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 algorithms for 3 coloring 3 edge coloring and constraint satisfaction"
  Abstract: We consider worst case time bounds for NP-complete problems including 3-SAT, 3-coloring, 3-edge-coloring, and 3-list-coloring. Our algorithms are based on a constraint satisfaction (CSP) formulation of these problems; 3-SAT is equivalent to (2,3)-CSP while the other problems above are special cases of (3,2)-CSP. We give a fast algorithm for (3,2)-CSP and use it to improve the time bounds for solving the other problems listed above. Our techniques involve a mixture of Davis-Putnam-style backtracking with more sophisticated matching and network flow based ideas.

Connected through hyperedge HE-1 (induced by source paper "worst case upper bound for 1 2 qsat"):
  with members:
    - "using csp to improve deterministic 3 sat"

Connected through hyperedge HE-2 (induced by source paper "an exact 2 9416 n algorithm for the three domatic number problem"):
  with members:
    - "small maximal independent sets and faster exact graph coloring"

Connected through hyperedge HE-3 (induced by source paper "quasiconvex analysis of backtracking algorithms"):
  with members:
    - "the traveling salesman problem for cubic graphs"
    - "confluent drawings visualizing non planar diagrams in a planar way"
    - "optimized color gamuts for tiled displays"
    - "small maximal independent sets and faster exact graph coloring"
    - "optimal point placement for mesh smoothing"

Connected through hyperedge HE-4 (induced by source paper "3 coloring in time o 1 3289 n"):
  with members:
    - "quasiconvex analysis of backtracking algorithms"
    - "small maximal independent sets and faster exact graph coloring"

Connected through hyperedge HE-5 (induced by source paper "small maximal independent sets and faster exact graph coloring"):
  with members:
    - "3 coloring in time o 1 3289 n"

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)