This post explores the basics of graphs. Specifically, we start by considering what graphs actually are (i.e., as a concept). Then we discuss a variety of ways to represent graphs in code. Then we move on to the two most fundamental graph traversal techniques: breadth-first search (BFS) and depth-first search (DFS).
Learning Tarjan's algorithm for finding the strongly connected components (SCCs) of a directed graph can be rather difficult at first. Many learning materials sketch out the concepts and may even provide pseudocode, but few materials provide fully worked out examples along with working code. This blog post seeks to change that. Example graphs are taken from other quality learning sources (with attribution), but, importantly, working code is provided (in Python) to test Tarjan's algorithm to see the results for yourself.