Submission #412202

#	Time	Username	Problem	Language	Result	Execution time	Memory
412202		Theo830	Exam (eJOI20_exam)	C++17	65 / 100	235 ms	524292 KiB

exam

#include <bits/stdc++.h>
using namespace std;
typedef int ll;
ll INF = 1e9+7;
ll MOD = 998244353;
typedef pair<ll,ll> ii;
#define iii pair<ii,ll>
#define f(i,a,b) for(ll i = a;i < b;i++)
#define pb push_back
#define vll vector<ll>
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
///I hope I will get uprating and don't make mistakes
///I will never stop programming
///sqrt(-1) Love C++
///Please don't hack me
///@TheofanisOrfanou Theo830
///Think different approaches (bs,dp,greedy,graphs,shortest paths,mst)
///Stay Calm
///Look for special cases
///Beware of overflow and array bounds
///Think the problem backwards
///Training
int main(void){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    ll n;
    cin>>n;
    ll a[n],b[n];
    f(i,0,n){
        cin>>a[i];
    }
    f(i,0,n){
        cin>>b[i];
    }
    ll l[n],r[n];
    priority_queue<ii,vector<ii>,greater<ii> >pq;
    f(i,0,n){
        pq.push(ii(a[i],i));
        while(pq.top().F < a[i]){
            r[pq.top().S] = i-1;
            pq.pop();
        }
    }
    while(!pq.empty()){
        r[pq.top().S] = n-1;
        pq.pop();
    }
    for(ll i=n-1;i >= 0;i--){
        pq.push(ii(a[i],i));
        while(pq.top().F < a[i]){
            l[pq.top().S] = i+1;
            pq.pop();
        }
    }
    while(!pq.empty()){
        l[pq.top().S] = 0;
        pq.pop();
    }
    ll dp[n+1][n+1];
    f(i,0,n+1){
        f(j,0,n+1){
            if(i == 0 || j == 0){
                dp[i][j] = 0;
            }
            else{
                dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
                if(a[i-1] == b[j-1] && (l[i-1] <= j-1 && j-1 <= r[i-1])){
                    dp[i][j] = max(dp[i][j],dp[i][j-1] + 1);
                }
            }
        }
    }
    cout<<dp[n][n]<<endl;
}

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