human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "a 9 7 approximation algorithm for graphic tsp in cubic bipartite graphs"):
  Abstract: We prove new results for approximating Graphic TSP. Specifically, we provide a polynomial-time \frac{9}{7}-approximation algorithm for cubic bipartite graphs and a (\frac{9}{7}+\frac{1}{21(k-2)})-approximation algorithm for k-regular bipartite graphs, both of which are improved approximation factors compared to previous results. Our approach involves finding a cycle cover with relatively few cycles, which we are able to do by leveraging the fact that all cycles in bipartite graphs are of even length along with our knowledge of the structure of cubic graphs.

Includes members:
  Member "improved approximations for cubic and cubic bipartite tsp":
    also connected through other hyperedges:
      (none)
  Member "an improved analysis of the m omke svensson algorithm for graph tsp on subquartic graphs":
    also connected through other hyperedges:
      (none)
  Member "tsp tours in cubic graphs beyond 4 3":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "simple cubic graphs with no short traveling salesman tour")
  Member "shorter tours by nicer ears 7 5 approximation for graphic tsp 3 2 for the path version and 4 3 for two edge connected subgraphs":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "travelling on graphs with small highway dimension")
  Member "approximating graphic tsp by matchings":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "simple cubic graphs with no short traveling salesman tour")
  Member "a 4 3 approximation for tsp on cubic 3 edge connected graphs":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "graph tsp from steiner cycles")
  Member "the traveling salesman problem on cubic and subcubic graphs":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "simple cubic graphs with no short traveling salesman tour")

Question: Please tell me which class the source paper 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)