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: "approximation algorithm for non boolean max k csp"
  Abstract: In this paper, we present a randomized polynomial-time approximation algorithm for k-CSPd. In k-CSPd, we are given a set of predicates of arity k over an alphabet of size d. Our goal is to find an assignment that maximizes the number of satisfied constraints. #R##N#Our algorithm has approximation factor Omega(kd/d^k) (when k > \Omega(log d)). This bound is asymptotically optimal assuming the Unique Games Conjecture. The best previously known algorithm has approximation factor Omega(k log d/d^k). #R##N#We also give an approximation algorithm for the boolean MAX k-CSP2 problem with a slightly improved approximation guarantee.

Connected through hyperedge HE-1 (induced by source paper "integrality gaps and approximation algorithms for dispersers and bipartite expanders"):
  with members:
    - "approximation algorithms for hypergraph small set expansion and small set vertex expansion"
    - "the complexity of approximating vertex expansion"
    - "constant factor lasserre integrality gaps for graph partitioning problems"
    - "explicit optimal hardness via gaussian stability results"
    - "better balance by being biased a 0 8776 approximation for max bisection"
    - "min max graph partitioning and small set expansion"
    - "polynomial integrality gaps for strong sdp relaxations of densest k subgraph"
    - "approximating csps with global cardinality constraints using sdp hierarchies"

Connected through hyperedge HE-2 (induced by source paper "approximation of non boolean 2csp"):
  with members:
    - "the unique games conjecture integrality gap for cut problems and embeddability of negative type metrics into ell_1"

Connected through hyperedge HE-3 (induced by source paper "simultaneous approximation of constraint satisfaction problems"):
  with members:
    - "rounding semidefinite programming hierarchies via global correlation"
    - "applications of discrepancy theory in multiobjective approximation"
    - "approximating csps with global cardinality constraints using sdp hierarchies"
    - "solving max r sat above a tight lower bound"

Connected through hyperedge HE-4 (induced by source paper "on the power of many one bit provers"):
  with members:
    - "combinatorial approximation algorithms for maxcut using random walks"
    - "a pcp characterization of am"
    - "approximation resistant predicates from pairwise independence"

Connected through hyperedge HE-5 (induced by source paper "approximation algorithm for sparsest k partitioning"):
  with members:
    - "many sparse cuts via higher eigenvalues"
    - "reductions between expansion problems"

Connected through hyperedge HE-6 (induced by source paper "explicit optimal hardness via gaussian stability results"):
  with members:
    - "approximation resistant predicates from pairwise independence"

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)