Source Map — Level 2: Modular Arithmetic¶
এই folder-এর প্রতিটা concept আর problem-এর উৎসের হিসাব। সব Bengali prose, ঘড়ির analogy, diagram আর code এই repo-র জন্য নতুন করে লেখা — কোনো বই/site-এর অনুবাদ বা copy নয়। Problem statement কোথাও copy করা হয়নি; শুধু official link।
| Concept / Problem | Source Type | Source Name | Link | How it is used | Copying status |
|---|---|---|---|---|---|
| Clock model, mod-এর যোগ/গুণ নিয়ম | Common knowledge | Elementary number theory | — | concept-notes.md section 1-2, ঘড়ি/spiral ছবি নিজের | original explanation |
| Negative mod-এর Python vs C++ আচরণ | Common knowledge | Language documentation behavior | — | concept-notes.md section 1 ও common mistakes | original explanation |
| Binary exponentiation | Reference article | CP-Algorithms | https://cp-algorithms.com/algebra/binary-exp.html | Algorithm reference; binary সিঁড়ি ছবি ও dry run নিজের | inspired by source |
| Exponentiation practice | Online judge | CSES Problem Set | https://cses.fi/problemset/task/1095 | Problem 029-এর মূল practice link | official link only |
| Pow(x, n) | Online judge | LeetCode Pow(x, n) | https://leetcode.com/problems/powx-n/ | Problem 030-এর মূল practice link; ব্যাখ্যা নিজের ভাষায় | rewritten problem |
| Modular inverse, Fermat's little theorem | Reference article | CP-Algorithms | https://cp-algorithms.com/algebra/module-inverse.html | Theorem ও inverse-এর reference; জোড়া-খোঁজা ছবি ও প্রমাণ-অনুভব নিজের | inspired by source |
| nCr mod p pipeline (factorial + inverse factorial) | Reference article | CP-Algorithms | https://cp-algorithms.com/combinatorics/binomial-coefficients.html | Problem 034 ও concept-notes section 7-এর reference; pipeline-এর ব্যাখ্যা নিজের | inspired by source |
| Polynomial string hashing | Reference article | CP-Algorithms | https://cp-algorithms.com/string/string-hashing.html | Problem 038-এর reference; fingerprint analogy নিজের | inspired by source |
| Remainder basics, modular add/multiply, large number mod, modular division | Common knowledge | Classic exercises | — | Problem 026-028, 031, 035 — নিজের ভাষায় বানানো অনুশীলনী | original explanation |
| Last digit cyclicity, clock word problems | Common knowledge | Classic exercises | — | Problem 036, 037 — নিজের ভাষায়; cycle টেবিল নিজে বানানো | original explanation |
| কেন 10⁹+7 / 998244353 | Common knowledge | CP folklore / standard practice | — | concept-notes.md section 3-এর আলোচনা | original explanation |
| Extended GCD backward link | This repo | Level 1 folder | ../01-divisibility-prime-gcd-lcm/ | Non-prime mod-এ inverse-এর প্রসঙ্গে রেফার | original explanation |
| nCr forward link | This repo | Level 3 folder | ../03-counting-combinatorics/ | nCr mod p → combinatorics 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 |