Diagonal Sudoku
1
8
9
6
5
9
2
3
1
8
3
4
9
2
9
3
8
1
7
7
1
3
6
9
4
7
8
9
2
3
6
3
5
8
2
2
8
6
Hvordan spille Diagonal Sudoku
Standard Sudoku-regler gjelder: plasser 1–9 i hver rad, kolonne og 3×3-boks. Ekstraregelen: begge uthevede diagonalene (↘ og ↙) må også inneholde hvert siffer nøyaktig én gang. Midtcellen sitter på begge diagonalene, noe som gjør den til den mest begrensede cellen på brettet.
Full guide →
Begge hoveddiagonaler må også inneholde 1–9
Diagonal Sudoku Enkel
Diagonal Sudoku Middels
Diagonal Sudoku Vanskelig
Diagonal Sudoku Ekspert
Hva er Diagonal Sudoku?
I Diagonal Sudoku gjelder standard 9×9-regler — men med en kraftig ekstra begrensning: begge hoveddiagonalene (øverst-venstre til nederst-høyre, og øverst-høyre til nederst-venstre) må hver inneholde alle sifre fra 1 til 9 nøyaktig én gang. Denne ekstra begrensningen gjør typisk oppgaven enklere å løse siden diagonalene fungerer som to ekstra enheter for eliminering.
På et øyeblikk
| Begrensningstype | Ekstra regioner |
| Typiske gitte tall | 22–28 |
| Vanskelighetsgradsvurdering | ★★☆☆☆ 2/5 |
| Gj.sn. løsningstid — Enkel | 4 min |
| Gj.sn. løsningstid — Middels | 10 min |
| Gj.sn. løsningstid — Vanskelig | 20 min |
| Gj.sn. løsningstid — Ekspert | 40 min |
Hvordan løse Diagonal Sudoku
| Teknikk | Hva det gjør | Nivå |
|---|---|---|
| Diagonal as a Unit | Treat each diagonal exactly like a row or column — every digit 1–9 appears exactly once. Standard scanning and counting apply. | Avansert |
| Diagonal–Box Interaction | When a digit on a diagonal is confined to one box segment, eliminate it from the rest of that box. | Avansert |
| Diagonal Naked Pairs | If two cells on a diagonal share the same two candidates, eliminate those values from all other diagonal cells. | Avansert |
| Three-Unit Intersection | A cell on the main diagonal also belongs to a row, column, and box — four constraint units simultaneously — maximising elimination power. | Avansert |
Gjennomsnittlige løsningstider
Enkel
4 min
Middels
10 min
Vanskelig
20 min
Ekspert
40 min
Ofte stilte spørsmål
Hva er Diagonal Sudoku?
Diagonal Sudoku adds two extra constraints on top of standard Sudoku: both main diagonals of the 9×9 grid must each contain the digits 1–9 exactly once. This means every cell on either diagonal belongs to four uniqueness groups simultaneously: its row, column, box, and diagonal.
Which cells are on the diagonals?
The main diagonals run from the top-left corner to the bottom-right corner, and from the top-right corner to the bottom-left corner. Together they cover 17 cells (the centre cell is on both). Any cell at position (r, c) is on a diagonal if r equals c or if r + c equals 10 (using 1-based numbering).
How does the diagonal constraint help solving?
Diagonal cells carry four constraints instead of the usual three, making them the most restricted cells on the board. Whenever you place a digit anywhere on a diagonal, it eliminates that digit from the entire row, column, box, and the diagonal simultaneously — often triggering a cascade of placements.
Is Diagonal Sudoku harder than regular Sudoku?
At easy difficulty, Diagonal Sudoku is actually easier than equivalent classic Sudoku because the extra constraints eliminate more candidates immediately. At hard and expert levels, the diagonal interactions create subtler deductions that experienced players find more challenging to spot.
Can I solve Diagonal Sudoku using standard techniques?
Yes — all standard Sudoku techniques (naked pairs, hidden singles, pointing pairs, X-Wings, etc.) apply. You simply treat each diagonal as an additional house. The most important habit is scanning both diagonals after every placement, the same way you scan rows, columns, and boxes.
How long does Diagonal Sudoku take to solve?
Easy puzzles take 5–12 minutes — often faster than equivalent classic puzzles because of the extra constraints. Medium puzzles run 12–25 minutes. Hard and expert puzzles can take 30–70 minutes depending on how heavily the diagonal interactions need to be exploited.