568. Maximum Vacation Days

class Solution {
    public int maxVacationDays(int[][] flights, int[][] days) {
        int n = flights.length, k = days[0].length;
        int[][] f = new int[k + 1][n];
        for(int i = 0; i < n; i++)
        {
            f[k][i] = days[i][k - 1];    // base case
            flights[i][i] = 1;
        }
        for(int d = k - 1; d >= 1; d--)
        {
            for(int i = 0; i < n; i++)
            {
                for(int j = 0; j < n; j++)
                {
                    if(flights[i][j] == 0) continue;
                    f[d][i] = Math.max(f[d][i], f[d + 1][j] + days[i][d - 1]);
                }
            }
        }
        // for(int[] ff : f) System.out.println(Arrays.toString(ff));
        int max = 0;
        for(int i = 0; i < n; i++)
        {
            if(flights[0][i] == 1) max = Math.max(max, f[1][i]);
        }
        return max;
    }
}