Submission #546443

#	Time	Username	Problem	Language	Result	Execution time	Memory
546443		aryan12	Global Warming (CEOI18_glo)	C++17	100 / 100	69 ms	8360 KiB

glo

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

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

void Solve() 
{
	int n, d;
	cin >> n >> d;
	vector<int> a(n + 1);
	for(int i = 1; i <= n; i++)
	{
		cin >> a[i];
	}
	vector<int> dp(n, 1e18);
	dp[0] = a[1];
	vector<int> pref(n + 1, 0);
	pref[1] = 1;
	int ans = 1;
	for(int i = 2; i <= n; i++)
	{
		int pos = lower_bound(dp.begin(), dp.end(), a[i]) - dp.begin();
		pref[i] = pos + 1;
		dp[pos] = a[i];
		ans = max(ans, pos + 1);
	}

	/*for(int i = 1; i <= n; i++)
	{
		cout << pref[i] << " ";
	}
	cout << "\n";*/

	dp = vector<int> (n + 1, 1e18);
	for(int i = n; i > 0; i--)
	{
		//increaseing suffix from 1...i, therefore i+1...n have to be in lds
		int cur_val = -a[i] + d;
		//cout << "cur_val = " << cur_val << "\n";
		int pos = lower_bound(dp.begin(), dp.end(), cur_val) - dp.begin();
		ans = max(ans, pref[i] + pos);
		pos = lower_bound(dp.begin(), dp.end(), cur_val - d) - dp.begin();
		dp[pos] = cur_val - d;
	}
	cout << ans << "\n";
}

int32_t main() 
{
	auto begin = std::chrono::high_resolution_clock::now();
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int t = 1;
	//cin >> t;
	while(t--) 
	{
		Solve();
	}
	auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\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