Submission #1090667

#	Time	Username	Problem	Language	Result	Execution time	Memory
1090667		Nurislam	Global Warming (CEOI18_glo)	C++17	100 / 100	50 ms	8540 KiB

glo

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

#define pb push_back
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define int long long


template <class F, class _S>
bool chmin(F &u, const _S &v){
	bool flag = false;
	if ( u > v ){
		u = v; flag |= true;
	}
	return flag;
}

template <class F, class _S>
bool chmax(F &u, const _S &v){
	bool flag = false;
	if ( u < v ){
		u = v; flag |= true;
	}
	return flag;
}

const int inf = 1e10, N = 2e5+55;
//int mod = 998244353
//int mod = 1000000007;
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//#define rnd(l, r) uniform_int_distribution <int> (l, r)(rng)


void solve(){
	int n, x;
	cin >> n >> x;
	vector<int> a(n);
	for(int &i:a)cin >> i;
	
	vector<int> lis (n+1, inf);
	lis[0] = -inf;
	vector<array<int,2>> at(n+1, {0, -inf});
	
	for(int i = 0; i < n; i++){
		int l = upper_bound(all(lis), a[i] - x) - lis.begin();
		if (lis[l - 1] < a[i] - x) {
			lis[l] = a[i] - x;
			at[i + 1] = {l, a[i] - x};
		}
	}
	int ans = at[n][0];
	lis.assign(n+1, inf);
	lis[0] = -inf;
	for(int i = n-1; i >= 0; i--){
		int l = upper_bound(all(lis), -a[i]) - lis.begin();
		if(lis[l-1] < -a[i]){
			lis[l] = -a[i];
		}
		l = lower_bound(all(lis), -at[i][1]) - lis.begin()-1;
		chmax(ans, at[i][0] + l);
	}
	cout << ans << '\n';
}

 
signed main(){
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	int tt = 1;
	//cin >> tt;
	while(tt--){
		solve();
	}
}
 
 
 
 
 
 
 
 
 
 
 
 
 

• 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