Graph Algorithms the Fun Way

2 NEIGHBORS AND NEIGHBORHOODS

Almost every algorithm in this book requires interacting with a node’s neighbors. The idea of a neighbor is intuitively quite familiar; in an undirected graph, the neighbors of a given node are those nodes with which it shares an edge. The terminology for neighbors is a little more complex in directed graphs, where there are different types of neighbors depending on whether the edge is incoming or outgoing.

Identifying the set of neighbors for a given node is a foundational step in most graph algorithms, such as searching for paths through a new graph, and many real-world tasks. When planning a trip through ...