Authors:
Ellips Masehian
1
;
Nasrin Mohabbati-Kalejahi
2
and
Hossein Akbaripour
1
Affiliations:
1
Tarbiat Modares University, Iran, Islamic Republic of
;
2
Amirkabir University of Technology, Iran, Islamic Republic of
Keyword(s):
n-Queens Problem, Imperialist Competitive Algorithm, Local Search, Effective Swap Operator.
Related
Ontology
Subjects/Areas/Topics:
Artificial Intelligence
;
Computational Intelligence
;
Evolutionary Computing
;
Evolutionary Multiobjective Optimization
;
Soft Computing
Abstract:
The n-queens problem is a classical combinatorial optimization problem which has been proved to be NP-hard. The goal is to place n non-attacking queens on an n×n chessboard. In this paper, the Imperialist Com-petitive Algorithm (ICA), which is a recent evolutionary metaheuristic method, has been applied for solving the n-queens problem. As another variation, the ICA was combined with a local search method, resulting the Hybrid ICA (HICA). Extensive experimental results showed that the proposed HICA outperformed the basic ICA in terms of average runtimes and average number of fitness function evaluations. The developed algorithms were also compared to the Cooperative PSO (CPSO) algorithm, which is currently the best algo-rithm in the literature for finding the first valid solution to the n-queens problem, and the results showed that the HICA dominates the CPSO by evaluating the fitness function fewer times.