Editing Maximum flow problem (section)

=== Closure problem ===
{{Main|Closure problem}}
A '''closure''' of a directed graph is a set of vertices ''C'', such that no edges leave ''C''. The '''closure problem''' is the task of finding the maximum-weight or minimum-weight closure in a vertex-weighted directed graph. It may be solved in [[Time complexity|polynomial time]] using a reduction to the maximum flow problem.