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: "combinatorial optimization algorithms via polymorphisms"
  Abstract: An elegant characterization of the complexity of constraint satisfaction problems has emerged in the form of the the algebraic dichotomy conjecture of [BKJ00]. Roughly speaking, the characterization asserts that a CSP {\Lambda} is tractable if and only if there exist certain non-trivial operations known as polymorphisms to combine solutions to {\Lambda} to create new ones. In an entirely separate line of work, the unique games conjecture yields a characterization of approximability of Max-CSPs. Surprisingly, this characterization for Max-CSPs can also be reformulated in the language of polymorphisms. #R##N#In this work, we study whether existence of non-trivial polymorphisms implies tractability beyond the realm of constraint satisfaction problems, namely in the value-oracle model. Specifically, given a function f in the value-oracle model along with an appropriate operation that never increases the value of f , we design algorithms to minimize f . In particular, we design a randomized algorithm to minimize a function f that admits a fractional polymorphism which is measure preserving and has a transitive symmetry. #R##N#We also reinterpret known results on MaxCSPs and thereby reformulate the unique games conjecture as a characterization of approximability of max-CSPs in terms of their approximate polymorphisms.

Connected through hyperedge HE-1 (induced by source paper "and testing and robust judgement aggregation"):
  with members:
    - "symmetric polymorphisms and efficient decidability of promise csps"
    - "impossibility theorems and the universal algebraic toolkit"
    - "analysis of boolean functions"
    - "approximately classic judgement aggregation"

Connected through hyperedge HE-2 (induced by source paper "algebraic approach to promise constraint satisfaction"):
  with members:
    - "topology is relevant in a dichotomy conjecture for infinite domain constraint satisfaction problems"
    - "promises make finite constraint satisfaction problems infinitary"
    - "dichotomy for symmetric boolean pcsps"
    - "an algorithmic blend of lps and ring equations for promise csps"
    - "improved inapproximability of rainbow coloring"
    - "super polylogarithmic hypergraph coloring hardness via low degree long codes"
    - "promise constraint satisfaction algebraic structure and a symmetric boolean dichotomy"
    - "a dichotomy theorem for nonuniform csps"

Connected through hyperedge HE-3 (induced by source paper "an algorithmic blend of lps and ring equations for promise csps"):
  with members:
    - "a dichotomy theorem for nonuniform csps"
    - "the proof of csp dichotomy conjecture"
    - "improved hardness of approximating chromatic number"

Connected through hyperedge HE-4 (induced by source paper "promise constraint satisfaction algebraic structure and a symmetric boolean dichotomy"):
  with members:
    - "dichotomy for digraph homomorphism problems two algorithms"
    - "a finer reduction of constraint problems to digraphs"
    - "the complexity of general valued csps"
    - "conservative constraint satisfaction re revisited"

Connected through hyperedge HE-5 (induced by source paper "towards a characterization of constant factor approximable finite valued csps"):
  with members:
    - "a dichotomy theorem for nonuniform csps"
    - "the proof of csp dichotomy conjecture"
    - "the complexity of finite valued csps"
    - "asking the metaquestions in constraint tractability"
    - "robust algorithms with polynomial loss for near unanimity csps"
    - "the complexity of general valued csps"
    - "local distribution and the symmetry gap approximability of multiway partitioning problems"
    - "robustly solvable constraint satisfaction problems"

Connected through hyperedge HE-6 (induced by source paper "the complexity of general valued csps"):
  with members:
    - "the power of sherali adams relaxations for general valued csps"
    - "a galois connection for valued constraint languages of infinite size"
    - "algebraic properties of valued constraint satisfaction problem"
    - "effectiveness of structural restrictions for hybrid csps"
    - "local distribution and the symmetry gap approximability of multiway partitioning problems"
    - "sherali adams relaxations for valued csps"
    - "robustly solvable constraint satisfaction problems"
    - "an algebraic theory of complexity for discrete optimization"

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.CC(Computational Complexity)