We devise a deterministic algorithm for minimum Steiner cut, which uses $(\log n)^{O(1)}$ maximum flow calls and additional near-linear time. This algorithm improves on Li and Panigrahi's (FOCS 2020) algorithm, which uses $(\log n)^{O(1/\epsilon^4)}$ maximum flow calls and additional $O(m^{1+\epsilon})$ time, for $\epsilon > 0$. Our algorithm thus shows that deterministic minimum Steiner cut can be solved in maximum flow time up to polylogarithmic factors, given any black-box deterministic maximum flow algorithm. Our main technical contribution is a novel deterministic graph decomposition method for terminal vertices that generalizes all existing $s$-strong partitioning methods, which we believe may have future applications.
翻译:我们设计了一种确定性最小斯坦纳割算法,该算法使用 $(\log n)^{O(1)}$ 次最大流调用及额外的近线性时间。此算法改进了 Li 和 Panigrahi(FOCS 2020)提出的算法,后者需要 $(\log n)^{O(1/\epsilon^4)}$ 次最大流调用及额外的 $O(m^{1+\epsilon})$ 时间(其中 $\epsilon > 0$)。因此,我们的算法表明,在给定任意黑盒确定性最大流算法的前提下,确定性最小斯坦纳割问题可在最大流时间至多多对数因子内求解。我们的主要技术贡献是提出了一种新颖的针对终端顶点的确定性图分解方法,该方法推广了所有现有的 $s$-强划分方法,我们认为该方法可能具有未来的应用前景。