A 2-D Parallel Convex Hull Algorithm with Optimal Communication Phases

We investigate the problem of finding the twodimensional convex hull of a set of points on a coarsegrained parallel computer. Recently Goodrich has devised a parallel sorting algorithm for n items on P processors which achieves an optimal number of communication phases for all ranges of P n. Ferreira et al. have recently introduced a deterministic convex hull algorithm with a constant number of communication phases for n and P satisfying n P 1+ . Here we obtain a new parallel 2-D convex hull algorithm with an optimal bound on number of communication phases for all values of P n while maintaining optimal local computation time.