获取 RoutingSolver 或工具的中间解决方案

如何解决获取 RoutingSolver 或工具的中间解决方案

我对 python 中的 ortools 有点陌生，我有默认的 CVRP 示例，我正在尝试获得中间解决方案，而不仅仅是最后一个。 我已经尝试在搜索参数中设置要收集的解决方案数量，但似乎没有效果。使用参数调用 solve 时可以选择传递赋值向量，但是将空列表传递给它（因为 python）会引发错误类型。

#this is how the routing model is initialized
routing = pywrapcp.RoutingModel(manager)
.
.
.
# setting search parameters
search_parameters = pywrapcp.DefaultRoutingSearchParameters()
search_parameters.first_solution_strategy = (routing_enums_pb2.FirstSolutionStrategy.PATH_CHEApest_ARC)
search_parameters.local_search_Metaheuristic = 1 #myNaturalBeauty #greedyDescent
search_parameters.log_search = True
search_parameters.solution_limit = 3
search_parameters.number_of_solutions_to_collect = 3

#attempt to get solutions
solutions = []
solution = routing.solveWithParameters(search_parameters,solutions)

出现这个错误

return _pywrapcp.RoutingModel_SolveWithParameters(self,search_parameters,solutions)

TypeError: Wrong number or type of arguments for overloaded function 'RoutingModel_SolveWithParameters'.
  Possible C/C++ prototypes are:
    operations_research::RoutingModel::SolveWithParameters(operations_research::RoutingSearchParameters const &,std::vector< operations_research::Assignment const * > *)
    operations_research::RoutingModel::SolveWithParameters(operations_research::RoutingSearchParameters const &)

任何帮助将不胜感激。