Submission #833298

#	Time	Username	Problem	Language	Result	Execution time	Memory
833298		vjudge1	Exam (eJOI20_exam)	C++17	0 / 100	3 ms	340 KiB

exam

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

#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
typedef long long ll;
const ll MAXN = 1e5 + 5;
const ll INF = 1e9;
#define endl '\n'
#define pll pair <ll, ll>
#define fi first
#define se second

ll n;
ll a [MAXN], b [MAXN];
ll par [MAXN];
ll dp [MAXN];

ll bpk(ll x){
    if(par[x] == x) return x;
    return par[x] = bpk(par[x]);
}

int main(){
    cin >> n;
    ll cnt2 = 0;
    for(ll i = 1; i <= n; i++){
        cin >> a[i];
        if(a[i-1] < a[i]) cnt2++;
    }
    ll cnt = 0;
    for(ll i = 1; i <= n; i++){
        cin >> b[i];
        if(b[1] == b[i]) cnt++;
    }
    if(cnt == n){
        for(ll i = 1; i <= n; i++){
            par[i] = i;
        }
        a[0] = INF * 2;
        for(ll i = 1; i <= n; i++){
            if(a[i] <= b[1]){
                if(a[i-1] <= b[1]){
                    if(a[i] >= a[i-1]){
                        par[bpk(i-1)] = bpk(i);
                    }
                    else{
                        par[bpk(i)] = bpk(i-1);
                    }
                }
            }
        }
        ll ans = 0;
        for(ll i = 1; i <= n; i++){
            if(a[bpk(i)] == b[1]){
                ans++;
            }
        }
        cout << ans << endl;
        exit(0);
    }
    if(cnt2 == n){
        for(ll i = 1; i <= n; i++){
            for(ll j = i; j <= n; j++){
                if(a[j] > b[i]){
                    par[i] = -1;
                }
                if(a[j] == b[i]){
                    par[i] = j;
                    break;
                }
            }
        }
        for(ll i = n; i >= 1; i--){
            dp[i] = dp[i+1];
            if(par[i] == -1) continue;
            ll tmp = 1;
            for(ll j = i+1; j <= par[i]-1; j++){
                if(par[j] == -1) continue;
                if(par[j] == par[i]) tmp++;
                if(par[j] > par[i]){
                    dp[i] = max(dp[i], tmp+dp[j]);
                }
            }
            // cout << tmp << " " <<par[i] << " " << dp[par[i]] << endl;
            dp[i] = max(dp[i], tmp+dp[par[i]]);
        }
        // for(ll i = 1; i <= n; i++){
        //     cout << dp[i] << " ";
        // }
        // cout << endl;
        cout << dp[1] << endl;
    }
}

• Subtask 1: 0 / 14
• Subtask 2: 0 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 23
• Subtask 5: 0 / 16
• Subtask 6: 0 / 22