Data Structures, Algorithms, & Applications in C++
Chapter 5, Exercise 9

The code is given below and in the file arrayListWithOverloadNotEqual.h. Test code is included in arrayListWithOverloadNotEqual.cpp. 
template<class T>
class arrayListWithOverloadNotEqual : public arrayList<T> 
{
   public:
      // constructor and destructor
      arrayListWithOverloadNotEqual(int initialCapacity = 10)
           : arrayList<T> (initialCapacity) {}

      bool operator!=(const arrayListWithOverloadNotEqual<T>& theList) const;
};

template<class T>
bool arrayListWithOverloadNotEqual<T>::operator!=(const arrayListWithOverloadNotEqual<T>& theList) const
{// Return true iff the two lists are not identical.

   if (listSize != theList.listSize)
      return true;

   // check the elements
   for (int i = 0; i < listSize; i++)
      if (element[i] != theList.element[i])
         return true;

   return false;
}