Wolfram Function Repository
Instant-use add-on functions for the Wolfram Language
Function Repository Resource:
Return vertices that are adjacent to two vertices
ResourceFunction["CommonNeighbors"][g,u,v] returns a list of vertices adjacent to vertices u and v in the graph g.  | 

Find the common neighbors in a graph for a pair of vertices:
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CommonNeighbors works with undirected graphs:
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Directed graphs:
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Weighted graphs:
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Multigraphs:
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Mixed graphs:
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Find common neighbors in a large graphs:
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Find common neighbors in a family network:
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We can identify immediate family members of Nancy and Linda:
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And highlight them:
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If there are no common neighbors an empty list is returned:
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Wolfram Language 13.0 (December 2021) or above
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