Citadel–styleSoftware EngineerSoftware EngineerQuestion #4

Given an array representing a sequence of user events (where each element is a user ID), find the length of the longest contiguous subarray where the most frequent user's frequency within the subarray equals the minimum frequency of any user in the entire event log. Implement an efficient function to return this maximum length.

Build Your Approach

State the assumptions, try a simple case, then work toward a general solution. Check the result and explain how it changes if an assumption changes.

Try the free diagnostic with worked solutions →

Get Free Interview Prep Resources

Practice the Reasoning Behind the Answer

Bring your target roles and interview timeline to a free quant consult. Discuss your preparation priorities and how Quant Blueprint’s lessons, practice and mock interviews can help.

Book a Free Quant Consult

Your goals · your preparation · your next steps