Submission #1096221

#	Time	Username	Problem	Language	Result	Execution time	Memory
1096221		Niosakaru	Global Warming (CEOI18_glo)	C++11	10 / 100	29 ms	5468 KiB

glo

#include <bits/stdc++.h>

using namespace std;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

#define int long long
#define N 200200

int n , x , l , r , mid , p , rt , a[N] , b[N] , f[N] , g[N];

int bs(int x){
    l = 1 , r = n;
    while (l <= r){
        mid = (l + r) >> 1;
        if (b[mid] <= x) p = mid , r = mid - 1; else l = mid + 1;
    }
    return p;
}

signed main(){
    cin.tie(0)->sync_with_stdio(0);

    cin >> n >> x;
    for (int i = 1 ; i <= n ; i ++) cin >> a[i] , b[i] = 2e9;
    
    for (int i = 1 ; i <= n ; i ++){
        p = lower_bound(b , b + n + 1 , a[i]) - b;
        rt = max(rt,p) , b[p] = a[i];
    }

    if (n <= 1000){
        for (int i = 1 ; i <= n ; i ++){
            f[i] = 1;
            for (int j = 1 ; j < i ; j ++) if (a[j] < a[i]) f[i] = max(f[i],f[j] + 1);
        }
        for (int i = n ; i ; i --){
            g[i] = 1;
            for (int j = i + 1 ; j <= n ; j ++) if (a[i] < a[j]) g[i] = max(g[i],g[j] + 1);
        }
        for (int i = 1 ; i <= n ; i ++){
            for (int j = 1 ; j <= n ; j ++){
                if (j < f[i]) b[j] = 0;
                if (j == f[i]) b[j] = a[i];
                if (j > f[i]) b[j] = 2e9;
            }
            for (int j = i + 1 ; j <= n ; j ++){
                p = lower_bound(b , b + n + 1 , a[j] + x) - b;
                rt = max(rt,p) , b[p] = a[j] + x;
            }
            for (int j = 1 ; j <= n ; j ++){
                if (j < f[i]) b[j] = 0;
                if (j == f[i]) b[j] = a[i];
                if (j > f[i]) b[j] = 2e9;
            }
            for (int j = i + 1 ; j <= n ; j ++){
                p = lower_bound(b , b + n + 1 , a[j] - x) - b;
                rt = max(rt,p) , b[p] = a[j] - x;
            }
        }
        for (int i = n ; i ; i --){
            for (int j = i - 1 ; j ; j --){
                if (j < g[i]) b[j] = 4e9;
                if (j == g[i]) b[j] = a[i];
                if (j > g[i]) b[j] = 0;                
            }
            for (int j = i - 1 ; j ; j --){
                p = bs(a[i] + x);
                rt = max(rt , p) , a[p] = rt;
            }
            for (int j = i - 1 ; j ; j --){
                if (j < g[i]) b[j] = 4e9;
                if (j == g[i]) b[j] = a[i];
                if (j > g[i]) b[j] = 0;                
            }
            for (int j = i - 1 ; j ; j --){
                p = bs(a[i] - x);
                rt = max(rt , p) , a[p] = rt;
            }
        }
    }

    cout << rt;


    return 0;
}

• Subtask 1: 0 / 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