title: When iterating over edges in Bellman-Ford, do we have to relax an undirected edge in both direction?
body: <p>If there's an <strong>undirected</strong> edge in the graph and we want to use Bellman-Ford to find the shortest paths. When we are iterating over edges, do we have to relax the undirected edge twice? One time for edge (u, v) and the next time for edge (v, u)? Or one time is enough?</p>