3D DP – Transporter – NPLQ2019

Problem : link
Solution approach: Memorisation
Time complexity: O(n * n * k)
can this be solved in O(n * k * k) ?
I have realized that this can be done in O(n * k * k) after looking into this solution (3D - DP)
@shubham__12 's submission (Time: 0.00) : Solution
Someone, please help me in understanding this solution
Is there any better approach to this problem?
Thanks in advance