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: "recognizing partial cubes in quadratic time"
  Abstract: We show how to test whether a graph with n vertices and m edges is a partial cube, and if so how to find a distance-preserving embedding of the graph into a hypercube, in the near-optimal time bound O(n^2), improving previous O(nm)-time solutions.

Connected through hyperedge HE-1 (induced by source paper "medians in median graphs in linear time"):
  with members:
    - "1 safe petri nets and special cube complexes equivalence and applications"
    - "subquadratic algorithms for the diameter and the sum of pairwise distances in planar graphs"

Connected through hyperedge HE-2 (induced by source paper "topology induced enhancement of mappings"):
  with members:
    - "better process mapping and sparse quadratic assignment"
    - "algorithms for mapping parallel processes onto grid and torus architectures"
    - "recent advances in graph partitioning"
    - "kahip v0 53 karlsruhe high quality partitioning user guide"
    - "advanced coarsening schemes for graph partitioning"

Connected through hyperedge HE-3 (induced by source paper "classification of vertex transitive cubic partial cubes"):
  with members:
    - "there are no finite partial cubes of girth more than 6 and minimum degree at least 3"

Connected through hyperedge HE-4 (induced by source paper "solving single digit sudoku subproblems"):
  with members:
    - "exact covers via determinants"
    - "nonrepetitive paths and cycles in graphs with application to sudoku"
    - "searching for spaceships"

Connected through hyperedge HE-5 (induced by source paper "isometric diamond subgraphs"):
  with members:
    - "the lattice dimension of a graph"
    - "algorithms for drawing media"

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)