PUSH: A generalized operator for the Maximum Vertex Weight Clique Problem

The Maximum Vertex Weight Clique Problem (MVWCP) is an important generalization of the well-known NP-hard Maximum Clique Problem. In this paper, we introduce a generalized move operator called PUSH, which generalizes the conventional ADD and SWAP operators commonly used in the literature and can be integrated in a local search algorithm for MVWCP. The PUSH operator also offers opportunities to define new search operators by considering dedicated candidate push sets. To demonstrate the usefulness of the proposed operator, we implement two simple tabu search algorithms which use PUSH to explore different candidate push sets. The computational results on 142 benchmark instances from different sources (DIMACS, BHOSLIB, and Winner Determination Problem) indicate that these algorithms compete favorably with the leading MVWCP algorithms. (C) 2016 Elsevier B.V. All rights reserved.