2026-07-26T17:15:15Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:21157 2024-09-23T09:13:18Z ddc:004 open_access

A Textbook Solution for Dynamic Strings Lipták, Zsuzsanna Masillo, Francesco Navarro, Gonzalo dynamic strings splay trees dynamic data structures LCP circular strings We consider the problem of maintaining a collection of strings while efficiently supporting splits and concatenations on them, as well as comparing two substrings, and computing the longest common prefix between two suffixes. This problem can be solved in optimal time O(log N) whp for the updates and O(1) worst-case time for the queries, where N is the total collection size [Gawrychowski et al., SODA 2018]. We present here a much simpler solution based on a forest of enhanced splay trees (FeST), where both the updates and the substring comparison take O(log n) amortized time, n being the lengths of the strings involved. The longest common prefix of length 𝓁 is computed in O(log n + log²𝓁) amortized time. Our query results are correct whp. Our simpler solution enables other more general updates in O(log n) amortized time, such as reversing a substring and/or mapping its symbols. We can also regard substrings as circular or as their omega extension. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Zsuzsanna Lipták and Francesco Masillo and Gonzalo Navarro 2024 Is Part Of LIPIcs, Volume 308, 32nd Annual European Symposium on Algorithms (ESA 2024) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.ESA.2024.86 urn:nbn:de:0030-drops-211576 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ESA.2024.86 eng https://creativecommons.org/licenses/by/4.0/legalcode