三明治数独
0
27
25
0
0
0
17
9
8
22
12
9
0
8
9
16
6
11
5
8
1
2
6
4
3
7
9
5
1
3
6
9
9
6
9
4
8
7
5
9
7
6
2
5
9
7
2
6
5
1
9
8
3
4
5
7
线索给出每行/列中1和9之间数字的和
什么是三明治数独？
三明治数独在网格外部放置线索。每个线索给出该行或列中1和9之间所有数字的和。1和9的位置变化，所以"三明治"可以有0到7个单元格，取决于它们的位置。线索0表示1和9相邻。线索35表示所有数字2-8都在它们之间。
一览
| 约束类型 | 外部线索 |
| 典型给定数 | 4–10 clue values |
| 难度评级 | ★★★★☆ 4/5 |
| 平均解题时间 — 简单 | 12 分钟 |
| 平均解题时间 — 中等 | 26 分钟 |
| 平均解题时间 — 困难 | 52 分钟 |
| 平均解题时间 — 专家 | 85 分钟 |
如何解三明治数独
| 技巧 | 它的作用 | 级别 |
|---|---|---|
| Clue 0 Means Adjacent 1 and 9 | A sandwich clue of 0 means 1 and 9 are side-by-side with nothing between them. Place this pair immediately. | 高级 |
| Clue 35 Means 1 and 9 at Ends | A clue of 35 = 2+3+4+5+6+7+8. All middle digits are sandwiched, placing 1 and 9 at the two ends of the row/column. | 高级 |
| Position Enumeration | For each clue, enumerate all valid positions of 1 and 9 such that the enclosed digits sum to the clue. Cross-reference with column clues. | 高级 |
| Sandwich Intersection | Row and column clues intersect at one cell. Combining row positions of 1 and 9 with column positions pinpoints key placements. | 高级 |
| Digit Forcing from Both Sides | Use clues from both the row and column sides to triangulate the positions of 1 and 9 simultaneously. | 高级 |
平均解题时间
简单
12 分钟
中等
26 分钟
困难
52 分钟
专家
85 分钟
每日三明治数独
常见问题
什么是三明治数独？
Sandwich Sudoku is a variant where clue numbers appear outside the grid, one per row and one per column. Each clue tells you the sum of all digits that appear between the 1 and the 9 in that row or column. Standard Sudoku rules apply throughout.
How do I use the sandwich clues?
First, find the positions of the 1 and 9 in each row or column — every other digit between them must sum to the outside clue. A clue of 0 means the 1 and 9 are adjacent. A clue equal to the maximum possible sum (e.g., 35 for a 7-cell sandwich) tells you the 1 and 9 are at the ends. Work from the most constrained clues first.
sandwich clue 0 是什么意思？
A clue of 0 means no digits are sandwiched between the 1 and 9 — they must be directly adjacent to each other. This is one of the most powerful clues because it immediately tells you where 1 and 9 can and cannot be placed relative to each other in that row or column.
Is Sandwich Sudoku harder than regular Sudoku?
Yes, generally. Sandwich Sudoku provides very few pre-filled digits inside the grid. Almost all deductions flow from working out where 1 and 9 can sit and what sums are achievable. The logic is more algebraic than classic Sudoku, which many players find both more challenging and more satisfying.
Can the 1 and 9 be at the ends of a row?
Yes. If the 1 is in column 1 and the 9 is in column 9 (or vice versa), the sandwiched digits are columns 2–8, giving a maximum possible sum of 2+3+4+5+6+7+8 = 35. Extreme clue values like this immediately fix the positions of both the 1 and the 9.
How long does Sandwich Sudoku take to solve?
Easy puzzles typically take 10–20 minutes. Medium puzzles run 20–35 minutes. Hard puzzles can take 45–75 minutes, and expert puzzles often exceed 90 minutes. The key bottleneck is working out 1/9 positions — once you pin those down, the rest of the grid often resolves quickly.