#adjacency-list

Graph Representation

Introduction Before you can run BFS, DFS, or any other graph algorithm, you need to decide how to store the graph in memory. That choice affects the time and space complexity of every operation you perform on it. There are two standard representations: the adjacency list and the adjacency matrix. This tutorial covers both, when to use each, and how to handle directed, undirected, and weighted graphs. You should be familiar with Graphs Introduction and Arrays before reading this. Read more →

March 31, 2026