Find Longest Error-Free Session | Dataford Interview Questions

Given a log of user interactions with an AI feature at Amplify HR, write a script to identify the longest session without errors. The input is a chronological list of dictionaries with session_id and boolean error fields. Return [session_id, interaction_count] for the longest session containing no errors. If multiple sessions tie, return the one whose first interaction appears earliest. Return ["", 0] when no error-free session exists.

Constraints

0 <= len(log) <= 10^4
Each interaction is a dictionary with string key session_id and boolean key error
Every interaction belongs to exactly one session
The log is ordered chronologically
If no session is error-free, return ["", 0]

Function Signature

def longest_error_free_session(log):

Your question is Find Longest Error-Free Session. 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(log) <= 10^4
Each interaction is a dictionary with string key session_id and boolean key error
Every interaction belongs to exactly one session
The log is ordered chronologically
If no session is error-free, return ["", 0]

Function Signature

def longest_error_free_session(log):

Your question is Find Longest Error-Free Session. 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.