Convex bipartite graph

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In the mathematical field of graph theory, a convex bipartite graph is a bipartite graph with specific properties. A bipartite graph, (U  V, E), is said to be convex over the vertex set U if U can be enumerated such that for all v  V the vertices adjacent to v are consecutive.

Convexity over V is defined analogously. A bipartite graph (U  V, E) that is convex over both U and V is said to be biconvex or doubly convex.

Formal definition

Let G = (U  V, E) be a bipartite graph, i.e, the vertex set is U  V where U  V = ∅. Let NG(v) denote the neighborhood of a vertex v  V. The graph G is convex over U if and only if there exists a bijective mapping, f: U  { 1, 2, ..., |U|  1, |U|}, such that for all v  V, for any two vertices x,y  NG(v)  U there does not exist a z  NG(v) such that f(x) < f(z) < f(y).

See also

  • Convex plane graph

References

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