Pattern Matching on Elastic-Degenerate Text with Errors

  • Giulia Bernardini
  • Nadia Pisanti
  • Solon P. Pissis
  • Giovanna RosoneEmail author
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 10508)


An elastic-degenerate string is a sequence of n sets of strings of total length N. It has been introduced to represent a multiple alignment of several closely-related sequences (e.g. pan-genome) compactly. In this representation, substrings of these sequences that match exactly are collapsed, while in positions where the sequences differ, all possible variants observed at that location are listed. The natural problem that arises is finding all matches of a deterministic pattern of length m in an elastic-degenerate text. There exists an \(\mathcal {O}(nm^2 + N)\)-time algorithm to solve this problem on-line after a pre-processing stage with time and space \(\mathcal {O}(m)\). In this paper, we study the same problem under the edit distance model and present an \(\mathcal {O}(k^2mG+kN)\)-time and \(\mathcal {O}(m)\)-space algorithm, where G is the total number of strings in the elastic-degenerate text and k is the maximum edit distance allowed. We also present a simple \(\mathcal {O}(kmG+kN)\)-time and \(\mathcal {O}(m)\)-space algorithm for Hamming distance.


Uncertain sequences Elastic-degenerate strings Degenerate strings Pan-genome Pattern matching 



NP and GR are partially supported by the project MIUR-SIR CMACBioSeq (“Combinatorial methods for analysis and compression of biological sequences”) grant n. RBSI146R5L. GB, NP, and GR are partially supported by the project UniPi PRA\(\_2017\_44\) (“Advanced computational methodologies for the analysis of biomedical data”). NP, SPP, and GR are partially supported by the Royal Society project IE 161274 (“Processing uncertain sequences: combinatorics and applications”).


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Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  • Giulia Bernardini
    • 1
  • Nadia Pisanti
    • 2
    • 3
  • Solon P. Pissis
    • 4
  • Giovanna Rosone
    • 2
    Email author
  1. 1.Department of MathematicsUniversity of PisaPisaItaly
  2. 2.Department of Computer ScienceUniversity of PisaPisaItaly
  3. 3.Erable TeamINRIAVilleurbanneFrance
  4. 4.Department of InformaticsKing’s College LondonLondonUK

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