Submission #92923

#	Time	Username	Problem	Language	Result	Execution time	Memory
92923		popovicirobert	Hacker (BOI15_hac)	C++14	100 / 100	547 ms	20344 KiB

hac

#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
#define ld long double
// 217
// 44

using namespace std;

const int MAXN = (int) 5e5 + 5;

int arr[MAXN + 1], n;
int pref[MAXN + 1], suff[MAXN + 1];

inline int get(int l, int r) {
    if(l <= 0) {
        return suff[n + l] + pref[r];
    }
    if(r > n) {
        return suff[l] + pref[r - n];
    }
    return pref[r] - pref[l - 1];
}

inline int get(multiset <int> &mst, int x) {
    if(mst.count(x) > 1) {
        return x;
    }
    return *prev(mst.find(x));
}

int main() {
    //ifstream cin("A.in");
    //ofstream cout("A.out");
    int i;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    cin >> n;
    for(i = 1; i <= n; i++) {
        cin >> arr[i];
        pref[i] = pref[i - 1] + arr[i];
    }
    for(i = n; i >= 1; i--) {
        suff[i] = suff[i + 1] + arr[i];
    }
    multiset <int> mst;
    int len = (n + 1) / 2;
    for(i = 1; i <= len; i++) {
        mst.insert(get(i - len + 1, i));
    }
    int ans = *mst.begin();
    for(i = 2; i <= n; i++) {
        mst.erase(mst.find(get(i - 1 - len + 1, i - 1)));
        mst.insert(get(i, i + len - 1));
        ans = max(ans, *mst.begin());
    }
    cout << ans;
    //cin.close();
    //cout.close();
    return 0;
}

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