GridWits

Grouped X-Cycles

Extreme Used by Smart Hint

X-Cycles generalized so a "node" can be a group of cells confined to one row-and-box or column-and-box intersection, not just a single cell.

A 1 B 2 C 3 D 4 E 5 F 6 G 7 H 8 I 9 1 6 4 6 3 6 6 8

How it works

  1. A1 and B1 together form a group node for digit 6 — both confined to row 1's leftmost box — linked by a strong link to G1 the same way a single cell would be in a plain X-Cycle.
  2. The rest of the loop proceeds exactly like X-Cycles, just treating that box-confined group as one link endpoint instead of a single cell.

Play a Sudoku that needs this technique →