Indexers Playground
(Eingestellt am 4. Januar 2026, 20:01 Uhr von Kutsumi Hane)
In a standard Sudoku grid, each cell can be identified in two different coordinate systems.
One way is by its row and column, e.g. the cell R5C7 lies in row 5 and column 7.
The other way is by its box and position index, e.g. the cell B6P4 lies in box 6 at position 4 within that box.
Actually, both notations refer to the very same cell in the 9×9 Sudoku — R5C7 is identical to B6P4.
Based on this dual coordinate system, we introduce two pairs of corresponding indexer constraints as follows:
One way is by its row and column, e.g. the cell R5C7 lies in row 5 and column 7.
The other way is by its box and position index, e.g. the cell B6P4 lies in box 6 at position 4 within that box.
Actually, both notations refer to the very same cell in the 9×9 Sudoku — R5C7 is identical to B6P4.
Based on this dual coordinate system, we introduce two pairs of corresponding indexer constraints as follows:
Rules:
Normal Sudoku rules apply, requiring that each row, column, and 3×3 box contains the digits 1-9 exactly once. Additionally:
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·Row indexer:
A marked cell in row X indicates the row in which the digit X appears in the same column. (Colored in blue)
·Column indexer:
A marked cell in column X indicates the column in which the digit X appears in the same row. (Colored in red)
·Box indexer:
A marked cell in box X indicates the box in which the digit X appears at the same position. (Colored in green)
·Position indexer:
A marked cell in position X indicates the position in which the digit X appears in the same box. (Colored in yellow)
Here is how the different indexers (row, column, box, position) work on a standard 4x4 Sudoku grid:
Here you can solve this puzzle online:
Solve on SudokuPad
The difficulty is probably 1-2 stars. I wish you joyful solving!
The difficulty is probably 1-2 stars. I wish you joyful solving!
Lösungscode: Digits in row 8.
Zuletzt geändert am 6. Januar 2026, 01:40 Uhr
Gelöst von CaseyM, cryptique, gdc, milxqueen, SKORP17, Counterfeitly, Dermerlin, Fisherman, MaxSmartable, jalebc, ManniMensen, flaemmchen, HeyItsErin, prismoid, dzamie, supersim2000, walid_tun, sparkymanu, Nagesh, zrbakhtiar, drmegadude, TeddieMilo, Gizmo, drf93, CitrusGremlin, JVA, Qodec, abadx, 72kchunshuai, Aidan488, zhangjinyang
Kommentare
am 8. Januar 2026, 17:54 Uhr von Qodec
Perfect way to introduce this constraint, enjoyed that!
(Perhaps explicitly specify that disjoint constraint doesn't apply, because of what it does to box indexers.)
am 8. Januar 2026, 15:08 Uhr von JVA
Imma be honest, I used Excel formulas to figure out what goes where
am 6. Januar 2026, 22:15 Uhr von walid_tun
Very creative idea, I am looking forward for same kind puzzles
am 5. Januar 2026, 20:08 Uhr von prismoid
Neat ruleset, would like to see it applied to a more challenging puzzle
