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: "approximate tree decompositions of planar graphs in linear time"
  Abstract: Many algorithms have been developed for NP-hard problems on graphs with small treewidth $k$. For example, all problems that are expressable in linear extended monadic second order can be solved in linear time on graphs of bounded treewidth. It turns out that the bottleneck of many algorithms for NP-hard problems is the computation of a tree decomposition of width $O(k)$. In particular, by the bidimensional theory, there are many linear extended monadic second order problems that can be solved on $n$-vertex planar graphs with treewidth $k$ in a time linear in $n$ and subexponential in $k$ if a tree decomposition of width $O(k)$ can be found in such a time. #R##N#We present the first algorithm that, on $n$-vertex planar graphs with treewidth $k$, finds a tree decomposition of width $O(k)$ in such a time. In more detail, our algorithm has a running time of $O(n k^2 \log k)$. We show the result as a special case of a result concerning so-called weighted treewidth of weighted graphs.

Connected through hyperedge HE-1 (induced by source paper "hitting topological minors is fpt"):
  with members:
    - "hitting topological minor models in planar graphs is fixed parameter tractable"
    - "improved analysis of highest degree branching for feedback vertex set"
    - "losing treewidth by separating subsets"
    - "a 2 approximation algorithm for feedback vertex set in tournaments"
    - "polylogarithmic approximation for minimum planarization almost"
    - "exact algorithms for maximum independent set"
    - "bidimensionality and kernels"
    - "exact algorithms via monotone local search"

Connected through hyperedge HE-2 (induced by source paper "reducing topological minor containment to the unique linkage theorem"):
  with members:
    - "hitting topological minor models in planar graphs is fixed parameter tractable"
    - "improved analysis of highest degree branching for feedback vertex set"
    - "losing treewidth by separating subsets"
    - "a 2 approximation algorithm for feedback vertex set in tournaments"
    - "polylogarithmic approximation for minimum planarization almost"
    - "exact algorithms for maximum independent set"
    - "linear kernels for edge deletion problems to immersion closed graph classes"
    - "bidimensionality and kernels"

Connected through hyperedge HE-3 (induced by source paper "ptas for steiner tree on map graphs"):
  with members:
    - "polynomial time approximation scheme for minimum k cut in planar and minor free graphs"
    - "local search yields approximation schemes for k means and k median in euclidean and minor free metrics"
    - "simple ptas s for families of graphs excluding a minor"
    - "an efficient polynomial time approximation scheme for steiner forest in planar graphs"
    - "approximation schemes for steiner forest on planar graphs and graphs of bounded treewidth"

Connected through hyperedge HE-4 (induced by source paper "on computing the hamiltonian index of graphs"):
  with members:
    - "parameterized edge hamiltonicity"
    - "solving connectivity problems parameterized by treewidth in single exponential time"

Connected through hyperedge HE-5 (induced by source paper "near linear time constant factor approximation algorithm for branch decomposition of planar graphs"):
  with members:
    - "all pairs minimum cuts in near linear time for surface embedded graphs"
    - "structured recursive separator decompositions for planar graphs in linear time"
    - "min st cut oracle for planar graphs with near linear preprocessing time"
    - "exact distance oracles for planar graphs"

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)