human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "eertree an efficient data structure for processing palindromes in strings"
  Abstract: We propose a new linear-size data structure which provides a fast access to all palindromic substrings of a string or a set of strings. This structure inherits some ideas from the construction of both the suffix trie and suffix tree. Using this structure, we present simple and efficient solutions for a number of problems involving palindromes.

Connected through hyperedge HE-1 (induced by source paper "palindromic k factorization in pure linear time"):
  with members:
    - "sturmian numeration systems and decompositions to palindromes"
    - "a subquadratic algorithm for minimum palindromic factorization"

Connected through hyperedge HE-2 (induced by source paper "prefix palindromic length of the thue morse word"):
  with members:
    - "sturmian numeration systems and decompositions to palindromes"
    - "a subquadratic algorithm for minimum palindromic factorization"
    - "enumeration and decidable properties of automatic sequences"

Connected through hyperedge HE-3 (induced by source paper "shortest unique palindromic substring queries on run length encoded strings"):
  with members:
    - "an in place framework for exact and approximate shortest unique substring queries"
    - "shortest unique substring query revisited"

Connected through hyperedge HE-4 (induced by source paper "palindromic decompositions with gaps and errors"):
  with members:
    - "a subquadratic algorithm for minimum palindromic factorization"

Connected through hyperedge HE-5 (induced by source paper "shortest unique palindromic substring queries in optimal time"):
  with members:
    - "diverse palindromic factorization is np complete"
    - "an in place framework for exact and approximate shortest unique substring queries"
    - "a subquadratic algorithm for minimum palindromic factorization"
    - "shortest unique substring query revisited"

Connected through hyperedge HE-6 (induced by source paper "detecting one variable patterns"):
  with members:
    - "online detection of repetitions with backtracking"
    - "weighted ancestors in suffix trees"
    - "internal pattern matching queries in a text and applications"
    - "a minimal periods algorithm with applications"

Connected through hyperedge HE-7 (induced by source paper "palindromic rich words and run length encodings"):
  with members:
    - "on the number of closed factors in a word"
    - "inverse star borders and palstars"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.DS(Data Structures and Algorithms)