Easiest Python question got me rejected from FAANG

Here was the prompt:

You have a list [(1,10), (1,12), (2,15),...,(1,18),...] with each (x, y) representing an action, where x is user and y is timestamp.

Given max_actions and time_window, return a set of user_ids that at some point had max_actions or more actions within a time window.

Example: max_actions = 3 and time_window = 10 Actions = [(1,10), (1, 12), (2,25), (1,18), (1,25), (2,35), (1,60)]

Expected: {1} user 1 has actions at 10, 12, 18 which is within time_window = 10 and there are 3 actions.

When I saw this I immediately thought dsa approach. I’ve never seen data recorded like this so I never thought to use a dataframe. I feel like an idiot. At the same time, I feel like it’s an unreasonable gotcha question because in 10+ years never have I seen data recorded in tuples 🙄

Thoughts? Fair play, I’m an idiot, or what