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
Hur man spelar Diagonal Sudoku
Standard Sudoku-regler gäller: placera 1–9 i varje rad, kolumn och 3×3-ruta. Extraregeln: båda markerade diagonalerna (↘ och ↙) måste också innehålla varje siffra exakt en gång. Mittcellen sitter på båda diagonalerna, vilket gör den till den mest begränsade cellen på brädet.
Fullständig guide →
Båda huvuddiagonalerna måste också innehålla 1–9
Diagonal Sudoku Lätt
Diagonal Sudoku Medel
Diagonal Sudoku Svår
Diagonal Sudoku Expert
Vad är Diagonal Sudoku?
I Diagonal Sudoku gäller standardreglerna för 9×9 — men med en kraftfull extra begränsning: båda huvuddiagonalerna (övre vänster till nedre höger, och övre höger till nedre vänster) måste var och en innehålla varje siffra från 1 till 9 exakt en gång. Denna extra begränsning gör vanligtvis pusslet lättare att lösa eftersom diagonalerna fungerar som två extra enheter för eliminering.
Översikt
| Begränsningstyp | Extra regioner |
| Typiska givna | 22–28 |
| Svårighetsbetyg | ★★☆☆☆ 2/5 |
| Genomsnittlig lösningstid — Lätt | 4 min |
| Genomsnittlig lösningstid — Medel | 10 min |
| Genomsnittlig lösningstid — Svår | 20 min |
| Genomsnittlig lösningstid — Expert | 40 min |
Hur man löser Diagonal Sudoku
| Teknik | Vad den gör | 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. | Avancerad |
| Diagonal–Box Interaction | When a digit on a diagonal is confined to one box segment, eliminate it from the rest of that box. | Avancerad |
| Diagonal Naked Pairs | If two cells on a diagonal share the same two candidates, eliminate those values from all other diagonal cells. | Avancerad |
| Three-Unit Intersection | A cell on the main diagonal also belongs to a row, column, and box — four constraint units simultaneously — maximising elimination power. | Avancerad |
Genomsnittliga lösningstider
Lätt
4 min
Medel
10 min
Svår
20 min
Expert
40 min
Vanliga frågor
Vad är 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.