I am wondering how to calculate the number of spanning arborescences in a directed graph when a root is specified. For example:
where there are 5 spanning arborescences. Note that there is an edge from
b3 and one from
Angela Pretorius mentioned a method in Number of Spanning Arborescences, Mathematics, but there is no euclidean circuit in this example. It seems that he/she is referring to BEST theorem.