Submission #464498

#	Time	Username	Problem	Language	Result	Execution time	Memory
464498		SamAnd	Exam (eJOI20_exam)	C++17	0 / 100	8 ms	3392 KiB

exam

#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define fi first
#define se second
typedef long long ll;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
mt19937 rnf(2106);
const int N = 100005, N0 = 203;

int n;
int a[N], b[N];

int ul[N0], ur[N0];

int maxi[N0][N0];
int ql[N0][N0], qr[N0][N0];

int dp[N0][N0];
int dpl[N0][N0];
int dpr[N0][N0];
void solv0()
{
    for (int i = 1; i <= n; ++i)
    {
        if (a[i] > b[i])
            continue;
        for (int j = i; j >= 1; --j)
        {
            if (a[j] == b[i])
            {
                ul[i] = j;
                break;
            }
            if (a[j] > b[i])
            {
                break;
            }
        }
        for (int j = i; j <= n; ++j)
        {
            if (a[j] == b[i])
            {
                ur[i] = j;
                break;
            }
            if (a[j] > b[i])
            {
                break;
            }
        }
    }

    for (int l = 1; l <= n; ++l)
    {
        maxi[l][l] = l;
        for (int r = l + 1; r <= n; ++r)
        {
            maxi[l][r] = maxi[l][r - 1];
            if (a[r] > a[maxi[l][r]])
                maxi[l][r] = r;
        }
    }

    for (int i = 1; i <= n; ++i)
    {
        for (int j = i; j >= 1; --j)
        {
            qr[j][i] = qr[j + 1][i] + (b[j] == a[i]);
        }
        for (int j = i; j <= n; ++j)
        {
            ql[i][j] = ql[i][j - 1] + (b[j] == a[i]);
        }
    }

    for (int d = 1; d <= n; ++d)
    {
        for (int l = 1; l <= n - d + 1; ++l)
        {
            int r = l + d - 1;
            int m = maxi[l][r];

            dpl[l][m] = max(dpl[l][m], dp[l][m - 1] + (a[m] == b[m]));
            dpr[m][r] = max(dpr[m][r], dp[m + 1][r] + (a[m] == b[m]));
            dpl[l][m] = max(dpl[l][m], qr[l][m]);
            dpr[m][r] = max(dpr[m][r], ql[m][r]);

            dp[l][r] = dpl[l][m] + dpr[m][r] - (a[m] == b[m]);

            if (ul[l - 1])
            {
                dpr[ul[l - 1]][r] = max(dpr[ul[l - 1]][r], ql[ul[l - 1]][l - 1] + dp[l][r]);
            }
            if (ur[r + 1])
            {
                dpl[l][ur[r + 1]] = max(dpl[l][ur[r + 1]], qr[r + 1][ur[r + 1]] + dp[l][r]);
            }
        }
    }

    cout << dp[1][n] << "\n";
}

void solv()
{
    cin >> n;
    for (int i = 1; i <= n; ++i)
        cin >> a[i];
    for (int i = 1; i <= n; ++i)
        cin >> b[i];

    if (n <= 5000)
    {
        solv0();
        return;
    }
}

int main()
{
    #ifdef SOMETHING
    freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    #endif // SOMETHING
    ios_base::sync_with_stdio(false), cin.tie(0);

    int tt = 1;
    //cin >> tt;
    while (tt--)
    {
        solv();
    }
    return 0;
}

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