Deduplicate Events Preserving First Order | Dataford Interview Questions

Given a list of customer event IDs events in arrival order, return a new list containing only the first occurrence of each event ID. If the same ID appears again later as a late-arriving duplicate, it should be ignored. The output must preserve the order of the first time each distinct event ID appeared.

Constraints

0 <= len(events) <= 10^5
Each event ID is hashable and can be compared for equality
Preserve the order of first occurrence exactly

Function Signature

def deduplicate_events(events):

Your question is Deduplicate Events Preserving First Order. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Constraints

0 <= len(events) <= 10^5
Each event ID is hashable and can be compared for equality
Preserve the order of first occurrence exactly

Function Signature

def deduplicate_events(events):

Your question is Deduplicate Events Preserving First Order. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.