## Interface MinimumSTCutAlgorithm<V,​E>

• Type Parameters:
V - the graph vertex type
E - the graph edge type
All Known Implementing Classes:
BoykovKolmogorovMFImpl, DinicMFImpl, 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 $s \in S, t \in T$, and that $S \cup T = V$. 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.
Author:
Joris Kinable
• ### Method Summary

All Methods
Modifier and Type Method Description
double calculateMinCut​(V source, V sink)
Computes a minimum capacity $s-t$ cut.
double getCutCapacity()
Returns the capacity of the cut obtained after the last invocation of calculateMinCut(Object, Object)
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.
java.util.Set<V> getSinkPartition()
Returns the sink partition $T$, $t \in T$, of the cut obtained after the last invocation of calculateMinCut(Object, Object)
java.util.Set<V> getSourcePartition()
Returns the source partition $S$, $s \in S$, of the cut obtained after the last invocation of calculateMinCut(Object, Object)
• ### 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
• #### getSourcePartition

java.util.Set<V> getSourcePartition()
Returns the source partition $S$, $s \in S$, 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 $T$, $t \in T$, 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 $T$