So Near Yet So Far (Remote Sums Rollercoaster Chaos Deconstruction)
(Published on 23. January 2026, 20:00 by tallcat)
Chaos Deconstruction: Nine orthogonally connected regions containing the digits 1-9 must be located. Digits may not repeat in any row, column, or region. Cells outside of a region do not contain digits.
Rollercoaster: Draw a non-intersecting loop that travels orthogonally between the centers of some cells in the grid. Clues on the left give the sum of digits on horizontal loop segments in that row in the correct order. Clues above give the sum of digits on vertical loop segments in that column in the correct order. A "?" may replace any value from 0-9, but for double digit numbers, the first digit may not be 0. A '*' designates a single section of the loop of unknown value. For each row or column, either all or no clues are provided. On a single round trip of the loop, every region must be visited exactly once. The loop may pass through empty cells, which count as 0 towards the sum(s) they are part of.
Loop Remote Sums: A value X in a cage points to two values Y and Z located X cells away in each direction along the loop. The number in the top left value of the cage indicates the sum of X + Y + Z. All cells pointed at by remote sums cages must have a digit in (they cannot be empty). All three values (X, Y, Z) may be the same if allowed by sudoku rules.
Example Puzzle to illustrate rules
As an example loop remote sum, the 13 cage in R3C1 reflect the sum of 3 (value in cage) + 4 (R2C1) + 6 (R6C1) as both R2C1 and R6C1 are 3 positions along the loop in each direction.
The Main Puzzle
Can be found at Penpa (answer check with green line) or Sudokupad
Solution code: Row 9 (left to right, with '-' denoting empty squares)
Comments
on 11. February 2026, 22:17 by SolveTrace
What a brain teasing challenge! Superb!
on 10. February 2026, 17:46 by Agent
Awesome puzzle, very consistent difficulty, lots of cool steps!
on 27. January 2026, 19:14 by marcmees
One of the nicest cc's solved recently. Very rewarding solve. Thanks.
on 27. January 2026, 10:09 by Christounet
Superb! Many interesting construction step in here. Thanks :)
on 26. January 2026, 01:39 by Chilly
One of my favourites that you have set. No single step was very hard, but overall there were a lot of steps to spot, making it tricky. But super fun all the way, and I was never stuck for very long.
on 25. January 2026, 21:00 by Fool on Hill
Seriously good puzzle - varied, interesting, surprising and hard. Also happens to be my 250th registered 5*/5 solve on LMD and very pleased that it was a milestone puzzle for me. Definitely deserves its (current) 100% rating.
on 25. January 2026, 16:24 by henrypijames
Upon opening the puzzle with excited anticipation, I was saddened to see that I've already solved it - three months ago in testing (it's been so long I've almost forgotten it). :P
on 25. January 2026, 08:32 by wullemuus
Rollercoaster at its best!
Felt more than 4 stars because of perfectly interacting clues :)
on 24. January 2026, 16:12 by Snookerfan
Amazing and brilliant puzzle! Very hard from start to finish and a very long solve for me (close to 3 hours), but the puzzle kept being interesting and rewarding. Thanks
on 24. January 2026, 10:45 by Piatato
Amazing! Great fun throughout!
on 24. January 2026, 07:11 by Playmaker6174
Super engrossing puzzle throughout with some touches of madness in the middle too!
I found it hard to believe that it even resolved at the end and despite its consistent difficulty, I still had a remarkably fun time there x)
on 23. January 2026, 21:52 by Jesper
Awesome puzzle, thanks!
on 23. January 2026, 20:32 by Mattisahuman
I haven’t begun yet, but I notice that ‘4’ to the left of row 8. If the loop doesn’t intersect itself and must have segments both above and below row 8, it cannot have only one segment in row 8. Do correct me if I’m wrong, but also since there are no partial clues, I think this is broken.
————
As per the rules, the clues by rows are sums on horizontal segments. This means there is a single horizontal segment in row 8 but there can be any number of vertical segments that cross row 8. Hope this helps.
