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: "a quasi polynomial algorithm for submodular tree orienteering in directed graphs"
  Abstract: We consider the following general network design problem on directed graphs. The input is an asymmetric metric $(V,c)$, root $r\in V$, monotone submodular function $f:2^V \xrightarrow{} \mathbb{R}_+$ and budget $B$. The goal is to find an $r$-rooted arborescence $T$ of cost at most $B$ that maximizes $f(T)$. Our main result is a quasi-polynomial time $O(\frac{\log k}{\log\log k})$-approximation algorithm for this problem, where $k\le |V|$ is the number of vertices in an optimal solution. To the best of our knowledge, this is the first non-trivial approximation ratio for this problem. As a consequence we obtain a simple $O(\frac{\log^2 k}{\log\log k})$-approximation algorithm for directed (polymatroid) Steiner tree in quasi-polynomial time. For the usual directed Steiner tree problem, this matches the best previous result known. For the polymatroid generalization, our result improves prior results by a logarithmic factor. Our approximation ratio is tight for quasi-polynomial algorithms under certain complexity assumptions.

Connected through hyperedge HE-1 (induced by source paper "polylogarithmic approximation algorithm for k connected directed steiner tree on quasi bipartite graphs"):
  with members:
    - "a logarithmic integrality gap bound for directed steiner tree in quasi bipartite graphs"
    - "approximating directed steiner problems via tree embedding"
    - "analytical approach to parallel repetition"
    - "parameters of two prover one round game and the hardness of connectivity problems"
    - "an improved approximation algorithm for the minimum cost subset k connected subgraph problem"
    - "approximating subset k connectivity problems"
    - "directed steiner tree and the lasserre hierarchy"
    - "an o k 3 log n approximation algorithm for vertex connectivity survivable network design"

Connected through hyperedge HE-2 (induced by source paper "tight approximation for variants of directed steiner tree via state tree decomposition and linear programming rounding"):
  with members:
    - "online weighted degree bounded steiner networks via novel online mixed packing covering"
    - "online buy at bulk network design"
    - "approximating directed steiner problems via tree embedding"
    - "directed steiner tree and the lasserre hierarchy"
    - "bicriteria network design problems"

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)