/**
* Concatenates the specified GraphWalk to the end of this GraphWalk. This action can only be
* performed if the end vertex of this GraphWalk is the same as the start vertex of the
* extending GraphWalk
*
* @param extension GraphPath used for the concatenation.
* @param walkWeightCalculator Function used to calculate the weight of the GraphWalk obtained
* after the concatenation.
* @return a GraphWalk that represents the concatenation of this object's walk followed by the
* walk specified in the extension argument.
*/
public GraphWalk <V, E> concat(
GraphWalk <V, E> extension, Func <GraphWalk <V, E>, Double> walkWeightCalculator)
{
if (this.isEmpty())
{
throw new ArgumentException("An empty path cannot be extended");
}
if (!this.endVertex.Equals(extension.getStartVertex()))
{
throw new ArgumentException(
"This path can only be extended by another path if the end vertex of the orginal path and the start vertex of the extension are equal.");
}
List <V> concatVertexList = null;
List <E> concatEdgeList = null;
if (vertexList != null)
{
concatVertexList = new List <V>(this.vertexList);
List <V> vertexListExtension = extension.getVertexList();
concatVertexList.AddRange(vertexListExtension.Skip(1));
}
if (edgeList != null)
{
concatEdgeList = new List <E>(this.edgeList);
concatEdgeList.AddRange(extension.getEdgeList());
}
GraphWalk <V, E> gw = new GraphWalk <V, E>(
this.graph, startVertex, extension.getEndVertex(), concatVertexList, concatEdgeList, 0);
gw.setWeight(walkWeightCalculator(gw));
return(gw);
}
public bool Equals(GraphWalk <V, E> o)
{
if (o == null || !(o is GraphWalk <V, E>))
{
return(false);
}
else if (this == o)
{
return(true);
}
GraphWalk <V, E> other = (GraphWalk <V, E>)o;
if (this.isEmpty() && other.isEmpty())
{
return(true);
}
if (!this.startVertex.Equals(other.getStartVertex()) ||
!this.endVertex.Equals(other.getEndVertex()))
{
return(false);
}
// If this path is expressed as a vertex list, we may get away by comparing the other path's
// vertex list
// This only works if its vertexList identifies a unique path in the graph
if (this.edgeList == null && !other.getGraph().getType().isAllowingMultipleEdges())
{
return(this.vertexList.Equals(other.getVertexList()));
}
else // Unlucky, we need to compare the edge lists,
{
return(this.getEdgeList().Equals(other.getEdgeList()));
}
}
