DM 63 - Heuristics for Combinatorial Optimization Problems – Lecture

Nodifferencewas detected on the performances of construction heuristics for TSP developed in Task 1 between Euclidean instances with points uniformly sparse and Euclidean instances with points clustered. Attention was given to the choice of data structures to represent and maintain a solution during a perturbative search. We described Tabu Search (TS) and its variations: robust and reactive. We gave examples on the GCP and QAP. Crucial for TS is the fast examination of the neighborhood to find the best neighbors. We saw methods to accomplish this task in O(nk) in the GCP and in O(1) in the QAP. We added Dynasearch and Ejection Chains to Variable Depth Search as methods that enlarge the neighborhood by maintaining a low complexity in its examination. We described Dynamic Local Search and its variant Guided Local Search. Finally, we went through the mechanisms that underlie Iterated Local Search.