Topics — Problem Mind-Maps

Each subdirectory is one LeetCode-style grouping (arrays-hashing, graphs, dp-1d, …). Inside every problems/ folder you get one markdown file per curated question, named NNN-kebab-title.md.

Concept layer vs problem layer

• Topic index pages (e.g. Arrays & Hashing, Sliding Window) explain the idea and when it applies.
• Pattern cards under Patterns are the recognition layer — cues, invariants, and recipes across companies.
• Individual problem files add full mind-maps: variants, diagrams, solution stories, and senior interview framing.

If you are stuck on why a technique works, stay on the topic index or pattern page until the invariant clicks; only then drill the problem write-ups.

Suggested first pass (concepts before volume)

One possible order that builds dependencies clearly:

1. Arrays & Hashing — indexing, frequency, trade space for time.
2. Two Pointers and Sliding Window — linear scans with invariants.
3. Stack — deferred work and monotonic variants.
4. Linked List and Fast & Slow in Patterns — pointer discipline.
5. Binary Search — monotonic predicates and “search on answer”.
6. Trees, then graphs in the broader topic tree — BFS vs DFS tradeoffs.
7. Heap / Priority Queue — “next best” without full sorting.
8. Dynamic programming and graph topics as your map widens (see Roadmap).

You can deviate anytime; the goal is to reuse the same mental models instead of memorizing isolated tricks.

Layout

topics/<topic>/problems/NNN-title.md

Canonical duplicates

Some numbers appear in multiple rows of the Problem index; only one on-disk file exists:

Validation

From the repository root:

npm run docs:check-dsa

Checks DSA frontmatter and internal .md / .mdx links. After editing canonical source files under content/core-docs/dsa, run:

npm run docs:sync-dsa

This normalizes the source tree and syncs it to content/docs/dsa.

See also: Problem mind-map template, Similar problems map, and Docs visual enrichment workflow.