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: "constant factor approximations for capacitated arc routing without triangle inequality"
  Abstract: Abstract   Given an undirected graph with edge costs and edge demands, the  Capacitated Arc Routing  problem ( CARP ) asks for minimum-cost routes for equal-capacity vehicles so as to satisfy all demands. Constant-factor polynomial-time approximation algorithms were proposed for  CARP  with triangle inequality, while  CARP  was claimed to be NP-hard to approximate within any constant factor in general. Correcting this claim, we show that any factor     α    approximation for  CARP  with triangle inequality yields a factor     α    approximation for the general  CARP .

Connected through hyperedge HE-1 (induced by source paper "polynomial time data reduction for weighted problems beyond additive goal functions"):
  with members:
    - "parameterized algorithms and data reduction for the short secluded s t path problem"
    - "fixed parameter algorithms for maximum profit facility location under matroid constraints"
    - "on approximate data reduction for the rural postman problem theory and experiments"
    - "fair knapsack"
    - "parameterized power vertex cover"
    - "a parameterized approximation algorithm for the mixed and windy capacitated arc routing problem theory and experiments"
    - "parameterized algorithms for power efficient connected symmetric wireless sensor networks"
    - "new algorithms for minimizing the weighted number of tardy jobs on a single machine"

Connected through hyperedge HE-2 (induced by source paper "on approximate data reduction for the rural postman problem theory and experiments"):
  with members:
    - "parameterized algorithms and data reduction for the short secluded s t path problem"
    - "revisiting connected vertex cover fpt algorithms and lossy kernels"
    - "a parameterized approximation algorithm for the mixed and windy capacitated arc routing problem theory and experiments"
    - "polynomial kernels for weighted problems"
    - "fixed parameter algorithms for minimum cost edge connectivity augmentation"
    - "new inapproximability bounds for tsp"

Connected through hyperedge HE-3 (induced by source paper "a parameterized approximation algorithm for the mixed and windy capacitated arc routing problem theory and experiments"):
  with members:
    - "approximation algorithms for mixed windy and capacitated arc routing problems"

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)