Interface MinimumSTCutAlgorithm<V,​E>

  • Type Parameters:
    V - the graph vertex type
    E - the graph edge type
    All Known Implementing Classes:
    EdmondsKarpMFImpl, GusfieldGomoryHuCutTree, MaximumFlowAlgorithmBase, PushRelabelMFImpl

    public interface MinimumSTCutAlgorithm<V,​E>
    Given a weighted graph G(V,E) (directed or undirected). This class computes a minimum s-t cut. A cut is a partitioning of the vertices into two disjoint sets S, T such that s ∈ S, t ∈ T, and that S ∪ T = V. The capacity of a cut is defined as the sum of the weights of the edges from S to T. In case of a directed graph, only the edges with their tail in S and their head in T are counted. In cased of a undirected graph, all edges with one endpoint in S and one endpoint in T are counted. For a given s and t, this class computes two partitions S and T such that the capacity of the cut is minimized. When each edge has equal weight, by definition this class minimizes the number of edges from S to T. Note: it is not recommended to use this class to calculate the overall minimum cut in a graph by iteratively invoking this class for all source-sink pairs. This is computationally expensive. Instead, use the StoerWagnerMinimumCut implementation.
    • Method Detail

      • calculateMinCut

        double calculateMinCut​(V source,
                               V sink)
        Computes a minimum capacity s-t cut.
        Parameters:
        source - s
        sink - t
        Returns:
        capacity of the cut
      • getCutCapacity

        double getCutCapacity()
        Returns the capacity of the cut obtained after the last invocation of calculateMinCut(Object, Object)
        Returns:
        capacity of the cut
      • getSourcePartition

        java.util.Set<V> getSourcePartition()
        Returns the source partition S, s ∈ S, of the cut obtained after the last invocation of calculateMinCut(Object, Object)
        Returns:
        source partition S
      • getSinkPartition

        java.util.Set<V> getSinkPartition()
        Returns the sink partition T, t ∈ T, of the cut obtained after the last invocation of calculateMinCut(Object, Object)
        Returns:
        source partition T
      • getCutEdges

        java.util.Set<E> getCutEdges()
        Returns the set of edges which run from S to T, in the s-t cut obtained after the last invocation of calculateMinCut(Object, Object) In case of a directed graph, only the edges with their tail in S and their head in T are returned. In cased of a undirected graph, all edges with one endpoint in S and one endpoint in T are returned.
        Returns:
        set of edges which run from S to T