hopcroft_karp_matching¶
- hopcroft_karp_matching(G, top_nodes=None)[source]¶
Returns the maximum cardinality matching of the bipartite graph
G
.A matching is a set of edges that do not share any nodes. A maximum cardinality matching is a matching with the most edges possible. It is not always unique. Finding a matching in a bipartite graph can be treated as a networkx flow problem.
The functions
hopcroft_karp_matching
andmaximum_matching
are aliases of the same function.- Parameters
- GNetworkX graph
Undirected bipartite graph
- top_nodescontainer of nodes
Container with all nodes in one bipartite node set. If not supplied it will be computed. But if more than one solution exists an exception will be raised.
- Returns
- matchesdictionary
The matching is returned as a dictionary,
matches
, such thatmatches[v] == w
if nodev
is matched to nodew
. Unmatched nodes do not occur as a key inmatches
.
- Raises
- AmbiguousSolution
Raised if the input bipartite graph is disconnected and no container with all nodes in one bipartite set is provided. When determining the nodes in each bipartite set more than one valid solution is possible if the input graph is disconnected.
Notes
This function is implemented with the Hopcroft–Karp matching algorithm for bipartite graphs.
See
bipartite documentation
for further details on how bipartite graphs are handled in NetworkX.References
- 1
John E. Hopcroft and Richard M. Karp. “An n^{5 / 2} Algorithm for Maximum Matchings in Bipartite Graphs” In: SIAM Journal of Computing 2.4 (1973), pp. 225–231. <https://doi.org/10.1137/0202019>.