public DifkstraSP(EdgeWeightedDigraph g, int s)
{
_edgeTo = new DirectedEdge[g.V];
_distTo = Enumerable.Repeat(double.PositiveInfinity, g.V).ToArray();
_pq = new IndexMinPQ <double>(g.V);
_distTo[s] = 0.0;
_pq.Insert(s, 0.0);
while (!_pq.IsEmpty())
{
Relax(g, _pq.DelMin());
}
}
private void Relax(EdgeWeightedDigraph g, int v)
{
foreach (var e in g.Adj(v))
{
int w = e.To;
if (_distTo[v] + e.Weight < _distTo[w])
{
_edgeTo[w] = e;
_distTo[w] = _distTo[v] + e.Weight;
if (_pq.Contains(e.To))
{
_pq.Change(e.To, _distTo[w]);
}
else
{
_pq.Insert(e.To, _distTo[w]);
}
}
}
}
public void DifkstraSPMy(EdgeWeightedDigraph g, int s)
{
_edgeTo = new DirectedEdge[g.V];
_distTo = Enumerable.Repeat(double.PositiveInfinity, g.V).ToArray();
_distTo[s] = 0.0;
_pq = new IndexMinPQ <double>(g.V);
foreach (var e in g.Adj(s))
{
_edgeTo[e.To] = e;
_distTo[e.To] = e.Weight;
_pq.Insert(e.To, e.Weight);
}
while (!_pq.IsEmpty())
{
var i = _pq.DelMin();
foreach (var e in g.Adj(i))
{
RelaxMy(i, e);
}
}
}
