public List<DoubleList<Split, Integer>> findConflictingSplitCounts(
int threshold, boolean thresholdIsLength) {
findGreedySplits();
List<DoubleList<Split, Integer>> results =
new Vector<DoubleList<Split, Integer>>(greedySplits.size());
// could be more efficient by storing where the greedy splits appear in the sorted list.
for (int i : greedySplitIndex) {
String splitStr = sortedSplits.elementAt(i);
Split split = splits.get(splitStr);
if (!thresholdIsLength && counts.get(splitStr) < threshold)
break; // ignore splits with frequency below threshold
DoubleList<Split, Integer> splitList = new DoubleList<Split, Integer>();
splitList.add(split, counts.get(splitStr));
// Only check splits after this one in sorted list: ones before this one are guaranteed to be
// compatible, else this split would not be in the greedy list.
for (int j = i + 1; j < sortedSplits.size(); j++) {
String otherSplitString = sortedSplits.elementAt(j);
if (!thresholdIsLength && counts.get(otherSplitString) < threshold)
break; // ignore conflicting splits with frequency below threshold
Split otherSplit = splits.get(otherSplitString);
if (!split.compatible(otherSplit)) {
splitList.add(otherSplit, counts.get(otherSplitString));
} // if !compatible
if (thresholdIsLength && splitList.size() == threshold)
break; // have enough secondary splits now
} // for otherSplit (j)
results.add(splitList);
} // for i over sortedSplits
return results;
}
/*
* Does not recalculate if greedySplits are already cached.
*/
private void findGreedySplits() {
if (greedySplits != null) return;
sortSplits();
int nGreedySplits = idg.getIdCount() - 3;
greedySplits = new Vector<Split>(nGreedySplits);
greedySplitIndex = new Vector<Integer>(nGreedySplits);
for (int i = 0; i < sortedSplits.size() && greedySplits.size() < nGreedySplits; i++) {
String splitStr = sortedSplits.elementAt(i);
Split split = splits.get(splitStr);
if (split.compatible(greedySplits)) {
greedySplits.add(split);
greedySplitIndex.add(i);
}
}
}
/*
* Will redo the sort-by-frequency even if it has already been done.
* Clears greedySplits.
*/
private void resortSplits() {
sortedSplits = new Vector<String>(counts.size()); // to be sorted by frequency
for (String splitStr : counts.keySet()) {
sortedSplits.add(splitStr);
}
shuffler.shuffle(sortedSplits);
Collections.sort(sortedSplits, frequencyComparator);
greedySplits = null;
greedySplitIndex = null;
}