/*
* Recursive descent into subclusters.
*/
private static void flatten(ArrayList<Cluster> flattened, Collection<Cluster> clusters) {
for (Cluster c : clusters) {
flattened.add(c);
final List<Cluster> subclusters = c.getSubclusters();
if (!subclusters.isEmpty()) {
flatten(flattened, subclusters);
}
}
}
/**
* Locate the first cluster that has id equal to <code>id</code>. The search includes all the
* clusters in the input and their sub-clusters. The first cluster with matching identifier is
* returned or <code>null</code> if no such cluster could be found.
*/
public static Cluster find(int id, Collection<Cluster> clusters) {
for (Cluster c : clusters) {
if (c != null) {
if (c.id != null && c.id == id) {
return c;
}
if (!c.getSubclusters().isEmpty()) {
final Cluster sub = find(id, c.getSubclusters());
if (sub != null) {
return sub;
}
}
}
}
return null;
}
/** A recursive routine for collecting unique documents from this cluster and subclusters. */
private static Set<Document> collectAllDocuments(Cluster cluster, Set<Document> docs) {
if (cluster == null) {
return docs;
}
docs.addAll(cluster.getDocuments());
final List<Cluster> subclusters = cluster.getSubclusters();
for (final Cluster subcluster : subclusters) {
collectAllDocuments(subcluster, docs);
}
return docs;
}