Find Conflicting Events

SDE II onsite coding. Given a list of events, each with a user name, region name, and timestamp, find conflicting events — pairs that satisfy all three: same user, different region, and timestamp difference below a threshold K. Group by user and scan time-ordered events within a window; the K-threshold and the different-region condition are the discriminating constraints. Requirements Input: a list of events, each with a user, a region, and a timestamp. Two events conflict when all of the following hold: same user, different region, timestamp difference is less than a threshold K. Return the conflicting events (or pairs). Notes Group events by user, then sort each user's events by timestamp; within a user, a sliding window over time bounded by K keeps the comparison local instead of all-pairs. Inside the window, only pairs from different regions count — a user logging repeatedly from the same region is not a conflict. Clarify the output contract up front: distinct conflicting pairs, the set of involved events, or a boolean — the prompt is reported thin on this. Define the K boundary precisely (strictly less than vs. ≤) and confirm whether timestamps can tie. Preparation Implement the group-by-user + time-sorted sliding-window scan and reason about why it beats the naive O(n²) pairwise check. Build a small test with one same-region (non-conflicting) pair and one cross-region in-window pair to validate the region and K conditions.