LeetCode Graph Tips I Actually Reuse

I do better on graph problems when I identify the shape before I write code.

My quick pattern map

• Shortest path with equal edge weights: BFS.
• Weighted shortest path with non-negative edges: Dijkstra.
• Connected groups: DFS, BFS, or Union-Find.
• Topological ordering: Kahn or DFS finishing order.

Small habit that helps

Before writing the solution, I ask one boring question: what is the node, and what exactly creates an edge?

That single sentence usually removes half the confusion.