public Path next()
{
Path cur_path = path_candidates.poll();
result_list.Add(cur_path);
airport cur_derivation = path_derivation_airport_index[cur_path];
int count = result_list.Count;
for (int i = 0; i < count - 1; ++i)
{
Path cur_result_path = result_list.ElementAt(i);
int cur_dev_airport_id =
cur_result_path.get_airports().IndexOf(cur_derivation);
airport cur_succ_airport =
cur_result_path.get_airports().ElementAt(cur_dev_airport_id + 1);
graph.remove_route(new KeyValuePair <int, int>(
cur_derivation.airport_ID, cur_succ_airport.airport_ID));
}
int path_length = cur_path.get_airports().Count;
List <airport> cur_path_airport_list = cur_path.get_airports();
for (int i = 0; i < path_length - 1; ++i)
{
graph.remove_airport(cur_path_airport_list.ElementAt(i).airport_ID);
graph.remove_route(new KeyValuePair <int, int>(
cur_path_airport_list.ElementAt(i).airport_ID,
cur_path_airport_list.ElementAt(i + 1).airport_ID));
}
DijkstraShortestPathAlg reverse_tree = new DijkstraShortestPathAlg((VariableGraph)graph);
reverse_tree.get_shortest_path_flower(target_airport);
bool is_done = false;
for (int i = path_length - 2; i >= 0 && !is_done; --i)
{
airport cur_recover_airport = cur_path_airport_list.ElementAt(i);
graph.recover_removed_airport(cur_recover_airport.airport_ID);
if (cur_recover_airport.airport_ID == cur_derivation.airport_ID)
{
is_done = true;
}
Path sub_path = reverse_tree.update_cost_forward(cur_recover_airport);
if (sub_path != null)
{
double cost = 0;
List <airport> pre_path_list = new List <airport>();
reverse_tree.correct_cost_backward(cur_recover_airport);
for (int j = 0; j < path_length; ++j)
{
airport cur_airport = cur_path_airport_list.ElementAt(j);
if (cur_airport.airport_ID == cur_recover_airport.airport_ID)
{
j = path_length;
}
else
{
cost += graph.get_route_distance_of_graph(cur_path_airport_list.ElementAt(j),
cur_path_airport_list.ElementAt(j + 1));
pre_path_list.Add(cur_airport);
}
}
pre_path_list.AddRange(sub_path.get_airports());
sub_path.set_distance(cost + sub_path.get_distance());
sub_path.get_airports().Clear();
sub_path.get_airports().AddRange(pre_path_list);
if (!path_derivation_airport_index.ContainsKey(sub_path))
{
path_candidates.add(sub_path);
path_derivation_airport_index[sub_path] = cur_recover_airport;
}
}
airport succ_airport = cur_path_airport_list.ElementAt(i + 1);
graph.recover_removed_route(new KeyValuePair <int, int>(
cur_recover_airport.airport_ID, succ_airport.airport_ID));
double cost_1 = graph.get_routes_distance(cur_recover_airport, succ_airport)
+ reverse_tree.get_start_airport_distance_index()[succ_airport.airport_ID];
if (reverse_tree.get_start_airport_distance_index()[cur_recover_airport.airport_ID] > cost_1)
{
reverse_tree.get_start_airport_distance_index()[cur_recover_airport.airport_ID] = cost_1;
reverse_tree.get_predecessor_index()[cur_recover_airport.airport_ID] = succ_airport;
reverse_tree.correct_cost_backward(cur_recover_airport);
}
}
graph.recover_removed_route();
graph.recover_removed_airport();
return(cur_path);
}