The process began with a phone interview, followed by a four-hour interview. During this second interview, I successfully solved the two questions presented to me. Afterward, I was left alone with a final question and no one available for explanations. It wasn't the most pleasant interview, per se.

Implement a virtual file system.

Sort an array with duplicates of 3 different objects, with only one inspection allowed per object.

Sort an array with duplicates of k objects with one inspection per object, O(n).