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: "approximating sparse covering integer programs online"
  Abstract: A covering integer program (CIP) is a mathematical program of the form: min {c^T x : Ax >= 1, 0 <= x <= u, x integer}, where A is an m x n matrix, and c and u are n-dimensional vectors, all having non-negative entries. In the online setting, the constraints (i.e., the rows of the constraint matrix A) arrive over time, and the algorithm can only increase the coordinates of vector x to maintain feasibility. As an intermediate step, we consider solving the covering linear program (CLP) online, where the integrality requirement on x is dropped. #R##N#Our main results are (a) an O(log k)-competitive online algorithm for solving the CLP, and (b) an O(log k log L)-competitive randomized online algorithm for solving the CIP. Here k<=n and L<=m respectively denote the maximum number of non-zero entries in any row and column of the constraint matrix A. By a result of Feige and Korman, this is the best possible for polynomial-time online algorithms, even in the special case of set cover.

Connected through hyperedge HE-1 (induced by source paper "on approximating sparse covering integer programs"):
  with members:
    - "approximating the held karp bound for metric tsp in nearly linear time"
    - "partial resampling to approximate covering integer programs"
    - "a nearly linear time ptas for explicit fractional packing and covering linear programs"
    - "submodular function maximization via the multilinear relaxation and contention resolution schemes"
    - "approximation algorithms for covering packing integer programs"

Connected through hyperedge HE-2 (induced by source paper "online unit clustering in higher dimensions"):
  with members:
    - "online unit covering in euclidean space"
    - "online lower bounds via duality"
    - "an improved lower bound for one dimensional online unit clustering"

Connected through hyperedge HE-3 (induced by source paper "online covering with sum of ell_q norm objectives"):
  with members:
    - "welfare maximization with production costs a primal dual approach"
    - "online packing and covering framework with convex objectives"
    - "welfare and profit maximization with production costs"

Connected through hyperedge HE-4 (induced by source paper "online convex covering and packing problems"):
  with members:
    - "welfare maximization with production costs a primal dual approach"
    - "online covering with convex objectives and applications"
    - "online packing and covering framework with convex objectives"
    - "online primal dual for non linear optimization with applications to speed scaling"
    - "welfare and profit maximization with production costs"

Connected through hyperedge HE-5 (induced by source paper "online packing and covering framework with convex objectives"):
  with members:
    - "welfare maximization with production costs a primal dual approach"
    - "online covering with convex objectives and applications"
    - "online primal dual for non linear optimization with applications to speed scaling"
    - "welfare and profit maximization with production costs"

Connected through hyperedge HE-6 (induced by source paper "changing bases multistage optimization for matroids and matchings"):
  with members:
    - "the power of deferral maintaining a constant competitive steiner tree online"
    - "on the tradeoff between stability and fit"

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)