private List <GridWorldSpace> RepeatedAStar()
{
int timeSteps = 0;
GridWorld currWorld = new GridWorld(world.Rows, world.Rows,
world.Width, world.Height);
currWorld.SetStart(0, 0);
currWorld.SetGoal(world.Rows - 1, world.Rows - 1);
int size = (world.Rows * world.Rows) + 1;
Node currNode = world.GetSpaceByCoord(world.GetStartCoord()).TreePointer;
Node goalNode = world.GetSpaceByCoord(world.GetGoalCoord()).TreePointer;
List <GridWorldSpace> repeatedPath = new List <GridWorldSpace>();
List <GridWorldSpace> tmpPath = new List <GridWorldSpace>();
CoordHeap openList = new CoordHeap();
while (currNode.key != goalNode.key)
{
repeatedPath.Add(currNode.key);
currNode.key.G = 0;
currNode.key.S = timeSteps;
goalNode.key.G = size;
goalNode.key.S = timeSteps;
currNode.key.F = currNode.key.G + currNode.key.H;
openList.Insert(currNode.key);
tmpPath = GetPath(currWorld);
currNode = openList.GetLeastF().TreePointer;
timeSteps++;
}
cost = timeSteps;
return(repeatedPath);
}
private List <GridWorldSpace> GetPath(GridWorld currWorld)
{
int timeSteps = 0;
CoordHeap openList = new CoordHeap();
List <GridWorldSpace> closedList = new List <GridWorldSpace>();
List <Node> backTrack = new List <Node>();
GridWorldSpace currSpace = currWorld.GetSpaceByCoord(currWorld.GetStartCoord());
GridWorldSpace goalSpace = currWorld.GetSpaceByCoord(currWorld.GetGoalCoord());
Node starting = new Node(currSpace);
backTrack.Add(starting);
openList.Insert(currSpace);
ComputeValues(currSpace, timeSteps);
while (!openList.isEmpty() && currSpace != goalSpace)
{
CardinalDir[] cardinals = { CardinalDir.UP,
CardinalDir.DOWN,
CardinalDir.LEFT,
CardinalDir.RIGHT };
int isBlocked = 0;
for (int i = 0; i < cardinals.Length; i++)
{
if (currWorld.IsTraversible(currSpace, cardinals[i]))
{
GridWorldSpace tmpSpace = GetAdjacentSpace(currSpace, cardinals[i]);
bool tmpbool = tmpSpace.isTraversible();
leastSpace = backTrack.First();
for (int it = 0; it < backTrack.Count; it++)
{
if (leastSpace.key.F > backTrack[it].key.F)
{
leastSpace.key = backTrack[it].key;
}
}
Node parent1 = leastSpace;
ComputeValues(tmpSpace, timeSteps);
if (tmpbool && !openList.Contains(tmpSpace) && !closedList.Contains(tmpSpace))
{
ComputeValues(tmpSpace, timeSteps);
openList.Insert(tmpSpace);
//Initialized a Node Object for tmpSpace
child = new Node(tmpSpace);
TT.Insert(parent1, child);
backTrack.Add(child);
if (child.key == goalSpace)
{
break;
}
}
if (tmpbool && openList.Contains(tmpSpace) && (tmpSpace.F < openList.SpaceF(tmpSpace.Id)))
{
child = new Node(tmpSpace);
openList.RemoveSpecific(tmpSpace.Id); //Remove anything with this ID
openList.Insert(tmpSpace);
for (int x = 0; x < backTrack.Count; x++)
{
if (tmpSpace.Id == backTrack[x].key.Id)
{
backTrack.Remove(child); //Remove anything with this ID
}
}
backTrack.Add(child);
TT.Insert(parent1, child);
if (child.key == goalSpace)
{
break;
}
}
else
{
isBlocked++;
}
}
else
{
isBlocked++;
}
if (isBlocked == 4)
{
currSpace.Blocked = true;
}
}
openList.Remove(currSpace);
closedList.Add(currSpace);
if (!openList.isEmpty())
{
currSpace = openList.GetLeastF();
}
backTrack.Remove(leastSpace);
timeSteppedPaths[timeSteps] = new List <GridWorldSpace>();
foreach (GridWorldSpace tmp in closedList)
{
timeSteppedPaths[timeSteps].Add(tmp);
}
timeStepStrings[timeSteps] = "";
Debug.WriteLine("");
Debug.WriteLine("Timestep: " + timeSteps);
Debug.WriteLine("Current Node: " + currSpace.Id);
Debug.WriteLine("Closed List:");
foreach (GridWorldSpace tmp in closedList)
{
Debug.Write(tmp.Id);
timeStepStrings[timeSteps] += tmp.Id;
timeStepStrings[timeSteps] += "->";
Debug.Write("->");
}
Debug.WriteLine("");
openList.PrintHeap();
timeSteps++;
}
if (currSpace.isGoal())
{
timeStepStrings[timeSteps] += timeStepStrings[timeSteps - 1];
timeStepStrings[timeSteps] += currSpace.Id;
timeSteppedPaths[timeSteps] = new List <GridWorldSpace>();
foreach (GridWorldSpace tmp in closedList)
{
timeSteppedPaths[timeSteps].Add(tmp);
}
solvable = true;
}
else
{
timeSteps = timeSteps - 1;
solvable = false;
}
List <GridWorldSpace> finalPath = new List <GridWorldSpace>();
//track parent pointers all the way up to Start
Node curr = child; //Go to Goal, where child = goal
while (curr != null)
{
finalPath.Add(curr.key);
curr = curr.parent;
}
finalPath.Reverse();
Debug.WriteLine("Final list: ");
foreach (GridWorldSpace tmp in finalPath)
{
Debug.Write(tmp.Id);
path_string += tmp.Id;
if (tmp.isGoal())
{
Debug.Write("(GOAL)");
path_string += "(GOAL)";
}
else
{
Debug.Write("->");
path_string += "->";
}
}
cost = timeSteps;
return(finalPath);
}
