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: "irrational guards are sometimes needed"
  Abstract: In this paper we study the art gallery problem, which is one of the fundamental problems in computational geometry. The objective is to place a minimum number of guards inside a simple polygon such that the guards together can see the whole polygon. We say that a guard at position $x$ sees a point $y$ if the line segment $xy$ is fully contained in the polygon. #R##N#Despite an extensive study of the art gallery problem, it remained an open question whether there are polygons given by integer coordinates that require guard positions with irrational coordinates in any optimal solution. We give a positive answer to this question by constructing a monotone polygon with integer coordinates that can be guarded by three guards only when we allow to place the guards at points with irrational coordinates. Otherwise, four guards are needed. By extending this example, we show that for every $n$, there is polygon which can be guarded by $3n$ guards with irrational coordinates but need $4n$ guards if the coordinates have to be rational. Subsequently, we show that there are rectilinear polygons given by integer coordinates that require guards with irrational coordinates in any optimal solution.

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"
    - "an approximation algorithm for the art gallery problem"
    - "engineering art galleries"
    - "approximability of guarding weak visibility polygons"
    - "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 "smoothed analysis of the art gallery problem"):
  with members:
    - "beyond worst case analysis"
    - "the complexity of drawing a graph in a polygonal region"
    - "a friendly smoothed analysis of the simplex method"
    - "constant approximation algorithms for guarding simple polygons using vertex guards"
    - "intersection graphs of rays and grounded segments"
    - "an approximation algorithm for the art gallery problem"
    - "the continuous 1 5d terrain guarding problem discretization optimal solutions and ptas"
    - "recognition and complexity of point visibility graphs"

Connected through hyperedge HE-3 (induced by source paper "the complexity of drawing a graph in a polygonal region"):
  with members:
    - "the art gallery problem is exists mathbb r complete"
    - "forall exists mathbb r completeness and area universality"
    - "on the complexity of minimum link path problems"
    - "the galois complexity of graph drawing why numerical solutions are ubiquitous for force directed spectral and circle packing drawings"
    - "drawing partially embedded and simultaneously planar graphs"
    - "intersection graphs of segments and exists mathbb r"
    - "drawing graphs in the plane with a prescribed outer face and polynomial area"

Connected through hyperedge HE-4 (induced by source paper "art gallery localization"):
  with members:
    - "detecting weakly simple polygons"

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)