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This paper presents a new deterministic algorithm for decremental maintenance of the transitive closure in a directed graph. The algorithm processes any sequence of edge deletions in <i>O</i>(<i>mn</i>) time and answers queries in constant time. Until now such time bound has only been achieved by a randomized Las Vegas algorithm. In addition to that, a few(More)
Let G = (V, E) be a planar n-vertex digraph. Consider the problem of computing max st-flow values in G from a fixed source s to all sinks t ∈ V \ {s}. We show how to solve this problem in near-linear O(n log 3 n) time. Previously, no better solution was known than running a single-source single-sink max flow algorithm n−1 times, giving a total time bound of(More)
It was experimentally observed that the majority of real-world networks are scale-free and follow power law degree distribution. The aim of this paper is to study the algorithmic complexity of such " typical " networks. The contribution of this work is twofold. First, we define a deterministic condition for checking whether a graph has a power law degree(More)
This article presents a new deterministic algorithm for decremental maintenance of the transitive closure in a directed graph. The algorithm processes any sequence of edge deletions in <i>O</i>(<i>mn</i>) time and answers queries in constant time. Previously, such time bound has only been achieved by a randomized Las Vegas algorithm. In addition to that, a(More)
In this paper we consider the problem of maintaining information about graphs with history -- so called <i>graph timeline</i>. A graph timeline is a sequence of graphs G<sub>1</sub>,..., G<sub>t</sub>, in which consecutive graphs are obtained from previous ones by small modifications, e.g., by adding or removing a single edge. We aim to devise algorithms(More)
We consider two core algorithmic problems for probabilistic verification: the maximal end-component decomposition and the almost-sure reachability set computation for Markov decision processes (MDPs). For MDPs with treewidth k, we present two improved static algorithms for both the problems that run in time O(n · k 2.38 · 2 k) and O(m · log n · k),(More)
In this paper we study the Steiner tree problem over a dynamic set of terminals. We consider the model where we are given an n-vertex graph G=(V,E,w) with positive real edge weights, and our goal is to maintain a tree which is a good approximation of the minimum Steiner tree spanning a terminal set S &#8838; V, which changes over time. The changes applied(More)