human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "the maximum binary tree problem"):
  Abstract: We introduce and investigate the approximability of the maximum binary tree problem (MBT) in directed and undirected graphs. The goal in MBT is to find a maximum-sized binary tree in a given graph. MBT is a natural generalization of the well-studied longest path problem, since both can be viewed as finding a maximum-sized tree of bounded degree in a given graph. #R##N#The connection to longest path motivates the study of MBT in directed acyclic graphs (DAGs), since the longest path problem is solvable efficiently in DAGs. In contrast, we show that MBT in DAGs is in fact hard: it has no efficient $\exp(-O(\log n/ \log \log n))$-approximation algorithm under the exponential time hypothesis. In undirected graphs, we show that MBT has no efficient $\exp(-O(\log^{0.63}{n}))$-approximation under the exponential time hypothesis. Our hardness results rely on self-improving reductions and structural properties of binary trees. We also show constant-factor inapproximability assuming $\mathbf{P} \neq \mathbf{NP}$. #R##N#Furthermore, motivated by the longest heapable subsequence problem (introduced by Byers, Heeringa, Mitzenmacher, and Zervas, ANALCO '11), which is equivalent to MBT in permutation DAGs, we study MBT in restricted graph families. We show that MBT admits efficient algorithms in two graph families: bipartite permutation graphs and bounded treewidth graphs.

Includes members:
  Member "narrow sieves for parameterized paths and packings":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "finding temporal patterns using algebraic fingerprints")
  Member "improved inapproximability results for maximum k colorable subgraph":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "new np hardness results for 3 coloring and 2 to 1 label cover")

Question: Please tell me which class the source paper 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.DM(Discrete Mathematics)