Chapter 14.3, Problem 18E

Hamilton and Euler Circuits In Exercises 15-20, determine whether an Eider circuit, a Hamilton circuit, or neither would solve the problem.

Western Europe The vertices of a graph represent the countries on the continent (Western Europe), and the edges represent border crossings between the countries. A traveler wants to travel over each border crossing exactly once, returning to the first country visited for his flight home to the United States.