LONGEST COMMON SUBSEQUENCE

//task LONGEST COMMON SUBSEQUENCE

#include <iostream>

using namespace std;

int max(int a, int b)
{
    return a > b ? a : b;
}

int main()
{
    int n_a, n_b;

    cin >> n_a >> n_b;

    int* a = new int[n_a];

    int* b = new int[n_b];

    for (int i = 0; i < n_a; i++)
    {
        cin >> a[i];
    }

    for (int i = 0; i < n_b; i++)
    {
        cin >> b[i];
    }

    int** m = new int*[n_a + 1];

    for (int i = 0; i <= n_a; i++)
    {
        m[i] = new int[n_b + 1];
    }

    for (int i = 0; i <= n_a; i++)
    {
        m[i][0] = 0;
    }

    for (int j = 0; j <= n_b; j++)
    {
        m[0][j] = 0;
    }

    for (int i = 1; i <= n_a; i++)
    {

        for (int j = 1; j <= n_b; j++)
        {

            m[i][j] = max(m[i - 1][j], m[i][j - 1]);

            if (a[i - 1] == b[j - 1])
            {
                m[i][j] = max(m[i][j], m[i - 1][j - 1] + 1);
            }

        }

    }

    cout << m[n_a][n_b];

    return 0;
}