Observations on optimal parallelizations of two-list algorithm

For more than three decades, the very well known and famous two-list Horowitz and Sahni algorithm [3] remains the serial upper-bound for the 0-1 Knapsack problem with n items (KP01) in a time bounded by O(2(n/2)). Recently, Chedid [2] Suggested an optimal parallelization for that algorithm to a KP01 variation - the subset-sum problem - in a PRAM CREW with p = 2(n/8) processors. It is presented here that, in addition to be incomplete, the Chedid result is a particular case given by Sanches et al. [6]. (c) 2009 Elsevier B.V. All rights reserved.