Parallel Priority Queues

This paper introduces the Parallel Priority Queue (PPQ) abstract data type. A PPQ stores a set of integer-valued items and provides operations such as insertion of n new items or deletion of the n smallest ones. Algorithms for realizing PPQ operations on an n-processor CREW-PRAM are based on two new data structures, the n-Bandwidth-Heap (n-H) and the n-Bandwidth-Leftist-Heap (n-L), that are obtained as extensions of the well known sequential binary-heap and leftist-heap, respectively. Using these structures, it is shown that insertion of n new items in a PPQ of m elements can be performed in parallel time O(h + log n), where h = log m n , while deletion of the n smallest items can be performed in time O(h + log log n).