Esempi in C++ (Cpp) per Convex::end

Esempio n. 1

File: ZOJ_3154_Mixed_Juice.cpp Progetto: wujysh/2015_ACM_Summer_Training

Convex convex_hull(Convex a) {
    Convex res(2 * a.size() + 5);
    sort(a.begin(), a.end(), comp_less);
    a.erase(unique(a.begin(), a.end()), a.end());
    int m = 0;
    for (int i = 0; i < a.size(); i++) {
        while (m > 1 && sgn(cross(res[m-1]-res[m-2], a[i]-res[m-2])) <= 0) {
            m--;
        }
        res[m++] = a[i];
    }
    int k = m;
    for (int i = a.size() - 2; i >= 0; i--) {
        while (m > k && sgn(cross(res[m-1]-res[m-2], a[i]-res[m-2])) <= 0) {
            m--;
        }
        res[m++] = a[i];
    }
    res.resize(m);
    if (a.size() > 1) {
        res.resize(m-1);
    }
    return res;
}