Difference-array

2 articles

dsa8 min read

Car Pooling — Difference Array and Event Sweep for Capacity Checking

Check if a car can complete all trips without exceeding capacity by using a difference array or event-sweep — a clean interval problem with an O(1) space solution that appears at Amazon, Facebook, and Google for testing interval manipulation skills.

March 19, 2026Read →

dsa10 min read

Shifting Letters II — Difference Array vs Segment Tree Range Update Patterns

Apply many range shift operations to a string in O(n + q) using a difference array. The textbook example of when a diff array beats a segment tree, and the canonical interview signal for offline range updates.

March 19, 2026Read →