A Hybrid Solver for Large Neighborhood Search: Mixing Gecode and EasyLocal + + 

  • Raffaele Cipriano
  • Luca Di Gaspero
  • Agostino Dovier
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5818)


We present a hybrid solver (called \(\mathbb{GELATO}\)) that exploits the potentiality of a Constraint Programming (CP) environment (Gecode) and of a Local Search (LS) framework (EasyLocal + + ). \(\mathbb{GELATO}\) allows to easily develop and use hybrid meta-heuristic combining CP and LS phases (in particular Large Neighborhood Search). We tested some hybrid algorithms on different instances of the Asymmetric Traveling Salesman Problem: even if only naive LS strategies have been used, our meta-heuristics improve the standard CP search, in terms of both goodness of the solution reached and execution time. \(\mathbb{GELATO}\) will be integrated into a more general tool to solve Constraint Satisfaction/Optimization Problems. Moreover, it can be seen as a new library for approximate and efficient searching in Gecode.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Raffaele Cipriano
    • 1
  • Luca Di Gaspero
    • 2
  • Agostino Dovier
    • 1
  1. 1.DIMIItaly
  2. 2.DIEGMUniversità di UdineUdineItaly

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