[jgrapht-users] StoerWagnerMinimumCut bugged?

[Joris K. <de...@gm...>]

Dear,

It seems that the StoerWagnerMinimumCut is bugged in jgrapht 0.8.3.
Attached are two small code samples, both resulting in a runtime
error.

Sample Test2. The graph contains just 2 vertices, joined with an edge.
StoerWagner fails to return a minimum cut for this trivial case. When
a third vertex+edge is added, StoerWagner works correctly.
Suggestion: either verify that this is a bug, or specify in the
documentation that the graph requires at least 3 vertices and 2 edges.

Sample Test. StoerWagner's constructor takes a WeightedGraph<V,E>
graph. So per definition, I should be able to run it on a
DefaultDirectedWeightedGraph. This however results in a runtime error:
Exception in thread "main" java.lang.NullPointerException
	at org.jgrapht.graph.AbstractBaseGraph.setEdgeWeight(Unknown Source)
	at org.jgrapht.alg.StoerWagnerMinimumCut.<init>(Unknown Source)
	at algorithms.mip.Test.<init>(Test.java:37)
	at algorithms.mip.Test.main(Test.java:44)

When I however switch the DefaultDirectedWeightedGraph to a
SimpleWeightedGraph, everything works fine again. Suggestion: either
verify that this is a bug, or change the constructor of the class such
that it only accepts a SimpleWeightedGraph.

br,

Joris

Ps. The bug report link on the home page of jgrapht returns an error:
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