public async Task <ShortestPathResult> GetShortestPathAsync(IDijkstraGraph graph, uint from, uint to, int depth)
{
var path = new Dictionary <uint, uint>();
var distance = new Dictionary <uint, int> {
[from] = 0
};
var d = new Dictionary <uint, int> {
[from] = 0
};
var q = new SortedSet <uint>(new[] { from }, new NodeComparer(distance));
var current = new HashSet <uint>();
int Distance(uint key)
{
return(distance.ContainsKey(key) ? distance[key] : Int32.MaxValue);
}
do
{
uint u = q.Deque();
boardState.visitNode(u);
if (u % 5 is 0)
{
await Task.Delay(1);
}
if (u == to)
{
return(new ShortestPathResult(from, to, distance[u], path));
}
current.Remove(u);
if (depth == d[u])
{
continue;
}
graph[u]((node, cost) =>
{
if (Distance(node) > Distance(u) + cost)
{
if (current.Contains(node))
{
q.Remove(node);
}
distance[node] = Distance(u) + cost;
q.Add(node);
current.Add(node);
path[node] = u;
d[node] = d[u] + 1;
}
});
} while (q.Count > 0 && depth > 0);
return(new ShortestPathResult(from, to));
}
public static ShortestPathResult GetShortestPath(IDijkstraGraph graph, uint from, uint to, Func <uint, uint, int> heuristic, int depth)
{
var path = new Dictionary <uint, uint>();
var distance = new Dictionary <uint, int> {
[from] = 0
};
var d = new Dictionary <uint, int> {
[from] = 0
};
var q = new SortedSet <uint>(new[] { from }, new HeuristicNodeComparer(distance, heuristic));
var current = new HashSet <uint>();
int Distance(uint key)
{
return(distance.ContainsKey(key) ? distance[key] : Int32.MaxValue);
}
do
{
uint u = q.Deque();
if (u == to)
{
return(new ShortestPathResult(from, to, distance[u], path));
}
current.Remove(u);
if (depth == d[u])
{
continue;
}
graph[u]((node, cost) =>
{
if (Distance(node) > Distance(u) + cost)
{
if (current.Contains(node))
{
q.Remove(node);
}
distance[node] = Distance(u) + cost;
q.Add(node);
current.Add(node);
path[node] = u;
d[node] = d[u] + 1;
}
});
} while (q.Count > 0 && depth > 0);
return(new ShortestPathResult(from, to));
}
/// <summary>
/// Get path from @from to @to
/// </summary>
/// <param name="graph">Source graph</param>
/// <param name="from">Start node</param>
/// <param name="to">End node</param>
/// <param name="depth">Depth of path</param>
/// <returns>Value with path</returns>
public static ShortestPathResult AStar(this IDijkstraGraph graph, uint from, uint to, Func <uint, uint, int> heuristic, int depth)
{
return(ShortestPath.AStar.GetShortestPath(graph, from, to, heuristic, depth));
}
/// <summary>
/// Get path from @from to @to
/// </summary>
/// <param name="graph">Source graph</param>
/// <param name="from">Start node</param>
/// <param name="to">End node</param>
/// <param name="depth">Depth of path</param>
/// <returns>Value with path</returns>
public static ShortestPathResult Dijkstra(this IDijkstraGraph graph, uint from, uint to, int depth)
{
return(ShortestPath.Dijkstra.GetShortestPath(graph, from, to, depth));
}
/// <summary> /// Get path from @from to @to /// </summary> /// <param name="graph">Source graph</param> /// <param name="from">Start node</param> /// <param name="to">End node</param> /// <returns>Value with path</returns> public static ShortestPathResult AStar(this IDijkstraGraph graph, uint from, uint to, Func <uint, uint, int> heuristic) => AStar(graph, from, to, heuristic, Int32.MaxValue);
/// <summary> /// Get path from @from to @to /// </summary> /// <param name="graph">Source graph</param> /// <param name="from">Start node</param> /// <param name="to">End node</param> /// <returns>Value with path</returns> public static ShortestPathResult Dijkstra(this IDijkstraGraph graph, uint from, uint to) => Dijkstra(graph, from, to, Int32.MaxValue);