networkx longest path
No, if you have a DAG (directed acyclic graph) then the problem becomes polynomial. Is there a generic term for these trajectories? NetworkX User Survey 2023 Fill out the survey to tell us about your ideas, complaints, praises of NetworkX! Last letter of first word == first letter of second word. Count the longest path in a directed graph - CodeProject By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Is it safe to publish research papers in cooperation with Russian academics? There are functions like nx.dag_longest_path_length but those do not directly support this. The best answers are voted up and rise to the top, Not the answer you're looking for? The radius of this sphere will eventually be the length, of the shortest path. Copyright 2023 ITQAGuru.com | All rights reserved. How to visualize shortest path that is calculated using Networkx? Horizontal and vertical centering in xltabular. Making statements based on opinion; back them up with references or personal experience. 1 I have a networkx digraph. How can I delete a file or folder in Python? Are you sure you know what problem you're trying to solve? A single path can be found in O ( V + E) time but the number of simple paths in a graph can be very large, e.g. This error ValueError: ('Contradictory paths found:', 'negative weights?') What were the most popular text editors for MS-DOS in the 1980s? the edge orientation. If you do this with all edges, and take the longest path from all tries, you should get the 2nd longest graph in the original graph. For multigraphs, the list of edges have elements of the form `(u,v,k)`. Can you still use Commanders Strike if the only attack available to forego is an attack against an ally? That isn't going to work in general. The answer here: How to find path with highest sum in a weighted networkx graph?, that uses all_simple_paths. It turns out my graph is already topologically sorted, and that I can solve the problem without using networkx at all (by keeping track of the longest incoming path per node and the previous node for each such path, as you point out). import networkx as nx def longest_path (G): dist = {} # stores [node, distance] pair for node in nx.topological_sort (G): pairs = [ [dist [v] [0]+1,v] for v in G.pred [node]] # incoming pairs if pairs: dist [node] = max (pairs) else: dist [node] = (0, node) node, max_dist = max (dist.items ()) path = [node] while node in dist: node, length = dist However, at position 115252166, C has a weight of 8.5 and G only has a weight of 0.5, so this should return only G. It won't let me edit my comment.. so above, sorry, it should return C at position 115252166.