Recently lexicographic breadth first search (LexBFS) has been shown to be a very powerful tool for the development of linear time, easily implementable recognition algorithms for various families of graphs. In this paper, we add to this work by producing a simple two LexBFS sweep algorithm to recognize the family of cographs. This algorithm extends to other related graph families such as P4-reducible, P4-sparse, and distance hereditary. It is an open question whether our cograph recognition algorithm can be extended to a similarly easy algorithm for modular decomposition. Key words. graph algorithms, cograph recognition, linear time algorithms, LexBFS, P4-free graphs, modular decomposition AMS subject classification. 05C85 DOI. 10.1137/060664690
Anna Bretscher, Derek G. Corneil, Michel Habib, Ch