Hitori· Advanced

Goal

Shade cells so no number appears more than once in any row or column.

Rules

  • Tap a cell to cycle: normal → shaded → circled → normal.
  • Shaded cells cannot be adjacent horizontally or vertically.
  • All unshaded cells must remain connected as one group.
2
1
3
4
5
1
3
5
2
4
3
4
1
5
2
4
5
2
1
3
5
2
4
3
1

Look for duplicate numbers in the same row or column first.

Start with edge and corner cells — they have fewer constraints.

Constraint satisfaction puzzles simultaneously train logical reasoning, spatial connectivity thinking, and working memory. Coordinating multiple constraints activates prefrontal executive functions.

  • Constraint satisfaction and prefrontal executive function (Goel & Grafman, 2000)