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: "improved approximation for two dimensional strip packing with polynomial bounded width"
  Abstract: We study the well-known two-dimensional strip packing problem. Given is a set of rectangular axis-parallel items and a strip of width $W$ with infinite height. The objective is to find a packing of these items into the strip, which minimizes the packing height. Lately, it has been shown that the lower bound of $3/2$ of the absolute approximation ratio can be beaten when we allow a pseudo-polynomial running-time of type $(n W)^{f(1/\varepsilon)}$. If $W$ is polynomially bounded by the number of items, this is a polynomial running-time. We present a pseudo-polynomial algorithm with approximation ratio $4/3 +\varepsilon$ and running time $(n W)^{1/\varepsilon^{\mathcal{O}(2^{1/\varepsilon})}}$.

Connected through hyperedge HE-1 (induced by source paper "improved pseudo polynomial time approximation for strip packing"):
  with members:
    - "approximating geometric knapsack via l packings"
    - "complexity and inapproximability results for parallel task scheduling and strip packing"
    - "closing the gap for pseudo polynomial strip packing"
    - "approximation schemes for maximum weight independent set of rectangles"

Connected through hyperedge HE-2 (induced by source paper "closing the gap for pseudo polynomial strip packing"):
  with members:
    - "improved pseudo polynomial time approximation for strip packing"
    - "scheduling monotone moldable jobs in linear time"
    - "complexity and inapproximability results for parallel task scheduling and strip packing"
    - "hardness of approximation for strip packing"
    - "power strip packing of malleable demands in smart grid"

Connected through hyperedge HE-3 (induced by source paper "complexity and inapproximability results for parallel task scheduling and strip packing"):
  with members:
    - "improved pseudo polynomial time approximation for strip packing"
    - "scheduling monotone moldable jobs in linear time"
    - "closing the gap for pseudo polynomial strip packing"
    - "hardness of approximation for strip packing"

Connected through hyperedge HE-4 (induced by source paper "approximating geometric knapsack via l packings"):
  with members:
    - "improved pseudo polynomial time approximation for strip packing"
    - "hardness of approximation for strip packing"
    - "approximation schemes for maximum weight independent set of rectangles"

Connected through hyperedge HE-5 (induced by source paper "hardness of approximation for strip packing"):
  with members:
    - "improved pseudo polynomial time approximation for strip packing"
    - "approximation schemes for maximum weight independent set of rectangles"

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)