Cách chơi Consecutive Sudoku

Consecutive Sudoku is a variant where white bars appear between some adjacent cells. A white bar means those two cells hold digits that differ by exactly 1. Crucially, all consecutive adjacent pairs are marked — if there is no bar between two cells, they are guaranteed not to be consecutive.

Every adjacent pair that is NOT consecutive has no bar. This negative information is extremely powerful — it eliminates all consecutive digit pairs from unmarked cell boundaries. Experienced players apply no-bar eliminations as aggressively as the positive bar clues.

Consecutive digits differ by exactly 1: 1&2, 2&3, 3&4, 4&5, 5&6, 6&7, 7&8, 8&9. The constraint applies to horizontally and vertically adjacent cells only — diagonal neighbours are not considered.

Look for long chains of consecutive bars — a chain of four bars forces four consecutive digits in those five cells. Also, digits 1 and 9 can only be consecutive with 2 and 8 respectively, so any cell surrounded by no-bar neighbours cannot hold 1 or 9 unless those specific partners are available nearby.

At easy difficulty it is comparable to medium classic Sudoku. The bars and no-bars together provide a dense constraint web that makes early eliminations fast. Hard and expert puzzles become much more demanding as bar chains grow longer and interact with more rows, columns, and boxes.

Easy puzzles take 8–18 minutes. Medium puzzles run 18–35 minutes. Hard puzzles average 35–65 minutes and expert puzzles often exceed 90 minutes. Applying both bar and no-bar logic simultaneously is the key to efficient solving at all levels.