C++ (Cpp) RMQ::query_max Beispiele

Beispiel #1

Datei: suggest.hpp Projekt: Ashwathama/cpp-libface

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;
}