Submission #1127558

#	Time	Username	Problem	Language	Result	Execution time	Memory
1127558		khanhphucscratch	Exam (eJOI20_exam)	C++20	65 / 100	760 ms	196832 KiB

exam

//n <= 5000, subtask 1, 3, 5, 6
#include<bits/stdc++.h>
using namespace std;
int dp[5005][5005], pre[5005][5005], a[5005], b[5005];
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n; cin>>n;
    for(int i = 1; i <= n; i++) cin>>a[i];
    for(int i = 1; i <= n; i++) cin>>b[i];
    int curmaxa = 0;
    for(int i = 1; i <= n; i++){
        curmaxa = max(curmaxa, a[i]);
        if(a[i] == curmaxa) dp[0][i] = 0;
        else dp[0][i] = -1e9;
    }
    for(int i = 1; i <= n; i++){
        for(int j = i; j <= n; j++) pre[i][j] = max(pre[i][j-1], a[j]);
    }
    for(int i = 1; i <= n; i++){
        int curbest = 0;
        for(int j = 1; j <= n; j++){
            curbest = max(curbest, dp[i-1][j]);
            dp[i][j] = curbest;
            if(pre[min(i, j)][max(i, j)] > a[j]) dp[i][j] = -1e9;
        }
        //Update b
        for(int j = 1; j <= n; j++) if(b[i] == a[j]) dp[i][j]++;
        //for(int j = 1; j <= n; j++) cout<<i<<" "<<j<<" "<<dp[i][j]<<endl;
    }
    int ans = 0, curmax = 0;
    for(int i = n; i >= 1; i--){
        curmax = max(curmax, a[i]);
        if(a[i] == curmax) ans = max(ans, dp[n][i]);
    }
    cout<<ans;
}

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