Video coming soon
We're producing a video walkthrough — check back soon.
What you'll learn
- Reason about time and space complexity of common array operations
- Recognise when a single-pass running-aggregate solves a problem that looks like it needs nested loops
- Apply prefix sums to answer range-sum questions in O(1) after O(n) preprocessing
Arrays are the first data structure most interview problems build on: contiguous memory, O(1) index access, and a set of traversal and two-pointer patterns that reappear across every other topic in this course.
Start by being fluent with single-pass and two-pass traversals, then move on to prefix sums and Kadane-style running aggregates before attempting anything with sorting or extra data structures.