Submission #465030

#	Time	Username	Problem	Language	Result	Execution time	Memory
465030		JovanB	Hacker (BOI15_hac)	C++17	100 / 100	71 ms	21512 KiB

hac

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

using ll = long long;
using ld = long double;

const int N = 500000;

ll pre[3*N+5];
int a[3*N+5];

deque <pair <int, int>> q;

void ubaci(pair <int, int> x){
    while(!q.empty() && q.back().first >= x.first) q.pop_back();
    q.push_back(x);
}

int main(){
    ios_base::sync_with_stdio(false), cin.tie(0);
    cout.precision(10);
    cout << fixed;

    int n;
    cin >> n;
    for(int i=1; i<=n; i++){
        cin >> a[i];
        a[i+n] = a[i+2*n] = a[i];
    }
    for(int i=1; i<=3*n; i++) pre[i] = pre[i-1] + a[i];
    int k = (n+1)/2;
    for(int j=n+1-k+1; j<=n+1; j++) ubaci({pre[j+k-1] - pre[j-1], j});
    int res = q.front().first;
    for(int i=n+2; i<=2*n; i++){
        ubaci({pre[i+k-1] - pre[i-1], i});
        while(q.front().second < i-k+1) q.pop_front();
        res = max(res, q.front().first);
    }
    cout << res << "\n";
    return 0;
}

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