TY - JOUR
T1 - A hardness result and new algorithm for the longest common palindromic subsequence problem
AU - Inenaga, Shunsuke
AU - Hyyrö, Heikki
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2018/1
Y1 - 2018/1
N2 - The 2-LCPS problem, first introduced by Chowdhury et al. (2014) [17], asks one to compute (the length of) a longest common palindromic subsequence between two given strings A and B. We show that the 2-LCPS problem is at least as hard as the well-studied longest common subsequence problem for four strings. Then, we present a new algorithm which solves the 2-LCPS problem in O(σM2+n) time, where n denotes the length of A and B, M denotes the number of matching positions between A and B, and σ denotes the number of distinct characters occurring in both A and B. Our new algorithm is faster than Chowdhury et al.'s sparse algorithm when σ=o(log2nloglogn).
AB - The 2-LCPS problem, first introduced by Chowdhury et al. (2014) [17], asks one to compute (the length of) a longest common palindromic subsequence between two given strings A and B. We show that the 2-LCPS problem is at least as hard as the well-studied longest common subsequence problem for four strings. Then, we present a new algorithm which solves the 2-LCPS problem in O(σM2+n) time, where n denotes the length of A and B, M denotes the number of matching positions between A and B, and σ denotes the number of distinct characters occurring in both A and B. Our new algorithm is faster than Chowdhury et al.'s sparse algorithm when σ=o(log2nloglogn).
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U2 - 10.1016/j.ipl.2017.08.006
DO - 10.1016/j.ipl.2017.08.006
M3 - Article
AN - SCOPUS:85029384363
VL - 129
SP - 11
EP - 15
JO - Information Processing Letters
JF - Information Processing Letters
SN - 0020-0190
ER -