Checks if there is at least one arborescence in the graph
Given a directed graph,
checkArbor searchs for an
arborescence from the list of arcs. An arborescence is a
directed graph with a source node and such that there is a
unique path from the source to any other node.
checkArbor(nodes, arcs, source.node = 1)
vector containing the nodes of the graph, identified by a number that goes from 1 to the order of the graph.
matrix with the list of arcs of the graph. Each row represents one arc. The first two columns contain the two endpoints of each arc and the third column contains their weights.
source node of the graph. Its default value is 1.
checkArbor found an arborescence it returns
TRUE, otherwise it returns
FALSE. If there is
an arborescence the function also returns the list of arcs
of the arborescence.
This function is an auxiliar function used in msArborEdmonds and getMinimumArborescence.