A Unified Approach for Treewidth and Minimum Fill-in Problems on Bipartite Permutation Graphs

碩士 === 國立東華大學 === 資訊工程學系 === 90 === A graph is chordal if every cycle of length greater than three has a chord. The treewidth (respectively, minimum ll-in) problem is to nd a chordal supergraph with the smallest possible maximum clique size (respectively, the minimum number of additional edges). S...

Full description

Bibliographic Details
Main Authors: Jun-Rong Lin, 林俊榮
Other Authors: Sheng-Lung Peng
Format: Others
Language:en_US
Published: 2002
Online Access:http://ndltd.ncl.edu.tw/handle/48153624534081967324
Description
Summary:碩士 === 國立東華大學 === 資訊工程學系 === 90 === A graph is chordal if every cycle of length greater than three has a chord. The treewidth (respectively, minimum ll-in) problem is to nd a chordal supergraph with the smallest possible maximum clique size (respectively, the minimum number of additional edges). Similarly, the pathwidth (respectively, interval graph completion) problem is to nd a interval supergraph with the smallest possible maximum clique size (respectively, the minimum number of additional edges). Both problems are NPcomplete on general graphs. They remain NP-complete even for cobipartite graphs, bipartite graphs and graphs of clique size at most 9. A bipartite permutation graph is a both bipartite and permutation graph. In this thesis, we present a uni ed approach to compute the treewidth and minimum ll-in on bipartite permutation graphs in linear time. The best previous result is O(n2) where n is the number of vertices in the input graph.