Counting Inversions in Lists
Year: 2018
Type: article
Abstract: In a recent paper, Ajtai et al. [1] give a streaming algorithm to count the number of inversions in a stream Lε[m]n using two passes and O(ε−1-√n log n(log m + log n)) space. Here, we present a simple randomized streaming algorithm for the same problem that uses one pass and O(ε−3 log2 n log m) space. Our algorithm is based on estimating quantiles of the items already seen in the stream, and using that to estimate the number of inversions involving each element.
DOI: 10.1184/r1/6604550
Authors: Gupta, Anupam, Zane, Francis X.
Language: English
Subfield: Information Systems
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2086366030