private static void Relax(MasterVertex u, MasterVertex v, int weight)
{
if (v.D > u.D + weight)
{
v.D = u.D + weight;
v.Parent = u;
}
}
private static void InitializeSingleSource(MasterVertex[] vertices, MasterVertex s)
{
foreach (MasterVertex v in vertices)
{
v.D = int.MaxValue;
v.Parent = null;
}
s.D = 0;
}
internal void Dijkstra(string fileName)
{
int source = 0;
int n = Math.Min(Math.Max(25, fileName.Length / 2), fileName.Length);
l.Text = "running Dijsktra's to find shortest paths from source " + source + " for graph in ...";
l.Text += fileName.Substring(fileName.Length - n, n);
statusStrip.Update();
int[][] graph = graphs[fileName];
MasterVertex[] vertices = new MasterVertex[graph.GetLength(0)];
//Source MasterVertex
for (int i = 0; i < vertices.Length; i++)
{
vertices[i] = new MasterVertex()
{
Name = i.ToString()
}
}
;
InitializeSingleSource(vertices, vertices[source]);
List <MasterVertex> result = new List <MasterVertex>();
//adding all MasterVertex to priority queue
PriorityQueue <MasterVertex> queue = new PriorityQueue <MasterVertex>(true);
for (int i = 0; i < vertices.Length; i++)
{
queue.Enqueue(vertices[i].D, vertices[i]);
}
//treversing to all vertices
int j = 0;
double maxJ = vertices.Length * (double)vertices.Length;
while (queue.Count > 0)
{
var u = queue.Dequeue();
result.Add(u);
//again traversing to all vertices
for (int v = 0; v < graph[Convert.ToInt32(u.Name)].Length; v++)
{
p.Value = (int)Math.Round(100 * (j++) / maxJ);
if (graph[Convert.ToInt32(u.Name)][v] > 0)
{
Relax(u, vertices[v], graph[Convert.ToInt32(u.Name)][v]);
//updating priority value since distance is changed
queue.UpdatePriority(vertices[v], vertices[v].D);
}
}
}
p.Value = 0;
l.Text = "Ready!";
statusStrip.Update();
ssspSolutions[fileName] = result;
}
private static void PrintStringPath(ref String accumulator, MasterVertex u, MasterVertex v, List <MasterVertex> vertices)
{
if (v != u)
{
PrintStringPath(ref accumulator, u, v.Parent, vertices);
accumulator = accumulator + ", " + v.Name;
}
else
{
accumulator = accumulator + v.Name;
}
}
private static void PrintPath(StreamWriter fileStreamWriter, MasterVertex u, MasterVertex v, List <MasterVertex> vertices)
{
if (v != u)
{
PrintPath(fileStreamWriter, u, v.Parent, vertices);
fileStreamWriter.Write(", " + v.Name);
}
else
{
fileStreamWriter.Write(v.Name);
}
}
