DSA in Python – Detect Cycle in Undirected Graph | BFS with Parent Tracking | GFG – Part 124 [Hindi]

🚀 Welcome to Part 124 of Code & Debug’s DSA in Python Course! In this video, we solve the Detect Cycle in an Undirected Graph problem from GeeksforGeeks using Breadth First Search (BFS). We maintain a parent pointer to safely detect cycles during traversal.

📚 What you’ll learn in this video:
✅ Understanding cycles in undirected graphs
✅ How BFS with (node, parent) helps avoid false cycle detection
✅ Building the adjacency list from the edge list
✅ Level-by-level BFS using deque
✅ Time & space complexity analysis

💡 Why is this important?
Cycle detection is a must-know concept in Graph Theory. It lays the groundwork for problems involving graph validation, disjoint sets, spanning trees, and network safety checks. The BFS method with parent tracking is frequently asked in FAANG coding rounds.

👉 Practice the problem on GeeksforGeeks:
🔗 https://www.geeksforgeeks.org/problems/detect-cycle-in-an-undirected-graph/1

👉 Refer to the article for better understanding:
📌 https://codeanddebug.in/blog/detect-cycle-in-an-undirected-graph-using-bfs/

👉 📄 Access the full YouTube DSA Playlist Sheet (All Questions in Order):
🔗 https://docs.google.com/spreadsheets/d/1AWE15Fy3wD2iqu2vjK_R7cCiuvSsjYQclcdZmHpF66o/edit?usp=sharing

👉 Enroll in this FREE DSA Python course here:
🔗 https://codeanddebug.in/course/master-dsa-with-leetcode

👉 Enroll for Self-Paced Advanced DSA course here:
🔗 https://codeanddebug.in/course/zero-to-hero-python-dsa

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