English

Solving Single-digit Sudoku Subproblems

Data Structures and Algorithms 2012-03-06 v2

Abstract

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.

Cite

@article{arxiv.1202.5074,
  title  = {Solving Single-digit Sudoku Subproblems},
  author = {David Eppstein},
  journal= {arXiv preprint arXiv:1202.5074},
  year   = {2012}
}

Comments

12 pages, 5 figures. To appear at the 6th International Conference on Fun with Algorithms (FUN 2012). This revision simplifies the algorithm description and adds more references to related prior work

R2 v1 2026-06-21T20:23:46.814Z