6
votes

There can be multiple min-cuts in a network. E.g:

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has four min-cuts and Ford-Fulkerson finds the one "nearer" to s (the source). Can we say the same for all networks? That is, Ford-Fulkerson finds the cut nearest to the source? If true, how do we formalize the concept of "nearest to the source" in flow networks?

1
have you find the answer? I want to hear the answer. Having same thought :)arslan

1 Answers

6
votes

Let's represent a cut as a set of vertices that contains the source but not the sink. Minimum cuts have the property that the intersection of two minimum cuts is a minimum cut (this is true for unions also). Thus, the intersection of all minimum cuts is in a sense the minimum cut "nearest" to the source, because it is a subset of every other minimum cut.