The FAST Algorithm for Submodular Maximization
Pith reviewed 2026-05-24 21:43 UTC · model grok-4.3
The pith
The FAST algorithm achieves an approximation ratio arbitrarily close to 1-1/e for monotone submodular maximization under cardinality constraint k with O(log n log²(log k)) adaptivity and O(n log log k) queries.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
FAST attains an approximation ratio arbitrarily close to 1-1/e for monotone submodular maximization under cardinality constraint k. It does so with O(log(n) log²(log k)) adaptivity and O(n log log(k)) queries in total. The algorithm is designed to be efficient both in its non-asymptotic worst-case query complexity and number of rounds and in its practical runtime, outperforming any algorithm for submodular maximization the authors are aware of on large data sets.
What carries the argument
Fast Adaptive Sequencing Technique (FAST), which sequences adaptive queries to reduce the number of rounds and total function evaluations while preserving the near-optimal approximation guarantee.
Load-bearing premise
The non-asymptotic query and round complexities hold without large hidden constants or implementation overheads that would negate the stated advantages over prior methods.
What would settle it
Running FAST and prior algorithms on a large dataset and measuring that the runtime difference is not orders of magnitude or that actual query counts exceed the claimed O(n log log k) bound by a large factor.
read the original abstract
In this paper we describe a new algorithm called Fast Adaptive Sequencing Technique (FAST) for maximizing a monotone submodular function under a cardinality constraint $k$ whose approximation ratio is arbitrarily close to $1-1/e$, is $O(\log(n) \log^2(\log k))$ adaptive, and uses a total of $O(n \log\log(k))$ queries. Recent algorithms have comparable guarantees in terms of asymptotic worst case analysis, but their actual number of rounds and query complexity depend on very large constants and polynomials in terms of precision and confidence, making them impractical for large data sets. Our main contribution is a design that is extremely efficient both in terms of its non-asymptotic worst case query complexity and number of rounds, and in terms of its practical runtime. We show that this algorithm outperforms any algorithm for submodular maximization we are aware of, including hyper-optimized parallel versions of state-of-the-art serial algorithms, by running experiments on large data sets. These experiments show FAST is orders of magnitude faster than the state-of-the-art.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper introduces the Fast Adaptive Sequencing Technique (FAST) for monotone submodular maximization under a cardinality constraint k. It claims an approximation ratio arbitrarily close to 1-1/e, O(log n log²(log k)) adaptivity, O(n log log k) total queries, and practical runtime outperformance by orders of magnitude over prior algorithms (including hyper-optimized parallel versions) on large datasets, attributing the practicality to small non-asymptotic constants unlike previous methods whose bounds involve large polynomials in precision parameters.
Significance. If the non-asymptotic query/round bounds hold with small leading constants and the experimental speedups are reproducible, the work would be significant for making near-optimal submodular maximization practical at large scale, directly addressing the gap between asymptotic theory and deployable algorithms in the field.
major comments (1)
- [Abstract] Abstract: the central practicality claim rests on FAST having 'extremely efficient' non-asymptotic query and round complexity with constants small enough to yield orders-of-magnitude speedups, yet the abstract supplies no explicit expansion of the O(n log log k) and O(log n log²(log k)) expressions (e.g., dependence on the precision parameter needed for (1-1/e-ε) approximation) that would allow verification that these constants are indeed smaller than the 'very large constants and polynomials' attributed to prior work.
Simulated Author's Rebuttal
We thank the referee for their detailed review and constructive suggestion regarding the abstract. We address the major comment below.
read point-by-point responses
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Referee: [Abstract] Abstract: the central practicality claim rests on FAST having 'extremely efficient' non-asymptotic query and round complexity with constants small enough to yield orders-of-magnitude speedups, yet the abstract supplies no explicit expansion of the O(n log log k) and O(log n log²(log k)) expressions (e.g., dependence on the precision parameter needed for (1-1/e-ε) approximation) that would allow verification that these constants are indeed smaller than the 'very large constants and polynomials' attributed to prior work.
Authors: We agree that the abstract would benefit from greater explicitness on the dependence on the approximation parameter ε to allow direct verification of the non-asymptotic constants. The body of the paper (Theorems 1 and 2, and the analysis in Sections 3–4) provides the full bounds, which incorporate only mild (logarithmic) dependence on 1/ε together with small leading constants that do not grow as large polynomials in the precision parameter. To address the referee’s concern, we will revise the abstract to include a concise statement of this dependence while preserving the high-level asymptotic claims. revision: yes
Circularity Check
No circularity: new algorithmic construction with independent guarantees
full rationale
The paper introduces FAST as a novel algorithm whose approximation ratio, adaptivity, and query complexity are derived from its explicit design and analysis rather than any self-definition, fitted inputs renamed as predictions, or load-bearing self-citations. The abstract and claims present these bounds as consequences of the algorithm's construction, with no equations reducing the stated O(log n log²(log k)) adaptivity or O(n log log k) queries to prior results by the authors. External benchmarks and practical experiments are invoked as independent validation, keeping the central claims self-contained.
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption The objective function is monotone and submodular
discussion (0)
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