text: /// Name: DivisorSieve
  /// Description: Computes all divisors of all numbers till [1,size]
  /// Detail: Factors, Divisors, Maths, Sieve
  /// Guarantee: } // DivisorSieve
  
  void divisor_sieve(vector< vector<int> > &divisor, int size)
  {
      divisor.resize(size + 1);
      for (int i = 1; i <= size; i++)
      {
          for (int j = i; j <= size; j += i)
              divisor[j].push_back(i);
      }
  } // DivisorSieve