A single-point crossover with a crossover probability PC was considered. The algorithm first checks the crossover probability to determine if crossover will take place. Then, the algorithm tries to obtain a crossover node by randomly selecting a position after the source and prior to the destination node, taking into account the size of the shortest path (see Fig. 3). If no common node exists, a crossover point is randomly selected. If the crossover node is common between the parents, there is a high probability of producing valid offspring.