Xor query

#include <unordered_map>
int helper(int sv , vector <int> adj[]  , unordered_map <int,int>&m)
{
    int res = sv ; 
    for(auto itr : adj[sv])
    {
    
      int a = helper(itr , adj , m) ;
      res = res ^ a ; 

    }
    m[sv] = res ; 
    return res  ;
}


vector<int> XORquery(int n, vector<vector<int>> &edges, int q, vector<int> &query) {
    // Write your code here.
    //construction of graph
     vector <int> adj[n] ;
     for(int i = 0 ; i < edges.size() ; i++)
     {
        adj[edges[i][0]].push_back(edges[i][1]);
     }
     
     //mapping it with xor
     
     unordered_map <int,int> m; 
     helper(0 , adj , m) ;
    //  for(auto itr : m)
    //  {
    //      cout << itr.first << " " << itr.second << endl ; 
    //  }

      //getting ans
       vector <int> ans ;  
      for(int i = 0 ; i < query.size() ; i++)
      {
           ans.push_back(m[query[i]]) ; 
      }
     
    
     return  ans ; 



}