/**
* Returns an array R of longs such that for each i, j in [0..R.length) i < j implies that the
* formula identified by (int)R[i] in this.hits contributes fewer clauses to the core of the given
* trace than the formula identified by (int)R[j].
*
* @return an array as described above
*/
private long[] sortByRelevance(ResolutionTrace trace, IntSet relevantVars) {
hits.indices().retainAll(relevantVars);
if (hits.get(hits.indices().min()) == null) { // first call, initialize the hits
for (IntIterator varItr = relevantVars.iterator(); varItr.hasNext(); ) {
final int var = varItr.next();
final IntSet varReachable = new IntBitSet(var + 1);
varReachable.add(var);
hits.put(var, varReachable);
}
for (Iterator<Clause> clauseItr = trace.reverseIterator(trace.axioms());
clauseItr.hasNext(); ) {
final Clause clause = clauseItr.next();
final int maxVar = clause.maxVariable();
for (IntSet reachableVars : hits.values()) {
if (reachableVars.contains(maxVar)) {
for (IntIterator lits = clause.literals(); lits.hasNext(); ) {
reachableVars.add(StrictMath.abs(lits.next()));
}
}
}
}
}
final long[] counts = new long[hits.size()];
for (Iterator<Clause> clauseItr = trace.iterator(trace.core()); clauseItr.hasNext(); ) {
final Clause clause = clauseItr.next();
final int maxVar = clause.maxVariable();
int i = 0;
for (IntSet reachableVars : hits.values()) {
if (reachableVars.contains(maxVar)) {
counts[i]++;
}
i++;
}
}
int i = 0;
for (IntIterator varItr = hits.indices().iterator(); varItr.hasNext(); ) {
final int var = varItr.next();
counts[i] = (counts[i] << 32) | var;
i++;
}
Arrays.sort(counts);
return counts;
}
/**
* Returns the set of all integers bound by this Bounds. The returned set does not support the add
* operation. It supports removal iff this is not an unmodifiable Bounds.
*
* @return this.intBounds.TupleSet
*/
public IntSet ints() {
return intbounds.indices();
}
