Linear Algorithms for Finding the Jordan Center and Path Center of a Tree

This paper contains linear algorithms for finding the Jordan center, the weighted Jordan center and the path center of a tree. All of these algorithms take advantage of an efficient data structure for representing a tree called a canonical recursive representation. As a result, the first two algorithms are different from and faster than similar algorithms in the literature. This paper also defines a new parameter of a graph called the path center, and shows that the path center of a tree T consists of a unique subpath of T.