Submission #926149

#	Time	Username	Problem	Language	Result	Execution time	Memory
926149		Ludissey	Hacker (BOI15_hac)	C++14	100 / 100	46 ms	11092 KiB

hac

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

signed main() {
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
	int n; cin >> n;
    vector<int> v(n*2+(n/2)+1,0);
    vector<int> mx(n*2+(n/2)+1,0);
    int tot=0;
    for (int i = 0; i < n; i++) {
        cin >> v[i];
        tot+=v[i];
    }
    for (int i = 0; i <= n; i++) v[i+n]=v[i];
    for (int i = 0; i < n*2; i++) v[i]+=v[i-1];
    
    int sum=0;
    for (int i = 0; i <= (n-1)/2; i++) sum+=v[i];
    mx[0]=sum;
    int half=((n+1)/2);
    for (int i = 0; i < n*2; i++){
        mx[i]=v[i+half-1]-v[i-1];
    }
    for (int i = 0; i <= n; i++) mx[i+n]=mx[i];
    deque<int> queue;
    for (int i = 0; i < half; i++)
    {
        while(!queue.empty()&&mx[queue.back()]>mx[i]) queue.pop_back();
        queue.push_back(i);
    }
    int outp=mx[queue.front()];
    for (int i = half; i < (n*2); i++)
    {
        if(!queue.empty()&&queue.front()==i-half) queue.pop_front();
        while(!queue.empty()&&mx[queue.back()]>mx[i]) queue.pop_back();
        queue.push_back(i);
        outp=max(mx[queue.front()], outp);
    }
    cout << outp << "\n";
    return 0;
}

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