Abstract
We prove the conjecture of D. A. Marcus (1981) that every strongly 2-arc-connected directed graph has a directed cycle with at least two chords. As a consequence, every strongly 2-arc-connected directed graph with m arcs has a spanning strong directed subgraph with less than 2/3m arcs. The constant 2/3 is best possible.
Original language | English |
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Journal | Journal of Combinatorial Theory. Series B |
Volume | 66 |
Issue number | 1 |
Pages (from-to) | 24-33 |
ISSN | 0095-8956 |
DOIs | |
Publication status | Published - 1996 |