“…The VRP is an NP-hard problem [ 33 ]. An exact algorithm is difficult to use to solve large-scale VRP, so lots of scholars usually use a metaheuristic algorithm to solve it [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ]. For example, the survey of metaheuristics for the VRP by Gendreau et al [ 36 ] shows that a tabu search (TS) algorithm emerges as the most effective approach.…”