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: "set cover and vertex cover with delay"
  Abstract: The set cover problem is one of the most fundamental problems in computer science. We present the problem of online set cover with delay (SCD). A family of sets with costs and a universe of elements are known in advance. Requests then arrive over time on the elements, and each request accumulates delay cost until served by the algorithm through buying a containing set. A request can only be served by sets that are bought after the request's arrival, and thus a set may be bought an unbounded number of times over the course of the algorithm. This property sets SCD apart from previous considerations of set cover in the online setting, in which there are no delays, elements are covered immediately, and sets stay bought permanently. This allows SCD to describe an unbounded process, with an unlimited number of requests for any given universe. #R##N#For the SCD problem, we show an $O(\log k\cdot\log n)$-competitive randomized algorithm, where $n$ is the number of elements and $k$ is the maximum number of sets containing any single element. We also show a lower bound of $\Omega(\sqrt{\log k})$ and $\Omega(\sqrt{\log n})$ on the competitiveness of any algorithm for SCD. For the special case of Vertex Cover with Delay (VCD), we show a simple $3$-competitive deterministic algorithm. The $O(\log k\cdot\log n)$-competitive algorithm is based on exponential weights combined with the max operator (in contrast to most algorithms employing exponential weights, which use summation). The lower bound is described by a recursive construction.

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)