,
Yucheng Fu
,
Minji Yang
,
Anqi Zhang
Creative Commons Attribution 4.0 International license
We study the problem of approximating the total variation distance between two mixtures of product distributions over an n-dimensional discrete domain. Given two mixtures ℙ and ℚ with k₁ and k₂ product distributions over [q]ⁿ, respectively, we give a randomized algorithm that approximates d_TV(ℙ,ℚ) within a multiplicative error of (1±ε) in time poly((nq)^{k₁+k₂}, 1/ε). We also study the special case of mixtures of Boolean subcubes over {0,1}ⁿ. For this class, we give a deterministic algorithm that exactly computes the total variation distance in time poly(n, 2^O(k₁+k₂)), and show that exact computation is #𝖯-hard when k₁+k₂ = Θ(n).
@InProceedings{feng_et_al:LIPIcs.APPROX/RANDOM.2026.51,
author = {Feng, Weiming and Fu, Yucheng and Yang, Minji and Zhang, Anqi},
title = {{On Computing Total Variation Distance Between Mixtures of Product Distributions}},
booktitle = {Approximation, Randomization, and Combinatorial Optimization. Algorithms and Techniques (APPROX/RANDOM 2026)},
pages = {51:1--51:21},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-449-9},
ISSN = {1868-8969},
year = {2026},
volume = {392},
editor = {Singh, Mohit and Gur, Tom},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.APPROX/RANDOM.2026.51},
URN = {urn:nbn:de:0030-drops-277689},
doi = {10.4230/LIPIcs.APPROX/RANDOM.2026.51},
annote = {Keywords: Randomized algorithm, Total variation distance}
}