LeetCode 743 Network Delay Time - Implementation

Here is the solution:

function networkDelayTime(times, n, k):
    adj = array of n + 1 empty lists
    for (u, v, w) in times:
        adj[u].append((v, w))

    dist = array of size n + 1, all infinity
    dist[k] = 0
    pq = min-heap with (0, k)

    while pq is not empty:
        (d, u) = pq.pop()
        if d > dist[u]:
            continue
        for (v, w) in adj[u]:
            if dist[u] + w < dist[v]:
                dist[v] = dist[u] + w
                pq.push((dist[v], v))

    maxTime = 0
    for i from 1 to n:
        if dist[i] == infinity:
            return -1
        maxTime = max(maxTime, dist[i])
    return maxTime

This runs in $O((V + E) \log V)$ time and uses $O(V)$ space.