vp_t
suggest(PhraseMap &pm, RMQ &st, std::string prefix, uint_t n = 16) {
pvpi_t phrases = pm.query(prefix);
// cerr<<"Got "<<phrases.second - phrases.first<<" candidate phrases from PhraseMap"<<endl;
uint_t first = phrases.first - pm.repr.begin();
uint_t last = phrases.second - pm.repr.begin();
if (first == last) {
return vp_t();
}
vp_t ret;
--last;
pqpr_t heap;
pui_t best = st.query_max(first, last);
heap.push(PhraseRange(first, last, best.first, best.second));
while (ret.size() < n && !heap.empty()) {
PhraseRange pr = heap.top();
heap.pop();
// cerr<<"Top phrase is at index: "<<pr.index<<endl;
// cerr<<"And is: "<<pm.repr[pr.index].first<<endl;
ret.push_back(pm.repr[pr.index]);
uint_t lower = pr.first;
uint_t upper = pr.index - 1;
// Prevent underflow
if (pr.index - 1 < pr.index && lower <= upper) {
// cerr<<"[1] adding to heap: "<<lower<<", "<<upper<<", "<<best.first<<", "<<best.second<<endl;
best = st.query_max(lower, upper);
heap.push(PhraseRange(lower, upper, best.first, best.second));
}
lower = pr.index + 1;
upper = pr.last;
// Prevent overflow
if (pr.index + 1 > pr.index && lower <= upper) {
// cerr<<"[2] adding to heap: "<<lower<<", "<<upper<<", "<<best.first<<", "<<best.second<<endl;
best = st.query_max(lower, upper);
heap.push(PhraseRange(lower, upper, best.first, best.second));
}
}
return ret;
}
vp_t
naive_suggest(PhraseMap& pm, RMQ& st, std::string prefix, uint_t n = 16) {
pvpi_t phrases = pm.query(prefix);
std::vector<uint_t> indexes;
vp_t ret;
while (phrases.first != phrases.second) {
indexes.push_back(phrases.first - pm.repr.begin());
++phrases.first;
}
while (ret.size() < n && !indexes.empty()) {
uint_t mi = 0;
for (size_t i = 1; i < indexes.size(); ++i) {
if (pm.repr[indexes[i]].weight > pm.repr[indexes[mi]].weight) {
mi = i;
}
}
ret.push_back(pm.repr[indexes[mi]]);
indexes.erase(indexes.begin() + mi);
}
return ret;
}