我们可以只打印第一个解决方案策略而不打印 Google OR 工具中的本地搜索解决方案吗？

Question

I am currently learning how to use Google OR-Tools, specifically on the CVRP Problem. The code is divided into two stages. The first one is finding the initial/first solution using path-cheapest-arc, savings algorithm, etc. the second stage is finding the solution using local search. `

# Setting first solution heuristic.
    search_parameters = pywrapcp.DefaultRoutingSearchParameters()
    search_parameters.first_solution_strategy = (
        routing_enums_pb2.FirstSolutionStrategy.PATH_CHEAPEST_ARC)
    search_parameters.local_search_metaheuristic = (
        routing_enums_pb2.LocalSearchMetaheuristic.GUIDED_LOCAL_SEARCH)
    search_parameters.time_limit.FromSeconds(1)

The code above contains two searching parameters, the first solution strategy (path cheapest arc) and the local search metaheuristic. My question is, can we only use the first solution strategy and not use the local search metaheuristic?

Thanks!

I'm trying to compare the solution that I obtain from only using the first solution and the metaheuristic one.

Answer 1

YES you can, simply don't set it, aka remove the line.

search_parameters.local_search_metaheuristic = (
        routing_enums_pb2.LocalSearchMetaheuristic.GUIDED_LOCAL_SEARCH)

Answer 2

Just to add to Mizux's answer, since you said you are new to OR-Tools and want to compare the solution.

You can add the following line to display the log in the terminal:

search_parameters.log_search = True