%0 Journal Article
%T Solving Single-digit Sudoku Subproblems
%A David Eppstein
%J Computer Science
%D 2012
%I arXiv
%X We show that single-digit "Nishio" subproblems in nxn Sudoku puzzles may be solved in time o(2^n), faster than previous solutions such as the pattern overlay method. We also show that single-digit deduction in Sudoku is NP-hard.
%U http://arxiv.org/abs/1202.5074v2