networkx/networkx — pull request #880 by Geo-Piskas (2013-06-01 13:37:24+00:00)
Title: Reworked Dijkstra's algorithm. Faster speed and less memory usage.

This revamped piece of code does not need a 'seen' list.
Also, it needs less values to be added to the Q, that is used as a heap.
Moreover, it does significantly less 'if' checks and other operations.

I have tested the implementation and it outputs the same results with the previous one.