public IEnumerable <DirectedEdge> PathTo(int v)
{
if (!HasPathTo(v))
{
return(null);
}
Stack <DirectedEdge> path = new Stack <DirectedEdge>();
for (DirectedEdge e = m_edgeTo[v]; e != null; e = m_edgeTo[e.From()])
{
path.Push(e);
}
return(path);
}
/// <summary>
/// relax edge e, but update if you find a *longer* path
/// </summary>
/// <param name="e"></param>
private void Relax(DirectedEdge e)
{
int v = e.From(), w = e.To();
if (_distTo[w] < _distTo[v] + e.Weight)
{
_distTo[w] = _distTo[v] + e.Weight;
_edgeTo[w] = e;
}
}
/// <summary>
/// Adds the directed edge <tt>e</tt> to the edge-weighted digraph (if there
/// is not already an edge with the same endpoints).
/// </summary>
/// <param name="e">e the edge</param>
public void AddEdge(DirectedEdge e)
{
var v = e.From();
var w = e.To();
if (_adj[v][w] != null) return;
E++;
_adj[v][w] = e;
}
private void TraceBackDirectedCycle(DirectedEdge e, int w)
{
_cycle = new Collections.Stack<DirectedEdge>();
while (e.From() != w)
{
_cycle.Push(e);
e = _edgeTo[e.From()];
}
_cycle.Push(e);
}
/// <summary>
/// relax edge e and update pq if changed
/// </summary>
/// <param name="e"></param>
private void Relax(DirectedEdge e)
{
int v = e.From(), w = e.To();
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]);
}
}
public void AddEdge(DirectedEdge e)
{
m_adj[e.From()].Add(e);
m_e++;
}
/// <summary>
/// Adds the directed edge <tt>e</tt> to this edge-weighted digraph.
/// </summary>
/// <param name="e">e the edge</param>
/// <exception cref="IndexOutOfRangeException">unless endpoints of edge are between 0 and V-1</exception>
public void AddEdge(DirectedEdge e)
{
var v = e.From();
var w = e.To();
ValidateVertex(v);
ValidateVertex(w);
_adj[v].Add(e);
E++;
}
