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: "preprocessing and cutting planes with conflict graphs"
  Abstract: This paper addresses the implementation of conflict graph-based routines into the COIN-OR Branch-and-Cut (CBC) solver, including: $(i)$ a conflict graph infrastructure with an improved version of a state-of-the-art conflict detection algorithm to quickly build conflict graphs; this version detects additional conflicts and has the same worst-case complexity of the original algorithm; $(ii)$ a preprocessing routine based on a clique-strengthening scheme that can both reduce the number of nonzeros in the constraint matrix and also produce stronger formulations; $(iii)$ a clique cut separator capable of obtaining dual bounds at the root node that are $26\%$ stronger than the ones provided by the equivalent cut generator of a state-of-the-art commercial solver, $467\%$ stronger than those attained by the clique cut separator of the GLPK solver and $500\%$ stronger than the dual bounds obtained by the clique separation routine of the COIN-OR Cut Generation Library; $(iv)$ an odd-cycle cut separator with a lifting module to produce valid odd-wheel inequalities. This new version of CBC obtained an average gap closed that is $26\%$ better than the previous one and solved $27\%$ more instances.

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)