title: All pairs shortest paths in graph directed with non-negative weighted edges
body: <p>I have a directed graph with non-negative weighted edges where there are multiple edges between two vertices.</p>
  
  <p>I need to compute all pairs shortest path.
  This graph is very big (20 milion vertices and 100 milion of edges).
  Is Floyd–Warshall the best algorithm ? There is a good library or tool to complete this task ?</p>