group_defenders.cpp

   void groupDefenders(vector<vector<int>> attackers, vector<int> defenders, int i) {
      int x = 0;
      for (vector<int> attackerBucket:attackers) {
         cout << x << ": ";
         for (int defender:attackerBucket) {
            cout << defender << " ";
         }
         cout << "\n";
         x+= 1;
      }

      if(i == defenders.size()) {
         return;
      }
       
      for(int v=0; v<attackers.size();++v) {
         vector<int> attacker = attackers[v];
         attacker.push_back(defenders[i]);
         attackers[v] = attacker;
         groupDefenders(attackers, defenders, i+1);
         attacker.pop_back();
         attackers[v] = attacker;
      }
   }