nr
Calculates the number of distinct paths from the starting node to the target node in the graph.
This function assumes that the graph is a Directed Acyclic Graph (DAG) and uses dynamic programming to count the number of paths efficiently.
Return
The number of distinct paths from the starting node to the target node.
Parameters
start
The starting node.
target
The target node.
Throws
If either the starting node or the target node is not found in the graph.