反國王數獨
8
2
5
1
7
4
7
4
3
5
9
1
4
5
9
7
8
2
1
6
9
6
5
4
2
7
2
9
3
5
3
6
6
3
9
5
4
1
相距一個 king's move 的兩個 cell 不能包含相同的數字
什麼是 反國王數獨？
反國王數獨增加了一個受國際象棋啟發的約束：在單次國王移動中可達到的單元格（正交或對角相鄰）不能共享相同的數字。這將不重複規則擴展到行、列和宮之外，包括對角鄰居，顯著收緊了整個網格的約束空間。
一覽
| 約束類型 | 反限制 |
| 典型給定數 | 22–28 |
| 難度評分 | ★★★☆☆ 3/5 |
| 平均解題時間 — 簡單 | 5分鐘 |
| 平均解題時間 — 中等 | 13分鐘 |
| 平均解題時間 — 困難 | 26分鐘 |
| 平均解題時間 — 專家 | 48分鐘 |
如何解 反國王數獨
| 技巧 | 它的作用 | 等級 |
|---|---|---|
| Diagonal Exclusion | The king constraint extends the exclusion zone to all 8 neighbours including diagonals. Apply diagonal exclusions before standard row/col/box logic. | 進階 |
| Corner Restriction | Corner cells (e.g., r1c1) only have 3 king-move neighbours. Start with corners and edges to build initial placements. | 進階 |
| King-Chain Elimination | When a digit is placed, eliminate it simultaneously from all 8 surrounding cells. | 進階 |
| Parity via King's Move | In Anti-King, consecutive digits often become mutually king-move incompatible — trace valid placement paths using this property. | 進階 |
平均解題時間
簡單
5分鐘
中等
13分鐘
困難
26分鐘
專家
48分鐘
常見問題
什麼是 Anti-King Sudoku？
Anti-King Sudoku is a variant where no two diagonally adjacent cells may contain the same digit. Combined with standard Sudoku rules (which already forbid matching digits in the same row, column, and box), this means a digit cannot appear in any of the eight cells surrounding a given cell.
Why is it called Anti-King?
The name comes from chess: a king can move to any of the eight adjacent squares (horizontally, vertically, or diagonally). The Anti-King constraint says no digit may be repeated within a king's move of any placed digit — it's the opposite of the king's reach being unrestricted.
How many cells does the anti-king constraint affect?
Each interior cell has eight neighbours (up to eight for corner and edge cells). All eight must hold different digits from the placed cell, on top of the standard uniqueness rules. Cells in the top-left to bottom-right diagonal neighbourhood are constrained in ways that standard Sudoku doesn't cover.
Is Anti-King Sudoku harder than regular Sudoku?
Easy Anti-King puzzles resolve faster than classic Sudoku because the extra diagonal constraint eliminates more candidates. Hard and expert puzzles compensate with fewer givens, and the diagonal interactions create subtle deduction chains that can be difficult to spot.
What is the best first move in Anti-King Sudoku?
Focus on corner cells first — they have the fewest anti-king neighbours (only 3 for a true corner). Then look at cells near already-placed digits and check how many of the eight neighbours already have that digit. Dense clustering of given digits often creates immediate anti-king placements.
How long does Anti-King Sudoku take to solve?
Easy puzzles take 6–15 minutes. Medium puzzles run 15–30 minutes. Hard puzzles average 30–60 minutes and expert puzzles can take 60–90 minutes. The diagonal constraint makes early progress fast but creates subtle interactions in the middle and end game.