U md;@sFdZddlZddlmZddlmZdgZededd dZdS) z Ramsey numbers. N)not_implemented_for)arbitrary_element ramsey_R2ZdirectedZ multigraphcs|sttfSt|fddt|D}t|}t||\}}t||\}}||t ||t dt ||t dfS)aHCompute the largest clique and largest independent set in `G`. This can be used to estimate bounds for the 2-color Ramsey number `R(2;s,t)` for `G`. This is a recursive implementation which could run into trouble for large recursions. Note that self-loop edges are ignored. Parameters ---------- G : NetworkX graph Undirected graph Returns ------- max_pair : (set, set) tuple Maximum clique, Maximum independent set. Raises ------ NetworkXNotImplemented If the graph is directed or is a multigraph. c3s|]}|kr|VqdS)N).0Znbrnodera/home/sam/Atlas/atlas_env/lib/python3.8/site-packages/networkx/algorithms/approximation/ramsey.py *szramsey_R2..)key) setrnxZ all_neighborsZ non_neighborsrZsubgraphcopyaddmaxlen)GZnbrsZnnbrsZc_1Zi_1Zc_2Zi_2rrr r s    ) __doc__ZnetworkxrZnetworkx.utilsrutilsr__all__rrrrr s