Abstract
We give new algorithms based on Markov chains to sample and approximately count satisfying assignments to k-uniform CNF formulas where each variable appears at most d times. For any k and d satisfying kd < no(1) and k ≥ 20logk + 20logd + 60, the new sampling algorithm runs in close to linear time, and the counting algorithm runs in close to quadratic time.
Our approach is inspired by Moitra (JACM, 2019) which remarkably utilizes the Lovász local lemma in approximate counting. Our main technical contribution is to use the local lemma to bypass the connectivity barrier in traditional Markov chain approaches, which makes the well developed MCMC method applicable on disconnected state spaces such as SAT solutions. The benefit of our approach is to avoid the enumeration of local structures and obtain fixed polynomial running times, even if k = ω(1) or d = ω(1).
Original language | English |
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Title of host publication | Proceedings of the 52nd Annual ACM SIGACT Symposium on Theory of Computing (STOC 2020) |
Publisher | ACM |
Pages | 854-867 |
Number of pages | 14 |
ISBN (Electronic) | 9781450369794 |
DOIs | |
Publication status | Published - 22 Jun 2020 |
Event | 52nd Annual ACM Symposium on Theory of Computing - Virtual conference, United States Duration: 22 Jun 2020 → 26 Jun 2020 http://acm-stoc.org/stoc2020/ |
Conference
Conference | 52nd Annual ACM Symposium on Theory of Computing |
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Abbreviated title | STOC 2020 |
Country/Territory | United States |
City | Virtual conference |
Period | 22/06/20 → 26/06/20 |
Internet address |
Keywords / Materials (for Non-textual outputs)
- Markov chain Monte Carlo
- Lovász local lemma
- k-SAT
- approximate counting