A good default for selecting neighbors that go along outgoing edges or follow along incoming edges:

An implementation of bellman ford algorithm, for finding shortest path between single source and all vertices. Returns them as a dictionary or an error in Result type.

Note: You may know error occurs in case there is a negative weight cycle.

This algorithms returns the minimum spanning tree for the given graph using Kruskal's algorithm.

Note :

1. Returns Minimum Spanning Arborescence in case of directed graph

2. Assumes directed graphs, so if you want MST on undirected graph, pass (Graph.symmetricClosure graph)