Phone Screen
Questions: Specific question not provided. However, it was a dynamic programming problem related to finding the size of the largest identical binary tree. The candidate mentioned using DP memoization to solve the problem.
Candidate's Approach
The candidate applied dynamic programming with memoization to compute the result of already computed subtrees, successfully solving the problem.
Interviewer's Feedback
No feedback provided.
Onsite Round 1
Questions: Please write a function that takes two rhyme schemes, one short and one long, and, if possible, extends the short one to make them equivalent. Examples:
// ABB ABBBA -> ABBBA // DEE ABBBA -> DEEED // AAB OORRQQ -> AABBCC (or AABBDD, etc.) // ABB OORRQQ has no valid extension
Candidate's Approach
The candidate faced confusion during the interview but managed to code the solution correctly at the last moment, which helped them proceed to the next round.
Interviewer's Feedback
The interviewer ended up giving a "Leaning No Hire" but acknowledged that the candidate coded the problem correctly.
Onsite Round 2
Questions: Given an undirected acyclic graph with each node having at most 3 edges. Given a color list which contains the color of each node where the color of each node can be Black or White. You need to find a root such that:
- It is a valid Binary tree
- It forms an alternating pattern like BWBW or WBWB across levels.
Candidate's Approach
The candidate struggled to find an optimized solution and ended up coding a brute force solution with O(n^2) complexity. Initially, they quickly identified that any node with degree <= 2 could be a valid root for a binary tree after receiving a hint. However, they could not implement the required O(N) solution for the alternating colors problem.
Interviewer's Feedback
The interviewer indicated that the review was not positive and decided on a "No Hire." The candidate's third round did not occur, and the recruiter suggested further preparation before reapplying in six months.