graph using queue c 2b 2b

1#include<iostream>
2#include <list>
3 
4using namespace std;
5 
6
7
8class Graph
9{
10    int V;   
11 
12  
13    list<int> *adj;   
14public:
15    Graph(int V);  
16 
17    
18    void addEdge(int v, int w); 
19 
20    
21    void BFS(int s);  
22};
23 
24Graph::Graph(int V)
25{
26    this->V = V;
27    adj = new list<int>[V];
28}
29 
30void Graph::addEdge(int v, int w)
31{
32    adj[v].push_back(w); 
33}
34 
35void Graph::BFS(int s)
36{
37  
38    bool *visited = new bool[V];
39    for(int i = 0; i < V; i++)
40        visited[i] = false;
41 
42   
43    list<int> queue;
44 
45   
46    visited[s] = true;
47    queue.push_back(s);
48 
49   
50    list<int>::iterator i;
51 
52    while(!queue.empty())
53    {
54       
55        s = queue.front();
56        cout << s << " ";
57        queue.pop_front();
58 
59      
60        for (i = adj[s].begin(); i != adj[s].end(); ++i)
61        {
62            if (!visited[*i])
63            {
64                visited[*i] = true;
65                queue.push_back(*i);
66            }
67        }
68    }
69}
70 
71
72int main()
73{
74    
75    Graph g(4);
76    g.addEdge(0, 1);
77    g.addEdge(0, 2);
78    g.addEdge(1, 2);
79    g.addEdge(2, 0);
80    g.addEdge(2, 3);
81    g.addEdge(3, 3);
82 
83    cout << "Following is Breadth First Traversal "
84         << "(starting from vertex 2) \n";
85    g.BFS(2);
86 
87    return 0;
88}

1int v means
2