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: "fast and compact regular expression matching"
  Abstract: We study 4 problems in string matching, namely, regular expression matching, approximate regular expression matching, string edit distance, and subsequence indexing, on a standard word RAM model of computation that allows logarithmic-sized words to be manipulated in constant time. We show how to improve the space and/or remove a dependency on the alphabet size for each problem using either an improved tabulation technique of an existing algorithm or by combining known algorithms in a new way.

Connected through hyperedge HE-1 (induced by source paper "approximating lcs in linear time beating the sqrt n barrier"):
  with members:
    - "approximating edit distance within constant factor in truly sub quadratic time"
    - "approximating edit distance in truly subquadratic time quantum and mapreduce"
    - "quadratic conditional lower bounds for string problems and dynamic time warping"
    - "edit distance cannot be computed in strongly subquadratic time unless seth is false"
    - "new tabulation and sparse dynamic programming based techniques for sequence similarity problems"
    - "approximating edit distance in near linear time"
    - "polylogarithmic approximation for edit distance and the asymmetric query complexity"

Connected through hyperedge HE-2 (induced by source paper "fast indexes for gapped pattern matching"):
  with members:
    - "optimal time text indexing in bwt runs bounded space"

Connected through hyperedge HE-3 (induced by source paper "sparse regular expression matching"):
  with members:
    - "which regular expression patterns are hard to match"
    - "new algorithms for regular expression matching"

Connected through hyperedge HE-4 (induced by source paper "tighter connections between formula sat and shaving logs"):
  with members:
    - "subquadratic algorithms for succinct stable matching"
    - "a dichotomy for regular expression membership testing"
    - "an improved combinatorial algorithm for boolean matrix multiplication"
    - "improved bounds for 3sum k sum and linear degeneracy"
    - "fr echet distance for curves revisited"
    - "subtree isomorphism revisited"
    - "which regular expression patterns are hard to match"
    - "simulating branching programs with edit distance and friends or a polylog shaved is a lower bound made"

Connected through hyperedge HE-5 (induced by source paper "multivariate fine grained complexity of longest common subsequence"):
  with members:
    - "faster str ic lcs computation via rle"
    - "a dichotomy for regular expression membership testing"
    - "which regular expression patterns are hard to match"
    - "simulating branching programs with edit distance and friends or a polylog shaved is a lower bound made"
    - "quadratic conditional lower bounds for string problems and dynamic time warping"
    - "approximation and fixed parameter subquadratic algorithms for radius and diameter"
    - "why walking the dog takes time frechet distance has no strongly subquadratic algorithms unless seth fails"
    - "popular conjectures imply strong lower bounds for dynamic problems"

Connected through hyperedge HE-6 (induced by source paper "from regular expression matching to parsing"):
  with members:
    - "which regular expression patterns are hard to match"
    - "new algorithms for regular expression matching"

Connected through hyperedge HE-7 (induced by source paper "dynamic time warping and geometric edit distance breaking the quadratic barrier"):
  with members:
    - "tighter connections between formula sat and shaving logs"
    - "improved bounds for 3sum k sum and linear degeneracy"
    - "simulating branching programs with edit distance and friends or a polylog shaved is a lower bound made"
    - "quadratic conditional lower bounds for string problems and dynamic time warping"
    - "approximating dynamic time warping and edit distance for a pair of point sequences"
    - "quadratic time hardness of lcs and other sequence similarity measures"
    - "why walking the dog takes time frechet distance has no strongly subquadratic algorithms unless seth fails"
    - "threesomes degenerates and love triangles"

Connected through hyperedge HE-8 (induced by source paper "quadratic time hardness of lcs and other sequence similarity measures"):
  with members:
    - "why walking the dog takes time frechet distance has no strongly subquadratic algorithms unless seth fails"
    - "0 1 integer linear programming with a linear number of constraints"
    - "faster all pairs shortest paths via circuit complexity"

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)