Célia Picinin de Mello

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Interval graphs are the intersection graphs of families of intervals in the real line. If the intervals can be chosen so that no interval contains another, we obtain the subclass of proper interval graphs. We show how to recognize proper interval graphs in linear time by constructing the clique partition from the output of a single lexicographic(More)
The clique graph of a graph G is the intersection graph K(G) of the (maximal) cliques of G. The iterated clique graphs Kn(G) are defined by K0(G) = G and Ki(G) = K(Ki−1(G)), i > 0 and K is the clique operator. In this article we use the modular decomposition technique to characterize the K-behaviour of some classes of graphs with few P4’s . These(More)
A graph is dually chordal if it is the clique graph of a chordal graph. Alternatively, a graph is dually chordal if it admits a maximum neighbourhood order. This class generalizes known subclasses of chordal graphs such as doubly chordal graphs, strongly chordal graphs and interval graphs. We prove that Vizing's total-colour conjecture holds for dually(More)
We characterize even and odd pairs in comparability and in P 4-comparability graphs. The characterizations lead to simple algorithms for deciding whether a given pair of vertices forms an even or odd pair in these classes of graphs. The complexities of the proposed algorithms are O(n + m) for comparability graphs and O(n 2 m) for P 4-comparability graphs.(More)