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: "approximability of guarding weak visibility polygons"
  Abstract: The art gallery problem enquires about the least number of guards that are sufficient to ensure that an art gallery, represented by a polygon $P$, is fully guarded. In 1998, the problems of finding the minimum number of point guards, vertex guards, and edge guards required to guard $P$ were shown to be APX-hard by Eidenbenz, Widmayer and Stamm. In 1987, Ghosh presented approximation algorithms for vertex guards and edge guards that achieved a ratio of $\mathcal{O}(\log n)$, which was improved upto $\mathcal{O}(\log\log OPT)$ by King and Kirkpatrick in 2011. It has been conjectured that constant-factor approximation algorithms exist for these problems. We settle the conjecture for the special class of polygons that are weakly visible from an edge and contain no holes by presenting a 6-approximation algorithm for finding the minimum number of vertex guards that runs in $\mathcal{O}(n^2)$ time. On the other hand, for weak visibility polygons with holes, we present a reduction from the Set Cover problem to show that there cannot exist a polynomial time algorithm for the vertex guard problem with an approximation ratio better than $((1 - \epsilon)/12)\ln n$ for any $\epsilon>0$, unless NP=P. We also show that, for the special class of polygons without holes that are orthogonal as well as weakly visible from an edge, the approximation ratio can be improved to 3. Finally, we consider the Point Guard problem and show that it is NP-hard in the case of polygons weakly visible from an edge.

Connected through hyperedge HE-1 (induced by source paper "the parameterized complexity of guarding almost convex polygons"):
  with members:
    - "a ptas for vertex guarding weakly visible polygons an extended abstract"
    - "constant approximation algorithms for guarding simple polygons using vertex guards"
    - "irrational guards are sometimes needed"
    - "an approximation algorithm for the art gallery problem"
    - "engineering art galleries"
    - "a new upper bound for the vc dimension of visibility regions"
    - "improved approximation for guarding simple galleries from the perimeter"
    - "unsolved problems in visibility graphs of points segments and polygons"

Connected through hyperedge HE-2 (induced by source paper "routing in histograms"):
  with members:
    - "plane hop spanners for unit disk graphs simpler and better"
    - "routing in unit disk graphs"
    - "routing in polygonal domains"
    - "constant approximation algorithms for guarding simple polygons using vertex guards"
    - "optimal local routing on delaunay triangulations defined by empty equilateral triangles"
    - "new routing techniques and their applications"
    - "competitive local routing with constraints"

Connected through hyperedge HE-3 (induced by source paper "a constant factor approximation algorithm for vertex guarding a wv polygon"):
  with members:
    - "a ptas for vertex guarding weakly visible polygons an extended abstract"
    - "constant approximation algorithms for guarding simple polygons using vertex guards"
    - "an approximation algorithm for the art gallery problem"
    - "the continuous 1 5d terrain guarding problem discretization optimal solutions and ptas"
    - "improved approximation for guarding simple galleries from the perimeter"

Connected through hyperedge HE-4 (induced by source paper "on conflict free chromatic guarding of simple polygons"):
  with members:
    - "a ptas for vertex guarding weakly visible polygons an extended abstract"
    - "an approximation algorithm for the art gallery problem"
    - "improved approximation for guarding simple galleries from the perimeter"

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.CG(Computational Geometry)