LINE Coding Interview Questions
25 LINE coding interview problems with full optimal solutions — 12 easy, 10 medium, 3 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an LINE interviewer values, and a FAQ section.
Showing 3 problems of 25
- #23hardfoundational
23. Find Median from Data Stream
Support adding numbers to a stream and reporting the running median — LINE uses this to test two-heap thinking, the same shape as their median-latency dashboards for chat delivery.
- #24hardfoundational
24. Sliding Window Maximum
Return the maximum value in every window of size k as it slides across the array — LINE uses this to gauge whether you reach for a monotonic deque, the same primitive behind peak-presence detection.
- #25hardfoundational
25. Sum of Subarray Ranges
Return the sum of (max - min) across every contiguous subarray — LINE uses this to push you past naive O(n^2) and into monotonic-stack contributions for max and min separately.