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: "counting perfect matchings as fast as ryser"
  Abstract: We show that there is a polynomial space algorithm that counts the number of perfect matchings in an $n$-vertex graph in $O^*(2^{n/2})\subset O(1.415^n)$ time. ($O^*(f(n))$ suppresses functions polylogarithmic in $f(n)$).The previously fastest algorithms for the problem was the exponential space $O^*(((1+\sqrt{5})/2)^n) \subset O(1.619^n)$ time algorithm by Koivisto, and for polynomial space, the $O(1.942^n)$ time algorithm by Nederlof. Our new algorithm's runtime matches up to polynomial factors that of Ryser's 1963 algorithm for bipartite graphs. We present our algorithm in the more general setting of computing the hafnian over an arbitrary ring, analogously to Ryser's algorithm for permanent computation. #R##N#We also give a simple argument why the general exact set cover counting problem over a slightly superpolynomial sized family of subsets of an $n$ element ground set cannot be solved in $O^*(2^{(1-\epsilon_1)n})$ time for any $\epsilon_1>0$ unless there are $O^*(2^{(1-\epsilon_2)n})$ time algorithms for computing an $n\times n$ 0/1 matrix permanent, for some $\epsilon_2>0$ depending only on $\epsilon_1$.

Connected through hyperedge HE-1 (induced by source paper "a faster hafnian formula for complex matrices and its benchmarking on the titan supercomputer"):
  with members:
    - "the classical complexity of boson sampling"
    - "faster exponential time algorithms in graphs of bounded average degree"
    - "invitation to algorithmic uses of inclusion exclusion"

Connected through hyperedge HE-2 (induced by source paper "counting integral points in polytopes via numerical analysis of contour integration"):
  with members:
    - "faster exponential time algorithms in graphs of bounded average degree"

Connected through hyperedge HE-3 (induced by source paper "families with infants speeding up algorithms for np hard problems using fft"):
  with members:
    - "families with infants a general approach to solve hard partition problems"
    - "faster exponential time algorithms in graphs of bounded average degree"
    - "a new direction for counting perfect matchings"
    - "fast hamiltonicity checking via bases of perfect matchings"
    - "narrow sieves for parameterized paths and packings"
    - "determinant sums for undirected hamiltonicity"
    - "trimmed moebius inversion and graphs of bounded degree"

Connected through hyperedge HE-4 (induced by source paper "faster exponential time algorithms in graphs of bounded average degree"):
  with members:
    - "on problems as hard as cnf sat"
    - "families with infants a general approach to solve hard partition problems"
    - "a new direction for counting perfect matchings"
    - "determinant sums for undirected hamiltonicity"
    - "known algorithms on graphs of bounded treewidth are probably optimal"
    - "trimmed moebius inversion and graphs of bounded degree"

Connected through hyperedge HE-5 (induced by source paper "families with infants a general approach to solve hard partition problems"):
  with members:
    - "faster exponential time algorithms in graphs of bounded average degree"
    - "a new direction for counting perfect matchings"
    - "fast hamiltonicity checking via bases of perfect matchings"
    - "determinant sums for undirected hamiltonicity"
    - "trimmed moebius inversion and graphs of bounded degree"

Connected through hyperedge HE-6 (induced by source paper "constrained multilinear detection and generalized graph motifs"):
  with members:
    - "on problems as hard as cnf sat"
    - "finding and counting vertex colored subtrees"
    - "constrained multilinear detection for faster functional motif discovery"
    - "narrow sieves for parameterized paths and packings"
    - "determinant sums for undirected hamiltonicity"

Connected through hyperedge HE-7 (induced by source paper "below all subsets for some permutational counting problems"):
  with members:
    - "fast hamiltonicity checking via bases of perfect matchings"
    - "determinant sums for undirected hamiltonicity"

Connected through hyperedge HE-8 (induced by source paper "a new direction for counting perfect matchings"):
  with members:
    - "exponential time complexity of the permanent and the tutte polynomial"

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)