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: "solving medium density subset sum problems in expected polynomial time an enumeration approach"
  Abstract: The subset sum problem (SSP) can be briefly stated as: given a target integer Eand a set Acontaining npositive integer a j , find a subset of Asumming to E. The densitydof an SSP instance is defined by the ratio of nto m, where mis the logarithm of the largest integer within A. Based on the structural and statistical properties of subset sums, we present an improved enumeration scheme for SSP, and implement it as a complete and exact algorithm (EnumPlus). The algorithm always equivalently reduces an instance to be low-density, and then solve it by enumeration. Through this approach, we show the possibility to design a sole algorithm that can efficiently solve arbitrary density instance in a uniform way. Furthermore, our algorithm has considerable performance advantage over previous algorithms. Firstly, it extends the density scope, in which SSP can be solved in expected polynomial time. Specifically, It solves SSP in expected O(nlogn) time when density $d \geq c\cdot \sqrt{n}/\log{n}$, while the previously best density scope is d? c·n/(logn)2. In addition, the overall expected time and space requirement in the average case are proven to be O(n5logn) and O(n5) respectively. Secondly, in the worst case, it slightly improves the previously best time complexity of exact algorithms for SSP. The worst-case time complexity of our algorithm is proved to be O(n·2n/2? c·2n/2+ n), while the previously best result is O(n·2n/2).

Connected through hyperedge HE-1 (induced by source paper "a proof for p np problem"):
  with members:
    - "the p versus np problem"
    - "on p vs np geometric complexity theory and the riemann hypothesis"
    - "oracles are subtle but not malicious"

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)