對角線數獨
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
如何遊玩對角線數獨
適用標準數獨規則：在每一行、每一列和每個 3×3 宮格中放置 1–9。額外規則：兩個突出顯示的對角線（↘ 和 ↙）也必須各包含每個數字恰好一次。中心儲存格位於兩條對角線上，使其成為棋盤上約束最多的儲存格。
完整指南 →
兩條主對角線也必須包含1–9
什麼是 對角線數獨？
在對角線數獨中，標準的9×9規則適用——但有一個強大的額外約束：兩條主對角線（左上到右下，以及右上到左下）都必須各自包含數字1到9恰好一次。這個額外約束通常使謎題更容易解決，因為對角線充當了兩個額外的刪除單元。
一覽
| 約束類型 | 額外區域 |
| 典型給定數 | 22–28 |
| 難度評分 | ★★☆☆☆ 2/5 |
| 平均解題時間 — 簡單 | 4分鐘 |
| 平均解題時間 — 中等 | 10分鐘 |
| 平均解題時間 — 困難 | 20分鐘 |
| 平均解題時間 — 專家 | 40分鐘 |
如何解 對角線數獨
| 技巧 | 它的作用 | 等級 |
|---|---|---|
| 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. | 進階 |
| Diagonal–Box Interaction | When a digit on a diagonal is confined to one box segment, eliminate it from the rest of that box. | 進階 |
| Diagonal Naked Pairs | If two cells on a diagonal share the same two candidates, eliminate those values from all other diagonal cells. | 進階 |
| Three-Unit Intersection | A cell on the main diagonal also belongs to a row, column, and box — four constraint units simultaneously — maximising elimination power. | 進階 |
平均解題時間
簡單
4分鐘
中等
10分鐘
困難
20分鐘
專家
40分鐘
常見問題
什麼是 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.