Chapter 3 - Graphs

This section offers a very broad introduction to graphs themselves. We are offered a definition of graphs: a collection of both edges and nodes, where the edges connect the nodes. There are also both directed and undirected graphs. In a directed graph, the edges actually have a tail and a head. The author then walks through various examples of graphs so that we can have a better sense for exactly how and what they represent.

The author then walks through the concept of connectivity. This brings into play the idea of paths between nodes which can be represented as a series of nodes, which are connected by edges. Additionally, there must not always be a finite distance between two nodes.

Following this, the author briefly covers trees, and the role they play in the graphing world. Having just covered heaps in Chapter 2, these seem very similar with some small variations. This section offered a strong introduction to graphs and was both understandable and concise. I would rate the readability of this section at 9/10.