Module 01 · Entry Point
Arrays & Sequences
The substrate. Contiguous memory, indexing arithmetic, and the first patterns (two pointers and sliding windows) applied on flat data.
Beginner18 min read
Open moduleCurriculum · Nine Modules
A guided path through the canon.
Nine modules, ordered by dependency rather than popularity. Each assumes nothing beyond the previous one; each ends with a concrete problem set. Read front to back, or treat it as a reference; the prerequisites are labelled honestly so you can skip without regret.
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Dynamic Programming
State, transition, base case: the three-part decomposition that turns intractable recursion into polynomial-time algorithms.
Enter module →Module 02The Discipline of Pointers
A linked list is the refusal to hold memory in one piece. Each node is a signpost: a small payload and an arrow pointing to the next signpos…
Module 03Advanced String Manipulation
Strings are arrays with a finite alphabet: usually ASCII, sometimes Unicode, occasionally just {A, C, G, T}. That constraint is a gift. A sm…
Module 04The Algebra of Membership
A hash map is a machine that converts the question 'have I seen this key before?' from a linear search into a constant-time lookup. That sin…
Module 05Recursion as Structural Induction
Trees are the first data structure where recursion stops being a cute control-flow trick and becomes the only natural language. A binary tre…
Module 07The Vocabulary of Relationships
Almost every problem involving connections (cities by roads, people by friendships, pages by links, tasks by dependencies) is a graph proble…
Module 08The Price of Order
Sorting is rarely the goal. Sorting is the <em>preparation</em> that makes the real goal cheap: finding duplicates, computing medians, apply…
Module 09Two Hands on a Number Line
The two-pointer technique and its cousin, the sliding window, are the single most transferable patterns in this curriculum. They appear in a…