Codenation

Role: Internship

College: IIT

Interview Date: 22-08-2020

Interview Type: Internship

Result: Selected

Difficulty: Hard (Coding round had 1 medium, 2 hard questions)

Rounds: 4 rounds

Topics Asked: Data Structures, Algorithms, Resume Projects, Real-life problems, Thought process.

Experience:

This candidate from IIT was selected for a CodeNation internship.

Round 0: Coding Round
This round consisted of 1 medium and 2 hard-level questions. The candidate solved two questions fully. Shortlisting required solving more than 1.5 questions.

Round 1: Phone call (50 minutes)
This round was resume-based. The interviewer asked the candidate to explain one of their projects, covering implementation details, and then posed some real-life problems. The round lasted longer than the expected 20 minutes, emphasizing the importance of showing energy and interest.

Round 2: Data Structure and Algorithm Round
Two questions were asked, requiring proper, neat code and dry runs on test cases.

1. Find the number of permutations of a given array such that adjacent elements' sum is a perfect square. Constraints: N<=12, A[i]<=10^9. (Link provided to LeetCode's Number of Squareful Arrays).
2. Given two numbers A and B, find the number of ways to make sum A from B non-negative integers. Constraints: A<=10^3, B<=10^3. (Hint: Recursive approach O(A*B*B), Iterative Approach O(A*B), Combinatory O(A)). (Link provided to GeeksforGeeks).

The candidate solved both questions with proper code and dry-ran test cases.

Round 3: Final Round (1 hour 15 minutes)
This round was with a friendly interviewer from the USA office. It was purely based on the candidate's thought process, with no coding. It started with a long discussion on projects from the resume, followed by real-life problems that were discussed extensively. The interviewer was noted to be writing down everything the candidate said and clarified every point.

Verdict: Selected.