Submission #31603

#	Time	Username	Problem	Language	Result	Execution time	Memory
31603		minhtung0404	Hacker (BOI15_hac)	C++14	100 / 100	219 ms	19752 KiB

hac

#include<bits/stdc++.h>
const int N = 5e5 + 5;
using namespace std;

deque <long long> mq;
long long n, a[2*N], sum[2*N], maxx, siz;

int main(){
    cin >> n;
    siz = (n+1)/2;
    for (int i = 1; i <= n; i++) cin >> a[i];
    for (int i = 1; i <= n; i++) a[i+n] = a[i];
    for (int i = 1; i <= siz; i++) sum[1] += a[i];
    for (int i = 2; i <= n; i++) sum[i] = sum[i-1] + a[i-1+siz] - a[i-1];
    for (int i = 1; i <= n; i++) sum[n+i] = sum[i];
    for (int i = 1; i <= 2*n; i++){
        while(mq.size() && sum[mq.front()] >= sum[i]) mq.pop_front();
        mq.push_front(i);
        if (i - mq.back() == siz) mq.pop_back();
        if(i >= siz) maxx = max(sum[mq.back()], maxx);
    }
    cout << maxx;
}

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