Diagonaal 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
Fouten
0/3
Score
-
Tijd
00:00
Voortgang0%
Gemakkelijk · Diagonaal Sudoku
Wissel moeilijkheidsgraad hierboven ↑
Hoe Diagonal Sudoku te spelen
Standaard Sudoku-regels zijn van toepassing: plaats 1–9 in elke rij, kolom en 3×3 blok. De extra regel: beide gemarkeerde diagonalen (↘ en ↙) moeten ook elk cijfer precies één keer bevatten. De middelste cel ligt op beide diagonalen, waardoor het de meest beperkte cel op het bord is.
Volledige gids →
Beide hoofddiagonalen moeten ook 1–9 bevatten
Diagonaal Sudoku Gemakkelijk
Diagonaal Sudoku Gemiddeld
Diagonaal Sudoku Moeilijk
Diagonaal Sudoku Expert
Wat is Diagonaal Sudoku?
Bij Diagonal Sudoku zijn de standaard 9×9 regels van toepassing — maar met één krachtige extra beperking: beide hoofddiagonalen (linksboven naar rechtsonder, en rechtsboven naar linksonder) moeten elk elk cijfer van 1 tot 9 precies één keer bevatten. Deze extra beperking maakt de puzzel doorgaans gemakkelijker op te lossen, omdat diagonalen fungeren als twee extra eenheden voor eliminatie.
In één oogopslag
| Beperkingstype | Extra Regio's |
| Typische gegeven cijfers | 22–28 |
| Moeilijkheidsbeoordeling | ★★☆☆☆ 2/5 |
| Gem. oplossingstijd — Gemakkelijk | 4 min |
| Gem. oplossingstijd — Gemiddeld | 10 min |
| Gem. oplossingstijd — Moeilijk | 20 min |
| Gem. oplossingstijd — Expert | 40 min |
Hoe Diagonaal Sudoku op te lossen
| Techniek | Wat het doet | Niveau |
|---|---|---|
| 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. | Beginner |
| Diagonal–Box Interaction | When a digit on a diagonal is confined to one box segment, eliminate it from the rest of that box. | Gevorderd |
| Diagonal Naked Pairs | If two cells on a diagonal share the same two candidates, eliminate those values from all other diagonal cells. | Gevorderd |
| Three-Unit Intersection | A cell on the main diagonal also belongs to a row, column, and box — four constraint units simultaneously — maximising elimination power. | Gevorderd |
Gemiddelde Oplossingstijden
Gemakkelijk
4 min
Gemiddeld
10 min
Moeilijk
20 min
Expert
40 min
Veelgestelde Vragen
Wat is 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.