}; // { row, col }
public static List <SearchNode> Get4WayNeighbors(SearchNode current, IMovable grid)
{
List <SearchNode> neighbors = new List <SearchNode>();
for (Direction4Way dir = ( Direction4Way )0; dir < Direction4Way.LENGTH; dir += 1)
{
Node newPos = new Node(current.Pos.Row + Way4Directions[( int )dir, 0], current.Pos.Col + Way4Directions[( int )dir, 1]);
// for specific constraints
if (grid != null && grid.IsMovableNode(newPos) == false)
{
continue;
}
SearchNode newNode = new SearchNode(newPos, current, 0, 0);
neighbors.Add(newNode);
}
return(neighbors);
}
public static List <Direction4Way> Search4WayNode(Node start, Node end, IMovable grid, out int distance)
{
Console.Error.WriteLine("Finding from {0} to {1} by A*", start, end);
distance = -1;
List <Direction4Way> pathWay = new List <Direction4Way>();
if (start.Equals(end))
{
distance = 0;
return(pathWay);
}
List <SearchNode> frontier = new List <SearchNode>();
List <SearchNode> explored = new List <SearchNode>();
SearchNode startNode = new SearchNode(start, null, 0, PathFinding.GetManhattanHeuristic(start, end));
frontier.Add(startNode);
bool found = false;
while (frontier.Count > 0)
{
SearchNode current = ( SearchNode )frontier[0];
frontier.RemoveAt(0);
explored.Add(current);
if (current.Pos.Equals(end))
{
distance = current.CostSoFar + current.CostToEnd;
SearchNode parent = current;
while (parent != null && parent.Pos.Equals(start) == false)
{
Direction4Way dir = PathFinding.Get4WayDirection(parent.Parent.Pos, parent.Pos);
pathWay.Add(dir);
parent = parent.Parent;
}
found = true;
break;
}
List <SearchNode> neighbors = PathFinding.Get4WayNeighbors(current, grid);
foreach (SearchNode node in neighbors)
{
if (explored.Contains(node))
{
continue;
}
node.CostSoFar = current.CostSoFar + 1;
node.CostToEnd = PathFinding.GetManhattanHeuristic(node.Pos, end);
int index = frontier.IndexOf(node);
if (index > 0)
{
if (node.CostSoFar < frontier[index].CostSoFar)
{
// if found better way
frontier[index].Parent = current;
frontier[index].CostSoFar = node.CostSoFar;
frontier[index].CostToEnd = node.CostToEnd;
}
}
else
{
frontier.Add(node);
}
}
frontier.Sort((item1, item2) => (item1.CostSoFar + item1.CostToEnd) - (item2.CostSoFar + item2.CostToEnd));
//Console.Error.WriteLine( "frontier = {0}", frontier.ToDebugString() );
}
pathWay.Reverse();
if (found)
{
Console.Error.WriteLine("Found : {0} to {1} : {2} of distance {3}", start, end, pathWay.ToDebugString(), distance);
}
else
{
Console.Error.WriteLine("No Way! : {0} to {1}", start, end);
}
return(pathWay);
}
public static List <Direction4Way> Search4WayNode(Node start, IReachable searchGrid, IMovable moveGrid, out int distance)
{
Console.Error.WriteLine("Finding from {0} by BFS", start);
distance = -1;
List <Direction4Way> pathWay = new List <Direction4Way>();
if (searchGrid.IsReachedDestination(start))
{
distance = 0;
return(pathWay);
}
List <SearchNode> frontier = new List <SearchNode>();
List <SearchNode> explored = new List <SearchNode>();
SearchNode startNode = new SearchNode(start, null, 0, 0);
frontier.Add(startNode);
bool found = false;
while (frontier.Count > 0)
{
SearchNode current = ( SearchNode )frontier[0];
frontier.RemoveAt(0);
explored.Add(current);
if (searchGrid.IsReachedDestination(current.Pos))
{
Console.Error.WriteLine("End node found : {0}", current.Pos);
distance = current.CostSoFar + current.CostToEnd;
SearchNode parent = current;
while (parent != null && parent.Pos.Equals(start) == false)
{
Direction4Way dir = PathFinding.Get4WayDirection(parent.Parent.Pos, parent.Pos);
//Console.Error.WriteLine( "iterate back to parent {0}", parent.Pos );
pathWay.Add(dir);
parent = parent.Parent;
}
found = true;
break;
}
List <SearchNode> neighbors = PathFinding.Get4WayNeighbors(current, moveGrid);
foreach (SearchNode node in neighbors)
{
if (explored.Contains(node))
{
continue;
}
node.CostSoFar = current.CostSoFar + 1;
int index = frontier.IndexOf(node);
if (index == -1)
{
frontier.Add(node);
}
}
//Console.Error.WriteLine( "frontier = {0}", frontier.ToDebugString() );
}
pathWay.Reverse();
if (found)
{
Console.Error.WriteLine("Found : from {0} through {1} of distance {2}", start, pathWay.ToDebugString(), distance);
}
else
{
Console.Error.WriteLine("No Way! Found from {0}", start);
}
return(pathWay);
}
public List <Direction4Way> SearchGraphByDijkstra(Node start, PathGrid grid, out int cost)
{
cost = -1;
List <Direction4Way> pathWay = new List <Direction4Way>();
if (grid.IsReachedDestination(start))
{
cost = 0;
return(pathWay);
}
List <SearchNode> frontier = new List <SearchNode>();
List <SearchNode> explored = new List <SearchNode>();
SearchNode startNode = new SearchNode(start, null, 0, 0);
frontier.Add(startNode);
bool found = false;
while (frontier.Count > 0)
{
SearchNode current = ( SearchNode )frontier[0];
frontier.RemoveAt(0);
explored.Add(current);
if (grid.IsReachedDestination(current.Pos))
{
cost = current.CostSoFar + current.CostToEnd;
SearchNode parent = current;
while (parent != null && parent.Pos.Equals(start) == false)
{
Direction4Way dir = PathFinding.Get4WayDirection(parent.Parent.Pos as Node, parent.Pos as Node);
pathWay.Add(dir);
parent = parent.Parent;
}
found = true;
break;
}
List <SearchNode> neighbors = PathFinding.Get4WayNeighbors(current, grid);
foreach (SearchNode node in neighbors)
{
if (explored.Contains(node))
{
continue;
}
node.CostSoFar = current.CostSoFar + 1;
node.CostToEnd = 0;
int index = frontier.IndexOf(node);
if (index > 0)
{
if (node.CostSoFar < frontier[index].CostSoFar)
{
// if found better way
frontier[index].Parent = current;
frontier[index].CostSoFar = node.CostSoFar;
frontier[index].CostToEnd = node.CostToEnd;
}
}
else
{
frontier.Add(node);
}
}
frontier.Sort((item1, item2) => (item1.CostSoFar + item1.CostToEnd) - (item2.CostSoFar + item2.CostToEnd));
//Console.Error.WriteLine( "frontier = {0}", frontier.ToDebugString() );
}
pathWay.Reverse();
if (found)
{
Console.Error.WriteLine("Found from {0} : {1} of distance {2}", start, pathWay.ToDebugString(), cost);
}
else
{
Console.Error.WriteLine("No Way! from {0}", start);
}
return(pathWay);
}
