Submission #1090035

#	Time	Username	Problem	Language	Result	Execution time	Memory
1090035		ssitaram	Global Warming (CEOI18_glo)	C++17	100 / 100	42 ms	5468 KiB

glo

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

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, x; cin >> n >> x;
	vector<int> a(n);
	for (int i = 0; i < n; ++i) cin >> a[i];
	vector<int> d(n + 1, INT32_MAX);
	d[0] = INT32_MIN;
	vector<pair<int, int>> at(n + 1, {0, INT32_MIN});
	for (int i = 0; i < n; ++i) {
		int l = upper_bound(d.begin(), d.end(), a[i] - x) - d.begin();
		if (d[l - 1] < a[i] - x) {
			d[l] = a[i] - x;
			at[i + 1] = {l, a[i] - x};
		}
	}
	int ans = at[n].first;
	d.assign(n + 1, INT32_MAX);
	d[0] = INT32_MIN;
	for (int i = n - 1; i >= 0; --i) {
		int l = upper_bound(d.begin(), d.end(), -a[i]) - d.begin();
		if (d[l - 1] < -a[i]) {
			d[l] = -a[i];
		}
		l = lower_bound(d.begin(), d.end(), -at[i].second) - d.begin() - 1;
		ans = max(ans, at[i].first + l);
	}
	cout << ans << '\n';
	return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 25 / 25