On digraphs with no two disjoint directed cycles


We obtain a result on configurations in 2-connected digraphs with no two disjoint dicycles. We derive various consequences, for example a short proof of the characterization of the minimal digraphs having no vertex meeting all dicycles and a polynomially bounded algorithm for finding a dicycle through any pair of prescribed arcs in a digraph with no two disjoint dicycles, a problem which is NP-complete for digraphs in general.

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Thomassen, C. On digraphs with no two disjoint directed cycles. Combinatorica 7, 145–150 (1987). https://doi.org/10.1007/BF02579210

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AMS subject classification (1980)

  • 05 C 20
  • 05 C 38