1) program to find height of a binary tree?

Complexity of above program

2) How do you know where the memory leaks when you have multiple files?

3) What are virtual destructors?

4) What should be done when an exception occurs in the constructor?

5) What can be maximum memory that a process can have in 32-bit machine? What assigns a process this memory?

6)Program to find the middle element of a linked list

7)algorithm of O(n) to find first unique element in a string

Ex:

input: abcabd

output:c

I couldnt answer theoretical questions so I wasnt shortlisted for the next round