o ˷eB @sHdZddlmZddlZddlmZddgZedddZd dZ dS) z Dominance algorithms. )reduceN)not_implemented_forimmediate_dominatorsdominance_frontiers undirectedcs||vr td||itt||}ddt|D||fdd}d}|rYd}|D]!}t|fdd |j|D}|vsP||krV||<d}q5|s1S) 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).0iurrT/var/www/ideatree/venv/lib/python3.10/site-packages/networkx/algorithms/dominance.py >sz(immediate_dominators..csd||kr0||kr|}||ks ||kr,|}||ks ||ks|SNr)r vdfnidomrr intersectBsz'immediate_dominators..intersectTFc3s|] }|vr|VqdSr r)rr)rrr Nsz'immediate_dominators..) nx NetworkXErrorlistdfs_postorder_nodes enumeratepopreverserpred)Gstartorderrchangedr new_idomrrr r s&+ cCst||}dd|D}|D].}t|j|dkr=|j|D]}||vr<|||kr<|||||}|||ks+qq|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)rrrdfr rrrr rVs %  ) __doc__ functoolsrnetworkxrnetworkx.utilsr__all__rrrrrr s    H