- A vertex cover is a set of vertices that are incident to every edge.
- VertexCoverQ works with undirected graphs, directed graphs, multigraphs, and mixed graphs.
Background & Context
- VertexCoverQ tests if a specified set of vertices forms a vertex cover for a given graph, where a vertex cover is a set of vertices satisfying the condition that each edge of the graph is incident to some vertex in the set. VertexCoverQ returns True if the set is a vertex cover and False otherwise.
- The entire vertex set of a graph is always a vertex cover (of maximum possible size). The smallest possible vertex cover for a given graph is known as a minimum vertex cover, and its size is known as the vertex cover number.
- Vertex covers are closely related to independent vertex sets (which are sets of vertices having the property that no two vertices are part of the same edge). In particular, a set of vertices is a vertex cover if and only if its complement forms an independent vertex set. As a result, the counts of vertex covers and independent vertex sets in a graph are the same.
- FindVertexCover can be used to find a single minimum vertex cover or a single vertex cover of any fixed size, but not all vertex covers. A trivial implementation for finding all vertex covers of a graph can be constructed by applying VertexCoverQ to all subsets of a graph's vertices. EdgeCoverQ performs the analogous test to VertexCoverQ for edge covers of a graph. FindIndependentVertexSet can be used to find one or more maximal independent vertex sets in a graph (each of whose complements is a vertex cover).
Introduced in 2010Updated in 2014