I got an email for round 1 of interview.
Round-1:
Java:
first he asked me about how strings work in java (about stringpool, why string are immutable), what is pass by object and pass by reference in java
OOPS:
what is polymorphism explain me the run time and compile time polymorphism and some basics on static keyword and other pillars
DSA:
Valid parenthesis question https://leetcode.com/problems/valid-parentheses/description/
Return the first unique character in a given string

Round-2:
Design Round:
Design a Data structure that can perform insert, delete, search and genrate a random number in O(1)-- avg time.(no duplicates)
https://leetcode.com/problems/insert-delete-getrandom-o1/description/
Follow up questions:
If you don't know the Random method in java how would implement it on your own
Now redesign the Data structure such that it will accept duplicates also.