/// <summary>
/// Finds all the paths from currentServerNode to destServerNode as a recursive method.
/// Passes all nodes, if destination node found, it is added to paths
/// </summary>
/// <param name="currentServerNode">Current server node</param>
/// <param name="destServerNode">Destination server node</param>
/// <param name="paths">All possible paths are inserted to this list</param>
/// <param name="passedNodes"></param>
private static void FindPaths(MDSServerNode currentServerNode, MDSServerNode destServerNode, ICollection <List <MDSServerNode> > paths, ICollection <MDSServerNode> passedNodes)
{
//Add current node to passedNodes to prevent multi-pass over same node
passedNodes.Add(currentServerNode);
//If current node is destination, then add passed nodes to found paths.
if (currentServerNode == destServerNode)
{
var foundPath = new List <MDSServerNode>();
foundPath.AddRange(passedNodes);
paths.Add(foundPath);
}
//Else, Jump to adjacents nodes of current node and conitnue searching
else
{
foreach (var adjacentServerNode in currentServerNode.Adjacents.Values)
{
//If passed over this adjacentServerNode before, skip it
if (passedNodes.Contains(adjacentServerNode))
{
continue;
}
//Search path from this adjacent server to destination (recursive call)
FindPaths(adjacentServerNode, destServerNode, paths, passedNodes);
//Remove node from passed nodes, because we may pass over this node for searching another path
passedNodes.Remove(adjacentServerNode);
}
}
}
/// <summary>
/// Find one of the shortest paths from given source node to destination node.
/// </summary>
/// <param name="sourceServerNode">Source node</param>
/// <param name="destServerNode">Destination node</param>
/// <returns>A path from source to destination</returns>
private static List <MDSServerNode> FindShortestPath(MDSServerNode sourceServerNode, MDSServerNode destServerNode)
{
//Find all paths
var allPaths = new List <List <MDSServerNode> >();
FindPaths(sourceServerNode, destServerNode, allPaths, new List <MDSServerNode>());
//Get shortest
if (allPaths.Count > 0)
{
var bestPath = allPaths[0];
for (var i = 1; i < allPaths.Count; i++)
{
if (bestPath.Count > allPaths[i].Count)
{
bestPath = allPaths[i];
}
}
return(bestPath);
}
//No path from sourceServerNode to destServerNode
return(null);
}
/// <summary>
/// Finds all the paths from currentServerNode to destServerNode as a recursive method.
/// Passes all nodes, if destination node found, it is added to paths
/// </summary>
/// <param name="currentServerNode">Current server node</param>
/// <param name="destServerNode">Destination server node</param>
/// <param name="paths">All possible paths are inserted to this list</param>
/// <param name="passedNodes"></param>
private static void FindPaths(MDSServerNode currentServerNode, MDSServerNode destServerNode, ICollection<List<MDSServerNode>> paths, ICollection<MDSServerNode> passedNodes)
{
//Add current node to passedNodes to prevent multi-pass over same node
passedNodes.Add(currentServerNode);
//If current node is destination, then add passed nodes to found paths.
if (currentServerNode == destServerNode)
{
var foundPath = new List<MDSServerNode>();
foundPath.AddRange(passedNodes);
paths.Add(foundPath);
}
//Else, Jump to adjacents nodes of current node and conitnue searching
else
{
foreach (var adjacentServerNode in currentServerNode.Adjacents.Values)
{
//If passed over this adjacentServerNode before, skip it
if (passedNodes.Contains(adjacentServerNode))
{
continue;
}
//Search path from this adjacent server to destination (recursive call)
FindPaths(adjacentServerNode, destServerNode, paths, passedNodes);
//Remove node from passed nodes, because we may pass over this node for searching another path
passedNodes.Remove(adjacentServerNode);
}
}
}
/// <summary>
/// Find one of the shortest paths from given source node to destination node.
/// </summary>
/// <param name="sourceServerNode">Source node</param>
/// <param name="destServerNode">Destination node</param>
/// <returns>A path from source to destination</returns>
private static List<MDSServerNode> FindShortestPath(MDSServerNode sourceServerNode, MDSServerNode destServerNode)
{
//Find all paths
var allPaths = new List<List<MDSServerNode>>();
FindPaths(sourceServerNode, destServerNode, allPaths, new List<MDSServerNode>());
//Get shortest
if (allPaths.Count > 0)
{
var bestPath = allPaths[0];
for (var i = 1; i < allPaths.Count; i++)
{
if (bestPath.Count > allPaths[i].Count)
{
bestPath = allPaths[i];
}
}
return bestPath;
}
//No path from sourceServerNode to destServerNode
return null;
}
