Submission #971799

#	Time	Username	Problem	Language	Result	Execution time	Memory
971799		fve5	Meetings (IOI18_meetings)	C++17	19 / 100	559 ms	2340 KiB

meetings

#include <bits/stdc++.h>
#include "meetings.h"
using namespace std;

struct Info {
    int len, pref, suff, sub;
    Info(int len, int pref, int suff, int sub) : len(len), pref(pref), suff(suff), sub(sub) { }
    Info(int val) : Info(1, !val, !val, !val) { }
    Info() : Info(1, 0, 0, 0) { }
};

Info merge(const Info &a, const Info &b) {
    return {a.len + b.len, a.pref + (a.pref == a.len) * b.pref , b.suff + (b.suff == b.len) * a.suff, max({a.sub, b.sub, a.suff + b.pref})};
}

struct SegTree {
    vector<Info> arr;
    int s;

    Info query(int l, int r) {
        Info ans_l, ans_r;
        for (l += s, r += s; l < r; l >>= 1, r >>= 1) {
            if (l & 1) ans_l = merge(ans_l, arr[l++]);
            if (r & 1) ans_r = merge(arr[--r], ans_r);
        }
        return merge(ans_l, ans_r);
    }

    SegTree(int N, const vector<int> &a) {
        s = 1 << (int)ceil(log2(N));
        arr.resize(2 * s);

        for (int i = 0; i < N; i++) arr[i + s] = Info(a[i]);
        for (int i = s - 1; i; i--) arr[i] = merge(arr[2 * i], arr[2 * i + 1]);
    }
};

vector<long long> minimum_costs(vector<int> H, vector<int> L, vector<int> R) {
    int N = H.size();
    int Q = L.size();
    
    vector<long long> ans(Q);

    if (Q <= 5000 && N <= 5000) {
        for (int i = 0; i < Q; i++) {
            vector<long long> cost_l(R[i] - L[i] + 2), cost_r(R[i] - L[i] + 2);

            stack<pair<int, int>> st;
            st.emplace(2e9, R[i] - L[i] + 1);
            for (int j = R[i] - L[i]; j >= 0; j--) {
                while (st.top().first <= H[j + L[i]]) st.pop();

                cost_r[j] = cost_r[st.top().second] + (long long)H[j + L[i]] * (st.top().second - j);
                st.emplace(H[j + L[i]], j);
            }

            while (!st.empty()) st.pop();

            st.emplace(2e9, 0);
            for (int j = 0; j <= R[i] - L[i]; j++) {
                while (st.top().first <= H[j + L[i]]) st.pop();

                cost_l[j + 1] = cost_l[st.top().second] + (long long)H[j + L[i]] * (j + 1 - st.top().second);
                st.emplace(H[j + L[i]], j + 1);
            }

            ans[i] = 1e18;
            for (int j = 0; j <= R[i] - L[i]; j++) {
                ans[i] = min(ans[i], cost_l[j + 1] + cost_r[j] - H[j + L[i]]);
            }
        }
    } else {
        SegTree segtree(N, H);
        for (int i = 0; i < Q; i++) {
            ans[i] = R[i] - L[i] + 1 - segtree.query(L[i], R[i] + 1).sub;
        }
    }

    return ans;
}

• Subtask 1: 4 / 4
• Subtask 2: 15 / 15
• Subtask 3: 0 / 17
• Subtask 4: 0 / 24
• Subtask 5: 0 / 40