问题描述
我正在使用谷歌或工具从距离矩阵中获取根，但我的限制是从
开始
最近的距离，但求解器给出了意想不到的路线。低于我的距离矩阵。我的预期输出是根据距离按顺序 1 到 10 个。
data['distance_matrix']=[[1000. 451.13 508.64 543.41 577.64 611.88 646.12 672.58 689.2
1231.78 1246.69]
[ 451.13 1000. 484.56 519.33 553.56 587.8 622.04 648.5 665.12
1207.7 1222.61]
[ 508.64 460.8 1000. 485.58 519.81 554.05 588.29 614.75 631.37
1173.95 1188.86]
[ 543.41 483.77 473.78 1000. 496.84 531.08 565.32 591.78 608.4
1150.98 1165.89]
[ 577.64 506.5 496.51 485.34 1000. 508.35 542.59 569.05 585.67
1128.25 1143.16]
[ 611.88 529.23 519.24 508.07 496.84 1000. 519.86 546.32 562.94
1105.52 1120.43]
[ 646.12 551.96 541.97 530.8 519.57 508.35 1000. 523.59 540.21
1082.79 1097.7 ]
[ 672.58 571.36 561.37 550.2 538.97 527.75 516.53 1000. 520.81
1063.39 1078.3 ]
[ 689.2 587.98 577.99 566.82 555.59 544.37 533.15 520.81 1000.
1046.77 1061.68]
[1231.78 1154.62 1144.63 1133.46 1122.23 1111.01 1099.79 1087.45 1070.83
1000. 495.04]
[1246.69 1171.32 1161.33 1150.16 1138.93 1127.71 1116.49 1104.15 1087.53
496.83 10. ]]
manager = pywrapcp.RoutingIndexManager(len(data['distance_matrix']),data['num_vehicles'],data['depot'])
routing = pywrapcp.RoutingModel(manager)
...
transit_callback_index = routing.RegisterTransitCallback(distance_callback)
routing.SetArcCostEvaluatorOfAllVehicles(transit_callback_index)
search_parameters = pywrapcp.DefaultRoutingSearchParameters()
search_parameters.first_solution_strategy = (
routing_enums_pb2.FirstSolutionStrategy.PATH_CHEApest_ARC)
solution= routing.solveWithParameters(search_parameters)
... 有没有办法向求解器添加约束以根据距离值顺序获取路线。如果距离值是 4、3、2，那么我的路线点应该是 4、3、2。？
解决方法
如果 j 是 nextVar(i) 然后 transit(i-1,i) >= transit(i,j)，你的意思是所有的 i 吗？
solver = routing.solver()
for index in range(routing.size()):
if routing.IsEnd(index):
continue
node = manager.IndexToNode(index)
for next_index in range(routing.size()):
if routing.IsEnd(next_index) or routing.IsStart(next_index):
continue
next_node = manager.IndexToNode(next_index)
first_cond = routing.NextVar(index) == next_index
for next_next_index in range(routing.size()):
if routing.IsStart(next_next_index):
continue
next_next_node = manager.IndexToNode(next_next_index)
second_cond = routing.NextVar(next_index) == next_next_index
sovler.Add(first_cond * second_cond * distance_matrix[node][next_node] >= first_cond * second_cond * distance_matrix[next_node][next_next_node])