Find >n/3 elements in sorted array
Company: TikTok
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: Medium
Interview Round: Technical Screen
Given a sorted array of integers nums of length n, return all values that occur more than floor(n/
3) times. Design an algorithm that runs in O(log n) time and O(
1) extra space. Justify correctness, cover edge cases (e.g., n < 3, runs near boundaries), and provide time/space analysis.
Quick Answer: This question evaluates understanding of algorithm design for sorted arrays, logarithmic-time search under constant-space constraints, frequency analysis for elements exceeding a threshold, and the ability to justify correctness and handle edge cases; it belongs to the Coding & Algorithms domain and emphasizes practical application with conceptual complexity analysis. It is commonly asked to assess proficiency in optimizing time and space complexity, reasoning about boundary conditions (e.g., small n or values near partition thresholds), and providing formal time/space analysis and correctness arguments.