This documents an unmaintained version of NetworkX. Please upgrade to a maintained version and see the current NetworkX documentation.


floyd_warshall_predecessor_and_distance(G, weight='weight')[source]

Find all-pairs shortest path lengths using Floyd’s algorithm.

Parameters :

G : NetworkX graph

weight: string, optional (default= ‘weight’)

Edge data key corresponding to the edge weight.

Returns :

predecessor,distance : dictionaries

Dictionaries, keyed by source and target, of predecessors and distances in the shortest path.

See also

floyd_warshall, floyd_warshall_numpy, all_pairs_shortest_path, all_pairs_shortest_path_length


Floyd’s algorithm is appropriate for finding shortest paths in dense graphs or graphs with negative weights when Dijkstra’s algorithm fails. This algorithm can still fail if there are negative cycles. It has running time O(n^3) with running space of O(n^2).