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: "ptas for minimax approval voting"
  Abstract: We consider Approval Voting systems where each voter decides on a subset of candidates he/she approves. We focus on the optimization problem of finding the committee of fixed size k, minimizing the maximal Hamming distance from a vote. In this paper we give a PTAS for this problem and hence resolve the open question raised by Carragianis et al. [AAAI’10]. The result is obtained by adapting the techniques developed by Li et al. [JACM’02] originally used for the less constrained Closest String problem. The technique relies on extracting information and structural properties of constant size subsets of votes.

Connected through hyperedge HE-1 (induced by source paper "on choosing committees based on approval votes in the presence of outliers"):
  with members:
    - "sample complexity for winner prediction in elections"
    - "justified representation in approval based committee voting"
    - "on approximating string selection problems with outliers"
    - "multimode control attacks on elections"
    - "a richer understanding of the complexity of election systems"
    - "anyone but him the complexity of precluding an alternative"
    - "exact complexity of the winner problem for young elections"

Connected through hyperedge HE-2 (induced by source paper "finding a collective set of items from proportional multirepresentation to group recommendation"):
  with members:
    - "generalizing the single crossing property on lines and trees to intermediate preferences on median graphs"
    - "structure in dichotomous preferences"
    - "properties of multiwinner voting rules"
    - "computational aspects of multi winner approval voting"
    - "approximating the maxcover problem with bounded frequencies in fpt time"
    - "on the computation of fully proportional representation"
    - "a social welfare optimal sequential allocation procedure"
    - "the complexity of fully proportional representation for single crossing electorates"

Connected through hyperedge HE-3 (induced by source paper "justified representation in approval based committee voting"):
  with members:
    - "proportional justified representation"
    - "structure in dichotomous preferences"
    - "properties of multiwinner voting rules"
    - "finding a collective set of items from proportional multirepresentation to group recommendation"
    - "computational aspects of multi winner approval voting"
    - "achieving fully proportional representation approximability results"
    - "on the computation of fully proportional representation"
    - "the complexity of fully proportional representation for single crossing electorates"

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)