The improved ColourAnt algorithm: a hybrid algorithm for solving the graph colouring problem

The graph colouring problem is interesting because of its application areas, ranging from register allocation, frequency association in telecommunications, timetabling and scheduling, and others. This problem is NP-complete and thus, several metaheuristic algorithms have been proposed in order to provide a good solution in an acceptable time-frame. Among several metaheuristics, this paper focuses on ant colony optimisation. In this context, a hybrid algorithm was developed called iColourAnt, which uses ant colony optimisation and an efficient local search strategy, consequently providing good solutions to the graph colouring problem. The experiment results indicate that iColourAnt outperforms its predecessor, ColourAnt.