It was an on-campus interview.

Round 1: Aptitude, CSE basics (DS, Algo, DBMS), and flowchart test. Total 100 minutes.

Round 2: Technical Round Discussion of C++, Java, and Information Security. Coding questions on sorting and binary trees.

Round 3: Technical An easy system design question, one string substring pattern question, and matrix multiplication.

Round 4: Technical + Managerial Basic managerial questions, one easy coding question, and one coding question on subset sum.

1. Given a sequence of n sorted numbers (n in billions), with numbers ranging from 1 to n. Find the missing and repeating numbers in O(n) time.

2. Check if two trees are identical or not.

3. Design a building system using classes.

4. Given S = "ABCD....Z". Print the substrings in this pattern: A CD GHI MNOP ....

5. From a sequence of numbers, find the numbers which sum up to 320.

There were 2-3 more coding questions, but those were basic.