Calculate the longest path in a directed acyclic graph in terms of node weights (Python)
Use this class to get (one of) the paths with the largest sum of node weights
in a directed acyclic graph (DAG). After constructing the empty object,
use add_node(label, weight) and add_edge(label1, label2) to build the graph,
and then call longest_path to retrieve the path and the sum of the weights.
This latter operation is destructive and will delete the graph.
dag = DAGLongestPath()
for i in range(6): dag.add_node(i, i)
dag.add_edge(3, 5)
dag.add_edge(2, 5)
dag.add_edge(2, 4)
dag.add_edge(1, 2)
print(dag.longest_path())