アロー数独
5
6
7
9
4
6
7
1
2
5
7
5
4
3
7
8
1
4
4
5
8
3
2
6
2
8
5
7
2
5
1
4
3
7
8
9
5
6
アロー数独の遊び方
標準数独ルールが適用されます。追加ルール: 各矢印の尾に沿った数字は、矢印の基部の丸の中の数字に合計されなければなりません。丸自体は通常の数独セルです — その値が矢印のセルの合計を決定します。
完全ガイド →
Arrow 上の Digits は、circle 内の digit に合計されなければなりません
アロー数独とは？
アロー数独は、グリッド上に矢印を配置し、それぞれが丸で囲まれたセルから始まります。矢印に沿ったすべてのセル（丸は含まない）の数字は、丸で囲まれたセルに入る数字の合計と等しくなければなりません。最大の数字は9であるため、多くのセルを持つ長い矢印は非常に制約が強くなります。アロー数独は、標準的な消去法や候補ロジックと美しく組み合わさることがよくあります。
概要
| 制約タイプ | ライン制約 |
| 典型的な初期数字 | 20–26 |
| 難易度評価 | ★★★★☆ 4/5 |
| 平均解答時間 — 簡単 | 12分 |
| 平均解答時間 — ミディアム | 25分 |
| 平均解答時間 — 難しい | 50分 |
| 平均解答時間 — エキスパート | 80分 |
アロー数独 の解き方
| テクニック | それが何をするか | レベル |
|---|---|---|
| Arrow Sum Bounding | The circle digit equals the sum of all arrow shaft cells. A 3-cell arrow with circle 5 means the three shaft cells average under 2 — severely constraining options. | 上級 |
| Max/Min Arrow Analysis | The maximum sum of N cells is 9+8+7+…; the minimum is 1+2+3+…. If the circle digit falls outside these bounds, a constraint error exists. | 上級 |
| Bifurcation on Short Arrows | For 2-cell arrows with a small circle (e.g., 3), only (1,2) or (2,1) works — enumerate cases to find forced placements quickly. | 上級 |
| Arrow–Region Interaction | Arrow cells sharing a box or row with the circle create indirect constraints — combine the sum equation with standard Sudoku uniqueness. | 上級 |
| Repeating Digits on Arrows | Arrow shaft cells can repeat digits (unlike Killer cages). Factor this in when enumerating possible sums. | 上級 |
平均解答時間
簡単
12分
ミディアム
25分
難しい
50分
エキスパート
80分
よくある質問
Arrow Sudokuとは何ですか？
Arrow Sudoku is a variant where arrows are drawn across the grid. Every digit placed along an arrow must sum to the number written inside the circle at the arrow's base. Standard Sudoku rules still apply — every row, column, and 3×3 box must contain the digits 1–9 exactly once.
How do the arrows and circles work?
Each arrow starts at a circle and extends through one or more cells. The digit in the circle is the target sum for all cells the arrow passes through. A single-cell arrow tells you the exact digit in that cell. Longer arrows have multiple possible combinations, which you narrow down using Sudoku constraints.
Is Arrow Sudoku harder than regular Sudoku?
It depends on your experience. Arrow Sudoku adds an arithmetic layer on top of standard logic. Easy puzzles are comparable in difficulty to medium classic Sudoku. Hard and expert arrow puzzles require simultaneous constraint-tracking that most players find significantly more challenging than any classic Sudoku difficulty.
Can a digit repeat along an arrow?
No — digits can repeat on an arrow only if standard Sudoku rules allow it. Because each row, column, and box must contain 1–9 once, a digit can appear twice on an arrow only if the two cells are in different rows, columns, and boxes. In practice, most arrow cells are highly constrained.
What is the best first move in Arrow Sudoku?
Start with single-cell arrows — the digit in that cell equals the circle value directly. Then look for short arrows with extreme sums. A 2-cell arrow summing to 3 can only be {1,2}; summing to 17 can only be {8,9}. These give you the tightest starting constraints without any guessing.
How long does Arrow Sudoku take to solve?
Easy puzzles take 5–15 minutes. Medium puzzles typically run 15–30 minutes. Hard puzzles average 30–60 minutes, and expert puzzles can take over an hour even for experienced solvers. Solve times improve quickly once you develop intuition for which arrow combinations are possible at a glance.