Submission #875911

#	Time	Username	Problem	Language	Result	Execution time	Memory
875911		maxFedorchuk	Exam (eJOI20_exam)	C++14	65 / 100	177 ms	99292 KiB

exam

#include<bits/stdc++.h>
#define FOR(i, begin, end) for(int i=(begin); i<(end); i++)

using namespace std;

const int N=5e3+10, L=28;
int n, a[N], b[N], st[N][L], dp[N][N];

void build()
{
    FOR(i, 1, L)
    {
        for(int j=1; j+(1<<i)-1<=n; j++)
        {
            st[j][i]=max(st[j][i-1], st[j+(1<<(i-1))][i-1]);
        }
    }
}

int get(int l, int r)
{
    int ln=r-l+1;
    int k=0;

    while((1<<(k+1))<=ln)
    {
        k++;
    }

    return max(st[l][k], st[r-(1<<k)+1][k]);
}

int main()
{
    cin >> n;
    FOR(i, 0, n)
    {
        cin >> a[i+1];
        st[i+1][0]=a[i+1];
    }

    FOR(i, 0, n) cin >> b[i+1];

    build();

    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=n;j++)
        {
            if(a[i]==b[j])
            {
                int mx=get(min(i, j), max(i, j));

                if(mx==a[i])
                {
                    dp[i][j]+=max(dp[i][j-1], dp[i-1][j-1])+1;
                }
                else
                {
                    dp[i][j]=max({ dp[i-1][j], dp[i][j-1], dp[i-1][j-1] });
                }
            }
            else
            {
                dp[i][j]=max({ dp[i-1][j], dp[i][j-1] , dp[i-1][j-1] });
            }
        }
    }

    cout << dp[n][n]<<"\n";
    return 0;
}

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