: Cells R6C26,R7C26: 6 in block and column: -6r12c26, -6r14c26
Hidden Single: R16C27: 6 in block
Hidden Single: R21C27: 9 in column
Hidden Single: R18C27: 24 in block
Hidden Single: R22C27: 29 in column
Naked Single: R14C26: 29
Hidden Single: R9C9: 29 in row
Naked Single: R10C26: 24
Hidden Single: R9C1: 24 in block
Hidden Single: R7C1: 19 in column
Naked Single: R14C9: 18
Pointing: Cells R14C3,R16C3: 23 in block and column: -23r6c3
Pointing: Cells R9C17,R11C17: 19 in block and column: -19r6c17, -19r19c17, -19r2c17
Pointing: Cells R17C3,R19C3,R21C3: 24 in block and column: -24r6c3, -24r1c3
Pointing: Cells R18C10,R19C10,R22C10,R23C10: 8 in block and column: -8r12c10
Pointing: Cells R2C17,R2C19: 30 in block and row: -30r2c10, -30r2c30, -30r2c12
Pointing: Cells R10C2,R10C3,R10C4: 29 in block and row: -29r10c24
Hidden Single: R15C24: 29 in block
Hidden Single: R12C24: 25 in block
Hidden Single: R9C26: 25 in block
Hidden Single: R15C12: 25 in block
Hidden Single: R3C11: 25 in block
Hidden Single: R12C26: 30 in block
Hidden Single: R17C30: 25 in row
Hidden Single: R8C29: 25 in block
Naked Single: R9C11: 8
Naked Single: R12C19: 8
Naked Single: R15C19: 3
Pointing: Cells R2C30,R3C30,R6C30,R8C30: 1 in block and column: -1r19c30
Pointing: Cells R10C30,R16C30: 3 in block and column: -3r31c30, -3r27c30, -3r23c30
Hidden Single: R31C32: 3 in row
Hidden Single: R31C30: 23 in row
Hidden Single: R3C32: 23 in block
Hidden Single: R6C2: 23 in block
Pointing: Cells R2C3,R6C3: 3 in block and column: -3r24c3, -3r27c3, -3r18c3, -3r21c3
Hidden Single: R27C2: 3 in block
Hidden Single: R27C3: 19 in block
Pointing: Cells R6C31,R7C31: 12 in block and column: -12r17c31, -12r24c31, -12r23c31
Pointing: Cells R10C2,R10C4: 19 in block and row: -19r10c30, -19r10c23, -19r10c24
Naked Single: R10C23: 3
Hidden Single: R16C30: 3 in block
Hidden Single: R16C20: 10 in row
Hidden Single: R16C11: 11 in row
Hidden Single: R13C11: 31 in block
Hidden Single: R18C12: 3 in row
Hidden Single: R19C12: 29 in block
Hidden Single: R19C3: 24 in row
Naked Single: R16C22: 31
Hidden Single: R10C5: 31 in block
Hidden Single: R10C28: 9 in row
Hidden Single: R10C24: 18 in row
Hidden Single: R14C24: 8 in block
Naked Single: R10C14: 32
Naked Single: R12C14: 27
Hidden Single: R11C12: 27 in block
Hidden Single: R14C31: 27 in block
Naked Single: R12C28: 18
Hidden Single: R13C5: 18 in block
Naked Single: R13C24: 10
Hidden Single: R7C23: 10 in block
Naked Single: R14C3: 23
Hidden Single: R16C21: 23 in block
Hidden Single: R12C21: 9 in block
Hidden Single: R16C5: 9 in block
Hidden Single: R15C8: 8 in block
Hidden Single: R12C5: 32 in block
Hidden Single: R14C21: 32 in block
Hidden Single: R16C29: 32 in block
Hidden Single: R16C3: 8 in row
Hidden Single: R18C21: 22 in column
Hidden Single: R12C29: 22 in row
Hidden Single: R17C4: 8 in row
Hidden Single: R19C4: 11 in block
Hidden Single: R23C4: 9 in block
Hidden Single: R17C18: 11 in block
Hidden Single: R32C20: 11 in block
Hidden Single: R32C18: 16 in row
Hidden Single: R13C17: 11 in block
Hidden Single: R15C20: 16 in block
Hidden Single: R13C28: 16 in block
Hidden Single: R13C18: 30 in row
Hidden Single: R18C14: 15 in row
Hidden Single: R18C8: 28 in row
Hidden Single: R1C7: 28 in block
Hidden Single: R4C6: 24 in block
Hidden Single: R7C2: 24 in block
Hidden Single: R4C5: 26 in block
Hidden Single: R4C2: 1 in row
Hidden Single: R8C8: 1 in block
Hidden Single: R6C9: 28 in block
Hidden Single: R1C9: 24 in block
Hidden Single: R2C9: 20 in block
Hidden Single: R1C3: 20 in block
Hidden Single: R6C17: 24 in block
Hidden Single: R8C24: 28 in block
Hidden Single: R28C7: 24 in block
Hidden Single: R28C6: 26 in block
Hidden Single: R28C5: 30 in block
Hidden Single: R18C6: 30 in column
Hidden Single: R21C19: 32 in row
Naked Single: R3C2: 7
Hidden Single: R7C13: 7 in column
Hidden Single: R3C13: 12 in column
Hidden Single: R12C11: 7 in column
Hidden Single: R7C11: 12 in column
Hidden Single: R6C31: 12 in block
Hidden Single: R2C23: 12 in block
Hidden Single: R7C31: 17 in block
Hidden Single: R6C19: 17 in block
Hidden Single: R7C4: 29 in row
Hidden Single: R1C4: 6 in block
Hidden Single: R7C26: 6 in row
Hidden Single: R6C26: 26 in block
Hidden Single: R7C24: 26 in block
Hidden Single: R6C24: 1 in block
Naked Single: R5C29: 15
Hidden Single: R10C30: 15 in block
Hidden Single: R10C29: 8 in block
Naked Single: R14C8: 6
Naked Single: R21C21: 18
Hidden Single: R24C3: 18 in block
Hidden Single: R2C12: 18 in column
Naked Single: R22C24: 12
Naked Single: R22C16: 20
Hidden Single: R23C21: 20 in block
Hidden Single: R22C21: 15 in column
Hidden Single: R19C7: 20 in block
Hidden Single: R23C28: 15 in block
Hidden Single: R22C28: 26 in block
Pointing: Cells R2C7,R3C7: 6 in block and column: -6r24c7
Pointing: Cells R2C10,R3C10: 1 in block and column: -1r18c10, -1r24c10, -1r19c10, -1r22c10
Hidden Single: R24C19: 1 in row
Hidden Single: R7C17: 1 in row
Hidden Single: R7C19: 27 in row
Hidden Single: R22C17: 27 in block
Hidden Single: R22C19: 30 in block
Hidden Single: R2C17: 30 in block
Hidden Single: R6C18: 3 in block
Hidden Single: R2C19: 19 in block
Hidden Single: R2C3: 3 in block
Hidden Single: R6C3: 11 in block
Hidden Single: R3C7: 19 in block
Hidden Single: R2C7: 6 in block
Hidden Single: R6C14: 6 in block
Hidden Single: R2C14: 11 in block
Hidden Single: R6C30: 19 in row
Hidden Single: R19C19: 2 in block
Hidden Single: R18C19: 26 in column
Hidden Single: R19C18: 19 in block
Hidden Single: R22C18: 6 in block
Hidden Single: R29C18: 21 in column
Hidden Single: R29C17: 3 in block
Hidden Single: R19C17: 21 in block
Hidden Single: R22C25: 2 in block
Hidden Single: R24C24: 19 in column
Hidden Single: R19C24: 32 in column
Hidden Single: R18C32: 19 in block
Hidden Single: R11C31: 19 in block
Hidden Single: R9C17: 19 in block
Hidden Single: R11C17: 13 in block
Hidden Single: R9C8: 13 in block
Hidden Single: R11C8: 30 in block
Hidden Single: R14C23: 19 in block
Hidden Single: R9C23: 22 in block
Hidden Single: R14C16: 22 in block
Hidden Single: R14C14: 7 in block
Hidden Single: R11C14: 31 in block
Hidden Single: R11C16: 21 in block
Hidden Single: R9C16: 26 in block
Hidden Single: R9C30: 30 in row
Hidden Single: R14C29: 21 in block
Hidden Single: R11C32: 29 in block
Hidden Single: R1C31: 29 in block
Hidden Single: R1C32: 31 in row
Hidden Single: R15C31: 31 in block
Hidden Single: R14C28: 31 in block
Hidden Single: R14C30: 11 in row
Hidden Single: R15C28: 11 in block
Hidden Single: R11C28: 10 in block
Hidden Single: R15C30: 10 in block
Hidden Single: R21C4: 19 in block
Hidden Single: R10C2: 19 in block
Hidden Single: R18C2: 29 in column
Hidden Single: R10C3: 29 in block
Hidden Single: R10C4: 1 in block
Hidden Single: R22C4: 3 in column
Hidden Single: R24C20: 3 in block
Hidden Single: R19C20: 12 in block
Hidden Single: R22C20: 18 in block
Hidden Single: R19C10: 18 in block
Hidden Single: R24C16: 12 in block
Hidden Single: R19C16: 7 in block
Hidden Single: R26C16: 9 in column
Hidden Single: R26C14: 21 in block
Hidden Single: R19C14: 9 in block
Hidden Single: R18C25: 7 in block
Hidden Single: R19C25: 6 in block
Hidden Single: R17C3: 7 in block
Hidden Single: R23C31: 3 in block
Hidden Single: R21C22: 3 in block
Hidden Single: R23C22: 28 in block
Hidden Single: R21C14: 28 in block
Hidden Single: R22C14: 25 in block
Hidden Single: R23C14: 8 in block
Hidden Single: R19C30: 8 in block
Hidden Single: R17C32: 12 in block
Hidden Single: R23C29: 31 in block
Hidden Single: R18C10: 31 in block
Hidden Single: R22C10: 8 in block
Hidden Single: R22C5: 1 in row
Hidden Single: R18C5: 8 in block
Hidden Single: R21C5: 6 in block
Hidden Single: R23C5: 12 in block
Hidden Single: R19C5: 25 in column
Hidden Single: R21C12: 12 in block
Hidden Single: R12C10: 12 in block
Hidden Single: R12C12: 6 in block
Hidden Single: R18C3: 12 in block
Hidden Single: R21C3: 1 in block
Hidden Single: R17C12: 24 in block
Hidden Single: R3C12: 30 in column
Hidden Single: R21C9: 25 in block
Hidden Single: R19C9: 26 in block
Hidden Single: R18C9: 1 in column
Hidden Single: R18C23: 6 in row
Hidden Single: R19C29: 1 in row
Hidden Single: R15C22: 6 in block
Hidden Single: R11C23: 26 in block
Hidden Single: R24C22: 26 in column
Hidden Single: R11C29: 6 in row
Hidden Single: R15C32: 26 in block
Hidden Single: R21C29: 26 in column
Hidden Single: R21C23: 24 in row
Hidden Single: R17C23: 1 in block
Hidden Single: R17C31: 30 in row
Hidden Single: R8C30: 26 in block
Hidden Single: R8C32: 30 in block
Hidden Single: R24C32: 6 in column
Hidden Single: R3C30: 6 in block
Hidden Single: R3C10: 1 in row
Hidden Single: R8C10: 6 in block
Hidden Single: R2C10: 7 in block
Hidden Single: R2C30: 1 in row
Hidden Single: R8C31: 7 in row
Hidden Single: R23C7: 26 in block
Hidden Single: R24C7: 7 in block
Hidden Single: R24C10: 30 in block
Hidden Single: R23C10: 32 in block
Hidden Single: R23C30: 7 in row
Hidden Single: R24C31: 32 in block
Hidden Single: R5C30: 32 in block
Hidden Single: R5C31: 20 in block
Hidden Single: R27C30: 20 in column
Hidden Single: R27C31: 10 in block

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Joined: 04 April 2018


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