public WeightedGraph GetMinimumSpanningTree()
{
var tree = new WeightedGraph();
if (!nodes.Any())
{
return(tree);
}
var edges = new PriorityQueue <Edge>();
var startNode = nodes.FirstOrDefault().Value;
foreach (var edge in startNode.GetEdges())
{
edges.Enqueue(edge);
}
tree.AddNode(startNode.Label);
if (edges.Count() == 0)
{
return(tree);
}
while (tree.nodes.Count() < nodes.Count())
{
var minEdge = edges.Dequeue();
var nextNode = minEdge.To;
if (tree.ContainsNode(nextNode.Label))
{
continue;
}
tree.AddNode(nextNode.Label);
tree.AddEdge(minEdge.From.Label, nextNode.Label, minEdge.Weight);
foreach (var edge in nextNode.GetEdges())
{
if (!tree.ContainsNode(edge.To.Label))
{
edges.Enqueue(edge);
}
}
}
return(tree);
}
public WeightedGraph MinimumSpaningTree()
{
var tree = new WeightedGraph();
var queue = new PriorityQueue <Edge, int>();
var firstNode = Nodes.Values.First();
foreach (var edge in firstNode.GetEdges())
{
queue.Enqueue(edge, edge.Weight);
}
tree.AddNode(firstNode.Label);
while (tree.Nodes.Count < Nodes.Count && queue.Count != 0)
{
var minEdge = queue.Dequeue();
var nextNode = minEdge.To;
if (tree.ContainsNode(nextNode.Label))
{
continue;
}
tree.AddNode(nextNode.Label);
tree.AddEdge(minEdge.From.Label, nextNode.Label, minEdge.Weight);
foreach (var edge in nextNode.GetEdges())
{
if (!tree.ContainsNode(edge.To.Label))
{
queue.Enqueue(edge, edge.Weight);
}
}
}
return(tree);
}