approximation and hardness results for label cut and related problems

	approximation and hardness results for label cut and related problems
	Zhang Peng; Cai Jin-Yi; Tang Linqing; Zhao Wenbo
	2009
会议名称	6th Annual Conference on Theory and Applications of Models of Computation, TAMC 2009
会议录名称	Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
页码	460-469
会议日期	43969
会议地点	Changsha, China
出版地	Germany
ISSN	3029743
ISBN	9783642020162
部门归属	(1) School of Computer Science and Technology, Shandong University, Jinan 250101, China; (2) Computer Sciences Department, University of Wisconsin, Madison, WI 53706, United States; (3) State Key Laboratory of Computer Science, Institute of Software, Chinese Academy of Sciences, Beijing 100080, China; (4) Dept. of Computer Science and Engineering, University of California, San Diego, San Diego, CA 92093, United States
摘要	We investigate a natural combinatorial optimization problem called the Label Cut problem. Given an input graph G with a source s and a sink t, the edges of G are classified into different categories, represented by a set of labels. The labels may also have weights. We want to pick a subset of labels of minimum cardinality (or minimum total weight), such that the removal of all edges with these labels disconnects s and t. We give the first non-trivial approximation and hardness results for the Label Cut problem. Firstly, we present an O(√m)-approximation algorithm for the Label Cut problem, where m is the number of edges in the input graph. Secondly, we show that it is NP-hard to approximate Label Cut within 2^log1-1/log ^logc nⁿ for any constant c < 1/2, where n is the input length of the problem. Thirdly, our techniques can be applied to other previously considered optimization problems. In particular we show that the Minimum Label Path problem has the same approximation hardness as that of Label Cut, simultaneously improving and unifying two known hardness results for this problem which were previously the best (but incomparable due to different complexity assumptions). © Springer-Verlag Berlin Heidelberg 2009.
关键词	Approximation Algorithms Combinatorial Optimization Computational Complexity Graph Theory Hardness
主办者	South Central University
语种	英语
内容类型	会议论文
URI标识	http://ir.iscas.ac.cn/handle/311060/8462
专题	基础软件与系统重点实验室
推荐引用方式 GB/T 7714	Zhang Peng,Cai Jin-Yi,Tang Linqing,et al. approximation and hardness results for label cut and related problems[C]. Germany,2009:460-469.