Interval Sums Sudoku
(Published on 28. November 2021, 02:08 by Qodec)
Another spark of inspiration, from RockyRoer's Interval Sums - recommended, it's a fantastic puzzle!
Please be aware that this puzzle use a slightly different version of the rules: instead of using absolute positions, this puzzle counts relative to the outside clue.
- Normal sudoku rules apply: Each row, column, and region indicated by thick borders in the grid must contain the digits 1 to 9 once each.
- Interval Sums: Let A and B are the two cells nearest an outside clue in the row or column indicated by that clue. Then the outside clue represents the sum of the digits in positions A through B, counted from that outside clue away into the grid (like in X-sums).
In above example, the first two cells in the row starting at the 15 clue contain a 7 and a 5. This means that all cells between the 7th and 5th cell in that row counted from the left must add up to 15. These cells are coloured dark blue. Now, at the right is a 4 clue, and the first two cells in the row starting at that 4 clue contain a 2 and a 3. This means that all cells between the 2nd and 3rd cell in that row counted from the right must add up to 4. These cells are coloured light green. The order of digits in the first two cells does not matter.
Here is an example 6x6 puzzle:
You can try it over here on f-puzzles: https://f-puzzles.com/?id=y6jb93rf or the CTC app: https://tinyurl.com/2p99yhk9.
The main puzzle:
You can play this puzzle online using:
- Penpa+ with answer check: https://git.io/JMcBJ
- CTC app: https://tinyurl.com/frx39868
- f-puzzles: https://f-puzzles.com/?id=yhpmfhce
Hope you'll enjoy!
Solution code: Row 5 and column 5. I.e. the 9 digits in row 5 from left to right, followed by the 9 digits in column 5 from top to bottom, for example: 123456789123456789
Comments
on 9. January 2022, 20:42 by ICHTUES
Cool puzzle, thanks Qodec!
on 29. November 2021, 19:15 by DVFrank
Some very neat deductions in this one, I liked it a lot! :^)
on 29. November 2021, 01:00 by SudokuExplorer
The ruleset feels more intuitive by indexing from the direction of the clue (like in X-sums). There are some interesting properties which make the break-in really nice. The ending was lovely too, thanks! :-)
on 28. November 2021, 21:53 by TheRiddler
That's the 100th puzzle I solved here on LMD :-)
I made progress only slowly because I had to get used to the ruleset, but despite the puzzle being quite challenging I never got seriously stuck! Thanks a lot, Qodec!
on 28. November 2021, 16:23 by Playmaker6174
Very clever construction, lots of beautiful deductions in this one (especially the ending) :)
on 28. November 2021, 16:14 by abed hawila
Elegant puzzle!
on 28. November 2021, 10:52 by Jesper
A pleasure to solve. Thanks!
on 28. November 2021, 06:32 by cmb
Nice one.
Inspiring ruleset, leading to neat conclusions especially in the late solve.
Thanks a lot!
on 28. November 2021, 05:55 by Vebby
Getting my head around this ruleset was great fun! Thanks Qodec :)
on 28. November 2021, 04:07 by Steven R
Lovely stuff! Thanks Qodec :)
