# Source Map — 09 Graphs

এই folder-এর প্রতিটা idea, link, আর problem reference — তার উৎস আর copying status সহ। এই repo-র problem description গুলো সবসময় আমাদের নিজেদের ভাষায় নতুন করে লেখা; link গুলো official statement-এ নিয়ে যায়।

| Concept / Problem | Source Type | Source Name | Link | How it is used | Copying status |
| --- | --- | --- | --- | --- | --- |
| City road map analogy | Original | This repo | — | concept.md-এর opening analogy | original explanation |
| Adjacency list vs matrix trade-offs | Textbook-common knowledge | Standard CS curriculum; see also Open Data Structures | [উৎস খুলুন](https://opendatastructures.org/) | concept.md-এর memory picture আর table | original explanation |
| BFS algorithm and shortest-path property | Reference write-up | cp-algorithms, Breadth-First Search | [উৎস খুলুন](https://cp-algorithms.com/graph/breadth-first-search.html) | bfs.md-এর background; আমাদের text স্বাধীন | original explanation |
| DFS, colors, entry/exit times | Reference write-up | cp-algorithms, Depth-First Search | [উৎস খুলুন](https://cp-algorithms.com/graph/depth-first-search.html) | dfs.md-এর background; আমাদের text স্বাধীন | original explanation |
| Dijkstra algorithm and proof idea | Reference write-up | cp-algorithms, Dijkstra | [উৎস খুলুন](https://cp-algorithms.com/graph/dijkstra.html) | shortest-path.md-এর background; আমাদের text স্বাধীন | original explanation |
| Topological sort (Kahn + DFS post-order) | Reference write-up | cp-algorithms, Topological Sorting | [উৎস খুলুন](https://cp-algorithms.com/graph/topological-sort.html) | topological-sort.md-এর background; আমাদের text স্বাধীন | original explanation |
| BFS wave / DFS string-in-cave framing | Original | This repo | — | visual-explanation.md-এর frames আর traces | original explanation |
| 0-1 BFS deque idea | Competitive-programming folklore | Covered on cp-algorithms and USACO Guide | [উৎস খুলুন](https://usaco.guide/) | shortest-path.md-এ একটা row + intuition | original explanation |
| Bellman-Ford sketch | Textbook-common knowledge | Standard CS curriculum | [উৎস খুলুন](https://en.wikipedia.org/wiki/Bellman%E2%80%93Ford_algorithm) | shortest-path.md-এর সংক্ষিপ্ত sketch | original explanation |
| Interactive graph animations | Visualizer | VisuAlgo (traversal, SSSP modules) | [উৎস খুলুন](https://visualgo.net/en) | README.md আর visual-explanation.md-এ recommend করা | official link only |
| Number of Islands | Online judge | LeetCode 200 | [উৎস খুলুন](https://leetcode.com/problems/number-of-islands/) | Practice list + dfs.md-এর example | rewritten problem |
| Number of Provinces | Online judge | LeetCode 547 | [উৎস খুলুন](https://leetcode.com/problems/number-of-provinces/) | Practice list; DSU-র দিকে bridge | rewritten problem |
| Rotting Oranges | Online judge | LeetCode 994 | [উৎস খুলুন](https://leetcode.com/problems/rotting-oranges/) | Multi-source BFS-এর example | rewritten problem |
| Clone Graph | Online judge | LeetCode 133 | [উৎস খুলুন](https://leetcode.com/problems/clone-graph/) | Practice list + dfs.md | rewritten problem |
| Course Schedule / Course Schedule II | Online judge | LeetCode 207 / 210 | [উৎস খুলুন](https://leetcode.com/problems/course-schedule/) | Cycle detection + topo sort-এর examples | rewritten problem |
| Flood Fill | Online judge | LeetCode 733 | [উৎস খুলুন](https://leetcode.com/problems/flood-fill/) | dfs.md-এর flood-fill section | rewritten problem |
| 01 Matrix | Online judge | LeetCode 542 | [উৎস খুলুন](https://leetcode.com/problems/01-matrix/) | Multi-source BFS practice | rewritten problem |
| Pacific Atlantic Water Flow | Online judge | LeetCode 417 | [উৎস খুলুন](https://leetcode.com/problems/pacific-atlantic-water-flow/) | Reverse-flood example | rewritten problem |
| Network Delay Time | Online judge | LeetCode 743 | [উৎস খুলুন](https://leetcode.com/problems/network-delay-time/) | Dijkstra practice | rewritten problem |
| Is Graph Bipartite? | Online judge | LeetCode 785 | [উৎস খুলুন](https://leetcode.com/problems/is-graph-bipartite/) | Coloring practice | rewritten problem |
| Word Ladder | Online judge | LeetCode 127 | [উৎস খুলুন](https://leetcode.com/problems/word-ladder/) | Implicit-graph BFS practice | rewritten problem |
| Alien Dictionary | Online judge | LeetCode 269 | [উৎস খুলুন](https://leetcode.com/problems/alien-dictionary/) | Topo-sort modeling practice | rewritten problem |
| Cheapest Flights Within K Stops | Online judge | LeetCode 787 | [উৎস খুলুন](https://leetcode.com/problems/cheapest-flights-within-k-stops/) | Bellman-Ford-flavor practice | rewritten problem |
| Bus Routes | Online judge | LeetCode 815 | [উৎস খুলুন](https://leetcode.com/problems/bus-routes/) | "What are my states?" example | rewritten problem |
| Swim in Rising Water | Online judge | LeetCode 778 | [উৎস খুলুন](https://leetcode.com/problems/swim-in-rising-water/) | Minimax Dijkstra practice | rewritten problem |
| Path With Minimum Effort | Online judge | LeetCode 1631 | [উৎস খুলুন](https://leetcode.com/problems/path-with-minimum-effort/) | Dijkstra-variant pointer | rewritten problem |
| Longest Increasing Path in a Matrix | Online judge | LeetCode 329 | [উৎস খুলুন](https://leetcode.com/problems/longest-increasing-path-in-a-matrix/) | DP-on-DAG teaser pointer | rewritten problem |
| Find Center of Star Graph / Find if Path Exists | Online judge | LeetCode 1791 / 1971 | [উৎস খুলুন](https://leetcode.com/problems/find-center-of-star-graph/) | Practice list-এর easy warm-ups | rewritten problem |
| Shortest Routes I | Online judge | CSES task 1671 | [উৎস খুলুন](https://cses.fi/problemset/task/1671) | CP scale-এ Dijkstra | rewritten problem |
| Building Roads | Online judge | CSES task 1666 | [উৎস খুলুন](https://cses.fi/problemset/task/1666) | Components practice | rewritten problem |
| Labyrinth | Online judge | CSES task 1193 | [উৎস খুলুন](https://cses.fi/problemset/task/1193) | Grid BFS + path reconstruction | rewritten problem |
| Building Teams | Online judge | CSES task 1668 | [উৎস খুলুন](https://cses.fi/problemset/task/1668) | Bipartite coloring practice | rewritten problem |
| Course Schedule (CSES) | Online judge | CSES task 1679 | [উৎস খুলুন](https://cses.fi/problemset/task/1679) | CP scale-এ topo sort | rewritten problem |
| General CP graph ladder | Online judge | Codeforces problemset / USACO Guide | [উৎস খুলুন](https://codeforces.com/problemset/) | CP-connection sections | official link only |