Sudoku Variants Series (483) - Coral
(Published on 4. September 2026, 06:00 by Richard)
For this Sudoku Variants Project I have planned to publish a unique Sudoku variant every week.
Coral
Inspiration for this type comes from me. Solve online in Sudokupad.
I will see how long it takes before I am running out of ideas.
Apply classic sudoku rules.
Shade some cells to create a single group of connected cells (the coral), without enclosing any white cells. No 2x2 area may be fully shaded. Clues outside the grid indicate the sums of separate blocks of shaded cells in the corresponding row or column, where there must be at least one unshaded cell between two blocks of shaded cells. Clues are given in ascending order and not necessarily in the order in which the shaded blocks appear.
Solution code: Row 6
Comments
on 26. September 2026, 06:22 by CharlesK
That was a fun puzzle but I was grateful for 9rookienumbers' rules clarification as that was not how I initially interpreted it
on 13. September 2026, 22:47 by Eisbär
Funny one! Easy puzzle when you understand the rules correctly :-)
on 6. September 2026, 22:33 by tretro
Wow, I struggled horribly with this one. Finally I made it through finding a logical way. Thanks for the great fun as always!
on 6. September 2026, 17:55 by AnnaTh
So machen auch Sudokus wieder Spaß! Toll!
on 5. September 2026, 16:22 by Krokant
Corals are among my favourites. This one is really lovely. :)
on 4. September 2026, 20:29 by Playmaker6174
@Niffyjiffy: yes, for every row/column, all outside clues are given.
on 4. September 2026, 20:25 by Niffyjiffy
Are the clues on the outside necessarily complete? Or could there be, for instance, more than one block of coral in C5?
Thanks for the puzzle, enjoying so far.
on 4. September 2026, 16:51 by mathpesto
A lot of fun!
on 4. September 2026, 14:35 by Franjo
Thank you very much for creating and sharing another beautiful SVS-puzzle It’s like Japanese Sums with a twist - a nice twist!
on 4. September 2026, 12:48 by 9Rookienumbers
What does “without enclosing any white cell” mean?
Edit: solved it, amazing puzzle!
For anyone wondering, it means that every consecutive group of white cells (one white cell is a group) needs to reach the border of the grid.
on 4. September 2026, 08:40 by FireTruckFuel
Enjoyed it very much!
on 4. September 2026, 08:08 by Piatato
Smooth and pleasant, thanks!
on 4. September 2026, 07:55 by Fizz
Fun puzzle with great logic, thanks!
on 4. September 2026, 07:02 by Playmaker6174
Fun approachable puzzle, thanks! I think this is a fair beginner introduction to this type of hybrid :)
