A reasoning language for algorithms, data structures, and proof.
The public Dictionary introduces the core CCF vocabulary. Master DSA members unlock applied examples, Case File references, proof translations, and code-level usage.
Public PreviewA glossary defines words. A reasoning dictionary explains how each concept helps you think, decide, repair, prove, and build correct solutions. In the CCF, terms are not labels to memorize; they are tools for seeing the structure of a problem.
Start with the terms the CCF uses to name reasoning decisions.
See how Intent, Frames, Constraints, Invariants, and Proof connect.
Use case files to practice the language inside real investigations.
Move into membership when you want structured practice and progression.
Name what information is, what must survive, and how lawful movement occurs before choosing a familiar technique.
A container is not a strategy. The same structure can hold original evidence, record facts for later frames, enforce an access law, or represent the answer. CCF classifies tools by the job they perform so selection follows evidence instead of pattern memory.
A data structure defines a form of evidence control. An algorithm defines the lawful procedure that operates on that evidence.
These structures contain the evidence the scanner must inspect.
These structures make relationships—not positions—the primary evidence.
These structures restrict which recorded item may be accessed next.
These preserve facts later frames cannot afford to rediscover.
These maintain enough organization to answer repeated selection, connectivity, or range questions efficiently.
An algorithm defines movement, decisions, repair, or construction. It acts on structures; it is not the structure itself.
| Category | Primary question | Examples |
|---|---|---|
| Evidence Space | Where does the original evidence live? | Array, String, List, Grid |
| Relationship Space | Which relationships define lawful routes? | Tree, Graph, Trie |
| Access Law | Which recorded item may be accessed next? | Stack, Queue, Deque |
| Recorder / Lookup | What fact must survive this frame? | Map, Set, Memo, Cache |
| Optimization / Query | What repeated query must stay efficient? | Heap, Union-Find, Range Trees |
| Algorithm / Procedure | How will the solution move and decide? | Scan, Search, BFS, DP |
The foundational wrapper of a CCF solution. It establishes the identity of the solution and holds every reasoning component added during the Reasoning Pipeline. At the Base layer, only the solution name is defined. No data structure, algorithm, pattern, operation, scanner, recorder, finalizer, or implementation decision is selected at this stage.
Read EntryThe ordered analysis process used to build a solution: Base Container, Answer Space, Problem Space, Decision Space, and Implementation. The Reasoning Pipeline describes how the learner moves through analysis.
Read EntryThe completed reasoning structure produced by the Reasoning Pipeline. Conceptually, Decision Space is stacked on Problem Space, Problem Space on Answer Space, and Answer Space on the Base Container. The Reasoning Pipeline builds the Reasoning Stack.
Read EntryIn a sliding window, the invariant might be that the current window contains no duplicate characters.
Read EntryThe part of an algorithm's reasoning signature that defines what the solution receives, including the inputs, parameters, data structures, values, and constraints that describe the problem.
Read EntryA word, phrase, constraint, guarantee, or relationship inside the Problem Statement that tells the learner what must be returned, what structure is being inspected, which movements are legal, or when failure is allowed.
Read EntryThe part of an algorithm's reasoning signature that defines what the solution must produce, including the output value, return type, shape, and required result.
Read EntryA two-pointer scanner can move inward from both ends of a sorted array.
Read EntryIn Two Sum, a hash map records numbers already seen and their indices.
Read EntryWhen a sliding window contains a duplicate, moving the left pointer repairs the window.
Read EntryAfter collecting a reversed list of characters, finalization may join them into the returned string.
Read EntryFor binary search, proof explains why the discarded half cannot contain the answer.
Read EntryAn array is the Evidence Space Structure in Two Sum.
Read EntryA graph represents cities and the routes connecting them.
Read EntryA queue enforces level-order access during BFS.
Read EntryA hash map records seen values and their indices in Two Sum.
Read EntryBinary search repeatedly eliminates an illegal half of a monotonic search space.
Read EntryMoving the left boundary is a repair operation in a sliding window.
Read EntryStarter members unlock expanded definitions and Case File references for the first 25 investigations.
Master DSA unlocks proof translations, code-level usage, common mistakes, and advanced decision checklists.
The dictionary gives you the language. CCF case files teach you how to apply that language to real algorithm, system, and software design problems.