Comment: Algorithms for computing relative neighbourhood graph
Godfried T. Toussaint · Electronics Letters · 1980
Until recently, no algorithm existed for computing the relative neighbourhood graph of n points on the plane in less than O(n2) worst-case time. Urquhart recently presented an O(n log n) algorithm for solving this problem. In this letter, it is shown that Urquhart's algorithm does not always work and hence finding an O(n log n) algorithm remains an open problem.