Submission #1060826

#	Time	Username	Problem	Language	Result	Execution time	Memory
1060826		sssamui	Global Warming (CEOI18_glo)	C++17	42 / 100	50 ms	7132 KiB

glo

#include <iostream>
#include <cstdio>
#include <vector>
#include <cmath>
#include <algorithm>
using namespace std;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n, x;
	cin >> n >> x;
	vector<int> t(n);
	for (int i = 0; i < n; i++) cin >> t[i];

	vector<pair<int, int>> pref(n);
	vector<int> lis(0);
	for (int i = 0; i < n; i++)
	{
		if (lis.empty() || (t[i] > lis.back())) pref[i].second = lis.size() + 1;
		else
		{
			int l = lower_bound(lis.begin(), lis.end(), t[i]) - lis.begin();
			pref[i].second = l + 1;
		}

		t[i] -= x;
		if (lis.empty() || (t[i] > lis.back()))
		{
			pref[i].first = lis.size() + 1;
			lis.push_back(t[i]);
		}

		else
		{
			int l = lower_bound(lis.begin(), lis.end(), t[i]) - lis.begin();
			pref[i].first = l + 1;
			lis[l] = t[i];
		}
	}

	for (int i = 0; i < n; i++) t[i] = -t[i];
	vector<pair<int, int>> sfx(n);
	vector<int> lds(0);
	for (int i = n - 1; i > -1; i--)
	{
		if (lds.empty() || (t[i] > lds.back())) sfx[i].second = lds.size() + 1;
		else
		{
			int l = lower_bound(lds.begin(), lds.end(), t[i]) - lds.begin();
			sfx[i].second = l + 1;
		}

		t[i] -= x;
		if (lds.empty() || (t[i] > lds.back()))
		{
			sfx[i].first = lds.size() + 1;
			lds.push_back(t[i]);
		}

		else
		{
			int l = lower_bound(lds.begin(), lds.end(), t[i]) - lds.begin();
			sfx[i].second = l + 1;
			lds[l] = t[i];
		}
	}

	int ans = 2;
	for (int i = 0; i < n; i++) ans = fmax(ans, pref[i].first + sfx[i].second);
	for (int i = 0; i < n; i++) ans = fmax(ans, pref[i].second + sfx[i].first);
	cout << --ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 13
• Subtask 4: 10 / 10
• Subtask 5: 0 / 20
• Subtask 6: 17 / 17
• Subtask 7: 0 / 25