LeetCode 433: Minimum Genetic Mutation | CSharp Solution | BFS Graph Traversal

## 🧬 Problem Overview In this problem, we need to find the minimum number of mutations required to convert a start gene string to an end gene string, where each mutation must result in a valid gene string from the given bank. #leetcode #graphtraversal #bfs #csharp ⏱️ **Time Complexity**: O(L * N), where L is the length of the gene string and N is the size of the bank 🗃️ **Space Complexity**: O(N), where N is the size of the bank ## ⏰ Timestamps 00:00 - Understanding problem statement 02:56 - Optimized solution 05:05 - Dry run 06:57 - Big O Notation calculated 07:56 - C# code walk-through 09:45 - Solution analysis - runtime + memory 09:53 - Conclusion ## 🔑 Key Concepts - Breadth-First Search (BFS) - Graph representation of mutations - String manipulation - Queue-based traversal - Visited set tracking ## 📚 Learning Points - How to model string mutation problems as graph traversal - Efficient BFS implementation in CSharp - Optimizing string comparisons - Managing visited nodes to avoid cycles - Handling edge cases like unreachable targets ## 🔗 Related LeetCode Problems - LeetCode 127: Word Ladder (similar mutation concept) - LeetCode 752: Open the Lock (BFS with state changes) - LeetCode 1091: Shortest Path in Binary Matrix (BFS pathfinding) - LeetCode 139: Word Break (string transformation) ## 👥 Target Audience This video is for intermediate programmers preparing for coding interviews who are familiar with C# and want to deepen their understanding of graph traversal algorithms. ## 📋 Prerequisites - Basic knowledge of C# programming - Understanding of queues and sets - Familiarity with graph concepts - Basic knowledge of breadth-first search ## 🔗 Links - LeetCode problem: https://leetcode.com/problems/minimum-genetic-mutation/ - Solution code: https://leetcode.com/problems/minimum-genetic-mutation/solutions/7080738/breadth-first-search-solution-in-c-with-video-explanation ## 💡 Additional Tips - Pay special attention to how we validate valid mutations using a dictionary for O(1) lookups - This problem has parallels to the famous "word ladder" problem - similar techniques can be applied - Remember to consider the case where no valid mutation path exists ## 🔔 Call to Action If you found this solution helpful, please subscribe to support more content like this! Share your approach and questions in the comments below, and let me know what LeetCode problems you'd like me to cover next. #codinginterviews #algorithms #graphtraversal