Shortest path negative weights
A directed graph on n nodes (0..n-1) has edges given as [u, v, w] where w may be negative. The graph contains NO negative cycle. Return the length of the shortest path from node s to node t, or -1 if t is unreachable. Because edges can be negative, plain Dijkstra is invalid. Constraints: 1 <= n <= 500; -1000 <= w <= 1000.
Implement
shortest_path_neg(n: int, edges: list[list[int]], s: int, t: int) → intExamples
in
[5,[[0,1,4],[0,2,5],[1,2,-3],[2,3,4],[1,3,8],[3,4,2]],0,4]out7What a strong answer looks like
State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
0:00 of about 25 min
solution.py
InputExpectedGot
[5,[[0,1,4],[0,2,5],[1,2,-3],[2,3,4],[1,3,8],[3,4,2]],0,4]7not run yetsample