// Build a spanning tree with the indicated root node.
private void FindSpanningTree(MazeNode root)
{
Random rand = new Random();
// Set the root node's predecessor so we know it's in the tree.
root.Predecessor = root;
// Make a list of candidate links.
List <MazeLink> links = new List <MazeLink>();
// Add the root's links to the links list.
foreach (MazeNode neighbor in root.Neighbors)
{
if (neighbor != null)
{
links.Add(new MazeLink(root, neighbor));
}
}
// Add the other nodes to the tree.
while (links.Count > 0)
{
// Pick a random link.
int link_num = rand.Next(0, links.Count);
MazeLink link = links[link_num];
links.RemoveAt(link_num);
// Add this link to the tree.
MazeNode to_node = link.ToNode;
link.ToNode.Predecessor = link.FromNode;
// Remove any links from the list that point
// to nodes that are already in the tree.
// (That will be the newly added node.)
for (int i = links.Count - 1; i >= 0; i--)
{
if (links[i].ToNode.Predecessor != null)
{
links.RemoveAt(i);
}
}
// Add to_node's links to the links list.
foreach (MazeNode neighbor in to_node.Neighbors)
{
if ((neighbor != null) && (neighbor.Predecessor == null))
{
links.Add(new MazeLink(to_node, neighbor));
}
}
}
}
public MazeLink(MazeNode from_node, MazeNode to_node)
{
FromNode = from_node;
ToNode = to_node;
}
