We consider the problem of monotone, submodular maximization over a ground set of size $n$ subject to cardinality constraint $k$. For this problem, we introduce the first deterministic algorithms with linear time complexity; these algorithms are streaming algorithms. Our single-pass algorithm obtains a constant ratio in $\lceil n / c \rceil + c$ oracle queries, for any $c \ge 1$. In addition, we propose a deterministic, multi-pass streaming algorithm with a constant number of passes that achieves nearly the optimal ratio with linear query and time complexities. We prove a lower bound that implies no constant-factor approximation exists using $o(n)$ queries, even if queries to infeasible sets are allowed. An empirical analysis demonstrates that our algorithms require fewer queries (often substantially less than $n$) yet still achieve better objective value than the current state-of-the-art algorithms, including single-pass, multi-pass, and non-streaming algorithms.
翻译:我们考虑的是单调、亚调式最大化在一组地面尺寸为美元,但受最基本限制的美元范围内的问题。 对于这个问题,我们引入了第一个具有线性时间复杂性的确定式算法;这些算法是流式算法。我们的单流算法为任何1美元查询都以美元/c\rceil n/c\rceil + cacle查询获得一个固定比率。此外,我们建议采用一种确定式、多流式算法,以固定数量的通过法,以线性查询和时间复杂性达到接近最佳比率。我们证明一个较低的约束,这意味着没有使用$(n)查询的常态要素近似值,即使允许查询不可行的数据集。一项实证分析表明,我们的算法需要的查询(通常大大低于$)比目前最先进的算法更客观的价值,包括单流式、多传式和非流式算法。