Fast Approximation Algorithm for Non-Monotone DR-submodular Maximization under Size Constraint
Tan D. Tran, Canh V. Pham
TL;DR
This work studies non-monotone DR-submodular maximization on the integer lattice under a size constraint and presents two deterministic near-linear-time algorithms, FastDrSub and FastDrSub+. FastDrSub achieves a constant $0.044$-approximation with $O(n \log k)$ oracle queries, while FastDrSub+ reaches a near $\tfrac{1}{4}$-approximation with $O\left(\frac{n}{\epsilon}\log\left(\frac{1}{\epsilon}\right)\log k\right)$ queries for any $\epsilon>0$, both built on a reduction to standard submodular knapsack optimization. The methods are shown to be efficient in practice, closely competitive with or surpassing state-of-the-art baselines in Revenue Maximization tasks while drastically reducing the number of oracle queries. The algorithms combine a novel two-vector construction with a thresholding/greedy framework, and the experimental results corroborate their practical impact for large-scale DR-submodular problems. Overall, the paper advances deterministic near-linear algorithms for DR-submodular maximization under size constraints and broadens the toolkit for scalable submodular optimization on the integer lattice.
Abstract
This work studies the non-monotone DR-submodular Maximization over a ground set of $n$ subject to a size constraint $k$. We propose two approximation algorithms for solving this problem named FastDrSub and FastDrSub++. FastDrSub offers an approximation ratio of $0.044$ with query complexity of $O(n \log(k))$. The second one, FastDrSub++, improves upon it with a ratio of $1/4-ε$ within query complexity of $(n \log k)$ for an input parameter $ε>0$. Therefore, our proposed algorithms are the first constant-ratio approximation algorithms for the problem with the low complexity of $O(n \log(k))$. Additionally, both algorithms are experimentally evaluated and compared against existing state-of-the-art methods, demonstrating their effectiveness in solving the Revenue Maximization problem with DR-submodular objective function. The experimental results show that our proposed algorithms significantly outperform existing approaches in terms of both query complexity and solution quality.
