Shortest path count modulo
Given an unweighted undirected graph with n nodes (0..n-1) and edges [u, v], return the number of distinct shortest paths from a source to a destination, taken modulo 1000000007. If the destination is unreachable, return 0; if source equals destination, return 1. Constraints: 1 <= n <= 2000.
Implement
count_shortest_paths(n: int, edges: list[list[int]], src: int, dst: int) → intExamples
in
[4,[[0,1],[0,2],[1,3],[2,3]],0,3]out2What 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 30 min
solution.py
InputExpectedGot
[4,[[0,1],[0,2],[1,3],[2,3]],0,3]2not run yetsample