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: "morphing planar graph drawings optimally"
  Abstract: We provide an algorithm for computing a planar morph between any two planar straight-line drawings of any $n$-vertex plane graph in $O(n)$ morphing steps, thus improving upon the previously best known $O(n^2)$ upper bound. Further, we prove that our algorithm is optimal, that is, we show that there exist two planar straight-line drawings $\Gamma_s$ and $\Gamma_t$ of an $n$-vertex plane graph $G$ such that any planar morph between $\Gamma_s$ and $\Gamma_t$ requires $\Omega(n)$ morphing steps.

Connected through hyperedge HE-1 (induced by source paper "how to morph a tree on a small grid"):
  with members:
    - "upward planar morphs"
    - "pole dancing 3d morphs for tree drawings"
    - "optimal morphs of planar orthogonal drawings"
    - "how to morph planar graph drawings"
    - "optimal morphs of convex drawings"
    - "morphing schnyder drawings of planar triangulations"
    - "drawing graphs in the plane with a prescribed outer face and polynomial area"

Connected through hyperedge HE-2 (induced by source paper "upward planar morphs"):
  with members:
    - "how to morph planar graph drawings"
    - "optimal morphs of convex drawings"
    - "morphing planar graph drawings with unidirectional moves"

Connected through hyperedge HE-3 (induced by source paper "pole dancing 3d morphs for tree drawings"):
  with members:
    - "tree drawings revisited"
    - "how to morph planar graph drawings"
    - "morphing planar graph drawings with unidirectional moves"

Connected through hyperedge HE-4 (induced by source paper "optimal morphs of convex drawings"):
  with members:
    - "compatible connectivity augmentation of planar disconnected graphs"
    - "morphing planar graph drawings with unidirectional moves"

Connected through hyperedge HE-5 (induced by source paper "morphing schnyder drawings of planar triangulations"):
  with members:
    - "how to morph planar graph drawings"
    - "morphing planar graph drawings with unidirectional moves"
    - "algorithms for sampling 3 orientations of planar triangulations"
    - "area universal rectangular layouts"

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)