A Novel Solution Encoding in the Differential Evolution Algorithm for Optimizing Tourist Trip Design Problems

In this paper, a tourist trip design problem is simulated by the Capacitated Team Orienteering Problem (CTOP). The objective of the CTOP is to form feasible solution, as a set of itineraries, that represent a sequence visit of nodes, that maximize the total prize collected from them. Each itinerary is constrained by the vehicle capacity and the total travelled time. The proposed algorithmic framework, the Distance Related Differential Algorithm (DRDE), is a combination of the widely-known Differential Evolution algorithm (DE) and a novel encoding/decoding process, namely the Distance Related (DR). The process is based on the representation of the solution vector by the Euclidean Distance of the included nodes and offers a data-oriented approach to apply the original DE to a discrete optimization problem, such as the CTOP. The efficiency of the proposed algorithm is demonstrated over computational experiments.