Implement bidirectional dijkstras as my re-routing solution

[cjprybol]

rough algorithm:

• build graph
• find all nodes with in-degree > 1 and all nodes with out-degree > 1, these are our branch points
• when looking for routes, accept all non-branch paths but run bd-dijkstras on branch points

[cjprybol]

https://www.cs.princeton.edu/courses/archive/spr06/cos423/Handouts/EPP%20shortest%20path%20algorithms.pdf https://digitalcommons.du.edu/cgi/viewcontent.cgi?article=2303&context=etd https://networkx.org/documentation/stable/reference/algorithms/generated/networkx.algorithms.shortest_paths.weighted.bidirectional_dijkstra.html#networkx.algorithms.shortest_paths.weighted.bidirectional_dijkstra https://www.sciencedirect.com/science/article/pii/S0004370217300905

[cjprybol]

https://www.homepages.ucl.ac.uk/~ucahmto/math/2020/05/30/bidirectional-dijkstra.html https://www.coursera.org/lecture/algorithms-on-graphs/bidirectional-dijkstra-7ml18 https://www.coursera.org/learn/algorithms-on-graphs#syllabus

[cjprybol]

https://www.youtube.com/watch?v=KyRSJRMz818

"highway hierarchy"

[cjprybol]

done!