private void visit(EdgeWightedGraph g, Int32 v)
{
marked[v] = true;
foreach (Edge e in g.Adj(v))
{
int w = e.Other(v);
if (marked[w])
{
continue;//访问过了
}
if (e.Weight < disTo[w])
{
//从MST到w的距离变短了。最佳边变成e
edgeTo[w] = e;
disTo[w] = e.Weight;
if (pq.Contains(w))
{
pq.Change(w, disTo[w]);
}
else
{
pq.Insert(w, disTo[w]);
}
}
}
}
private void Relax(DirectedWeightedGraph g, int v)
{
foreach (DirectedEdge edge in g.GetEdge(v))
{
int w = edge.End;
//如果存在放松的条件
if (disTo[w] > disTo[v] + edge.Weight)
{
//存在，需要更新
disTo[w] = disTo[v] + edge.Weight;
edgeTo[w] = edge;
//重新累计从 s 到某个点的最短距离。这个距离只有可能减小
if (pq.Contains(w))
{
pq.Change(w, disTo[w]);
}
else
{
pq.Insert(w, disTo[w]);
}
}
}
}