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 approaches for the travelling thief problem"
  Abstract: Many evolutionary and constructive heuristic approaches have been introduced in order to solve the Traveling Thief Problem (TTP). However, the accuracy of such approaches is unknown due to their inability to find global optima. In this paper, we propose three exact algorithms and a hybrid approach to the TTP. We compare these with state-of-the-art approaches to gather a comprehensive overview on the accuracy of heuristic methods for solving small TTP instances.

Connected through hyperedge HE-1 (induced by source paper "the node weight dependent traveling salesperson problem approximation algorithms and randomized search heuristics"):
  with members:
    - "evolutionary computation plus dynamic programming for the bi objective travelling thief problem"
    - "a fully polynomial time approximation scheme for packing while traveling"
    - "a case study of algorithm selection for the traveling thief problem"
    - "evolutionary computation for multicomponent problems opportunities and future directions"

Connected through hyperedge HE-2 (induced by source paper "a non dominated sorting based customized random key genetic algorithm for the bi objective traveling thief problem"):
  with members:
    - "evolutionary computation plus dynamic programming for the bi objective travelling thief problem"
    - "a fully polynomial time approximation scheme for packing while traveling"
    - "a case study of algorithm selection for the traveling thief problem"

Connected through hyperedge HE-3 (induced by source paper "dynamic multi objective optimization of the travelling thief problem"):
  with members:
    - "the packing while traveling problem"

Connected through hyperedge HE-4 (induced by source paper "evolutionary computation plus dynamic programming for the bi objective travelling thief problem"):
  with members:
    - "a fully polynomial time approximation scheme for packing while traveling"
    - "a case study of algorithm selection for the traveling thief problem"
    - "the packing while traveling problem"

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)