K-shortest path

Dijkstra's algorithm and the A* algorithm only return one possible shortest path between two nodes. If you are interested in the second shortest path, you will have to go for the k-shortest path or Yen's algorithm. Its usage within the GDS plugin is very similar to the previous algorithms we studied, except we have to specify the number of paths to return. In the following example, we specify k=2:

MATCH (A:Node {name: "A"})
MATCH (E:Node {name: "E"})
CALL gds.alpha.kShortestPaths.stream("graph_weighted", {
            startNode: A, 
            endNode: E, 
            k:2, 
            relationshipWeightProperty: "weight"}
)
YIELD index, sourceNodeId, targetNodeId, nodeIds
RETURN index, 
       gds.util.asNode(sourceNodeId).name as source, 
       gds.util.asNode(targetNodeId).name as target, 
       gds.util.asNodes(nodeIds) as path 

The results are represented in the following table. The first shortest path is the one we already...