Open the Lock — BFS on State Space (LeetCode 752)
Open the Lock problem solved with BFS on 4-digit state space. Python solution with deadend handling, bidirectional BFS optimization, and complexity analysis.
·6 min read · #dsa#queues#bfs
#bfs
7 posts · page 1 of 1
Snakes and Ladders BFS — Shortest Path on Game Board (LeetCode 909)
Solve Snakes and Ladders with BFS to find minimum dice rolls. Python solution with 1D-2D conversion, boustrophedon layout, and step-by-step trace.
·7 min read · #dsa#queues#bfs
Word Ladder BFS Approach — Shortest Transformation Sequence
Word Ladder solved with BFS and pattern matching optimization. Step-by-step Python solution for LeetCode 127 with complexity analysis and interview tips.
·6 min read · #dsa#queues#bfs
Graph Traversal Patterns: BFS, DFS, Topological Sort, and Shortest Path
Master graph traversal patterns for LeetCode including BFS, DFS, topological sort, Dijkstra, and practical templates with solutions.
·7 min read · #leetcode#graphs#bfs
Binary Tree Level Order Traversal — Queue Size Snapshot
The queue-with-size BFS pattern, why DFS still works, and how this template extends to zigzag and right-side view.
·5 min read · #dsa#leetcode#trees
Pacific Atlantic Water Flow — Flood Inward From the Borders
Why reverse traversal beats per-cell flood fill, and how the intersection of two reach sets gives the answer.
·7 min read · #dsa#leetcode#graphs
Word Ladder — BFS Over Wildcard-Pattern Buckets
The wildcard-pattern adjacency trick, why BFS is mandatory, and the bidirectional speedup.
·6 min read · #dsa#leetcode#graphs