Algorithms 1001 Nights

A thousand tiny steps turn into LC legend!

this repo records each step as a solution so the grind eventually makes you the algorithm sage you’re chasing. Every src/<topic> folder carries a guide plus implementations and Jest specs, letting you move from idea to proof without pausing to hunt for context.

Repository layout

• src/<topic>/<problem-id-name>/: Source, Jest spec, and optional notes for each puzzle (e.g. src/array/189-rotate-array/189.ts).
• src/<topic>/readme.md: Topic playbook that explains the approach for that data structure/question type.
• build/src/...: Generated JavaScript after npm run compile. Never edit the build artifacts directly.
• static/: Diagrams and supporting material such as static/img/binary-tree/review.png.
• Scripts: npm run compile (tsc to build/), npm run test (compile + Jest + lint), npm run lint (gts checks), and npm run fix (auto-format).

Topic guides

• Array patterns
• Binary search tree flow
• Binary tree traversals
• Hash map & counting
• Interval scheduling
• Linked list mechanics
• Matrix simulation
• Sliding window control
• Stack & queue utilities
• String transformations
• Two-pointer drills

Learning workflow

• Pick a problem, open its folder under src/<topic>/<problem-id-name>/, and read the topic guide in src/<topic>/readme.md.
• Implement or update the solution in <id>.ts with the recommended pattern (two pointers, BFS, etc.).
• Keep changes type-safe: npm run compile surfaces TypeScript errors even before running tests.
• When exploring new ideas, capture strategy notes in a local README.md inside the problem folder.

Adding or updating unit tests

1. In src/<topic>/<problem-id-name>/, locate the existing <id>.spec.ts or create a new one beside the solution file.
2. Import the exported function(s) from <id>.ts.
3. Use Jest describe blocks named after the problem and include it cases for happy paths, edge cases, and regressions.
4. Run npm run test -- <pattern> to focus on a single spec or npm run test for the full suite.