Tip 1 : Prepare DSA well and I personally recommend Coding Ninjas and GeeksForGeeks for interview preparation.
Tip 2 : Be confident & relaxed during the interview.
Tip 3 : Do revise your projects i.e how it works and what are its functionalities.
Tip 1 : Make your resume short and try to make it one page only and mention all your skills that you are confident in.
Tip 2 : Do not put false things on your resume.
Try to use Dynamic programming
By using Memorization Approach
If the input tree is as depicted in the picture:
By using Level Order traversal (BFS)
By Using Priority Queue
Solve this question by using Two Pointers
Interviewer also gave some hints.