public static List<Point> PathToPill(Maze maze, Point start, Point destination)
{
var list = new List<Point>();
var closedSet = new List<PathNode>();
var hScore = Math.Abs(start.X - destination.X) + Math.Abs(start.Y - destination.Y);
var openSet = new List<PathNode>
{
new PathNode
{
Position = start,
GScore = 0,
HScore = hScore,
FScore = hScore
}
};
while (openSet.Count != 0)
{
var current = BestNode(openSet);
if (current.Position.Equals(destination))
{
list.Add(new Point { X = current.GScore });
list.Add(ReconstructPath(start, current).Position);
return list;
}
openSet.Remove(current);
closedSet.Add(current);
var childpoints = GenerateMoves(maze, current.Position);
foreach (var childpoint in childpoints)
{
var gScore = current.GScore + 1;
hScore = Math.Abs(childpoint.X - destination.X) + Math.Abs(childpoint.Y - destination.Y);
var newChild = new PathNode
{
Position = childpoint,
GScore = gScore,
HScore = hScore,
FScore = gScore + hScore
};
if (closedSet.Contains(newChild))
continue;
var _newChild = FindChild(newChild, openSet);
if (_newChild != null
&& gScore < _newChild.GScore)
{
openSet.Remove(_newChild);
current.InsertChild(newChild);
openSet.Add(newChild);
}
else if (_newChild == null)
{
current.InsertChild(newChild);
openSet.Add(newChild);
}
}
}
return list;
}
private static PathNode ReconstructPath(Point start, PathNode current)
{
while (current.Parent.Position != start)
current = current.Parent;
return current;
}
private static bool isChildExplored(PathNode root, Point childPoint)
{
while (root != null)
{
if (root.Position == childPoint)
return true;
root = root.Parent;
}
return false;
}
private static PathNode FindChild(PathNode newChild, List<PathNode> openSet)
{
foreach (var node in openSet)
if (node.Position == newChild.Position)
return node;
return null;
}
public static Point SelectPath(Maze maze, Point start, int depth)
{
var openSet = new List<PathNode>
{
new PathNode{Position = start}
};
var closedSet = new List<PathNode>();
var _depth = 0;
while (openSet.Count != 0 && _depth < depth)
{
var root = openSet.First();
openSet.Remove(root);
var childPoints = GenerateMoves(maze, root.Position);
foreach (var childPoint in childPoints)
{
if (!isChildExplored(root, childPoint))
{
var _case = maze.GetSymbol(childPoint);
switch (_case)
{
case '.':
var newChild = new PathNode
{
Position = childPoint,
Score = root.Score + 1
};
root.InsertChild(newChild);
openSet.Add(newChild);
break;
case '*':
newChild = new PathNode
{
Position = childPoint,
Score = root.Score + 10
};
root.InsertChild(newChild);
openSet.Add(newChild);
break;
default:
break;
}
}
}
closedSet.Add(root);
_depth++;
}
var current = new PathNode();
if (openSet.Count != 0)
{
current = closedSet.OrderByDescending(pathNode => pathNode.Score).First();
return ReconstructPath(start, current).Position;
}
current = closedSet.OrderByDescending(pathNode => pathNode.Score).First();
var longestStreaks = closedSet.Where(pathNode => pathNode.Score == current.Score).ToList();
if (longestStreaks.Count == 1)
return ReconstructPath(start, current).Position;
var random = new Random();
var longestStreakIndex = random.Next(0, longestStreaks.Count);
return ReconstructPath(start, longestStreaks[longestStreakIndex]).Position;
}
public void InsertChild(PathNode newChild)
{
newChild.parent = this;
}