U ?hB @sHdZddlmZddlZddlmZddgZedddZd dZ dS) z Dominance algorithms. )reduceN)not_implemented_forimmediate_dominatorsdominance_frontiersZ undirectedcs||krtd||itt||}ddt|D||fdd}d}|rd}|D]B}t|fdd |j|D}|ks||krj||<d}qjq^S) a'Returns the immediate dominators of all nodes of a directed graph. Parameters ---------- G : a DiGraph or MultiDiGraph The graph where dominance is to be computed. start : node The start node of dominance computation. Returns ------- idom : dict keyed by nodes A dict containing the immediate dominators of each node reachable from `start`. Raises ------ NetworkXNotImplemented If `G` is undirected. NetworkXError If `start` is not in `G`. Notes ----- Except for `start`, the immediate dominators are the parents of their corresponding nodes in the dominator tree. Examples -------- >>> G = nx.DiGraph([(1, 2), (1, 3), (2, 5), (3, 4), (4, 5)]) >>> sorted(nx.immediate_dominators(G, 1).items()) [(1, 1), (2, 1), (3, 1), (4, 3), (5, 1)] References ---------- .. [1] K. D. Cooper, T. J. Harvey, and K. Kennedy. A simple, fast dominance algorithm. Software Practice & Experience, 4:110, 2001. zstart is not in GcSsi|]\}}||qSr).0iurrO/var/www/html/venv/lib/python3.8/site-packages/networkx/algorithms/dominance.py >sz(immediate_dominators..csB||kr>||kr"|}q||kr|}q"q|SNr)r vdfnidomrr intersectBs   z'immediate_dominators..intersectTFc3s|]}|kr|VqdSr r)rr )rrr Nsz'immediate_dominators..) nxZ NetworkXErrorlistZdfs_postorder_nodes enumeratepopreverserpred)Gstartorderrchangedr Znew_idomrrr r s"+ cCsvt||}dd|D}|D]R}t|j|dkr|j|D]0}||kr>|||kr>|||||}qJq>q|S)aReturns the dominance frontiers of all nodes of a directed graph. Parameters ---------- G : a DiGraph or MultiDiGraph The graph where dominance is to be computed. start : node The start node of dominance computation. Returns ------- df : dict keyed by nodes A dict containing the dominance frontiers of each node reachable from `start` as lists. Raises ------ NetworkXNotImplemented If `G` is undirected. NetworkXError If `start` is not in `G`. Examples -------- >>> G = nx.DiGraph([(1, 2), (1, 3), (2, 5), (3, 4), (4, 5)]) >>> sorted((u, sorted(df)) for u, df in nx.dominance_frontiers(G, 1).items()) [(1, []), (2, [5]), (3, [5]), (4, [5]), (5, [])] References ---------- .. [1] K. D. Cooper, T. J. Harvey, and K. Kennedy. A simple, fast dominance algorithm. Software Practice & Experience, 4:110, 2001. cSsi|] }|tqSr)set)rr rrr r }sz'dominance_frontiers..)rrlenradd)rrrZdfr r rrr rVs%  ) __doc__ functoolsrZnetworkxrZnetworkx.utilsr__all__rrrrrr s   H