Between Lines数独
4
6
9
1
4
7
5
7
9
1
3
2
6
1
5
4
3
1
6
9
7
1
6
4
3
3
5
8
4
7
1
5
7
8
6
8
7
3
Line 上の Digits は、2 つの endpoint values の間に厳密に収まらなければなりません
Between Lines数独 簡単
Between Lines数独 ミディアム
Between Lines数独 難しい
Between Lines数独 エキスパート
Between Lines数独とは？
ビトウィーンラインズ数独は、円形の端点を持つラインを描きます。ラインに沿ったすべての数字（端点自体を除く）は、小さい方の端点より厳密に大きく、大きい方の端点より厳密に小さくなければなりません。端点が2と8の場合、ライン上のすべての中間セルは3、4、5、6、または7のいずれかでなければなりません。端点の値が近いほど、中間セルはより制約されます。
概要
| 制約タイプ | ライン制約 |
| 典型的な初期数字 | 20–28 |
| 難易度評価 | ★★★☆☆ 3/5 |
| 平均解答時間 — 簡単 | 8分 |
| 平均解答時間 — ミディアム | 18分 |
| 平均解答時間 — 難しい | 36分 |
| 平均解答時間 — エキスパート | 64分 |
Between Lines数独 の解き方
| テクニック | それが何をするか | レベル |
|---|---|---|
| Endpoint Gap Analysis | The gap between endpoint values must be large enough to accommodate all middle cells. If endpoints are 2 and 8, middle cells must come from {3,4,5,6,7}. | 上級 |
| Endpoint Ordering | The endpoint values have no fixed order — the constraint is that all middle cells are strictly between the minimum and maximum endpoint. | 上級 |
| Tight Endpoint Constraint | If endpoints would be consecutive (e.g., 3 and 4), no middle cell could satisfy the strict inequalities — use this to force endpoints apart. | 上級 |
| Between-Line–Box Interaction | All middle cells sharing a box must satisfy the between constraint. Use the box to eliminate candidates outside the valid range. | 上級 |
平均解答時間
簡単
8分
ミディアム
18分
難しい
36分
エキスパート
64分
よくある質問
Between Lines Sudokuとは何ですか？
Between Lines Sudoku is a variant where lines with circular endpoints are drawn on the grid. Every digit along a line (excluding the endpoint circles) must be strictly between the two endpoint values. The endpoints themselves are placed during solving — only the line positions are given.
How do I read the between-line clues?
The two circles at the ends of each line are the boundary values. Every cell between them must be strictly greater than the smaller endpoint and strictly less than the larger one. You deduce which endpoint is larger as part of the solve.
Can the endpoints be any digits?
Yes. Endpoint circles are not pre-filled — you place digits in them during solving. The only rule is that every cell along the line (excluding endpoints) must sit strictly between whatever ends up in the two circles.
What is the best strategy for Between Lines Sudoku?
Look for short between-lines — a single cell between two endpoints is tightly constrained. Combined with row, column, and box rules, the valid range for that cell is often very small. Also look for lines where available candidates in a given row or column form a narrow range.
Is Between Lines Sudoku hard to learn?
The concept is straightforward but the deductions require careful range analysis. Tracking the minimum and maximum possible values for each endpoint and inferring the valid range for in-between cells is the core skill. Easy puzzles make this very accessible.
How long does Between Lines Sudoku take to solve?
Easy puzzles take 8–18 minutes. Medium puzzles run 18–35 minutes. Hard puzzles average 35–65 minutes and expert puzzles can take over 90 minutes. Solve time scales with the number of overlapping lines and the complexity of range interactions.