public static PathStats ShortestPath(GraphBase g, int s)
{
#region Initialization
var ps = new PathStats(g.V);
for (int i = 0; i < ps.Dist.Length; i++)
{
ps.Dist[i] = int.MaxValue;
ps.Prev[i] = -1;
}
ps.Dist[s] = 0;
#endregion
for (int i = 0; i < g.V - 1; i++)//run |V|-1 times
{
for (var u = g.V - 1; u >= 0; u--)//'S' starts first, earlier to get finall status
{
foreach (var e in g.Adjacent(u))
{
if (ps.Dist[u] == int.MaxValue)//if distance of u hasn't ever be udpated, skip
break;
if (ps.Dist[e.V2] > ps.Dist[e.V1] + e.Weight)
{
ps.Dist[e.V2] = ps.Dist[e.V1] + e.Weight;
ps.Prev[e.V2] = u;
}
}
}
}
return ps;
}
/// <summary>
/// Breadth-first search on g with start vertice: s
/// </summary>
/// <param name="g">Graph for search</param>
/// <param name="s">Start vertice</param>
/// <returns>Breadth-first search results</returns>
public static BfsStats BreadthFirstSearch(GraphBase g, int s)
{
var stats = new BfsStats(g.V);
stats.Dist[s] = 0;
var q = new Ds.Queue.Queue<int>();
q.Enqueue(s);
while (!q.IsEmpty())
{
var u = q.Dequeue();
foreach (var e in g.Adjacent(u))
{
if (stats.Dist[e.V2] == int.MaxValue)
{
q.Enqueue(e.V2);
stats.Dist[e.V2] = stats.Dist[u] + 1;
}
}
}
return stats;
}