Need some help in finding why SIGSEGV is occurring in my submission.(TREE2)

My submission
Question

I googled about SIGSEGV and it said that make sure that you aren’t declaring too much memory or accessing an element which is out of bounds. But I can’t see either of that happening in my program(as of now).

Edit - Was thinking about some testcases and came to a conclusion that my older way of solving the problem would give wrong answer at some testcases, made some changes and wrote this instead.
Getting TLE now…

Check the following solution.

Accepted