Submission #892496

#	Time	Username	Problem	Language	Result	Execution time	Memory
892496		vjudge1	Discharging (NOI20_discharging)	C++17	100 / 100	111 ms	18624 KiB

Discharging

#include <bits/stdc++.h>
using namespace std;
struct Line {
	mutable long long int k, m, p;
	bool operator<(const Line& o) const { return k > o.k; }
	bool operator<(long long int x) const { return p < x; }
};
struct LineContainer : multiset<Line, less< > > {
	static const long long int inf = LLONG_MAX;
	long long int div(long long int a, long long int b) {
		return a / b - ((a ^ b) < 0 && a % b); }
	bool isect(iterator x, iterator y) {
		if (y == end()) return x->p = inf, 0;
		if (x->k == y->k)
        {
            x->p = x->m < y->m ? inf : -inf;
        }
		else x->p = div(y->m - x->m, x->k - y->k);
		return x->p >= y->p;
	}
	void add(long long int k, long long int m) {
		auto z = insert({k, m, 0}), y = z++, x = y;
		while (isect(y, z)) z = erase(z);
		if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
		while ((y = x) != begin() && (--x)->p >= y->p)
			isect(x, erase(y));
	}
	long long int get(long long int x) {
		assert(!empty());
		auto l = *lower_bound(x);
		return l.k * x + l.m;
	}
} st;
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    long long int n;
    cin >> n;
    vector<pair<long long int, int>> v;
    for (int i = 1; i <= n; i++) {
        int x;
        cin >> x;
        if (v.empty()) {
            v.push_back({x, 1});
        }
        else {
            if (v.back().first < x) v.push_back({x, 1});
            else {
                v[v.size() - 1].second++;
            }
        }
    }
    long long int c = 0, d = 0;
    st.add(0, 0);
    for (auto w : v) {
        c += w.second;
        d = 1ll * w.first * n + st.get(w.first);
        st.add(-c, d);
    }
    cout << d;
}

• Subtask 1: 9 / 9
• Subtask 2: 13 / 13
• Subtask 3: 25 / 25
• Subtask 4: 11 / 11
• Subtask 5: 14 / 14
• Subtask 6: 28 / 28