# How to make a digraph strongly connected

@article{Frank1981HowTM,
title={How to make a digraph strongly connected},
author={Andr{\'a}s Frank},
journal={Combinatorica},
year={1981},
volume={1},
pages={145-153}
}
• A. Frank
• Published 1 June 1981
• Mathematics, Computer Science
• Combinatorica
Given a directed graphG, acovering is a subsetB of edges which meets all directed cuts ofG. Equivalently, the contraction of the elements ofB makesG strongly connected. AnO(n5) primal-dual algorithm is presented for finding a minimum weight covering of an edge-weighted digraph. The algorithm also provides a constructive proof for a min-max theorem due to Lucchesi and Younger and for its weighted version.

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