# Breadth-First Search

Can tell you if there's a path between A and B and will find the shortest.

In these examples, 1st degree Mango sellers are found before 2nd degree, 2nd before 3rd and so on.

Visted nodes should be stored in a set to ensure no infinite loops.

Running time for BFS on a directed graph: `O(V + E`) where V = vertices, E = edges.