Submission #516241

#	Time	Username	Problem	Language	Result	Execution time	Memory
516241		sidon	Hacker (BOI15_hac)	C++17	100 / 100	53 ms	8588 KiB

hac

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

int main() {
	ios::sync_with_stdio(0), cin.tie(0);
	int N; cin >> N;
	int a[N] = {}, b[2*N], pref = 0;
	int x = (N + 1) / 2;

	for(int &i : a) cin >> i;

	for(int i = 0; i - x < N; i++) {
		if(i && i < N) a[i] += a[i-1];
		pref = a[i % N];
		if(i >= N) pref += a[N - 1];
		if(i >= x)
			b[i-x+N] = b[i-x] = pref - a[i-x];
	}

	int *l = a, *r = a, res = 0;

	for(int i = 0; i < 2*N; i++) {
		while(l != r && b[*(r-1)] >= b[i]) --r;
		(*r++) = i;
		while(*l <= i-x) ++l;

		if(i >= x-1) res = max(res, b[*l]);
	}

	cout << res;
}

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