Isofill Quad Sums
(Published on 2. September 2026, 23:08 by Christounet)
This is my attempt at making puzzle with the new Isofill constraint introduced by Marty Sears. Below you can find a list of other puzzles made with this constraint. Have fun solving!
The puzzle :
Rules :
- Isofill : divide the grid into 10 regions, each comprised of 10 orthogonally connected cells. Every cell in a region contains the same digit. All of the digits 0-9 appear in the grid.
- Quad sums : the number in each circle is the sum of the digits in the 4 cells touched by the circle. Each "?" represents a digit from 1-9.
Solution code: Row 9
Comments
yesterday, 19:59 by kangaroo
The best puzzle of the week!
yesterday, 09:33 by goldpuffle
What an interesting puzzle... the way the logic unfolds is clever and beautiful!
on 4. September 2026, 21:06 by Bellsita
I loved it!
on 4. September 2026, 20:55 by Miatc
Lovely puzzle, the constraints realy don't feel strong enough until you really think about it.
I think this puzzle would really benefit from a given solution in Sudokupad, currently there's no way to check if you actually solved it without entering the code here, and the program thinks it's trying to work by traditional Sudoku rules if you try to check.
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Thanks for solving the puzzle and glad you enjoyed.
Most of the times, I don't use the answer check as a solver because this option did not exist when I started solving puzzles from LM, so that's why I rarely think about adding it to my links, especially when I set on Penpa.
on 3. September 2026, 14:58 by mathpesto
Beautiful yet tricky!
on 3. September 2026, 13:59 by Snookerfan
Excellent puzzle, lovely break-in and a bit of a sting in the end, enjoyed it a lot, thanks!
on 3. September 2026, 08:12 by marcmees
very nice. Thanks
on 3. September 2026, 06:22 by Piatato
Great fun! Very cleverly constructed :D
on 3. September 2026, 00:04 by cyddrdrd
Very cool!
