public IDictionary <T, DistanceInfo <T> > BuildDistanceTable(IGraph <T> graph, T source)
{
if (graph == null)
{
throw new ArgumentNullException(nameof(graph));
}
var distances = InitializeDistanceTable(graph, source);
for (var iteration = 0; iteration < graph.Count; iteration++)
{
foreach (var sourceVertex in graph)
{
foreach (var destinationVertex in graph.GetAdjacentVertices(sourceVertex))
{
var step = StepMetadata <T> .ForPath(sourceVertex, destinationVertex, distances);
if (step.FoundShorterDistance() ||
step.SameDistanceButLessEdges())
{
if (CheckingForCycles(graph, iteration))
{
return(InitializeDistanceTable(graph, source));
}
distances[destinationVertex] = step.ToSource();
}
}
}
}
return(distances);
}
public IDictionary <T, DistanceInfo <T> > BuildDistanceTable(IGraph <T> graph, T source)
{
if (graph == null)
{
throw new ArgumentNullException(nameof(graph));
}
var distances = InitializeDistanceTable(graph, source);
var verticesToProcess = new MinBinaryHeap <DistanceInfo <T> >(DistanceInfo <T> .DistanceAndEdgeComparer);
var processedVertices = new HashSet <T>(graph.Comparer);
verticesToProcess.Push(DistanceInfo <T> .Zero(source));
while (verticesToProcess.Count > 0)
{
var sourceVertex = verticesToProcess.Pop().Single().PreviousVertex;
processedVertices.Add(sourceVertex);
foreach (var destinationVertex in graph.GetAdjacentVertices(sourceVertex))
{
if (processedVertices.Contains(destinationVertex))
{
continue;
}
var step = StepMetadata <T> .ForPath(sourceVertex, destinationVertex, distances);
if (step.FoundShorterDistance() ||
step.SameDistanceButLessEdges())
{
distances[destinationVertex] = step.ToSource();
verticesToProcess.Push(step.ToDestination());
}
}
}
return(distances);
}