This is a 2-hour implementation of a "Distributed Dijkstra" shortest path exercise. It was part of an university exam and I thought it was kinda cool.
The given constraint for the exercise is that this node can only access its own data, and the data it receives from other nodes.
This solution is built upon the idea that every running instance of this program is a node in the graph, and it will listen on some port. The nodes then have to send messages between themselves to calculate the shortest paths from the source node to all others.
The idea is the same as classical Dijkstra algorithm, but instead of popping from a priority queue and processing the next node, a message is sent to the next node with all the current information about the visited nodes and costs, and then that node is processed.