GFG_BFSTraversal.cpp

/* https://practice.geeksforgeeks.org/problems/bfs-traversal-of-graph/1#
 * Given a directed graph. The task is to do Breadth First Traversal of this graph starting from 0.
 */

 // } Driver Code Ends
class Solution {
  public:
    // Function to return Breadth First Traversal of given graph.
    vector<int> bfsOfGraph(int V, vector<int> adj[]) {
        // Code here
        
        vector<int> bfs_lists;
        queue<int> q;
        vector<bool> visited(V,0);
        
        q.push(0);
        visited[0]=true;
        
        while(!q.empty())
        {
            int i = q.front(); q.pop();
            bfs_lists.push_back(i);
            
            for(int w: adj[i])
            {
                if(!visited[w])
                    {
                        visited[w] = true;
                        q.push(w);
                    }
            }
            
        }// while
        
        return bfs_lists;
    }
};