Abstract : A string is called a palindrome if it reads the same from left to right. In this paper we define the new concept of an abelian palindrome which satisfies the property of being abelian equivalent to some palindrome of the same length. The identification of abelian palindromes presents a novel combinatorial problem, with potential applications in filtering strings for palindromic factors. We present an algorithm to efficiently identify abelian palindromes, and additionally generate an abelian palindromic array, indicating the longest abelian palindrome at each location. Specifically, for an alphabet of size $$|\varSigma | \le \log _2(n)$$|Σ|≤log2(n) and after $$\mathcal {O}(n)$$O(n) time preprocessing using $$\mathcal {O}(n + |\varSigma |)$$O(n+|Σ|) space, we may determine if any factor is abelian palindromic in $$\mathcal {O}(1)$$O(1) time. Additionally, we may determine the abelian palindromic array in $$\mathcal {O}(|\varSigma |n)$$O(|Σ|n) time. We further specify the algorithmic complexity when this condition on alphabet size $$|\varSigma |$$|Σ| is relaxed.
https://hal.inria.fr/hal-01821324 Contributor : Hal IfipConnect in order to contact the contributor Submitted on : Friday, June 22, 2018 - 2:14:10 PM Last modification on : Friday, June 22, 2018 - 2:24:07 PM Long-term archiving on: : Tuesday, September 25, 2018 - 1:38:08 AM
Costas Iliopoulos, Steven Watts. Efficient Recognition of Abelian Palindromic Factors and Associated Results. 14th IFIP International Conference on Artificial Intelligence Applications and Innovations (AIAI), May 2018, Rhodes, Greece. pp.211-223, ⟨10.1007/978-3-319-92016-0_20⟩. ⟨hal-01821324⟩