private LinkedList <ScoredCoordinates> getNeighbors(Coordinates current, Maze maze)
{
LinkedList <ScoredCoordinates> neighborList = new LinkedList <ScoredCoordinates>();
ScoredCoordinates[] potNebr = new ScoredCoordinates[8];
potNebr[0] = new ScoredCoordinates(current.x + 1, current.y);
potNebr[1] = new ScoredCoordinates(current.x + 1, current.y + 1);
potNebr[2] = new ScoredCoordinates(current.x, current.y + 1);
potNebr[3] = new ScoredCoordinates(current.x - 1, current.y + 1);
potNebr[4] = new ScoredCoordinates(current.x - 1, current.y);
potNebr[5] = new ScoredCoordinates(current.x - 1, current.y - 1);
potNebr[6] = new ScoredCoordinates(current.x, current.y - 1);
potNebr[7] = new ScoredCoordinates(current.x + 1, current.y - 1);
foreach (ScoredCoordinates spot in potNebr)
{
if (maze.isTraversible(spot))
{
neighborList.AddLast(spot);
}
}
return(neighborList);
}
public override Path solve(Maze maze)
{
LinkedList <ScoredCoordinates> closedSet = new LinkedList <ScoredCoordinates>();
LinkedList <ScoredCoordinates> openSet = new LinkedList <ScoredCoordinates>();
ScoredCoordinates start = new ScoredCoordinates(maze.startPosition);
start.f = start.heuristic_cost(maze.endPosition);
openSet.AddFirst(start);
while (openSet.Count >= 1)
{
ScoredCoordinates current = openSet.First();
foreach (ScoredCoordinates node in openSet)
{
if (node.f < current.f)
{
current = node;
}
}
if (current.Equals(maze.endPosition))
{
// Return Reconstructed path
Path reconstructedPath = new Path(maze.startPosition);
while (current != null)
{
reconstructedPath.AddAfter(reconstructedPath.First, current);
current = current.cameFrom;
}
return(reconstructedPath);
}
openSet.Remove(current);
closedSet.AddLast(current);
foreach (ScoredCoordinates neighbor in getNeighbors(current, maze))
{
if (closedSet.Contains(neighbor))
{
continue;
}
// Selecting the node in the openSet if it was already added
bool isNew = true;
ScoredCoordinates exploredNeighbor = neighbor;
foreach (ScoredCoordinates openSetMember in openSet)
{
if (neighbor.Equals(openSetMember))
{
exploredNeighbor = openSetMember;
isNew = false;
break;
}
}
if (isNew)
{
openSet.AddLast(neighbor);
}
double tentative_g = current.g + maze.valueAt(exploredNeighbor);
if (tentative_g >= exploredNeighbor.g)
{
continue;
}
exploredNeighbor.cameFrom = current;
exploredNeighbor.g = tentative_g;
exploredNeighbor.f = exploredNeighbor.g + exploredNeighbor.heuristic_cost(maze.endPosition);
}
}
return(null);
}
public ScoredCoordinates(int x, int y) : base(x, y)
{
this.f = 0;
this.g = double.PositiveInfinity;
this.cameFrom = null;
}
