Unread Notification Badge Counter | Dataford Interview Questions

Given a list of notification events for a mobile app, return the unread badge count after processing all events. Each event is a list where the first value is the event type: "receive", "read", or "clear". A receive event adds a notification with a unique integer id, a read event marks that id as read if it exists and is unread, and a clear event removes all unread notifications. Return the final unread count as an integer.

Constraints

1 <= len(events) <= 10^5
For receive and read, event format is [type, id] where 0 <= id <= 10^9
For clear, event format is ["clear"]
Notification ids are unique across receive events

Function Signature

def unread_badge_count(events):

Your question is Unread Notification Badge Counter. 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

1 <= len(events) <= 10^5
For receive and read, event format is [type, id] where 0 <= id <= 10^9
For clear, event format is ["clear"]
Notification ids are unique across receive events

Function Signature

def unread_badge_count(events):

Your question is Unread Notification Badge Counter. 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.