/** Remove all Nodes that have no Edges to them (but not <s>) */
protected void removeHangingNodes()
{
foreach (Node n in lattice.getCopyOfNodes())
{
if (lattice.hasNode(n))
{
if (n == lattice.getInitialNode())
{
}
else if (n == lattice.getTerminalNode())
{
}
else
{
if (n.getLeavingEdges().Count == 0 ||
n.getEnteringEdges().Count == 0)
{
lattice.removeNodeAndEdges(n);
removeHangingNodes();
return;
}
}
}
}
}
public List <String> getNbest(int n)
{
lattice.computeNodePosteriors(1.0f);
HashSet <String> result = new HashSet <String>();
BoundedPriorityQueue <NBestPath> queue =
new BoundedPriorityQueue <NBestPath>(n);
queue.add(new NBestPath("<s>", lattice.getInitialNode(), 0, 0));
while (result.Count < n && queue.size() > 0)
{
NBestPath path = queue.poll();
if (path.node.Equals(lattice.terminalNode))
{
result.Add(path.path);
continue;
}
foreach (Edge e in path.node.getLeavingEdges())
{
Node newNode = e.getToNode();
double newForwardScore = path.forwardScore
+ e.getAcousticScore() + e.getLMScore();
double newScore = newForwardScore + newNode.getBackwardScore();
String newPathString = getNewPathString(path, newNode);
NBestPath newPath = new NBestPath(newPathString, newNode, newScore, newForwardScore);
queue.add(newPath);
}
// printQueue(queue);
}
return(result.ToList());
}
/**
* /// Returns true if the given Lattice is equivalent to this Lattice. Two lattices are equivalent if all their nodes
* /// and edges are equivalent.
*
* /// @param other the Lattice to compare this Lattice against
* /// @return true if the Lattices are equivalent; false otherwise
*/
public Boolean isEquivalent(Lattice other)
{
return(checkNodesEquivalent(initialNode, other.getInitialNode()));
}