Japanische Summen mit Renban und Mauern
(Published on 26. August 2026, 17:41 by Rätselmann)
Shade some cells and enter digits from 1 to 9 in all remaining cells. Although the grid is 11×11, only the digits 1 to 9 are used.
1. Japanese Sums: No digit may repeat in any row or column. The clues around the grid give the sums of consecutive blocks of white cells in the corresponding row or column, in reading order: from left to right or from top to bottom. Two blocks are separated by at least one shaded cell. The number of clues for a row or column is exactly equal to the number of its white blocks.
A ? represents an unknown one-digit block sum, while ?? represents an unknown two-digit block sum.
2. Wall: All shaded cells form one single orthogonally connected region. No 2×2 area of the grid may be completely shaded.
3. Renban Islands: The wall divides the white cells into orthogonally connected islands. The digits in each island are all different and form an uninterrupted set of consecutive numbers, although they may appear in any order within the island. For example, a five-cell island could contain exactly the digits 3, 4, 5, 6 and 7.
The puzzle has a unique solution.
Solve online:
Open the puzzle in SudokuPad
SudokuPad note: To shade a cell black, select the cell and use the darkest grey colour in the colour palette.
Solution code: For the solution code, enter the 3rd row from left to right. Enter shaded cells as 0.
Comments
on 27. August 2026, 22:00 by marcmees
Great use of renban islands. Thanks
on 26. August 2026, 22:21 by Christounet
Excellent! Vielen Dank :)
on 26. August 2026, 19:31 by zuzanina
Sehr schön! Vielen Dank!
Joachim Vetter: Danke dir!
on 26. August 2026, 18:30 by Christounet
Can islands have only 1 cell ?
Joachim Vetter:
Interesting question, thank you for bringing it up!
Yes, one-cell islands are allowed. The puzzle still has a unique solution.
For this puzzle it doesn't come up though. I checked every clue-consistent candidate grid, and none of them contains an isolated single cell — so you never have to decide the question either way. The solution is unique and reachable by pure logic without any assumption about minimum island size.
Thanks for asking!
on 26. August 2026, 18:29 by Rätselmann
Schreibfehler in Titel geändert…von Rennbahn (Autokorrektur) zu Renban
