Lendl Stefan, Woeginger Gerhard, Wulf Lasse
Department of Operations and Information Systems, University of Graz, Graz, Styria Austria.
Department of Computer Science, RWTH Aachen, Aachen, North Rhine-Westphalia Germany.
Algorithmica. 2023;85(3):783-804. doi: 10.1007/s00453-022-01026-7. Epub 2022 Aug 23.
An instance of the non-preemptive tree packing problem consists of an undirected graph together with a weight () for every edge . The goal is to activate every edge for some time interval of length (), such that the activated edges keep connected for the longest possible overall time. We derive a variety of results on this problem. The problem is strongly NP-hard even on graphs of treewidth 2, and it does not allow a polynomial time approximation scheme (unless P=NP). Furthermore, we discuss the performance of a simple greedy algorithm, and we construct and analyze a number of parameterized and exact algorithms.
非抢占式树打包问题的一个实例由一个无向图以及每条边(e)的权重(w(e))组成。目标是在长度为(w(e))的某个时间间隔内激活每条边(e),使得激活的边在尽可能长的总时间内保持图连通。我们得出了关于这个问题的各种结果。即使在树宽为(2)的图上,该问题也是强NP难的,并且它不允许多项式时间近似方案(除非(P = NP))。此外,我们讨论了一种简单贪心算法的性能,并构造和分析了一些参数化算法和精确算法。