我应该记住哪些和？
最后更新
强大的三明治解题者不会重新计算组合——他们识别它们。一个强制和与长度范围的简短列表，瞬间回忆，涵盖了实际谜题中的大多数推理。
强制组合
These clue/length pairs have exactly one solution - Free information the moment you spot them:
- 0 - Empty sandwich: 1 and 9 adjacent.
- 2, 3, 4 - One cell, holding exactly that digit (two distinct digits from 2-8 cannot sum below 5).
- 5 with two cells - {2,3}. 15 with two cells - {7,8}.
- 9 with three cells - {2,3,4}. 21 with three cells - {6,7,8}.
- 27 to 33 with six cells - The one digit left outside is 35 − clue (clue 33 leaves out 2; clue 27 leaves out 8).
- 35 - All of 2-8 inside; 1 and 9 at the ends.
长度范围
记住每长度和范围：1个单元格跨度2-8，2个单元格5-15，3个单元格9-21，4个单元格14-26，5个单元格20-30，6个单元格27-33。它们遵循一个简单模式——最小值从2开始加下一个最小数字，最大值从8开始加下一个最大数字——所以如果回忆失败，你可以在脑中重建表格。这些范围是你如何将任何线索转换为可能的1/9位置对短列表的方法，这是整个变体的核心动作。
一个有用的对称性
Inside and outside mirror each other: the digits outside the sandwich always sum to 35 − clue, and an outside region of k cells obeys the same ranges as a sandwich of k cells. A clue of 30 therefore leaves outside digits summing to 5 - Either the single digit 5 (six-cell sandwich) or the pair {2,3} (five-cell sandwich, forcing the inside to be {4,5,6,7,8}). One memorized table covers both sides of every line.