public int NetworkDelayTime(int[][] times, int N, int K)
{
var graph = new Dictionary <int, List <Node> >();
foreach (var edge in times)
{
if (!graph.ContainsKey(edge[0]))
{
graph.Add(edge[0], new List <Node>());
}
graph[edge[0]].Add(new Node(edge[2], edge[1]));
}
var pq = new MinPriorityQueue();
pq.Insert(new Node(0, K));
var distances = new Dictionary <int, int>();
while (pq.Size() > 0)
{
var node = pq.DeleteMin();
if (distances.ContainsKey(node.Target))
{
continue;
}
distances.Add(node.Target, node.Distance);
if (graph.ContainsKey(node.Target))
{
foreach (var edge in graph[node.Target])
{
if (!distances.ContainsKey(edge.Target))
{
pq.Insert(new Node(node.Distance + edge.Distance, edge.Target));
}
}
}
}
if (distances.Count != N)
{
return(-1);
}
return(distances.Values.Max());
}
public Kruskal(EdgeWeightedGraph <TVertex, TWeight> graph, WeightedEdge <TVertex, TWeight> initialMst)
{
if (graph == null)
{
throw new ArgumentNullException(nameof(graph));
}
var edges = new MinPriorityQueue <WeightedEdge <TVertex, TWeight> >(graph.EdgeNumber);
foreach (var edge in graph.Edges)
{
if (!edge.Equals(initialMst))
{
edges.Add(edge);
}
}
var mst = new UnionFind <TVertex>(graph.Vertices);
MinimumSpanningTree = new List <WeightedEdge <TVertex, TWeight> >(graph.VertexNumber - 1);
if (initialMst != null)
{
var vertex1 = initialMst.GetVertex();
var vertex2 = initialMst.GetTheOtherVertex(vertex1);
mst.Union(vertex1, vertex2);
MinimumSpanningTree.Add(initialMst);
}
while (!edges.IsEmpty && MinimumSpanningTree.Count < graph.VertexNumber - 1)
{
var edge = edges.DeleteMin();
var vertex1 = edge.GetVertex();
var vertex2 = edge.GetTheOtherVertex(vertex1);
if (!mst.IsConnected(vertex1, vertex2))
{
mst.Union(vertex1, vertex2);
MinimumSpanningTree.Add(edge);
}
}
if (MinimumSpanningTree.Count < graph.VertexNumber - 1)
{
throw new ArgumentException();
}
}
