1st a) create tree from array . there were 2 more follow up parts which i forgot now sorry . Interviewer was friendly.
2nd phone round . had difficulty in understanding problem. came up with approach using map and storing . Interviewer didnt interact much or might have kept quiet seeing me in gng in other direction.
after interview noticed same problem on leetcode .

https://leetcode.com/problems/bricks-falling-when-hit/

I will try again after cooling period which i think is 6 months.

Good luck all