why is the 10th element 4? isn't it 3?

Ummm, I have got my answer accepted and I must tell you that you're right about the value is 3. Well, it's the answer value which is 4. Because 4 is the maximum value among all values up to the 10th index.
i.e.
0 1 1 2 1 3 2 3 1 {4} 3    <----- Respected Values
0 1 2 3 4 5 6 7 8 9 10   <----- INDEX

I hope that helped.
If not ping me. I'll send you my solution.
ping me at my ain't account - id (aquarius_gaurav).
Peace.

Edited by author 21.04.2020 00:36