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

We present a hybrid solver (called GELATO) that exploits the potentiality of a Constraint Programming (CP) environment (Gecode) and of a Local Search (LS) framework (EasyLocal++ ). 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 metaheuristics improve the standard CP search, in terms of both goodness of the solution reached and execution time. 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.

• Type: Conference
• Year: 2009
• Where: HM
• Authors: Raffaele Cipriano, Luca Di Gaspero, Agostino Dovier
• Keywords: HM 2009, Meta-heuristic Combining Cp, Naive Ls Strategies, Optimization, Standard Cp Search