How to clone a graph without copying a node twice
5 min read A deep copy of a graph only works if you record each clone the moment you make it, before you ever touch its neighbors. Read article
Coding Interview Questions
Coding Interview Questions
Number of Islands solved three ways, and the follow-ups
7 min read The grid-counting question turns up everywhere from Google to Citadel, and the part that gets scored is the follow-up, not the first solution. Read article
Graphs
Word Ladder: BFS on Implicit Graphs Explained
4 min read Word Ladder (LeetCode 127) is the canonical example of BFS on an implicit graph — the nodes are words, the Read article
Graphs
Clone a Graph: Deep Copy with DFS and BFS
2 min read Clone a Graph (LeetCode 133) is a foundational graph problem that tests your understanding of deep copy vs shallow copy, Read article
Graphs
Number of Islands: Flood Fill Pattern Explained
4 min read Number of Islands (LeetCode 200) is the most common entry-level graph problem in technical interviews. It appears at Google, Amazon, Read article
Graphs
BFS vs DFS: When to Use Each with Examples
5 min read BFS and DFS are the two foundational graph traversal algorithms. Every other graph algorithm — Dijkstra, Bellman-Ford, topological sort, cycle Read article
