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: "on subexponential parameterized algorithms for steiner tree and directed subset tsp on planar graphs"
  Abstract: There are numerous examples of the so-called square root phenomenon in the field of parameterized algorithms: many of the most fundamental graph problems, parameterized by some natural parameter $k$, become significantly simpler when restricted to planar graphs and in particular the best possible running time is exponential in $O(\sqrt{k})$ instead of $O(k)$ (modulo standard complexity assumptions). We consider two classic optimization problems parameterized by the number of terminals. The Steiner Tree problem asks for a minimum-weight tree connecting a given set of terminals T in an edge-weighted graph. In the Subset Traveling Salesman problem we are asked to visit all the terminals $T$ by a minimum-weight closed walk. We investigate the parameterized complexity of these problems in planar graphs, where the number $k = |T|$ of terminals is regarded as the parameter. Our results are the following: (1) Subset TSP can be solved in time $2^{O(\sqrt{k} \log k)} \cdot n^{O(1)}$ even on edge-weighted directed planar graphs. (2) Assuming the Exponential-Time Hypothesis, Steiner Tree on undirected planar graphs cannot be solved in time $2^{o(k)} \cdot n^{O(1)}$, even in the unit-weight setting. (3) Steiner Tree can be solved in time $n^{O(\sqrt{k})} \cdot W$ on undirected planar graphs with maximum edge weight $W$. A direct corollary of the combination of our results for Steiner Tree is that this problem does not admit a parameter-preserving polynomial kernel on planar graphs unless ETH fails.

Connected through hyperedge HE-1 (induced by source paper "tight bounds for planar strongly connected steiner subgraph with fixed number of terminals and extensions"):
  with members:
    - "fpt inapproximability of directed cut and connectivity problems"
    - "complexity of the steiner network problem with respect to the number of terminals"
    - "the parameterized complexity of finding point sets with hereditary properties"
    - "homomorphisms are a good basis for counting small subgraphs"
    - "parameterized approximation algorithms for directed steiner network problems"
    - "the graph motif problem parameterized by the structure of the input graph"
    - "on the parameterized complexity of red blue points separation"
    - "subexponential parameterized algorithms for planar and apex minor free graphs via low treewidth pattern covering"

Connected through hyperedge HE-2 (induced by source paper "almost tight lower bounds for hard cutting problems in embedded graphs"):
  with members:
    - "a framework for eth tight algorithms and lower bounds in geometric intersection graphs"
    - "computational topology of graphs on surfaces"
    - "subexponential parameterized algorithms for planar and apex minor free graphs via low treewidth pattern covering"
    - "a near linear approximation scheme for multicuts of embedded graphs with a fixed number of terminals"
    - "the limited blessing of low dimensionality when 1 1 d is the best possible exponent for d dimensional geometric problems"
    - "optimal parameterized algorithms for planar facility location problems using voronoi diagrams"
    - "multicuts in planar and bounded genus graphs with bounded number of terminals"
    - "a fixed parameter tractable approximation scheme for the optimal cut graph of a surface"

Connected through hyperedge HE-3 (induced by source paper "a ptas for subset tsp in minor free graphs"):
  with members:
    - "truly optimal euclidean spanners"
    - "greedy spanners are optimal in doubling metrics"
    - "minor free graphs have light spanners"
    - "the greedy spanner is existentially optimal"
    - "linear size distance preservers"
    - "graph minors for preserving terminal distances approximately lower and upper bounds"
    - "a light metric spanner"
    - "better distance preservers and additive spanners"

Connected through hyperedge HE-4 (induced by source paper "nearly eth tight algorithms for planar steiner tree with terminals on few faces"):
  with members:
    - "flow cut gaps and face covers in planar graphs"
    - "subexponential parameterized algorithms for planar and apex minor free graphs via low treewidth pattern covering"
    - "optimal parameterized algorithms for planar facility location problems using voronoi diagrams"
    - "approximation schemes for steiner forest on planar graphs and graphs of bounded treewidth"

Connected through hyperedge HE-5 (induced by source paper "parameterized approximation algorithms for directed steiner network problems"):
  with members:
    - "complexity of the steiner network problem with respect to the number of terminals"
    - "eth hardness of approximating 2 csps and directed steiner network"
    - "the complexity landscape of fixed parameter directed steiner network problems"
    - "from gap eth to fpt inapproximability clique dominating set and more"
    - "parameterized complexity and approximability of directed odd cycle transversal"
    - "subexponential parameterized algorithms for planar and apex minor free graphs via low treewidth pattern covering"
    - "almost polynomial ratio eth hardness of approximating densest k subgraph"
    - "fixed parameter approximations for k center problems in low highway dimension graphs"

Connected through hyperedge HE-6 (induced by source paper "network sparsification for steiner problems on planar and bounded genus graphs"):
  with members:
    - "a deterministic polynomial kernel for odd cycle transversal and vertex multiway cut in planar graphs"
    - "improved guarantees for vertex sparsification in planar graphs"
    - "bidimensionality and kernels"
    - "on problems as hard as cnf sat"
    - "an o 1 84 k parameterized algorithm for the multiterminal cut problem"
    - "mimicking networks and succinct representations of terminal cuts"
    - "representative sets and irrelevant vertices new tools for kernelization"
    - "an efficient polynomial time approximation scheme for steiner forest in 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)