Frank Kane's Taming Big Data with Apache Spark and Python

First pass through the graph

So, in our next pass through the graph, we will take our gray node, which was the Hulk, and color it black. This means that we have processed it completely and that we don't have to look at it again. Then we go out to all of its connections and color those connections gray, this means that they need to be expanded upon next. We then increment the distance from the original node by 1:

Zero plus one is one, so we now know that the r and w nodes, whoever they happen to represent, are one degree of separation from the Hulk, the s node.