public class VrpGlobalSpan {

	static void printSolution(
			DataModel data, RoutingModel routing, RoutingIndexManager manager, Assignment solution) {
		if(solution == null) {
			System.out.println("No solution");
		} else {
                        System.out.println("There is a solution");
                }
	}

        static class DataModel {
		public final long[][] distanceMatrix = {
				{0, 10, 20},
				{10, 0, 20},
				{20, 20, 0}
		};
		public final int vehicleNumber = 1;
		public final int depot = 0;
	}

	public static void main(String[] args) {
		Loader.loadNativeLibraries();
		// Instantiate the data problem.
		final DataModel data = new DataModel();

		// Create Routing Index Manager
		RoutingIndexManager manager =
				new RoutingIndexManager(data.distanceMatrix.length, data.vehicleNumber, data.depot);

		// Create Routing Model.
		RoutingModel routing = new RoutingModel(manager);

//		routing.setFixedCostOfAllVehicles(100);
		routing.setAmortizedCostFactorsOfAllVehicles(100, 1);

		// Create and register a transit callback.
		final int transitCallbackIndex =
				routing.registerTransitCallback((long fromIndex, long toIndex) -> {
					// Convert from routing variable Index to user NodeIndex.
					int fromNode = manager.indexToNode(fromIndex);
					int toNode = manager.indexToNode(toIndex);
					return data.distanceMatrix[fromNode][toNode];
				});

		// Define cost of each arc.
		routing.setArcCostEvaluatorOfAllVehicles(transitCallbackIndex);

		// Setting first solution heuristic.
		RoutingSearchParameters searchParameters =
				main.defaultRoutingSearchParameters()
						.toBuilder()
						.setTimeLimit(Duration.newBuilder().setSeconds(5).build())
						.setLocalSearchMetaheuristic(LocalSearchMetaheuristic.Value.GUIDED_LOCAL_SEARCH)
						.setFirstSolutionStrategy(FirstSolutionStrategy.Value.PATH_MOST_CONSTRAINED_ARC)
						.build();

		// Solve the problem.
		Assignment solution = routing.solveWithParameters(searchParameters);

		// Print solution on console.
		printSolution(data, routing, manager, solution);
	}
}