Hitori is a binary determination puzzle in which the cells in a grid are split into either shaded or unshaded.
The objective is to divide the grid into shaded and unshaded cells, subject to the following rules:
- No two numbers with the same value can appear unshaded in the same row or column.
- Unshaded cells must form one, connected area.
- Shaded cells must never touch horizontally or vertically.
A standard 10x10 hitori and its solution.
Unless otherwise indicated, standard tapa rules apply to all variants.
Regional: The grid is divided into regions. No two numbers with the same value can appear unshaded in the same region.