Find the town judge

class Solution {
public:
    int findJudge(int n, vector<vector<int>>& trust) {
        vector<vector<int>>adj(n+1);
        int m = trust.size();

        for(int i=0; i<m; i++)  adj[trust[i][0]].push_back(trust[i][1]);

        bool flag = false;
        int judge = -1, cnt=0;

        for(int i=1; i<=n; i++)
        {
            if(adj[i].size() == 0)
            {
                judge = i;

                for(int j=1; j<=n; j++)
                {
                   for(int k =0; k< adj[j].size(); k++)
                   {
                       if(adj[j][k] == judge)
                       {
                           cnt++;
                           break;
                       }
                   }
                }

                if(cnt != n-1) judge = -1;
                break;
            }

        }

        return judge;
    }
};