Source Map — Level 9: Geometry & Coordinate Math¶
এই folder-এর প্রতিটা concept আর problem-এর উৎসের হিসাব। সব Bengali prose, diagram আর code এই repo-র জন্য নতুন করে লেখা — বাইরের কোনো লেখার অনুবাদ বা copy নয়। Problem statement কোথাও copy করা হয়নি; শুধু official link দেওয়া আছে।
| Concept / Problem | Source Type | Source Name | Link | How it is used | Copying status |
|---|---|---|---|---|---|
| Point as vector, squared distance, cross multiplication | Common knowledge | Standard coordinate geometry | — | concept-notes.md section 1-3; analogy ও dry run নিজের | original explanation |
| Distance Between Points (113), Slope and Collinearity (114), Area of Triangle (115), Circle and Point (119) | Common knowledge | Classic exercises | — | নিজের ভাষায় বানানো অনুশীলনী | original explanation |
| Orientation of Three Points (116) | Reference site | CP-Algorithms Oriented area of a triangle | https://cp-algorithms.com/geometry/oriented-triangle-area.html | Problem 116-এর reference; ব্যাখ্যা ও ছবি নিজের | inspired by source |
| Line Intersection Basic (117) | Reference site | CP-Algorithms geometry section | https://cp-algorithms.com/ | Problem 117-এর reference; orientation-test কাঠামো নিজের ভাষায় | inspired by source |
| Rectangle Overlap (118) | Online judge | LeetCode Rectangle Overlap | https://leetcode.com/problems/rectangle-overlap/ | Problem 118-এর practice link; negation trick ব্যাখ্যা নিজের | official link only |
| Convex Hull Intro (120) | Reference site | CP-Algorithms Convex Hull | https://cp-algorithms.com/geometry/convex-hull.html | Problem 120-এর algorithm reference; rubber band analogy নিজের | inspired by source |
| Convex Hull Intro (120, practice) | Online judge | CSES Convex Hull | https://cses.fi/problemset/task/2195 | Problem 120-এর practice link | official link only |
| Manhattan Distance Tricks (121) | Common knowledge | Classic CP trick (45° rotation) | — | নিজের ভাষায় ব্যাখ্যা ও verify | original explanation |
| Rotate Matrix and Coordinates (122) | Online judge | LeetCode Rotate Image | https://leetcode.com/problems/rotate-image/ | Problem 122-এর practice link; coordinate map নিজের | official link only |
| Grid Movement Math (123) | Common knowledge | Classic exercise | — | parity reachability নিজের ভাষায়; level 0 cross-reference | original explanation |
| Pick's Theorem Intro (124) | Reference site | CP-Algorithms Pick's theorem | https://cp-algorithms.com/geometry/picks-theorem.html | Problem 124-এর reference; teaser উদাহরণ নিজের | inspired by source |
| Shoelace formula | Common knowledge | Standard computational geometry | — | concept-notes.md section 5; rectangle dry run নিজের | original explanation |
| Rubber band / steering / taxi analogies | This repo | concept-notes.md, visualization-ideas.md | ./concept-notes.md | শেখানোর নিজস্ব framing | original explanation |
| Graphs forward link | This repo | Graphs folder (grid BFS) | ../../09-graphs/ | coordinate দক্ষতা কোথায় লাগবে — cross-reference | original explanation |
| Problem note template | This repo | math-problem-note-template.md | ../../templates/math-problem-note-template.md | problems/README.md থেকে রেফার করা | original explanation |