/// <summary>
/// Adds the undirected edge <tt>e</tt> to this edge-weighted graph.
/// </summary>
/// <param name="e">e the edge</param>
/// <exception cref="IndexOutOfRangeException">unless both endpoints are between 0 and V-1</exception>
public void AddEdge(EdgeW e)
{
var v = e.Either();
var w = e.Other(v);
ValidateVertex(v);
ValidateVertex(w);
_adj[v].Add(e);
_adj[w].Add(e);
E++;
}
/// <summary>
/// relax edge e and update pq if changed
/// </summary>
/// <param name="e"></param>
/// <param name="v"></param>
private void Relax(EdgeW e, int v)
{
var w = e.Other(v);
if (_distTo[w] > _distTo[v] + e.Weight)
{
_distTo[w] = _distTo[v] + e.Weight;
_edgeTo[w] = e;
if (_pq.Contains(w))
{
_pq.DecreaseKey(w, _distTo[w]);
}
else
{
_pq.Insert(w, _distTo[w]);
}
}
}