English

Words with Repeated Letters in a Grid

Combinatorics 2025-12-01 v2

Abstract

Given a word ww, what is the maximum possible number of appearances of ww reading contiguously along any of the directions in {1,0,1}d{0}\{-1, 0, 1\}^d \setminus \{\mathbf{0}\} in a large dd-dimensional grid (as in a word search)? Patchell and Spiro first posed a version of this question, which Alon and Kravitz completely answered for a large class of "well-behaved" words, including those with no repeated letters. We study the general case, which exhibits greater variety and is often more complicated (even for d=1d=1). We also discuss some connections to other problems in combinatorics, including the storied nn-queens problem.

Keywords

Cite

@article{arxiv.2511.19678,
  title  = {Words with Repeated Letters in a Grid},
  author = {Zachary Halberstam and Carl Schildkraut},
  journal= {arXiv preprint arXiv:2511.19678},
  year   = {2025}
}

Comments

42 pages, 12 figures

R2 v1 2026-07-01T07:53:08.195Z