Minimum Weight Pseudo-Triangulations

We consider the problem of computing a minimum weight pseudo-triangulation of a set S of n points in the plane. We first present an O(n log n)-time algorithm that produces a pseudo-triangulation of weight O(wt(M(S)) · log n) which is shown to be asymptotically worstcase optimal, i.e., there exists a point set S for which every pseudotriangulation has weight Ω(log n · wt(M(S))), where wt(M(S)) is the weight of a minimum spanning tree of S. We also present a constant factor approximation algorithm running in cubic time. In the process we give an algorithm that produces a minimum weight pseudo-triangulation of a simple polygon.