/**
* Do the work
*/
protected void DetermineShortestPaths(BaseVertex sourceVertex,
BaseVertex sinkVertex, bool isSource2sink)
{
// 0. clean up variables
Clear();
// 1. initialize members
BaseVertex endVertex = isSource2sink ? sinkVertex : sourceVertex;
BaseVertex startVertex = isSource2sink ? sourceVertex : sinkVertex;
startVertexDistanceIndex.Add(startVertex, 0d);
startVertex.SetWeight(0d);
vertexCandidateQueue.add(startVertex, startVertex.GetWeight());
// 2. start searching for the shortest path
while (!vertexCandidateQueue.isEmpty())
{
BaseVertex curCandidate = vertexCandidateQueue.poll();
if (curCandidate.Equals(endVertex))
{
break;
}
determinedVertexSet.Add(curCandidate);
UpdateVertex(curCandidate, isSource2sink);
}
}
/**
* Note that this may not be used externally, because some other members in the class
* should be updated at the same time.
*
* @param startVertexId
* @param endVertexId
* @param weight
*/
protected void AddEdge(int startVertexId, int endVertexId, double weight)
{
// actually, we should make sure all vertices ids must be correct.
if (!idVertexIndex.ContainsKey(startVertexId) ||
!idVertexIndex.ContainsKey(endVertexId) ||
startVertexId == endVertexId)
{
throw new ArgumentException("The edge from " + startVertexId +
" to " + endVertexId + " does not exist in the graph.");
}
// update the adjacent-list of the graph
ISet <BaseVertex> fanoutVertexSet = new HashSet <BaseVertex>();
if (fanoutVerticesIndex.ContainsKey(startVertexId))
{
fanoutVertexSet = fanoutVerticesIndex[startVertexId];
}
fanoutVertexSet.Add(idVertexIndex[endVertexId]);
fanoutVerticesIndex.AddOrReplace(startVertexId, fanoutVertexSet);
//
ISet <BaseVertex> faninVertexSet = new HashSet <BaseVertex>();
if (faninVerticesIndex.ContainsKey(endVertexId))
{
faninVertexSet = faninVerticesIndex[endVertexId];
}
faninVertexSet.Add(idVertexIndex[startVertexId]);
faninVerticesIndex.AddOrReplace(endVertexId, faninVertexSet);
// store the new edge
vertexPairWeightIndex.Add(
new Pair <int, int>(startVertexId, endVertexId),
weight);
++edgeNum;
}
/**
* @author Tomas Johansson, added this method as a refactoring, by extracting code from method 'importFromFile' into this method.
* Fork: https://github.com/TomasJohansson/k-shortest-paths-java-version
*/
protected void SetNumberOfVertices(int numberOfVertices)
{
vertexNum = numberOfVertices;
for (int i = 0; i < vertexNum; ++i)
{
BaseVertex vertex = new Vertex();
vertexList.Add(vertex);
idVertexIndex.Add(vertex.GetId(), vertex);
}
}
