# Interface BipartiteMatchingProblem<V,E>

Type Parameters:
V - the graph vertex types
E - the graph edge type
All Known Implementing Classes:
BipartiteMatchingProblem.BipartiteMatchingProblemImpl

public interface BipartiteMatchingProblem<V,E>
This class represents a bipartite matching problem. The problem can be weighted or unweighted depending on the isWeighted().

The minimum weight (minimum cost) perfect bipartite matching problem is defined as follows: \begin{align} \mbox{minimize}~& \sum_{e \in E}c_e\cdot x_e &\\ \mbox{s.t. }&\sum_{e\in \delta(v)} x_e = 1 & \forall v\in V\\ &x_e \in \{0,1\} & \forall e\in E \end{align} Here $\delta(v)$ denotes the set of edges incident to the vertex $v$. The parameters $c_{e}$ define a cost of adding the edge $e$ to the matching. If the problem is unweighted, the values $c_e$ are equal to 1 in the problem formulation.

This class can define bipartite matching problems without the requirement that every edge must be matched, i.e. non-perfect matching problems. These problems are called maximum cardinality bipartite matching problems. The goal of the maximum cardinality matching problem is to find a matching with maximum number of edges. If the cost function is used in this setup, the goal is to find the cheapest matching among all matchings of maximum cardinality.

Author:
Timofey Chudakov
• ## Nested Class Summary

Nested Classes
Modifier and Type
Interface
Description
static class
BipartiteMatchingProblem.BipartiteMatchingProblemImpl<V,E>
Default implementation of a Bipartite Matching Problem
• ## Method Summary

Modifier and Type
Method
Description
default void
dumpCosts()
Dumps the problem edge costs to the underlying graph.
Function<E,Double>
getCosts()
Returns a cost function of this problem.
Graph<V,E>
getGraph()
Returns the graph, which defines the problem
Set<V>
getPartition1()
Returns one of the 2 partitions of the graph (no 2 vertices in this set share an edge)
Set<V>
getPartition2()
Returns one of the 2 partitions of the graph (no 2 vertices in this set share an edge)
boolean
isWeighted()
Determines if this problem is weighted or not.
• ## Method Details

• ### getGraph

Graph<V,E> getGraph()
Returns the graph, which defines the problem
Returns:
the graph, which defines the problem
• ### getPartition1

Set<V> getPartition1()
Returns one of the 2 partitions of the graph (no 2 vertices in this set share an edge)
Returns:
one of the 2 partitions of the graph
• ### getPartition2

Set<V> getPartition2()
Returns one of the 2 partitions of the graph (no 2 vertices in this set share an edge)
Returns:
one of the 2 partitions of the graph
• ### getCosts

getCosts()
Returns a cost function of this problem. This function must be defined for all edges of the graph. In the case the problem is unweighted, the function must return any constant value for all edges.
Returns:
a cost function of this problem
• ### isWeighted

boolean isWeighted()
Determines if this problem is weighted or not.
Returns:
true is the problem is weighted, false otherwise
• ### dumpCosts

default void dumpCosts()
Dumps the problem edge costs to the underlying graph.