Submission #723790

#	Time	Username	Problem	Language	Result	Execution time	Memory
723790		The_Samurai	Hacker (BOI15_hac)	C++17	100 / 100	377 ms	21576 KiB

hac

#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2")

#include "bits/stdc++.h"

using namespace std;
using ll = long long;
int INF = 2e9;

void solve() {
    int n;
    cin >> n;
    vector<int> a(2 * n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
        a[i + n] = a[i];
    }
    int sum = 0;
    for (int i = 0; i < n / 2; i++) sum += a[i];
    vector<int> range(2 * n);
    range[0] = sum;
    multiset<int, greater<int>> st;
    int all_sum = 0, ans = 0, l = 1, r = 1;
    for (int i = n / 2; i < 2 * n; i++) {
        sum += a[i] - a[i - n / 2];
        range[i - n / 2 + 1] = sum;
        if (i < n) {
            st.insert(sum);
            r = i - n / 2 + 1;
        }
    }
    for (int i = 0; i < n; i++) {
        all_sum += a[i];
    }
    for (int i = 0; i < n; i++) {
        ans = max(ans, all_sum - *st.begin());
        st.erase(st.find(range[l++]));
        st.insert(range[++r]);
    }
    cout << ans;

}

int main() {
    ::srand(::time(0));
    ios_base::sync_with_stdio(false);
    cout.tie(nullptr);
    cin.tie(nullptr);

    int queries = 1;
#ifdef test_cases
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
//    cin >> queries;
#else
    //    cin >> queries;
#endif

    for (int test_case = 1; test_case <= queries; test_case++) {
        solve();
//        cout << '\n';
    }
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 40 / 40