Decision pages

Patterns library.

37 decision pages and archetype catalogues for the patterns that come up in every coding interview. Each page is a self-contained 2,000–3,000-word guide that names the discriminator, gives a one-line routing rule, and points at the signature problem. Use it when you've classified a problem as "looks like sliding window" but aren't sure whether it wants the fixed or variable form.

Patterns
37
Decision pages
22
Archetype pages
15
Words
91,380
37/ 37

Foundations

3 patterns

Data Structures

4 patterns

Search, Sort, & Selection

4 patterns

Pointers, Window, Prefix

6 patterns

Stack & Queue

3 patterns

Trees & Heaps

6 patterns

Graphs

5 patterns

Dynamic Programming & Backtracking

6 patterns

Decision vs archetype

Decision pages route between cousins (X vs Y vs Z) and name the discriminator that decides. Archetype pages catalogue the canonical forms inside one technique family — the four shapes of sliding window, the three flavours of two-pointer, the five archetypes of monotonic stack.

How to use it

Open the page that matches your hesitation. Read the routing rule first; the discriminator is usually one sentence. The signature problem at the end is the canonical implementation — code it once and the family snaps into focus.

Missing a pattern?

Open an issue "Add pattern: X vs Y" on GitHub. Include a one-paragraph justification — it must come up in real coding interviews and draw a meaningful comparison or catalogue a real archetype family.