a ‘Àhéã@s<dZddlZddlmZmZdgZedƒejdd„ƒƒZdS)zSemiconnectedness.éN)Únot_implemented_forÚpairwiseÚis_semiconnectedZ undirectedcsNt|ƒdkrt d¡‚t |¡s$dSt |¡‰t‡fdd„tt ˆ¡ƒDƒƒS)aÝReturns True if the graph is semiconnected, False otherwise. A graph is semiconnected if and only if for any pair of nodes, either one is reachable from the other, or they are mutually reachable. This function uses a theorem that states that a DAG is semiconnected if for any topological sort, for node $v_n$ in that sort, there is an edge $(v_i, v_{i+1})$. That allows us to check if a non-DAG `G` is semiconnected by condensing the graph: i.e. constructing a new graph `H` with nodes being the strongly connected components of `G`, and edges (scc_1, scc_2) if there is a edge $(v_1, v_2)$ in `G` for some $v_1 \in scc_1$ and $v_2 \in scc_2$. That results in a DAG, so we compute the topological sort of `H` and check if for every $n$ there is an edge $(scc_n, scc_{n+1})$. Parameters ---------- G : NetworkX graph A directed graph. Returns ------- semiconnected : bool True if the graph is semiconnected, False otherwise. Raises ------ NetworkXNotImplemented If the input graph is undirected. NetworkXPointlessConcept If the graph is empty. Examples -------- >>> G = nx.path_graph(4, create_using=nx.DiGraph()) >>> print(nx.is_semiconnected(G)) True >>> G = nx.DiGraph([(1, 2), (3, 2)]) >>> print(nx.is_semiconnected(G)) False See Also -------- is_strongly_connected is_weakly_connected is_connected is_biconnected rz-Connectivity is undefined for the null graph.Fc3s|]\}}ˆ ||¡VqdS)N)Zhas_edge)Ú.0ÚuÚv©ÚH©úh/var/www/html/assistant/venv/lib/python3.9/site-packages/networkx/algorithms/components/semiconnected.pyÚ Fóz#is_semiconnected..)ÚlenÚnxZNetworkXPointlessConceptZis_weakly_connectedZcondensationÚallrZtopological_sort)ÚGr rrrs4ÿ ) Ú__doc__ZnetworkxrZnetworkx.utilsrrÚ__all__Z _dispatchrr r r rÚs