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arXiv · 2611.04852

Faster Regular Expression Matching via Two-Dimensional Tabulation

Philip Bille·Inge Li Gørtz
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Abstract

Regular expression matching asks whether a string of length $n$ belongs to the language described by a regular expression of length $m$. We give an algorithm that solves this problem in linear space and $O(nm \log \log n/\log^2 n + n + m)$ time. This improves the leading term of the previous best worst-case constant-alphabet time bound by a factor of $\sqrt{\log n}$. The key new technique is a two-dimensional tabulation specialized to the regular expression.

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Philip Bille, Inge Li Gørtz. 2026-11-03. Faster Regular Expression Matching via Two-Dimensional Tabulation. https://arxiv.org/abs/2611.04852

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