The first screening interview was with a campus recruiter. Then I was given an online assessment. After passing the assessment, a Skype interview was arranged with a team lead from the company.

The first screening interview touched only on my experience and included a few questions about why I want to work at IMC. The assessment had some basic algorithm/data structure questions. The Skype interview was all technical, focusing on Java basics and a simple algorithm question.

Given a binary tree, a node is visible if the value it holds is no greater than all the values along the path from the root. Write pseudocode for an efficient algorithm to find the number of visible nodes in this tree.

In the Java specification, it is considered good practice to override .equals() and .hashCode() both together. In the context of HashMap, explain why implementing only one of the two instead of both can cause problems. You must consider both cases.