Member-only story
Mastering Graph Algorithms in Java: DFS, BFS, Dijkstra’s, and More

Graphs are fundamental data structures in computer science and are widely used to model complex relationships between entities. They are versatile and can represent a variety of real-world scenarios such as social networks, transportation networks, and computer networks. In this blog post, we’ll delve into some essential graph algorithms implemented in Java, covering Depth-First Search (DFS), Breadth-First Search (BFS), Dijkstra’s Shortest Path Algorithm, detecting cycles in a directed graph, and performing a topological sort.
Understanding Graphs
Before diving into the algorithms, let’s briefly review what graphs are. We know that data arranged linearly is called linear data structures, such as Arrays, LinkedLists, Stacks, and Queues. Whereas, when data is stored non-linearly, it is referred to as non-linear data structures, such as Trees and Graphs. A graph consists of a set of vertices (nodes) and a set of edges (connections) that establish relationships between these vertices. Edges can be directed or undirected, depending on whether they have a specific direction or not. Graphs can also be weighted, where each edge has an associated weight or cost.
A graph can be formally represented as an ordered pair G = (V, E), where: