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: "bubble flip a new generation algorithm for prefix normal words"
  Abstract: We present a new recursive generation algorithm for prefix normal words. These are binary strings with the property that no substring has more 1s than the prefix of the same length. The new algorithm uses two operations on binary strings, which exploit certain properties of prefix normal words in a smart way. We introduce infinite prefix normal words and show that one of the operations used by the algorithm, if applied repeatedly to extend the string, produces an ultimately periodic infinite word, which is prefix normal and whose period's length and density we can predict from the original word.

Connected through hyperedge HE-1 (induced by source paper "generating a gray code for prefix normal words in amortized polylogarithmic time per word"):
  with members:
    - "on collapsing prefix normal words"
    - "on prefix normal words and prefix normal forms"
    - "clustered integer 3sum via additive combinatorics"
    - "on combinatorial generation of prefix normal words"
    - "normal abby normal prefix normal"
    - "on hardness of jumbled indexing"
    - "new algorithms for binary jumbled pattern matching"
    - "binary jumbled pattern matching on trees and tree like structures"

Connected through hyperedge HE-2 (induced by source paper "on collapsing prefix normal words"):
  with members:
    - "on prefix normal words and prefix normal forms"
    - "clustered integer 3sum via additive combinatorics"
    - "on combinatorial generation of prefix normal words"
    - "normal abby normal prefix normal"
    - "algorithms for jumbled pattern matching in strings"
    - "on prefix normal words"

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)