Graph - adjacency list - BFS

/***
Graph based - BFS
http://www.geeksforgeeks.org/breadth-first-traversal-for-a-graph/
***/

// adjacent list represented graph
class graph
{
                int V; // # of vertices
                list<int> *adj; //Pointer to an array containing adjacency lists
                void BFSUtil(int v, queue<int> &bfsqueue);
public:
                graph(int V);
                void add_edge(int v, int w); //edge between w and v
                void BFS(int v);
};

graph::graph(int V)
{
    this->V = V;
    adj = new list<int>[V];
}

void graph::add_edge(int v, int w)
{
    adj[v].push_back(w); // Add w to v’s list.
}

void graph::BFSUtil(int v, queue<int> bfsgraph, bool *visited) {
               
                list<int>::iterator it;

                while(!bfsgraph.empty()) {
                                int n = bfsgraph.front();
                                cout<< n <<" ";
                                bfsgraph.pop();
               
                                for(it = adj[v].begin(); it != adj[v].end(); it++) {
                                                if(!visited[*it]) {
                                                                bfsgraph.push(*it);
                                                                visited[*it] = true;
                                                }
                                }
                }
}

void graph::BFS() {
                //mark all the vertices as not visited
                bool *visited = new bool[V];
                for(int i = 0; i<V; i++) visited[i] = false;

                queue<int> bfsgraph;
               
                for(int i=0; i<V; i++) {
                                if(!visited[i]) {
                                                visited[v] = true;
                                                bfsgraph.push(v);
                                                BFSUntil(i, bfsgraph, visited);
                                }
                }

}

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