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: "new hardness results for routing on disjoint paths"
  Abstract: In the classical Node-Disjoint Paths (NDP) problem, the input consists of an undirected $n$-vertex graph $G$, and a collection $\mathcal{M}=\{(s_1,t_1),\ldots,(s_k,t_k)\}$ of pairs of its vertices, called source-destination, or demand, pairs. The goal is to route the largest possible number of the demand pairs via node-disjoint paths. The best current approximation for the problem is achieved by a simple greedy algorithm, whose approximation factor is $O(\sqrt n)$, while the best current negative result is an $\Omega(\log^{1/2-\delta}n)$-hardness of approximation for any constant $\delta$, under standard complexity assumptions. Even seemingly simple special cases of the problem are still poorly understood: when the input graph is a grid, the best current algorithm achieves an $\tilde O(n^{1/4})$-approximation, and when it is a general planar graph, the best current approximation ratio of an efficient algorithm is $\tilde O(n^{9/19})$. The best currently known lower bound on the approximability of both these versions of the problem is APX-hardness. #R##N#In this paper we prove that NDP is $2^{\Omega(\sqrt{\log n})}$-hard to approximate, unless all problems in NP have algorithms with running time $n^{O(\log n)}$. Our result holds even when the underlying graph is a planar graph with maximum vertex degree $3$, and all source vertices lie on the boundary of a single face (but the destination vertices may lie anywhere in the graph). We extend this result to the closely related Edge-Disjoint Paths problem, showing the same hardness of approximation ratio even for sub-cubic planar graphs with all sources lying on the boundary of a single face.

Connected through hyperedge HE-1 (induced by source paper "an approximation algorithm for fully planar edge disjoint paths"):
  with members:
    - "almost polynomial hardness of node disjoint paths in grids"
    - "improved approximation for node disjoint paths in planar graphs"
    - "routing in undirected graphs with constant congestion"

Connected through hyperedge HE-2 (induced by source paper "almost polynomial hardness of node disjoint paths in grids"):
  with members:
    - "improved approximation for node disjoint paths in grids with sources on the boundary"
    - "almost polynomial ratio eth hardness of approximating densest k subgraph"
    - "new algorithms for maximum disjoint paths based on tree likeness"
    - "improved approximation for node disjoint paths in planar graphs"
    - "routing in undirected graphs with constant congestion"

Connected through hyperedge HE-3 (induced by source paper "new algorithms for maximum disjoint paths based on tree likeness"):
  with members:
    - "improved approximation for node disjoint paths in planar graphs"
    - "on routing disjoint paths in bounded treewidth graphs"
    - "maximum edge disjoint paths in k sums of graphs"
    - "a polylogarithimic approximation algorithm for edge disjoint paths with congestion 2"
    - "routing in undirected graphs with constant congestion"
    - "flow cut gaps for integer and fractional multiflows"

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)