Adjacency matrix vs adjacency list.

Overview

Adjacency matrix vs adjacency list.

Example 

  Map<Integer, List<Integer>> graph = new HashMap<>();
// Build adjacency list representation

Common Use Cases

  • Network routing
  • Dependency resolution
  • Social graph analysis

Pitfalls to Avoid

  • Stack overflow on deep recursion — use iterative DFS
  • Not handling disconnected graphs
  • BFS vs DFS trade-offs
  • Graph vs Tree

Best Practices

  • Understand when to use graph representation versus simpler alternatives
  • Write unit tests covering edge cases and failure paths
  • Follow Java conventions and prefer standard library APIs when available
  • Profile before optimizing — measure impact in your specific workload