private Path FinalPath(MazeCoordinate start,
MazeCoordinate target,
IDictionary <MazeCoordinate, MazeCoordinate> previous)
{
var final = new List <MazeCoordinate>();
var u = target;
if (!previous.ContainsKey(u))
{
return(Path.Empty);
}
while (previous[u] != null)
{
if (final.Contains(u))
{
throw new InvalidOperationException("How are we doing this?");
}
final.Insert(0, u);
u = previous[u];
}
final.Insert(0, u);
return(Path.From(start, target, final));
}
public static Path From(MazeCoordinate start, MazeCoordinate end, IEnumerable <MazeCoordinate> route)
{
if (!route.First().Equals(start) || !route.Last().Equals(end))
{
return(Path.Empty);
}
return(new Path(start, end, route));
}
private static IEnumerable <MazeCoordinate> Neighbors(MazeCoordinate current,
int minX, int maxX,
int minY, int maxY,
int input)
{
var surrounding = new[]
{
new MazeCoordinate(current.X - 1, current.Y), new MazeCoordinate(current.X + 1, current.Y),
new MazeCoordinate(current.X, current.Y - 1), new MazeCoordinate(current.X, current.Y + 1)
};
return(surrounding.Where(s => IsOpenSpace(s.X, s.Y, input))
.Where(s => s.X >= minX && s.X <= maxX && s.Y >= minY && s.Y <= maxY));
}
public IDictionary <MazeCoordinate, Path> StepsToAllSpaces(MazeCoordinate start)
{
var paths = new ConcurrentDictionary <MazeCoordinate, Path>();
Parallel.ForEach(this.graph.Keys, node =>
{
var route = FindOptimalRoute(start, node);
if (!paths.TryAdd(node, route))
{
throw new InvalidOperationException("Bang");
}
});
return(paths.ToDictionary(kvp => kvp.Key, kvp => kvp.Value));
}
private Path(MazeCoordinate start, MazeCoordinate end, IEnumerable <MazeCoordinate> path)
{
if (path == null)
{
throw new ArgumentNullException("path");
}
if (!path.Any())
{
throw new ArgumentException("Path does not contain any coordinates");
}
this.Start = start;
this.End = end;
this.FullPath = path;
this.Length = path.Count() - 1;
}
public Path FindOptimalRoute(MazeCoordinate start, MazeCoordinate end)
{
var notVisited = new HashSet <MazeCoordinate>();
var distanceToStart = new Dictionary <MazeCoordinate, int>();
var previousInOptimalPath = new Dictionary <MazeCoordinate, MazeCoordinate>();
foreach (var openSpace in this.graph.Keys)
{
distanceToStart[openSpace] = Int32.MaxValue;
previousInOptimalPath[openSpace] = null;
notVisited.Add(openSpace);
}
distanceToStart[start] = 0;
while (notVisited.Any())
{
var u = SelectClosestUnvisited(notVisited, distanceToStart);
notVisited.Remove(u);
foreach (var neighbor in this.graph[u].Neighbors.Where(n => notVisited.Contains(n)))
{
var a = (distanceToStart[u] == Int32.MaxValue) ? 1 : distanceToStart[u] + 1;
if (a < distanceToStart[neighbor])
{
distanceToStart[neighbor] = a;
previousInOptimalPath[neighbor] = u;
}
}
}
var finalPath = FinalPath(start, end, previousInOptimalPath);
return(finalPath);
}
private bool CoordinateNotReachable(MazeCoordinate start, MazeCoordinate end, IEnumerable <MazeCoordinate> route)
{
var reachable = route.Contains(start) && route.Contains(end);
return(reachable);
}
public MazeNode AddNeighbor(MazeCoordinate neighbor)
{
this.neighbors.Add(neighbor);
return(this);
}
public MazeNode(MazeCoordinate coordinate)
{
this.Coordinate = coordinate;
}