public IEnumerable <NodePath> FindMoves(Node start, int distance, IEnumerable <Node> occupiedNodes = null)
{
if (occupiedNodes == null)
{
occupiedNodes = new List <Node>();
}
BoardGraph boardGraph = new BoardGraph(occupiedNodes.ToList());
NodeMapKey nodeMapKey = new NodeMapKey(start.Id, distance);
List <NodePath> nodePaths = new List <NodePath>();
if (boardGraph.NodeMap.ContainsKey(nodeMapKey))
{
nodePaths = boardGraph.NodeMap[new NodeMapKey(start.Id, distance)];
}
return(nodePaths);
}
// Well, it certainly ain't pretty, but it's past my bed time - ianb 20160831
private Dictionary <NodeMapKey, List <NodePath> > BuildMapForNode(List <Node> nodes, Node sourceNode)
{
List <Node> unvisitedNodes = new List <Node>();
Dictionary <Node, int> shortestDistanceToNode = new Dictionary <Node, int>();
Dictionary <Node, Node> previousNodeAlongShortestPath = new Dictionary <Node, Node>();
if (!nodes.Contains(sourceNode))
{
shortestDistanceToNode.Add(sourceNode, 0);
previousNodeAlongShortestPath.Add(sourceNode, null);
unvisitedNodes.Add(sourceNode);
}
foreach (Node node in nodes)
{
shortestDistanceToNode.Add(node, int.MaxValue);
previousNodeAlongShortestPath.Add(node, null);
unvisitedNodes.Add(node);
}
while (unvisitedNodes.Any())
{
unvisitedNodes.Sort((x, y) => shortestDistanceToNode[x] - shortestDistanceToNode[y]);
Node currentNode = unvisitedNodes[0];
unvisitedNodes.Remove(currentNode);
foreach (Node adjacentNode in currentNode.AdjacentNodes)
{
int currentPathDistance = shortestDistanceToNode[currentNode] + 1;
if (currentPathDistance < shortestDistanceToNode[adjacentNode] && currentPathDistance > 0)
{
shortestDistanceToNode[adjacentNode] = currentPathDistance;
previousNodeAlongShortestPath[adjacentNode] = currentNode;
}
}
}
Dictionary <NodeMapKey, List <NodePath> > shortestPathMap = new Dictionary <NodeMapKey, List <NodePath> >();
foreach (Node node in nodes)
{
int distance = 0;
NodePath shortestPath = new NodePath
{
DestinationNode = node
};
Node currentPathNode = node;
while (previousNodeAlongShortestPath[currentPathNode] != null)
{
distance++;
shortestPath.PathToDestination.Insert(0, currentPathNode);
currentPathNode = previousNodeAlongShortestPath[currentPathNode];
}
NodeMapKey currentTupleKey = new NodeMapKey(sourceNode.Id, distance);
if (!shortestPathMap.Keys.Any(k => k.Equals(currentTupleKey)))
{
shortestPathMap.Add(currentTupleKey, new List <NodePath>());
}
shortestPathMap[currentTupleKey].Add(shortestPath);
}
return(shortestPathMap);
}