Topic
Big-O Notation
A way to describe how an algorithm's running time or memory use grows as the input gets larger.
Topic
Arrays
The simplest data structure: a contiguous block of memory with instant access to any element by index.
Topic
Recursion
Solving a problem by having a function call itself on smaller versions of the same problem.
Topic
Linked Lists
A chain of nodes where each element points to the next — trading indexed access for O(1) insertion anywhere you hold a pointer.
Topic
Stacks & Queues
Two restricted lists that power everything from undo history to breadth-first search: last-in-first-out and first-in-first-out.
Topic
Hash Tables
Key → value lookup in O(1) average time, by turning keys into array indexes with a hash function.