Hitori is short for <em>Hitori ni shite kure,</em> ひとりにしてくれ, that is, “Leave me alone”, possibly in reference to the lack of any duplicated digits in any row or column in the solution.
Hitori was invented by Nikoli and first appeared in 1990.
Puzzle and Goal
An unsolved puzzle consists of a square grid filled entirely with numbers, ranging from 1 to <em>n</em>, where <em>n</em> is the size of the grid.
The goal is to color some of the cells black, leaving the remaining white.
The solved grid must satisfy the following conditions:
All white cells are orthogonally contiguous.
No two orthogonal neighbors are black.
The digits in the white cells form an incomplete Latin square.
Federstrich; Hitori ni shite kure; Singles