Algorithm Learning Platform

Why indexing is one calculation, not a search — and what it costs to disturb a contiguous layout.

Why push is amortised O(1), and what the textbook hides behind that word.

How a key turns into an index — and what bookkeeping the rest of the data structure exists to do.

A hash map with the value column thrown away — and one operation that justifies the whole separate API.

Why a string is an array of integers with an encoding rule on top — and where the gap between integers and characters becomes a bug.

A chain of pointers, not a row of slots — and what you actually pay for the cheap splice the textbook keeps promising.