Faster Fixed Parameter Tractable Algorithms for Finding Feedback Vertex Sets

被引:41
作者
Raman, Venkatesh [1 ]
Saurabh, Saket [1 ]
Subramanian, C. R. [1 ]
机构
[1] Inst Math Sci, Theoret Comp Sci, CIT Campus, Chennai 600113, Tamil Nadu, India
关键词
Feedback vertex set; girth; parameterized complexity;
D O I
10.1145/1159892.1159898
中图分类号
TP301 [理论、方法];
学科分类号
081202 ;
摘要
A feedback vertex set (fvs) of a graph is a set of vertices whose removal results in an acyclic graph. We show that if an undirected graph on n vertices with minimum degree at least 3 has a fvs on at most 1/3n(1-epsilon) vertices, then there is a cycle of length at most 6/epsilon (for epsilon >= 1/2, we can even improve this to just 6). Using this, we obtain a O (( 12 logk/log log + 6)(k) n(omega)) algorithm for testing whether an undirected graph on n vertices has a fvs of size at most k. Here n(omega) is the complexity of the best matrix multiplication algorithm. The previous best parameterized algorithm for this problem took O ((2k + 1)(k) n(2)) time. We also investigate the fixed parameter complexity of weighted feedback vertex set problem in weighted undirected graphs.
引用
收藏
页码:403 / 415
页数:13
相关论文
共 17 条
[11]  
Fomin FV, 2003, SIAM PROC S, P168
[12]  
Guo J, 2005, LECT NOTES COMPUT SC, V3608, P158
[13]   FINDING A MINIMUM CIRCUIT IN A GRAPH [J].
ITAI, A ;
RODEH, M .
SIAM JOURNAL ON COMPUTING, 1978, 7 (04) :413-423
[14]  
Kanj I, 2004, LECT NOTES COMPUT SC, V3162, P235
[15]  
Kanj IA, 2002, LECT NOTES COMPUT SC, V2420, P399
[16]  
Raman V, 2002, LECT NOTES COMPUT SC, V2518, P241
[17]  
RAMAN V., 2005, ELECT NOTES DISCRETE, V19, P273