Network Delay Time
MediumP2Coding
A network has n nodes labelled 1..n. Each entry [u, v, w] of times is a directed edge: a signal sent from u reaches v after w units of time.
A signal starts at node k. Return the time it takes for all n nodes to receive it, or -1 if some node never gets it.
Example 1
- Input
- times = [[2,1,1],[2,3,1],[3,4,1]], n = 4, k = 2
- Output
- 2
Example 2
- Input
- times = [[1,2,1]], n = 2, k = 2
- Output
- -1
- Why
- Node 2 has no outgoing edge, so node 1 is never reached.
Constraints
- 1 <= k <= n <= 100
- 1 <= times.length <= 6000
- 1 <= u, v <= n, u != v
- 0 <= w <= 100
Hints
Give it a real attempt first. Run shows which examples fail.
Saved automatically
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