Linear time optimization algorithms for P4-sparse graphs
نویسندگان
چکیده
منابع مشابه
Linear time recognition of P4-indifference graphs
A P4 is a chordless path of four vertices. A graph is P4-indifference if it admits an ordering < on its vertex set such that every P4 abcd has a < b < c < d or d < c < b < a. Such an ordering is called a P4-indifference ordering. The P4-indifference graphs were introduced in [Chv84] as a particular class of perfectly orderable graphs. A graph is perfectly orderable if there exists an ordering o...
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A simple graph is P4-indifferent if it admits a total order < on its nodes such that every chordless path with nodes a, b, c, d and edges ab, bc, cd has a < b < c < d or a > b > c > d. P4-indifferent graphs generalize indifferent graphs and are perfectly orderable. Recently, Hoàng, Maffray and Noy gave a characterization of P4-indifferent graphs in terms of forbidden induced subgraphs. We clari...
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7)) algorithm for the 3-clique-width problem. Preprint, 1998. Sha98] A. Sharell. Complexit e Descriptive et l'approximation des fonctions de d enombrement. J. Makowsky and U. Rotics. On the cliquewidth of graphs with few P4's. Linear time solvable optimization problems on certain structured graph families, extended abstract. Cou99] B. Courcelle. The monadic second order logic of graphs, XIV: un...
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متن کاملLaplacian integrality in P4-sparse and P4-extendible graphs
Let G be a simple graph and L = L(G) the Laplacian matrix of G. G is called L-integral if all its Laplacian eigenvalues are integer numbers. It is known that every cograph, a graph free of P4, is L-integral. The class of P4-sparse graphs and the class of P4-extendible graphs contain the cographs. It seems natural to investigate if the graphs in these classes are still L-integral. In this paper ...
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ژورنال
عنوان ژورنال: Discrete Applied Mathematics
سال: 1995
ISSN: 0166-218X
DOI: 10.1016/0166-218x(94)00012-3