private LinkedList <WeightedAdjacencyNode <T> > MakePath(Graph <T> graph, WeightedAdjacencyNode <T> startingPoint)
{
var path = new LinkedList <WeightedAdjacencyNode <T> >(new [] { startingPoint });
var currentNode = startingPoint.Vertex;
while (true)
{
var nextVertexAdjancencyNode = GetNextVertex(graph, currentNode);
if (nextVertexAdjancencyNode == null)
{
break;
}
path.AddLast(new WeightedAdjacencyNode <T>(nextVertexAdjancencyNode.Vertex, nextVertexAdjancencyNode.Distance, 0, nextVertexAdjancencyNode.MustHit));
graph.ReduceEdgeCardinality(nextVertexAdjancencyNode.Vertex, currentNode);
currentNode = nextVertexAdjancencyNode.Vertex;
}
if (!path.First.Value.Vertex.Equals(path.Last.Value.Vertex))
{
throw new InvalidOperationException(
"Found a path that didn't start/end at same time. This implies that there are vertices with odd edge counts.");
}
return(path);
}
/// <summary>
/// Follow available paths until one returns to the starting point, using each edge at most as many
/// times as its cardinality.
/// </summary>
/// <param name="graph"></param>
/// <param name="startingPoint"></param>
/// <returns></returns>
private LinkedList <WeightedAdjacencyNode <T> > MakePath(Graph <T> graph, T startingPoint)
{
var wan = new WeightedAdjacencyNode <T>(startingPoint, 0, 0, true);
return(MakePath(graph, wan));
}
