Exemplo n.º 1
0
        private void NextGeneration(int parentID)
        {
            Node parent = new Node();

            parent = Stations[parentID];

            List <Node> children = new List <Node>();

            children = MetroNetwork.GenChildren(parent); // generates list of neighbouring nodes
            int index;

            // nondeterministic element:
            Shuffle(children); // mixes up children so that different ones are selected first each time

            foreach (var child in children)
            {
                index       = child.StationId;
                child.Score = Stations[index].Score;

                if (child.UpdateScore(parent, OriginStationId))     // returns true only if it is a valid forwards step
                {
                    Stations[index].CopyLineBranchIndexFrom(child); // must only edit location when sure new route is faster
                    Stations[index].Score = child.Score;            // assign new score
                    Enqueue(index);                                 // adds this stationId onto list of stations to visit
                }
            }
        }
Exemplo n.º 2
0
        // basic methods

        internal void RewindUntilOrigin(List <Node> stations) // retraces steps from destination to origin
        {
            Path.AddLast(stations[DestinationId]);

            int  index;
            bool ongoing = true;
            int  parentCount;

            Random      rand           = new Random();
            List <Node> neighbours     = new List <Node>();
            List <int>  validParentIds = new List <int>();

            do
            {
                neighbours = MetroNetwork.GenChildren(Path.First());

                foreach (Node n in neighbours)
                {
                    index = n.StationId;

                    if (Path.First().ValidRewind(stations[index], OriginId))
                    {
                        validParentIds.Add(index);
                    }
                }

                parentCount = validParentIds.Count();

                if (parentCount > 0)
                {
                    index = validParentIds[rand.Next(parentCount)]; // goes down a random path
                    AddOn(stations[index]);

                    if (index == OriginId) // terminates when reached origin
                    {
                        ongoing = false;
                    }
                }

                else // there are no valid ancestors >> no route exists (disconnected graph)
                {
                    ongoing = false;
                }

                validParentIds.Clear();
                neighbours.Clear();
            } while (ongoing);
        }