Задача на тему Стеки, очереди, деки, списки, кольца

#include <iostream>
#include <string>
 
class Pupil {
 public:
  Pupil() : grade(), surname() {}
  Pupil(int grade, const std::string &surname) : grade(grade),
    surname(surname) {}
  int getGrade() const { return grade; }
  const std::string &getSurname() const { return surname; }
 private:
  int grade;
  std::string surname;
};
 
std::ostream &operator<<(std::ostream &stream, const Pupil &p) {
  return stream << p.getGrade() << " " << p.getSurname();
}
 
std::istream &operator>>(std::istream &stream, Pupil &p) {
  int grade;
  std::string surname;
  stream >> grade >> surname;
  p = Pupil(grade, surname);
  return stream;
}
 
template <class ForwardIterator, class T>
ForwardIterator upperBound(ForwardIterator first, ForwardIterator last,
  const T& val) {
  size_t count = last - first;
  while (count>0) {
    size_t step = count / 2;
    ForwardIterator it = first + step;
    if (!(val<*it)) {
      first = ++it;
      count -= step + 1; 
    } else {
      count=step;
    }
  }
  return first;
}
 
bool operator<(const Pupil &a, const Pupil &b) {
  return a.getGrade() < b.getGrade();
}
 
template <class T>
class Array {
 public:
  typedef T* Iterator;
  typedef const T* ConstIterator;
 
  Array(size_t capacity) : capacity(capacity), size(0),
    data(new T[capacity]) {}
  virtual ~Array() {
    delete [] data;
  }
 
  Iterator begin() { return data; }
  ConstIterator begin() const { return data; }
  Iterator end() { return data + size; }
  ConstIterator end() const { return data + size; }
 
  Iterator insert(Iterator position, const T &value) {
    size_t distance = position - begin();
    if (size >= capacity) {
      increaseCapacity(capacity - size + 1);
    }
    position = data + distance;
    for (Iterator i = end(); i != position; --i) {
      *i = *(i - 1);
    }
    *position = value;
    ++size;
    return position;
  }
 
  size_t getSize() const { return size; }
  size_t getCapacity() const { return capacity; }
 
  void increaseCapacity(size_t n) {
    T *newData = new T[capacity += n];
    for (size_t i = 0; i < size; ++i) {
      newData[i] = data[i];
    }
    delete [] data;
    data = newData;
  }
 private:
  Array(const Array&);
  Array &operator=(const Array&);
  size_t capacity;
  size_t size;
  T *data;
};
 
template <class Container, class Value>
void insertSorted(Container &container, const Value &value) {
  container.insert(upperBound(container.begin(), container.end(), value), value);
}
 
int main(int argc, char *argv[]) {
  Array<Pupil> pupils(10);
 
  insertSorted(pupils, Pupil(9, "Petrov"));
  insertSorted(pupils, Pupil(10, "Petrov"));
  insertSorted(pupils, Pupil(10, "Sidorov"));
  insertSorted(pupils, Pupil(9, "Ivanov"));
  insertSorted(pupils, Pupil(10, "Ivanov"));
  insertSorted(pupils, Pupil(9, "Sidorov"));
  
  for (Array<Pupil>::Iterator i = pupils.begin(); i != pupils.end(); ++i) {
    std::cout << *i << std::endl;
  }
  
  return 0;
}