Submission #582792

#	Time	Username	Problem	Language	Result	Execution time	Memory
582792		Alan	Bigger segments (IZhO19_segments)	C++17	100 / 100	81 ms	20996 KiB

segments

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

ll ps[500005], dp[500005];
const ll inf = 1e9;

int main () {
	ios::ios_base::sync_with_stdio(false);
	cin.tie(0);
	int n;
	cin >> n;
	vector<pair<ll, ll>> st;
	for (int i = 1; i <= n; i++) cin >> ps[i], ps[i] += ps[i-1];
	for (int i = 1; i <= n; i++) {
		auto iter = upper_bound(st.begin(), st.end(), make_pair(ps[i], inf));
		int j = iter == st.begin() ? 0 : (--iter)->second;
		dp[i] = dp[j] + 1;
		ll sum = ps[i]*2 - ps[j];
		while (!st.empty() && sum < st.back().first) st.pop_back();
		st.push_back({sum, i});
	}
	cout << dp[n] << "\n";

	return 0;
}

• Subtask 1: 13 / 13
• Subtask 2: 14 / 14
• Subtask 3: 10 / 10
• Subtask 4: 36 / 36
• Subtask 5: 27 / 27