public Dijkstra(Graph graph, int source)
{
this.graph = graph;
this.source = source;
distance = new int[graph.Vertices.Count];
}
public static Graph<int> FromFile(string path, bool isDirected)
{
var g = new Graph<int>();
using (var stream = File.OpenRead(path))
{
using (var reader = new StreamReader(stream))
{
string line;
while ((line = reader.ReadLine() ) != null)
{
var vertices = line.Split(new[] {' ', '\t'}, StringSplitOptions.RemoveEmptyEntries);
if (vertices.Any())
{
var v = g.GetOrCreateVertex(int.Parse(vertices[0]));
foreach (var adj in vertices.Skip(1))
{
var tokens = adj.Split(',');
if (tokens.Length == 2)
{
int i2 = int.Parse(tokens[0]);
int weight = int.Parse(tokens[1]);
var v2 = g.GetOrCreateVertex(i2);
v.AddEdge(v2.Key, weight);
}
}
}
}
}
}
g.IsDirected = isDirected;
return g;
}
static void Main(string[] args)
{
const string path = @"D:\Projects\Algorithms\ShortestPath\dijkstraData.txt";
//const string path = @"D:\Projects\Algorithms\ShortestPath\temp.txt";
Stopwatch sw = new Stopwatch();
sw.Start();
var graph = new Graph(path);
var loadTime = sw.Elapsed;
sw.Restart();
//var route = new Route();
//Vertex currentNode = graph.Vertices[0];
//route.Add(currentNode);
//for (int i = 0; i < 5; i++)
//{
// route.Add(currentNode.AdjacentEdges[0].Tail);
// currentNode = currentNode.AdjacentEdges[0].Tail;
//}
foreach (var i in new[] { 7, 37, 59, 82, 99, 115, 133, 165, 188, 197 })
{
var cost = graph.GetShortestPath(1, i).Cost;
}
sw.Stop();
var workTime = sw.Elapsed;
Console.WriteLine("Load time: {0}ms, work time: {1}ms, total: {2}ms", loadTime.Milliseconds, workTime.Milliseconds, (loadTime+workTime).Milliseconds);
//result.Clear();
//foreach (var i in new[] { 7, 37, 59, 82, 99, 115, 133, 165, 188, 197 })
//{
// result.Add(graph.GetShortestPath(i, 1).Cost);
// //Console.WriteLine("from 1 to {0} {1}", i, );
//}
//Console.WriteLine(String.Join(",", result));
//for (int i = 2; i < 31; i++)
//{
// var route = graph.GetShortestPath(1, i);
// result.Add(route == null ? 1000000 : route.Cost);
//}
//Console.WriteLine(String.Join(",", result));
//result.Clear();
//for (int i = 2; i < 31; i++)
//{
// var route = graph.GetShortestPath(i, 1);
// result.Add(route == null ? 1000000 : route.Cost);
//}
//Console.WriteLine(String.Join(",", result));
}
/// <summary>
/// Parallel Dijkstra algorithm
/// </summary>
///
/// <param name="graph">
/// <see cref="Graph"/> object to check the path for
/// </param>
///
/// <param name="start">
/// Start
/// </param>
///
/// <returns>
/// List of <see cref="Link"/> objects
/// </returns>
private static List<Link> Dijkstra_p(Graph graph, int start)
{
List<Vertex> P =
(from v in graph.Vertices
select new Vertex(v, graph.Links)).ToList();
var qT =
from vertex in P
where vertex.ID != start
orderby vertex.ID ascending
select vertex;
Queue<Vertex> Q = new Queue<Vertex>(qT);
Vertex curr = P[start];
curr.closest_distance = 0.0f;
while (Q.Count > 0)
{
Barrier barrier = new Barrier(curr.neighbors.Count + 1);
foreach (Tuple<int, double> n in curr.neighbors)
{
var tuple = n;
ThreadPool.QueueUserWorkItem(
obj =>
{
Vertex neighbor = P[tuple.Item1];
double dist = tuple.Item2 + curr.closest_distance;
bool contains = (from v in Q where v.ID == tuple.Item1 select v).Count() > 0;
if (contains && (dist < neighbor.closest_distance))
{
neighbor.closest = curr;
neighbor.closest_distance = dist;
}
barrier.SignalAndWait();
},
null);
}
barrier.SignalAndWait();
barrier.Dispose();
curr = Q.Dequeue();
}
return
(from v in P
where v.ID != start
select new Link(v.ID, v.closest.ID, v.closest_distance)).ToList();
}
public void TestSmallGraph()
{
var g = new Graph<int>();
for (int i = 0; i < 4; ++i) g.GetOrCreateVertex(i);
g.Get(0).AddEdge(1, 1);
g.Get(0).AddEdge(2, 3);
g.Get(1).AddEdge(2, 1);
g.Get(1).AddEdge(3, 3);
g.Get(2).AddEdge(3, 1);
var algorithm = new Dijkstra<int>(g, 0);
algorithm.Run();
Assert.AreEqual(0, g.Get(0).Score);
Assert.AreEqual(1, g.Get(1).Score);
Assert.AreEqual(2, g.Get(2).Score);
Assert.AreEqual(3, g.Get(3).Score);
}
/// <summary>
/// Sequential version
/// </summary>
///
/// <param name="graph">
/// <see cref="Graph"/> object to check the path for
/// </param>
///
/// <param name="start">
/// Start
/// </param>
///
/// <returns>
/// List of <see cref="Link"/> objects
/// </returns>
private static List<Link> Dijkstra(Graph graph, int start)
{
List<Vertex> P =
(from v in graph.Vertices
select new Vertex(v, graph.Links)).ToList();
var qT =
from vertex in P
where vertex.ID != start
orderby vertex.ID ascending
select vertex;
Queue<Vertex> Q = new Queue<Vertex>(qT);
Vertex curr = P[start];
curr.closest_distance = 0.0f;
while (Q.Count > 0)
{
foreach (Tuple<int, double> n in curr.neighbors)
{
Vertex neighbor = P[n.Item1];
double dist = n.Item2 + curr.closest_distance;
bool contains = (from v in Q where v.ID == n.Item1 select v).Count() > 0;
if (contains && (dist < neighbor.closest_distance))
{
neighbor.closest = curr;
neighbor.closest_distance = dist;
}
}
curr = Q.Dequeue();
}
return
(from v in P
where v.ID != start
select new Link(v.ID, v.closest.ID, v.closest_distance)).ToList();
}
static void Main(string[] args)
{
Graph graph = new Graph();
graph.AddEdge(0, 1, 7);
graph.AddEdge(0, 2, 9);
graph.AddEdge(0, 5, 14);
graph.AddEdge(1, 2, 10);
graph.AddEdge(1, 3, 15);
graph.AddEdge(2, 3, 11);
graph.AddEdge(2, 5, 2);
graph.AddEdge(3, 4, 6);
graph.AddEdge(4, 5, 9);
Dijkstra dijkstra = new Dijkstra(graph, graph.Vertices.First());
dijkstra.Run();
Console.WriteLine(dijkstra.Output());
Console.WriteLine("Press any key..");
Console.ReadKey();
}
public EditNode(Graph graph)
{
InitializeComponent();
this.CurrentGraph = graph.Copy();
}
/// <summary>
///
/// </summary>
/// <param name="graph"></param>
public DijkstraModule(Graph graph)
{
this.graph = graph;
}