Submission #926362

#	Time	Username	Problem	Language	Result	Execution time	Memory
926362		Ludissey	Hacker (BOI15_hac)	C++14	100 / 100	40 ms	5408 KiB

hac

#include <bits/stdc++.h>

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

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