如何遊玩 線間數獨
線上的數字必須嚴格落在兩個端點值之間
規則
標準數獨規則適用： 用數字1–9填滿每一行、列和3×3宮，每個數字恰好出現一次。
線之間數獨繪製帶有圓形端點的線。沿線的每個數字（不包括端點本身）必須嚴格大於較小的端點並嚴格小於較大的端點。如果端點是2和8，線上的每個中間單元格必須是3、4、5、6或7之一。端點值越接近，中間單元格越受限制。
如需了解此謎題的來源、與相關變體的比較及策略摘要，請參閱我們的 線間數獨 變體概述.
一覽
如何解 線間數獨
常見問題
乜嘢係Between Lines Sudoku？ ▾
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.