제출 #926349

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
926349		Nonoze	Hacker (BOI15_hac)	C++17	100 / 100	42 ms	10328 KiB

hac

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

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>ordered_set;
typedef long long ll;


#define int long long
#define sz(x) (int)(x.size())
#define debug(x) cerr << (#x) << ": " << (x) << endl
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()


int n, k, m;
vector<int> a;

void solve() {
	cin >> n;
	a.clear(), a.resize(n);
	for (auto &u: a) cin >> u;
	vector<int> sum(n, 0);
	int mid=n/2+n%2;
	for (int i=0; i<mid; i++) sum[0]+=a[i];
	for (int i=1; i<n; i++) {
		sum[i]=sum[i-1]+a[(i+mid-1)%n]-a[i-1];
	}
	// priority_queue<int, vector<int>, greater<int>> curr;
	deque<int> curr;
	for (int i=0; i<mid; i++) {
		while (!curr.empty() && sum[curr.front()]>=sum[i]) curr.pop_front();
		curr.push_front(i);
	}
	int ans=0;
	for (int i=mid; i<n+mid; i++) {
		ans=max(ans, sum[curr.back()]);
		while (!curr.empty() && sum[curr.front()]>=sum[i%n]) curr.pop_front();
		if (!curr.empty() && curr.back()==i-mid) curr.pop_back();
		curr.push_front(i%n);
	}
	cout << ans << endl;
	return;
}

signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	int tt=1;// cin >> tt;
	while(tt--) solve();
	return 0;
}

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