“…Early methods include direct heuristics [3], graph coloring [4,5], integer programming [6][7][8], network flow techniques [9,10], all of which have a limitation on the scale of the problem. With the development of computer technology, especially since the 1990s, an increasing number of intelligent algorithms have been applied to solve the timetabling problem, such as genetic algorithm [11][12][13], simulated annealing algorithm [14], taboo search algorithm [15] and hybrid algorithm [16,17]. All these intelligent algorithms above have been proved to be efficient.…”