getCheapArcs function substracts to each arc of
a given graph the value of the minimum weight of the arcs
pointing to the same node.
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.
getCheapArcs returns a matrix with a new list of
This function is an auxiliar function used in msArborEdmonds and getMinimumArborescence.