title: "Cannot allocate an object of abstract type" error
body: <p>Error is here:</p>
  
  <pre><code>vector&lt;Graduate *&gt; graduates;
  graduates.push_back(new AliceUniversity(identifier,id,salary,average));
  </code></pre>
  
  <p>Grandparent class:</p>
  
  <pre><code>Graduate::Graduate(char identifier,
                     long id,
                     int salary,
                     double average)
      : _identifier(identifier),
        _id(id),_salary(salary),
        _average(average)
  {
  }
  </code></pre>
  
  <p>Parent class:</p>
  
  <pre><code>UniversityGraduate::UniversityGraduate(char identifier,
                                         long id,
                                         int salary,
                                         double average)
      : Graduate(identifier,id,salary,average)
  {
  }
  </code></pre>
  
  <p>Actual/child class:</p>
  
  <pre><code>AliceUniversity::AliceUniversity(char identifier,
                                   long id,
                                   int salary,
                                   double average)
      : UniversityGraduate(identifier,id,salary,average)
  {
      _graduateNum++;
      _sumOfGrades += average;
      _avrA = getAverage();
  }
  </code></pre>
  
  <p>I know it's a long shot, I cant write the entire code here…</p>