how to determine the level of each node in the given tree 3f

1void bfs (int start)
2{
3            deque <int > Q;     //Double-ended queue
4            Q.push_back( start); 
5            distance[ start ] = 0;       
6            while( !Q.empty ())
7            {
8                int v = Q.front( );
9                Q.pop_front(); 
10                for( int i = 0 ; i < edges[v].size(); i++)
11               {
12
13
14/* if distance of neighbour of v from start node is greater than sum of distance of v from start node and edge weight between v and its neighbour (distance between v and its neighbour of v) ,then change it */  
15
16
17                    if(distance[ edges[ v ][ i ].first ] > distance[ v ] + edges[ v ][ i ].second ) 
18                {
19
20                    distance[ edges[ v ][ i ].first ] = distance[ v ] + edges[ v ][ i ].second;
21
22                /*if edge weight between v and its neighbour is 0 then push it to front of
23        double ended queue else push it to back*/
24
25                    if(edges[ v ][ i ].second == 0)
26                    {
27                        Q.push_front( edges[ v ][ i ].first);
28                    }
29                    else
30                    {
31                            Q.push_back( edges[ v ][ i ].first);
32
33                    }
34                }
35              }
36           }
37    }

1   vector <int> v[10] ;   //Vector for maintaining adjacency list explained above
2    int level[10]; //To determine the level of each node
3    bool vis[10]; //Mark the node if visited 
4    void bfs(int s) {
5        queue <int> q;
6        q.push(s);
7        level[ s ] = 0 ;  //Setting the level of the source node as 0
8        vis[ s ] = true;
9        while(!q.empty())
10        {
11            int p = q.front();
12            q.pop();
13            for(int i = 0;i < v[ p ].size() ; i++)
14            {
15                if(vis[ v[ p ][ i ] ] == false)
16                {
17            //Setting the level of each node with an increment in the level of parent node
18                    level[ v[ p ][ i ] ] = level[ p ]+1;                 
19                     q.push(v[ p ][ i ]);
20                     vis[ v[ p ][ i ] ] = true;
21      }
22            }
23        }
24    }

1          node                            level [node]   
2
3              s (source node)               0  
4              1                            1  
5              2                            1  
6              3                            2  
7              4                            2  
8              5                            2  
9              6                            2  
10              7                            3