A Linear-Time On-Line Recognition Algorithm for “Palstar”

Abstract

Let [formula-omitted] be the set of all nontnvial pahndromes over X A hneartime on-hne recogmtmn algorithm is presented for P1 (“palstar”) on a random-access machine with addmon and umform cost criterion Also presented are a hnear-tlme on-line recognmonalgorithm for P1 on a muitltape Turmg machine and a recognition algorithm for Pt 2 on a two-way deterministic pushdownautomaton. The correctness of these algorithms is based on new “cancellationiemmas” for the languages P1 and P1. © 1978, ACM. All rights reserved.