Longest path on a tree

#1

Can you please provide the implementation with use of priority queues. It would be highly helpful if you provide the implementation in java otherwise c++ will also work.

#2

Yes you can implement dijkstra using priority queue. Below is the implementation.

priority_queue< iPair, vector , greater > pq;

vector<int> dist(V, INF); 
pq.push(make_pair(0, src)); 
dist[src] = 0; 
while (!pq.empty()) 
{ 
    int u = pq.top().second; 
    pq.pop(); 

    list< pair<int, int> >::iterator i; 
    for (i = adj[u].begin(); i != adj[u].end(); ++i) 
    { 
        // Get vertex label and weight of current adjacent 
        // of u. 
        int v = (*i).first; 
        int weight = (*i).second; 

        if (dist[v] > dist[u] + weight) 
        { 
        
            dist[v] = dist[u] + weight; 
            pq.push(make_pair(dist[v], v)); 
        } 
    } 
}
#3

Sorry sir it was mistakenly written. Actually I wanted the implementation of above code without the use of priority queues.

#4

Not dijkstra but the code of longest path in a tree using dp without the use of priority queues.

#5

@aman2382000 I do not understand what is real doubt here. Please close this doubt and initiate a new doubt.

#6

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