Submission #984564

#	Time	Username	Problem	Language	Result	Execution time	Memory
984564		Acanikolic	Global Warming (CEOI18_glo)	C++14	15 / 100	37 ms	7388 KiB

glo

#include <bits/stdc++.h>

#define int long long

#define pb push_back

#define F first

#define S second

const int N = 500 + 10;

const int inf = 2e9;

const int mod = 998244353;

using namespace std;

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

	int n,x,res = 0;
	cin >> n >> x;
	vector<int>a(n);
	for(int i = 0; i < n; i++) {
		cin >> a[i];
		a[i] -= x;
	}
	vector<pair<int,int>>pref(n);
	vector<int>v;
	for(int i = 0; i < n; i++) {
		if(v.empty() || v.back() < a[i]) {
			v.pb(a[i]);
		}else {
			int lb = lower_bound(v.begin(),v.end(),a[i]) - v.begin();
			v[lb] = a[i];
		}
		pref[i] = {v.back(),v.size()};
	}
	res = pref[n - 1].S;
	for(int i = 0; i < n; i++) a[i] += x;
	vector<int>vec;
	for(int i = n - 1; i > 0; i--) {
		if(vec.empty() || vec.back() > a[i]) {
			vec.pb(a[i]);
		}else {
			if(vec[0] < a[i]) {
				vec[0] = a[i];
				continue;
			}
			int lb = lower_bound(v.begin(),v.end(),a[i],greater<int>()) - v.begin();
			v[lb] = a[i];
		}
		int l = 0,r = i - 1,ans = -1;
		while(l <= r) {
			int mid = (l + r) / 2;
			if(pref[mid].F < vec.back()) {
				ans = mid;
				l = mid + 1;
			}else {
				r = mid - 1;
			}
		}
		res = max(res,(int)vec.size() + (ans != -1 ? pref[ans].S : 0));
	}
	cout << res;
    return 0;
}

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