Class Solution


  • public class Solution
    extends Object
    743 - Network Delay Time.

    Medium

    You are given a network of n nodes, labeled from 1 to n. You are also given times, a list of travel times as directed edges times[i] = (ui, vi, wi), where ui is the source node, vi is the target node, and wi is the time it takes for a signal to travel from source to target.

    We will send a signal from a given node k. Return the time it takes for all the n nodes to receive the signal. If it is impossible for all the n nodes to receive the signal, return -1.

    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 = 1

    Output: 1

    Example 3:

    Input: times = [[1,2,1]], n = 2, k = 2

    Output: -1

    Constraints:

    • 1 <= k <= n <= 100
    • 1 <= times.length <= 6000
    • times[i].length == 3
    • 1 <= ui, vi <= n
    • ui != vi
    • 0 <= wi <= 100
    • All the pairs (ui, vi) are unique. (i.e., no multiple edges.)
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • networkDelayTime

        public int networkDelayTime​(int[][] times,
                                    int n,
                                    int k)