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: "extending upward planar graph drawings"
  Abstract: In this paper we study the computational complexity of the Upward Planarity Extension problem, which takes in input an upward planar drawing $\Gamma_H$ of a subgraph $H$ of a directed graph $G$ and asks whether $\Gamma_H$ can be extended to an upward planar drawing of $G$. Our study fits into the line of research on the extensibility of partial representations, which has recently become a mainstream in Graph Drawing. #R##N#We show the following results. #R##N#First, we prove that the Upward Planarity Extension problem is NP-complete, even if $G$ has a prescribed upward embedding, the vertex set of $H$ coincides with the one of $G$, and $H$ contains no edge. #R##N#Second, we show that the Upward Planarity Extension problem can be solved in $O(n \log n)$ time if $G$ is an $n$-vertex upward planar $st$-graph. This result improves upon a known $O(n^2)$-time algorithm, which however applies to all $n$-vertex single-source upward planar graphs. #R##N#Finally, we show how to solve in polynomial time a surprisingly difficult version of the Upward Planarity Extension problem, in which $G$ is a directed path or cycle with a prescribed upward embedding, $H$ contains no edges, and no two vertices share the same $y$-coordinate in $\Gamma_H$.

Connected through hyperedge HE-1 (induced by source paper "an spqr tree like embedding representation for upward planarity"):
  with members:
    - "bend minimum orthogonal drawings in quadratic time"
    - "level planarity transitivity vs even crossings"
    - "simultaneous embedding edge orderings relative positions cutvertices"
    - "orthogonal graph drawing with inflexible edges"
    - "planar embeddings with small and uniform faces"
    - "optimal orthogonal graph drawing with convex bend costs"
    - "a kuratowski type theorem for planarity of partially embedded graphs"
    - "simultaneous embedding of planar graphs"

Connected through hyperedge HE-2 (induced by source paper "extending simple drawings with one edge is hard"):
  with members:
    - "extending simple drawings"
    - "the partial visibility representation extension problem"
    - "saturated simple and 2 simple topological graphs with few edges"
    - "extending partial representations of circle graphs"
    - "adding one edge to planar graphs makes crossing number and 1 planarity hard"
    - "extending partial representations of subclasses of chordal graphs"
    - "a kuratowski type theorem for planarity of partially embedded graphs"
    - "extending partial representations of function graphs and permutation graphs"

Connected through hyperedge HE-3 (induced by source paper "extending simple drawings"):
  with members:
    - "topological drawings of complete bipartite graphs"
    - "saturated simple and 2 simple topological graphs with few edges"
    - "adding one edge to planar graphs makes crossing number and 1 planarity hard"
    - "a kuratowski type theorem for planarity of partially embedded graphs"

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)