DSA Python - Number of Enclaves | Boundary BFS Grid Traversal | Leetcode 1020 - Part 128 [Hindi]

🚀 Welcome to Part 128 of Code & Debug’s DSA Python Course 2025! In this video, we solve Leetcode 1020: Number of Enclaves, where we count all land cells (1) that cannot reach the boundary. We solve this using BFS from boundary land cells and then count unvisited 1s. 📚 What you’ll learn in this video: ✅ What is an enclave and why boundary-connected land must be excluded ✅ BFS from all boundary 1s to mark reachable land ✅ Visited matrix usage to track reachable cells ✅ Final counting logic for unreachable 1s ✅ Time and space complexity analysis 💡 Why is this important? This is a classic problem that enhances your understanding of boundary-based BFS in grids, and builds intuition for related problems like surrounded regions, number of islands, and flood-fill edge protection. Frequently asked in product-based interviews. 👉 Practice the problem on Leetcode: 🔗 https://leetcode.com/problems/number-... 👉 Refer to the article for better understanding: 📌 https://codeanddebug.in/blog/number-o... 👉 📄 Access the full YouTube DSA Playlist Sheet (All Questions in Order): 🔗 https://docs.google.com/spreadsheets/... 👉 Enroll in this FREE DSA Python course here: 🔗 https://codeanddebug.in/course/master... 👉 Enroll for Self-Paced Advanced DSA course here: 🔗 https://codeanddebug.in/course/zero-t... 🙏 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. #NumberOfEnclaves #BoundaryBFS #GridTraversal #Leetcode1020 #EnclaveCount #PythonDSA #DSAPythonCourse #CodeAndDebug #DSA2025 #MatrixProblems #Part128 #CodingInterviews