Logic Masters Deutschland e.V.

XV Snake VX

(Published on 9. May 2021, 04:55 by Zombie Hunter)

Title: XV Snake VX
Type: Sudoku
Link: Penpa+ link to XV Snake VX Sudoku You may use Normal/Large/Medium/Small Blue, Green, or Red numbers in any combination. Shade the entire snake dark grey for the answer check to function correctly.
Link: F-puzzles link to XV Snake VX Sudoku
Variants: XV, Modified VX, Snake

1) Snake

  • 1.1) A snake has spent all day looking for food and now has to get back to its den. The heat has fogged poor snake's brain and the path home cannot be remembered. Can you discover the path back?
    • a) The path starts in the blue square in Box 1 and ends in the blue square in Box 9.
    • b) The path is one cell wide and cannot touch itself, even diagonally.
  • 1.2) Unfortunately the sun has baked some rocks and made them to hot to slither over. These cells are colored grey.
    • a) The digit in each grey cell indicates how many times the path touches the rock.
    • b) All grey cells have been given.
  • 1.3) Snake really likes the feel of the X's on its scales. Every digit of every X, whether sum or multiplication, must be on the path--this includes the product. (Example a 6 X 7 4 2 will have all four digits on the path). This means the path is entirely constructed of all of the X's in the puzzle. There is an example at the bottom of the page. Note: Overlapping of clues and products is possible. e.g. 4 X 8 3 X 2 6.
  • 1.4) The V's on the FIVE SUMS hurt poor snake's belly. There are not any V sums in line with the path. Although, one digit of the two cell V sum may be on the path, both digits cannot. e.g. 4 X 8 3 X 2 6. is an invalid path because the 3 is next to the 2 (all V sums have been given).
    Any two cells that sum to five should be considered a sum and not an inequality.
  • 1.5) There are no restrictions of V's on the path when the V functions as an inequality.

2) Normal Sudoku

  • 2.1) Place the digits 0 through 8 once each in every row, column, and box.
  • 2.2) When using f-puzzle, the 9 digit represents a zero. Treat the 9 as if the value is zero in all aspects of the puzzle (including mathematical operations and inequalities).
  • 2.3) 36 is the secret number.

3) XV and modified VX
  • 3.1) An X either sums or multiplies two adjacent cells (being simultaneously a sum and a multiplication is permitted).
    • a) When X acts as a sum, the two cells sum to 10.
    • b) When X acts as a multiplication sign, the two cells are multiplied together with their product immediately following to the right for rows or downward for columns. Multiplications cannot have a leading zero. e.g. 4 X 8 0 3 2 is not permitted, but 4 X 5 2 0 is permitted.
      • i) Not all sums of 10 are given.
      • ii) Not all multiplications are given.
  • 3.2) A V either sums or represents an inequality between two adjacent cells (being simultaneously a sum and an inequality is permitted).
    • a) When V acts as a sum, the two cells sum to 5.
    • b) When V acts as an inequality, the one cell is greater than the other in the direction of the V.
      • i) All sums of 5 are given. Negative constraints apply.
      • ii) Not all inequalities are given.

Green cells represent the path. Blue squares are the start and stop. Grey cells represent rocks. Note the 4 X 6 is red because it is not allowed as it does not connect to the rest of the snake.

Examples (0 for Penpa+, 9 for f-puzzles):
ROW 2--Six multiplied by five equals thirty (6 X 5 3 0/9).
ROW 3--Five summed with zero equals five (5 V 0/9).
ROW 4--Three summed with two equals five, also two multiplied by four equals eight (3 V 2 X 4 8).
COLUMN 1--Six is greater than five, also five is greater than three (6 V 5 V 3).
COLUMN 2--Five is greater than zero but also five summed with zero equals zero (5 V 0/9).
COLUMN 3--Two multiplied by three equals six, also six summed with four equals ten (2 X 3 6 X 4).
COLUMN 4--Seven is greater zero, also two summed with eight equals ten (7 V 0 2 X 8)

Solution code: Please enter the 18 digits of Column 8 followed by Row 9 without any spaces. If you solved the puzzle using f-puzzle, please replace any 9's with 0's.

Last changed on on 15. October 2022, 01:50

Solved by henrypijames, BMEP, codewizard
Full list

Comments

Last changed on 30. September 2022, 22:49

on 23. September 2022, 03:32 by codewizard
That was some puzzle! At the start I thought "no way", didn't have a clue how to make sense of all the rules, but slowly it started to unfold. Probably wouldn't be that hard if you were comfortable with the rules. As it was, I was extremely paranoid the whole way through... Towards the end, got stuck I seemed to be unable to make the path (X's) work and close to giving up, was sure I had made some mistake earlier on. Glad I stayed on :)

---

A tough one for sure. Thank you for sticking with it! The XV ? VX puzzles were fun to make even though they do not have many solves. Tell your friends if you liked it!
~ZH

Last changed on 13. May 2021, 21:38

on 11. May 2021, 01:11 by Zombie Hunter
@BMEP I am glad you enjoyed it. I tried to make something logical that did not require forcing chains or endless trial and error. You have no idea how many grids I went through that we really pleasing except for 1 flaw that broke everything.

on 11. May 2021, 01:04 by BMEP
very nice puzzle! It's kinda hard to wrap the head around the rule set, but once you do, it's very enjoyable! thanks!

Last changed on 13. May 2021, 21:35

on 10. May 2021, 20:58 by Zombie Hunter
@henrypijames Originally I did not have a restriction on V sums but constructing a grid without it was exceedingly difficult. I also had a variant where the multiplication was in the direction of the path, but I thought that would be too hard for the solve. Another variant with simpler rules involving the inequalities but the path was entirely predictable. If you want to move the discussion to CtC discord, perhaps you could help me make a XV Snake VX that is enjoyable. I am sorry I let you down.

Last changed on 10. May 2021, 20:48

on 10. May 2021, 20:48 by Zombie Hunter
Thanks to henrypijames for addition to the (already complicated) rules.

on 10. May 2021, 20:42 by Zombie Hunter
@henrypijames I have a XV ? VX series and I struggled to find a way to make a snake type puzzle. Just finding a grid that worked took me two weeks. I will amend the rules as per your suggestions. You might like my arrow or killer puzzle better.

Last changed on 10. May 2021, 22:50

on 10. May 2021, 20:22 by henrypijames
BTW, despite of how complicated they already are, the rules are actually incomplete. For example, it doesn't specify if a vertical sum relationship counts as sum or inequality (or solver's choice), which affects the snake's ability to slither over it. It also doesn't explicitly forbid leading zero as in 3x6=018. These omissions didn't matter here, but they could have (or maybe I oversaw some possibilities for leading zeros). And there might be more corner cases that I haven't thought of - when there are so many moving parts involved, the interaction becomes increasingly chaotic (as in chaos theory).

Last changed on 10. May 2021, 20:27

on 10. May 2021, 20:06 by henrypijames
The idea is very interesting (and I'm a sucker for any snake sudoku), but the rule set is excessively complex (and partially arbitrary, in particular regarding which negative constraints apply and which don't) to the point of being distracting. When it requires more mental effort to keep the rules in my head than to actually solve the puzzle (and that's not at all an exaggeration), it takes out quite a chunk of the fun. Not to mention that I broke the puzzle a couple of times before realizing it was because I didn't understand the rules correctly (specifically, that a cell can be part of more than one X relationship) - which, unlike many other instances, is really excusable here given how crazy complicated the rules are.

I'd love to see this concept developed further by significantly streamlining the ruleset.

on 10. May 2021, 16:10 by Zombie Hunter
@henrypijames

1) Yes, non grey cells cannot have snakesweeper properties. Example, a non grey 0 (zero) must touch the path. Determining the value of the rocks is a great place to start.

2) Your logic is sound.

3) The X cells and their product must be deduced. Example, R1C1 contains the start, therefore it must be part of an X somehow (either a sum or a multiplication).

If you get stuck send me a hidden comment and I'll get you along your way!

Last changed on 10. May 2021, 09:14

on 10. May 2021, 09:07 by henrypijames
Does "All grey cells have been given" mean non-grey cells cannot have a minesweeper (or shall I say snakesweeper) digit?

Also, since all V's are upright, does it mean a horizontal paar of cells connected by a V cannot have an inequality relationship?

Finally, "This means the path is entirely constructed of all of the X's in the puzzle", but there are no X's in the puzzle?

Difficulty:3
Rating:N/A
Solved:3 times
Observed:11 times
ID:00065I

Variant combination Online solving tool

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