,
Suneel Sarswat
Creative Commons Attribution 4.0 International license
Auctions are widely used in exchanges to match buy and sell requests. Once the buyers and sellers place their requests, the exchange determines how these requests are to be matched. The two most popular objectives used while determining the matching are maximizing volume with dynamic pricing and maximizing volume at a uniform price. In this work, we study the algorithmic complexity of the problems arising from these matching tasks. For dynamic-price matching, we establish a lower bound of Ω(n log n) on the running time, thereby proving that the currently best-known O(n log n) algorithm is time-optimal. In contrast, for uniform-price matching, we present a linear-time algorithm, improving upon previous methods that require O(n log n) time to match n requests.
@InProceedings{garg_et_al:LIPIcs.AFT.2025.25,
author = {Garg, Mohit and Sarswat, Suneel},
title = {{The Exchange Problem}},
booktitle = {7th Conference on Advances in Financial Technologies (AFT 2025)},
pages = {25:1--25:19},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-400-0},
ISSN = {1868-8969},
year = {2025},
volume = {354},
editor = {Avarikioti, Zeta and Christin, Nicolas},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.AFT.2025.25},
URN = {urn:nbn:de:0030-drops-247449},
doi = {10.4230/LIPIcs.AFT.2025.25},
annote = {Keywords: Exchanges, Double Auctions, Matching Algorithms, Element Distinctness, Time Complexity}
}