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 algorithms for hard capacitated k facility location problems"
  Abstract: We study the capacitated $k$-facility location problem, in which we are given a set of clients with demands, a set of facilities with capacities and a constant number $k$. It costs $f_i$ to open facility $i$, and $c_{ij}$ for facility $i$ to serve one unit of demand from client $j$. The objective is to open at most $k$ facilities serving all the demands and satisfying the capacity constraints while minimizing the sum of service and opening costs. #R##N#In this paper, we give the first fully polynomial time approximation scheme (FPTAS) for the single-sink (single-client) capacitated $k$-facility location problem. Then, we show that the capacitated $k$-facility location problem with uniform capacities is solvable in polynomial time if the number of clients is fixed by reducing it to a collection of transportation problems. Third, we analyze the structure of extreme point solutions, and examine the efficiency of this structure in designing approximation algorithms for capacitated $k$-facility location problems. Finally, we extend our results to obtain an improved approximation algorithm for the capacitated facility location problem with uniform opening cost.

Connected through hyperedge HE-1 (induced by source paper "facility location problem with capacity constraints algorithmic and mechanism design perspectives"):
  with members:
    - "the capacity constrained facility location problem"
    - "on the power of deterministic mechanisms for facility location games"

Connected through hyperedge HE-2 (induced by source paper "improved local search based approximation algorithm for hard uniform capacitated k median problem"):
  with members:
    - "constant approximation for capacitated k median with 1 epsilon capacity violation"
    - "constant factor approximation algorithms for uniform hard capacitated facility location problems natural lp is not too bad"
    - "an approximation algorithm for uniform capacitated k median problem with 1 epsilon capacity violation"
    - "an improved approximation algorithm for the hard uniform capacitated k median problem"
    - "on uniform capacitated k median beyond the natural lp relaxation"
    - "approximation algorithms for capacitated facility location problem with penalties"
    - "bi factor approximation algorithms for hard capacitated k median problems"

Connected through hyperedge HE-3 (induced by source paper "fixed parameter algorithms for maximum profit facility location under matroid constraints"):
  with members:
    - "inferring the strength of social ties a community driven approach"
    - "on the relation of strong triadic closure and cluster deletion"
    - "parameterized aspects of strong subgraph closure"
    - "deterministic truncation of linear matroids"
    - "parameterized exact and approximation algorithms for maximum k set cover and related satisfiability problems"
    - "improved approximation algorithms for matroid and knapsack median problems and applications"

Connected through hyperedge HE-4 (induced by source paper "on the cost of essentially fair clusterings"):
  with members:
    - "fair clustering through fairlets"
    - "constant approximation for k median and k means with outliers via iterative rounding"
    - "on uniform capacitated k median beyond the natural lp relaxation"
    - "an improved approximation for k median and positive correlation in budgeted optimization"
    - "fairness through awareness"
    - "clustering with diversity"

Connected through hyperedge HE-5 (induced by source paper "constant factor approximation algorithms for uniform hard capacitated facility location problems natural lp is not too bad"):
  with members:
    - "constant approximation for capacitated k median with 1 epsilon capacity violation"
    - "an approximation algorithm for uniform capacitated k median problem with 1 epsilon capacity violation"
    - "an improved approximation algorithm for the hard uniform capacitated k median problem"
    - "on uniform capacitated k median beyond the natural lp relaxation"
    - "an improved approximation for k median and positive correlation in budgeted optimization"
    - "lp based algorithms for capacitated facility location"
    - "improved approximation algorithms for matroid and knapsack median problems and applications"
    - "bi factor approximation algorithms for hard capacitated k median problems"

Connected through hyperedge HE-6 (induced by source paper "constant approximation for capacitated k median with 1 epsilon capacity violation"):
  with members:
    - "an approximation algorithm for uniform capacitated k median problem with 1 epsilon capacity violation"
    - "an improved approximation algorithm for the hard uniform capacitated k median problem"
    - "on uniform capacitated k median beyond the natural lp relaxation"
    - "an improved approximation for k median and positive correlation in budgeted optimization"
    - "lp based algorithms for capacitated facility location"
    - "bi factor approximation algorithms for hard capacitated k median problems"
    - "approximating k median via pseudo approximation"

Connected through hyperedge HE-7 (induced by source paper "an approximation algorithm for uniform capacitated k median problem with 1 epsilon capacity violation"):
  with members:
    - "on uniform capacitated k median beyond the natural lp relaxation"
    - "an improved approximation for k median and positive correlation in budgeted optimization"
    - "lp based algorithms for capacitated facility location"
    - "approximating capacitated k median with 1 epsilon k open facilities"
    - "bi factor approximation algorithms for hard capacitated k median problems"
    - "approximating k median via pseudo approximation"

Connected through hyperedge HE-8 (induced by source paper "data driven resource allocation for distributed learning"):
  with members:
    - "an improved approximation algorithm for the hard uniform capacitated k median problem"
    - "improved distributed principal component analysis"
    - "decompositions of triangle dense graphs"
    - "bi factor approximation algorithms for hard capacitated k median problems"
    - "greedy facility location algorithms analyzed using dual fitting with factor revealing lp"

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)