Abstract

Minimum spanning tree problem is a very important problem in VLSI CAD. Given n points in a plane, a min-imum spanning tree is a set of edges which connects all the points and has a minimum total length. A naive ap-proach enumerates edges on all pairs of points and takes at least R(n2) time. More efficient approaches find a min-imum spanning tree only among edges in the Delaunay triangulation of the points. However, Delaunay triangu-lation is not well defined in rectilinear distance. In this paper, we first establish a framework for minimum span-ning tree construction which is based on a general con-cept of spanning graphs. A spanning graph is a natural definition and not necessarily a Delaunay triangulation. Based on this framework, we then design an O(n log n) sweep-line algorithm to construct a rectilinear minimum spanning tree without using Delaunay triangulation. 1

Citations