ABSTRACT
This chapter focuses on the power of graphical representation, illustrated in a number of different contexts. Even though the problems explored may seem unrelated, their commonality is revealed by exhibiting an underlying graph structure. Then we can apply an appropriate solution method to produce an answer to the original problem. Specifically, a number of puzzles can be represented as graphs in which we wish to start at an initial vertex (or state) s and arrive at a desired final vertex (state) t. Finding a path in the graph from vertex s to vertex t then reveals a solution to the puzzle. A breadth-first or depth-first search can aid us in discovering such a path when the underlying graph is large or complex. At times we may wish to find not just any path from s to t, but rather a most efficient (shortest) such path.
