Submission #1165718

#	Time	Username	Problem	Language	Result	Execution time	Memory
1165718		altern23	Global Warming (CEOI18_glo)	C++20	15 / 100	24 ms	9408 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<pii> ps(n + 5), sf(n + 5);
        ps[0] = {0, -INF};
        sf[n + 1] = {0, INF};
        vector<ll> cur;
        for(int i = 1; i <= n; i++){
            if(cur.empty() || cur.back() < a[i] - x){
                cur.push_back(a[i] - x);
            }
            else{
                ll pt = lower_bound(cur.begin(), cur.end(), a[i] - x) - cur.begin();
                if(pt != cur.size()) cur[pt] = a[i] - x;
            }
            ps[i] = {(ll)cur.size(), cur.back()};
        }
        cur.clear();
        for(int i = n; i >= 1; --i){
            if(cur.empty() || cur.back() > a[i]){
                cur.push_back(a[i]);
            }
            else{
                ll pt = lower_bound(cur.begin(), cur.end(), a[i]) - cur.begin();
                if(pt != cur.size()) cur[pt] = a[i];
            }
            sf[i] = {(ll)cur.size(), cur.back()};
        }

        ll ans = ps[n].fi;
        for(int i = 0; i <= n; i++){
            if(ps[i].sec < sf[i + 1].sec) ans = max(ans, ps[i].fi + sf[i + 1].fi);
        }

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

/*

*/ 

• 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