Submission #1165728

#	Time	Username	Problem	Language	Result	Execution time	Memory
1165728		altern23	Global Warming (CEOI18_glo)	C++20	100 / 100	44 ms	4936 KiB

glo

#include <bits/stdc++.h>
using namespace std;
 
#define ll long long
#define pii pair<ll, ll>
#define fi first
#define sec second
#define ld long double

const ll N = 1e5;
const ll INF = 4e18;
const ll MOD = 1e9 + 7;

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int tc = 1;
    // cin >> tc;
    for(;tc--;){
        ll n, x; cin >> n >> x;
        vector<ll> a(n + 5);
        for(int i = 1; i <= n; i++) cin >> a[i];

        vector<ll> ps(n + 5);
        vector<ll> dp(n + 5, INF);

        ll ans = 0;
        for(int i = 1; i <= n; i++){
            ll pt = lower_bound(dp.begin(), dp.end(), a[i]) - dp.begin();
            ps[i] = pt + 1;
            ans = max(ans, pt + 1);
            dp[pt] = a[i];
        } 

        for(int i = 0; i <= n; i++) dp[i] = INF;

        for(int i = n; i >= 1; --i){
            ll pt = lower_bound(dp.begin(), dp.end(), -(a[i] - x)) - dp.begin();
            ans = max(ans, ps[i] + pt);
            pt = lower_bound(dp.begin(), dp.end(), -a[i]) - dp.begin();
            dp[pt] = -a[i];
        }

        cout << ans << "\n";
    }   
}

/*

*/ 

• 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