Computes a weighted vertex cover in an undirected graph. A vertex cover of a graph is a set of
vertices such that each edge of the graph is incident to at least one vertex in the set. A
minimum vertex cover is a vertex cover having the smallest possible number of vertices for a
given graph. The size of a minimum vertex cover of a graph G is known as the vertex cover number.
A vertex cover of minimum weight is a vertex cover where the sum of weights assigned to the
individual vertices in the cover has been minimized. The minimum vertex cover problem is a
special case of the minimum weighted vertex cover problem where all vertices have equal weight.
Consequently, any algorithm designed for the weighted version of the problem can also solve
instances of the unweighted version.