Network Delay Time

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] = [u_i, v_i, w_i]`, where `u_i` is the source node, `v_i` is the target node, and `w_i` 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 minimum 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`. ### Constraints - `1 <= k <= n <= 100` - `1 <= times.length <= 6000` - `times[i].length == 3` - `1 <= u_i, v_i <= n` - `u_i != v_i` - `0 <= w_i <= 100` - All pairs `(u_i, v_i)` are unique. ### Input Format - Line 1: Three space-separated integers `n`, `k`, and `m` (number of edges). - Next `m` lines: Three space-separated integers `u v w`. ### Output Format Print the minimum time for all nodes to receive the signal, or -1.