BFS in c++
#include<iostream>
#include <list>
using namespace std;
class Graph
{
int V;
list<int> *adj;
public:
Graph(int V);
void addEdge(int v, int w);
void BFS(int s);
};
Graph::Graph(int V)
{
this->V = V;
adj = new list<int>[V];
}
void Graph::addEdge(int v, int w)
{
adj[v].push_back(w);
}
void Graph::BFS(int s)
{
bool *visited = new bool[V];
for(int i = 0; i < V; i++)
visited[i] = false;
list<int> queue;
visited[s] = true;
queue.push_back(s);
list<int>::iterator i;
while(!queue.empty())
{
s = queue.front();
cout << s << " ";
queue.pop_front();
for (i = adj[s].begin(); i != adj[s].end(); ++i)
{
if (!visited[*i])
{
visited[*i] = true;
queue.push_back(*i);
}
}
}
}
int main()
{
Graph g(4);
g.addEdge(0, 1);
g.addEdge(0, 2);
g.addEdge(1, 2);
g.addEdge(2, 0);
g.addEdge(2, 3);
g.addEdge(3, 3);
cout << "Following is Breadth First Traversal "
<< "(starting from vertex 2) \n";
g.BFS(2);
return 0;
}