wtwolfe@hubcap.clemson.edu (Bill Wolfe) (09/04/89)
Here are some other articles which may be of interest to readers of this group; I probably won't have time to review them, but they do seem to be quite interesting, so here's a brief summary of each: Cascading Divide & Conquer: A Technique For Designing Parallel Algorithms (SIAM Journal on Computing, Vol. 18, No. 3, pp. 499-512, 5/89) This paper presents a number of general techniques for parallel divide-and-conquer which can be applied to any problem solvable by a divide-and-conquer method such that the subproblem merging step can be implemented using a restricted, but powerful, set of operations, which include (i) merging sorted lists, (ii) computing the values of labeling functionf on elements stored in sorted lists, and (iii) changing the identity of elements in a sorted list monotonically. The elements stored in such sorted lists need not belong to a total order, so long as the computation can be specified so that we will never try to compare two incomparable elements. Efficient parallel algorithms are then presented for solving a number of fundamental problems from computational geometry, such as finding maxima in three dimensions; several of these algorithms are optimal in that their time complexity per processor, multiplied by the number of processors, is equal to the sequential lower bound for the problem. New Trie Data Structures Which Support Very Fast Search Operations (Journal of Computer & System Sciences, Vol. 28, No. 3, pp. 379-394, June 1984) A new data structure called the q-fast trie is introduced. Given a set of N records whose keys are distinct nonnegative integers less than some initially specified bound M, a q-fast trie uses space O(N) and time O(square_root(log(M))) for insertions, deletions, and all the retrieval operations commonly associated with binary trees. A simpler but less space efficient data structure called the p-fast trie is defined. Bill Wolfe, wtwolfe@hubcap.clemson.edu