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: "exact algorithms for owa optimization in multiobjective spanning tree problems"
  Abstract: This paper deals with the multiobjective version of the optimal spanning tree problem. More precisely, we are interested in determining the optimal spanning tree according to an Ordered Weighted Average (OWA) of its objective values. We first show that the problem is weakly NP-hard. In the case where the weights of the OWA are strictly decreasing, we then propose a mixed integer programming formulation, and provide dedicated optimality conditions yielding an important reduction of the size of the program. Next, we present two bounds that can be used to prune subspaces of solutions either in a shaving phase or in a branch and bound procedure. The validity of these bounds does not depend on specific properties of the weights (apart from non-negativity). All these exact resolution algorithms are compared on the basis of numerical experiments, according to their respective validity scopes.

Connected through hyperedge HE-1 (induced by source paper "approximating multiobjective combinatorial optimization problems with the owa criterion"):
  with members:
    - "using the wowa operator in robust discrete optimization problems"
    - "improved approximation algorithms for the min max selecting items problem"
    - "combinatorial optimization problems with uncertain costs and the owa criterion"

Connected through hyperedge HE-2 (induced by source paper "using the wowa operator in robust discrete optimization problems"):
  with members:
    - "combinatorial optimization problems with uncertain costs and the owa criterion"
    - "on the approximability of minmax regret network optimization problems"

Connected through hyperedge HE-3 (induced by source paper "on the complexity of optimization problems based on compiled nnf representations"):
  with members:
    - "algebraic model counting"
    - "a knowledge compilation map"

Connected through hyperedge HE-4 (induced by source paper "combinatorial optimization problems with uncertain costs and the owa criterion"):
  with members:
    - "improved approximation algorithms for the min max selecting items problem"
    - "on the approximability of minmax regret network optimization 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)