Submission #342557

#	Time	Username	Problem	Language	Result	Execution time	Memory
342557		dimashii	Bigger segments (IZhO19_segments)	C++17	100 / 100	364 ms	44524 KiB

segments

#include <bits/stdc++.h>

#define f first
#define s second

#define fastio ios :: sync_with_stdio(0), cin.tie(0), cout.tie(0);

#define ll long long

using namespace std;

const int mxN = 1e6 + 45, mod = 1e9 + 7;
const ll inf = 2e18 + 43;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

int n, a[mxN], dp[mxN];

ll p[mxN];

set <pair <ll, int> > st;

void add(int idx, ll sum) {
	if (st.empty()) {
		st.insert({sum, idx});
		return;
	}
	auto it = st.lower_bound({sum + 1, 0});
	vector <pair <ll, int> > del;
	while (it != st.end()) del.push_back(*(it++));
	for (auto x : del) st.erase(x);
	st.insert({sum, idx});
}

int get(int idx, ll sum) {
	auto it = st.lower_bound({sum + 1, 0});
	it--;
	return it -> second;
}

int main() {
	fastio;
	cin >> n;
	for (int i = 1; i <= n; ++i) cin >> a[i], p[i] = p[i - 1] + a[i];
	add(0, 0);
	for (int i = 1; i <= n; ++i) {
		int L = get(i, p[i]);
		dp[i] = dp[L] + 1;
		add(i, p[i] * 2 - p[L]);
	}
	cout << dp[n];
	return 0;
}

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