A new algorithm for on-line coloring bipartite graphs

Haitze J. Broersma, A. Capponi, Daniël Paulusma

Research output: Contribution to journalArticleAcademicpeer-review

13 Citations (Scopus)


We first show that for any bipartite graph $H$ with at most five vertices there exists an on-line competitive algorithm for the class of $H$-free bipartite graphs. We then analyze the performance of an on-line algorithm for coloring bipartite graphs on various subfamilies. The algorithm yields new upper bounds for the on-line chromatic number of bipartite graphs. We prove that the algorithm is on-line competitive for $P_7$-free bipartite graphs, i.e., that do not contain an induced path on seven vertices. The number of colors used by the on-line algorithm for $P_6$-free and $P_7$-free bipartite graphs is, respectively, bounded by roughly twice and roughly eight times the on-line chromatic number. In contrast, it is known that there exists no competitive on-line algorithm to color $P_6$-free (or $P_7$-free) bipartite graphs, i.e., for which the number of colors is bounded by any function depending only on the chromatic number.
Original languageUndefined
Article number10.1137/060668675
Pages (from-to)72-91
Number of pages20
JournalSIAM journal on discrete mathematics
Issue numberWoTUG-31/1
Publication statusPublished - Feb 2008


  • IR-62553
  • EWI-14147
  • METIS-254918

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