Data Structures and Algorithms with Python | Free DSA with Python Course - DSA Python 2025 - Surrounded Regions | Boundary DFS Grid Fill | Leetcode 130 - Part 127 [Hindi]

🚀 Welcome to Part 127 of Code & Debug’s DSA Python Course 2025! In this lecture, we solve Leetcode 130: Surrounded Regions, where we identify and flip all 'O' regions completely surrounded by 'X'. We use a boundary DFS approach to mark safe 'O's and then flip the rest. 📚 What you’ll learn in this video: ✅ Problem explanation with visual intuition of safe vs unsafe 'O' ✅ DFS traversal from all boundary 'O' cells ✅ Tracking visited cells with a matrix ✅ Final flipping logic for the remaining unvisited 'O's ✅ Time and space complexity analysis 💡 Why is this important? This problem is an excellent test of your understanding of grid-based DFS, boundary traversal, and region capture. It strengthens your skills for tackling problems like number of islands, capture surrounded land, and board-based flood fill. 👉 Practice the problem on Leetcode: 🔗 https://leetcode.com/problems/surrounded-regions/ 👉 Refer to the article for better understanding: 📌 https://codeanddebug.in/blog/surrounded-regions-leetcode-130/ 👉 📄 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 🙏 Thank you for supporting Code & Debug! Don’t forget to like, share, and subscribe to our channel. Hit the 🔔 bell icon to stay updated with our latest lectures. #SurroundedRegions #GridDFS #FloodFill #Leetcode130 #MatrixTraversal #RegionCapture #PythonDSA #DSAPythonCourse #CodeAndDebug #DSA2025 #CodingInterviews #Part127