The New Sudoku Players' Forum

[groston]

I typically use Enjoy Sudoku on my phone (Difficult level - working on stepping up a level), but occasionally I visit puzzlemix.com. I tried one of their Consecutive Sudoku puzzles. The one added constraint is that white bars between squares indicate that the squares are consecutive - meaning that the numbers in these two squares have a numerical difference of '1'.

This http://pairofdocs.net/wp-content/uploads/2023/01/NowWhat.jpg is the puzzle that is troubling me. Yes, I can cheat, try one of the 50% squares, and see if it is the correct number; but I haven't got the foggiest idea of how to solve this properly. Any suggestions? Could simply be a bad puzzle and I know those happen on this site because one I completed the other day got down to a configuration in which there were several square with the same two numbers and no way to chose one or the other.

[Hajime]

r5c8=5 => r4c8<>6 => r4c7=6 if I trust the candidates, but I hesitate.
Why is r4c9 and r6c9 not having candidate 6?
Why in box8 the sequence of found clues 6,7,8 in stead of 6,5,4?
But you are right. Difficult puzzle. Too hard for manual solving?

Edit: Image recovered and in code

Code: Select all

#1//B4,CS
.............3.......................7.....5.......................6.............
.....1..............1..1.....1...1..1....11.........1...............1......1..1..
....1...1...1.1...1..........1.11..1.1.............1....11.1......1..............


[thelardoffear]

The puzzle is valid and has a single solution if using the additional constraint that cells without a bar are not consecutive.

I also couldn't see any mistakes with the eliminations in the picture.

My solver only required naked pairs to clean up box 4 and did the rest with standard sudoku and (non-)consecutive rules.

The sequence in box 8 is not 6,5,4 or it would be impossible to make the other sequence in the box (r7c4-r9c5).

[groston]

I missed the rule "that cells without a bar are not consecutive". With this rule, I now see what to do.

[Hajime]

My solver only required naked pairs to clean up...

The 3 in box2 can be erased, leaving only 3 clues and the puzzle can still be solved using naked pairs.
Even if all clues are erased, a clueless Sudoku, forcing/guessing methods are needed but there are only two solutions:

Code: Select all

183946527925731846647852319592184673871693452364275198739518264258467931416329785 
927164583185379264463258791518926437239417658746835912371592846852643179694781325

The 2x72 constraints of (non)consecutive pairs-of-cells are pretty strong.
So one non-5 single clue determines the unique solution.

[1to9only]

The OP image link is dead. The puzzle was first posted on 11 Dec here: https://puzzlemix.com/playgrid.php?id=92977&type=consecutive&share=1

puzzle in text format: Show

Code: Select all

 0 . 0 . 0 . 0 . 0 . 0 | 0 . 0 . 0
 .   .   .   .   -   .   .   .   -
 0 . 0 . 0 . 0 . 3 . 0 . 0 . 0 . 0
 .   .   .   -   .   -   .   .   .
 0 . 0 . 0 | 0 . 0 . 0 | 0 . 0 . 0
 -   .   .   .   .   .   .   .   .
 0 . 0 . 0 | 0 . 0 . 0 . 0 | 0 . 0
 .   .   -   .   -   -   .   .   -
 0 | 7 . 0 . 0 . 0 . 0 | 0 | 5 . 0
 .   -   .   .   .   .   .   .   .
 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 | 0
 .   .   .   .   .   .   -   .   .
 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0
 .   .   -   -   .   -   .   .   .
 0 . 0 . 0 . 0 . 6 | 0 . 0 . 0 . 0
 .   .   .   -   .   .   .   .   .
 0 . 0 . 0 . 0 | 0 . 0 . 0 | 0 . 0

000000000000030000000000000000000000070000050000000000000000000000060000000000000

.....|......-...-...........-.-.....|..|..-..........|...|...-.--..-|....||..-..............|......-............--.-.......|......-........|..|.



As noted earlier naked pairs needed to solve, SE rates the puzzle ED=3.0/2.3/2.3.

[urhegyi]

There is in the code posted by Hajime a dot to much between R8C6 and R8C7, which should be between R8C5 and R8C6.

Code: Select all

#1//B4,CS
.............3.......................7.....5.......................6.............
.....1..............1..1.....1...1..1....11.........1..............1.......1..1..
....1...1...1.1...1..........1.11..1.1.............1....11.1......1..............


[Hajime]

Yes, should be shifted one cell to the left !
That is consistent in the posted solution with a consecutive cell to the right of the "6".