Submission #1010959

#	Time	Username	Problem	Language	Result	Execution time	Memory
1010959		LOLOLO	Hacker (BOI15_hac)	C++17	40 / 100	20 ms	7264 KiB

hac

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
 
#define           f     first
#define           s     second
#define           pb    push_back
#define           ep    emplace
#define           eb    emplace_back
#define           lb    lower_bound
#define           ub    upper_bound
#define       all(x)    x.begin(), x.end()
#define      rall(x)    x.rbegin(), x.rend()
#define   uniquev(v)    sort(all(v)), (v).resize(unique(all(v)) - (v).begin())
#define     mem(f,x)    memset(f , x , sizeof(f))
#define        sz(x)    (ll)(x).size()
#define  __lcm(a, b)    (1ll * ((a) / __gcd((a), (b))) * (b))
#define          mxx    *max_element
#define          mnn    *min_element
#define    cntbit(x)    __builtin_popcountll(x)
#define       len(x)    (int)(x.length())
 
const int N = 5e5 + 10;
int a[N], s[N], p[N];

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int n;
    cin >> n;

    int sz = n / 2 + (n % 2);

    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        a[i + n] = a[i];
    }

    for (int i = 1; i <= n * 2; i++) {
        s[i] = s[i - 1] + a[i];
        p[i] = s[i] - s[i - sz];
    }

    deque <int> dq;

    int ans = 0;
    for (int i = n * 2; i >= sz; i--) {
        while (sz(dq) && p[i] < p[dq.back()])
            dq.pop_back();

        dq.push_back(i);

        while (dq.front() - i >= sz)
            dq.pop_front();

        if (i + sz - 1 <= n * 2)
            ans = max(ans, p[dq.front()]);
    }

    cout << ans << '\n';

    return 0;
} 

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 40