The eccentricity of a vertex in an unrooted tree is the
Chapter 10, Problem 10.1.39(choose chapter or problem)
The eccentricity of a vertex in an unrooted tree is the length ofthe longest simple path beginning at this vertex. A vertex is called a center if no vertex in the tree has smaller eccentricity than this vertex. In Exercises 39-41 find every vertex that is a center in the given tree.
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