public (int index, List <GridPos> list) PathToShortest(int startX, int startY, MapGrid mapGrid, List <GridPos> path)
{
foreach (var paths in ToPath)
{
if (paths.Any(t => t.XPos == startX && t.YPos == startY))
{
return(paths.IndexOf(paths.First(t => t.XPos == startX && t.YPos == startY)), paths);
}
}
LinkedList <GridPos> toReturn = new LinkedList <GridPos>();
Queue <GridPos> gridPos = new Queue <GridPos>();
Dictionary <string, bool> visitedDic = new Dictionary <string, bool>();
visitedDic.Add(startX + "" + startY, true);
gridPos.Enqueue(new GridPos(startX, startY, true, null));
do
{
var currentPiece = gridPos.Dequeue();
for (int x = 0; x < 4; x++)
{
int tempX = currentPiece.XPos + 1;
int tempY = currentPiece.YPos;
if (x == 1)
{
tempX -= 2;
}
else if (x == 2)
{
tempX -= 1;
tempY += 1;
}
else if (x == 3)
{
tempX -= 1;
tempY -= 1;
}
//if you can't enqueue then go to the next
if (!CanEnqueue(tempX, tempY, mapGrid, visitedDic))
{
continue;
}
visitedDic.Add(tempX + "" + tempY, true);
var toBeQueued = new GridPos(tempX, tempY, true, currentPiece);
gridPos.Enqueue(toBeQueued);
//If this is true then we have reached the end and we can confidently say we have found the shortest path!
if (path.Any(t => t.XPos == tempX && t.YPos == tempY))
{
var toAddToPath = new GridPos(toBeQueued);
bool done = false;
do
{
toReturn.AddFirst(toAddToPath);
if (toAddToPath.Previous != null)
{
toAddToPath = new GridPos(toAddToPath.Previous);
}
else
{
var last = toReturn.Last();
var indexOfLast = path.FindIndex(t => t.XPos == last.XPos && t.YPos == last.YPos);
for (int i = indexOfLast + 1; i < path.Count; i++)
{
toReturn.AddLast(path[i]);
}
done = true;
}
} while (done != true);
var toReturnList = toReturn.ToList();
ToPath.Add(toReturnList);
return(0, toReturnList);
}
}
} while (gridPos.Count > 0);
return(0, null);
}
/// <summary>
/// performs a breadth first search
/// </summary>
/// <param name="mapGrid"></param>
/// <returns></returns>
public LinkedList <GridPos> CalculateShortestPath(MapGrid mapGrid, int startX, int startY, int endX, int endY)
{
ToPath = new List <List <GridPos> >();
var pathToReturn = new LinkedList <GridPos>();
Queue <GridPos> gridPos = new Queue <GridPos>();
Dictionary <string, bool> visitedDic = new Dictionary <string, bool>();
visitedDic.Add(startX + "" + startY, true);
gridPos.Enqueue(new GridPos(startX, startY, true, null));
do
{
var currentPiece = gridPos.Dequeue();
for (int x = 0; x < 4; x++)
{
int tempX = currentPiece.XPos + 1;
int tempY = currentPiece.YPos;
if (x == 1)
{
tempX -= 2;
}
else if (x == 2)
{
tempX -= 1;
tempY += 1;
}
else if (x == 3)
{
tempX -= 1;
tempY -= 1;
}
//if you can't enqueue then go to the next
if (!CanEnqueue(tempX, tempY, mapGrid, visitedDic))
{
continue;
}
visitedDic.Add(tempX + "" + tempY, true);
var toBeQueued = new GridPos(tempX, tempY, true, currentPiece);
gridPos.Enqueue(toBeQueued);
//If this is true then we have reached the end and we can confidently say we have found the shortest path!
if (tempX == endX && tempY == endY)
{
var toAddToPath = new GridPos(toBeQueued);
do
{
pathToReturn.AddFirst(toAddToPath);
if (toAddToPath.Previous != null)
{
toAddToPath = new GridPos(toAddToPath.Previous);
}
else
{
toAddToPath = null;
}
} while (toAddToPath != null);
return(pathToReturn);
}
}
} while (gridPos.Count > 0);
return(null);
}
