Hitori

Hitori is an easy to learn addictive logic puzzle which was invented by Nikoli Puzzles in Japan.

Hitori is played with a grid of squares or cells, and each cell contains a number.
The objective is to eliminate numbers by filling in the squares such that remaining cells do not contain numbers that appear more than once in either a given row or column.

Filled-in cells cannot be horizontally or vertically adjacent, although they can be diagonally adjacent. The remaining un-filled cells must form a single component connected horizontally and vertically.

Simple rules:

1.) Numbers never appear more than once in each row or column.
2.) Painted cells are never adjacent in a row or a column.
3.) Empty cells create a single continuous area, undivided by painted cells.

Tutorial video:
http://nikoli.co.jp/en/puzzles/hitori/

Tags: Hitori, hitori, logic, game, puzzle, brain