Дополнить класс динамическим массивом

// FILE: sequence2.h
// CLASS PROVIDED: sequence (part of the namespace main_savitch_4)
// There is no implementation file provided for this class since it is
// an exercise from Chapter 4 of "Data Structures and Other Objects Using C++"
//
// TYPEDEFS and MEMBER CONSTANTS for the sequence class:
//   typedef ____ value_type
//     sequence::value_type is the data type of the items in the sequence. It
//     may be any of the C++ built-in types (int, char, etc.), or a class with a
//     default constructor, an assignment operator, and a copy constructor.
//
//   typedef ____ size_type
//     sequence::size_type is the data type of any variable that keeps track of
//     how many items are in a sequence.
//
//   static const size_type DEFAULT_CAPACITY = _____
//     sequence::DEFAULT_CAPACITY is the initial capacity of a sequence that is
//     created by the default constructor.
//
// CONSTRUCTOR for the sequence class:
//   sequence(size_t initial_capacity = DEFAULT_CAPACITY)
//     Postcondition: The sequence has been initialized as an empty sequence.
//     The insert/attach functions will work efficiently (without allocating
//     new memory) until this capacity is reached.
//
// MODIFICATION MEMBER FUNCTIONS for the sequence class:
//   void resize(size_type new_capacity)
//     Postcondition: The sequence's current capacity is changed to the 
//     new_capacity (but not less that the number of items already on the
//     list). The insert/attach functions will work efficiently (without
//     allocating new memory) until this new capacity is reached.
//
//   void start( )
//     Postcondition: The first item on the sequence becomes the current item
//     (but if the sequence is empty, then there is no current item).
//
//   void advance( )
//     Precondition: is_item returns true.
//     Postcondition: If the current item was already the last item in the
//     sequence, then there is no longer any current item. Otherwise, the new
//     current item is the item immediately after the original current item.
//
//   void insert(const value_type& entry)
//     Postcondition: A new copy of entry has been inserted in the sequence
//     before the current item. If there was no current item, then the new entry 
//     has been inserted at the front of the sequence. In either case, the newly
//     inserted item is now the current item of the sequence.
//
//   void attach(const value_type& entry)
//     Postcondition: A new copy of entry has been inserted in the sequence after
//     the current item. If there was no current item, then the new entry has 
//     been attached to the end of the sequence. In either case, the newly
//     inserted item is now the current item of the sequence.
//
//   void remove_current( )
//     Precondition: is_item returns true.
//     Postcondition: The current item has been removed from the sequence, and the
//     item after this (if there is one) is now the new current item.
//
// CONSTANT MEMBER FUNCTIONS for the sequence class:
//   size_type size( ) const
//     Postcondition: The return value is the number of items in the sequence.
//
//   bool is_item( ) const
//     Postcondition: A true return value indicates that there is a valid
//     "current" item that may be retrieved by activating the current
//     member function (listed below). A false return value indicates that
//     there is no valid current item.
//
//   value_type current( ) const
//     Precondition: is_item( ) returns true.
//     Postcondition: The item returned is the current item in the sequence.
//
// VALUE SEMANTICS for the sequence class:
//    Assignments and the copy constructor may be used with sequence objects.
//
// DYNAMIC MEMORY USAGE by the List
//   If there is insufficient dynamic memory, then the following functions
//   throw a BAD_ALLOC exception: The constructors, insert, attach. 
 
#ifndef MAIN_SAVITCH_SEQUENCE_H
#define MAIN_SAVITCH_SEQUENCE_H
#include <cstdlib>  // Provides size_t
 
namespace main_savitch_4
{
    class sequence
    {
    public:
        // TYPEDEFS and MEMBER CONSTANTS
        typedef double value_type;
        typedef std::size_t size_type;
        static const size_type DEFAULT_CAPACITY = 30;
        // CONSTRUCTORS and DESTRUCTOR
        sequence(size_type initial_capacity = DEFAULT_CAPACITY);
        sequence(const sequence& source);
    ~sequence( );
        // MODIFICATION MEMBER FUNCTIONS
    void resize(size_type new_capacity);
        void start( );
        void advance( );
        void insert(const value_type& entry);
        void attach(const value_type& entry);
        void remove_current( );
        void operator =(const sequence& source);
        // CONSTANT MEMBER FUNCTIONS
        size_type size( ) const;
        bool is_item( ) const;
        value_type current( ) const;
    private:
        value_type* data;
        size_type used;
        size_type current_index;
    size_type capacity;
    };
}
 
#endif

// Section CSC-161-500 - Computer Science II: C++
// File Name: sequence1.cxx
// Student: Anna Pavlenko
// Homework Number: Homework Two
// Description: sequence1.cxx - an implementation file for the sequence class, version 1
// Last Changed:
    
// FILE:    sequence1.cxx
//CLASS IMPLEMENTED: sequence
//INVARIANT for sequence class:
//   1. The number of items in the sequence is in the member variable used;
//   2. For an empty sequence, we do not care what is stored in any of data; for a
//      non-empty sequence the items in the bag are stored in data[0] through
//      data[used-1]. The items in a sequence are arranged in an order, one after another
 
#include <iostream> 
#include <algorithm>
#include <cassert> // Provides assert function
#include "sequence1.h" // With value_type defined as double
using namespace std;
 
namespace main_savitch_3
{
    // MODIFICATION MEMBER FUNCTIONS
    sequence::sequence() 
    {
     current_index = 0;
     used = 0;
    }    
    
    void sequence::start( )
    {
    current_index = 0;
    }   
    
     void sequence::advance( )
    {
    assert(it_item());      
    current_index++;
    }             
   
    //insert member function
    
    void sequence::insert(const value_type&entry)
    {
        size_type i;
         
        assert(size() < CAPACITY);
        
        if(!is_item())
           current_index = 0;
        for (i = used; i > current_index; --i)
        {
           data[i] = data[i - 1];
           data[current_index] = entry;
           used++;
        }
     }
 
   // attach member function
   
     void sequence::attach(const value_type& entry);
     {
        size_type i;
         
        assert(size() < CAPACITY);
        
        if(!is_item())
           data[current_index] = entry;
           
        else 
        {  
        for (i = used; i > current_index+1; --i)
           data[i] = data[i - 1];
           data[current_index+1] = entry;
           current_index++;
        }
        used++;
     }
     
     
     void sequence::remove_current( )
    {
        size_type i;
         
        assert(is_item( ));
 
       for (i = current_index+1; i < used; i++)
       data[i-1] = data[i];
       used--;
    }
     
   
    // CONSTANT MEMBER FUNCTIONS
      sequence::size_type sequence::size( ) const
       {
       return used; 
       }
 
      bool sequence::is_item( ) const
      {    
      return (current_index < used);
      }
 
      sequence::value_type sequence::current( ) const
      {  
       assert(is_item( ));                      
       return data[current_index];
      }
 
      
      
    system("Pause");
    return 0;
}

#include <stdexcept>
 
class sequence {
 public:
  // TYPEDEFS and MEMBER CONSTANTS
  typedef double value_type;
  typedef std::size_t size_type;
  static const size_type DEFAULT_CAPACITY = 30;
  // CONSTRUCTORS and DESTRUCTOR
  sequence(size_type initial_capacity = DEFAULT_CAPACITY);
  sequence(const sequence& source);
  ~sequence();
  // MODIFICATION MEMBER FUNCTIONS
  void resize(size_type new_capacity);
  void start();
  void advance();
  void insert(const value_type& entry);
  void attach(const value_type& entry);
  void remove_current();
  void operator =(const sequence& source);
  void copy_from(const sequence &source);
  // CONSTANT MEMBER FUNCTIONS
  size_type size() const;
  bool is_item() const;
  value_type current() const;
 private:
  value_type* data;
  size_type used;
  size_type current_index;
  size_type capacity;
};
 
// CONSTRUCTOR for the sequence class:
//   sequence(size_t initial_capacity = DEFAULT_CAPACITY)
//     Postcondition: The sequence has been initialized as an empty sequence.
//     The insert/attach functions will work efficiently (without allocating
//     new memory) until this capacity is reached.
sequence::sequence(size_type initial_capacity)
  : data(0), used(0), current_index(0), capacity(0) {
  resize(initial_capacity);
}
 
// VALUE SEMANTICS for the sequence class:
//    Assignments and the copy constructor may be used with sequence objects.
sequence::sequence(const sequence& source)
  : data(0), used(0), current_index(0), capacity(0) {
  copy_from(source);
}
 
sequence::~sequence() {
  delete [] data;
}
 
// COPYING FUNCTION
// copies a sequence into current sequence
void sequence::copy_from(const sequence &source) {
  if (this != &source) {
    delete [] this->data;
    this->used = source.used;
    this->current_index = source.current_index;
    this->capacity = source.capacity;
    this->data = new value_type[capacity];
    for (size_type i = 0; i < this->used; ++i) {
      this->data[i] = source.data[i];
    }
  }
}
 
//   void resize(size_type new_capacity)
//     Postcondition: The sequence's current capacity is changed to the 
//     new_capacity (but not less that the number of items already on the
//     list). The insert/attach functions will work efficiently (without
//     allocating new memory) until this new capacity is reached.
void sequence::resize(size_type new_capacity) {
  new_capacity = (new_capacity < used) ? used : new_capacity;
  // no meaningless action
  if (new_capacity == capacity) {
    return;
  }
  value_type *new_data = new value_type[new_capacity];
  for (size_type i = 0; i < used; ++i) {
    new_data[i] = data[i];
  }
  delete [] data;
  data = new_data;
  capacity = new_capacity;
}
 
//   void start( )
//     Postcondition: The first item on the sequence becomes the current item
//     (but if the sequence is empty, then there is no current item).
void sequence::start() {
  current_index = 0;
}
 
//   void advance( )
//     Precondition: is_item returns true.
//     Postcondition: If the current item was already the last item in the
//     sequence, then there is no longer any current item. Otherwise, the new
//     current item is the item immediately after the original current item.
void sequence::advance() {
  ++current_index;
}
 
//   void insert(const value_type& entry)
//     Postcondition: A new copy of entry has been inserted in the sequence
//     before the current item. If there was no current item, then the new entry 
//     has been inserted at the front of the sequence. In either case, the newly
//     inserted item is now the current item of the sequence.
void sequence::insert(const value_type &entry) {
  if (size() >= capacity) {
    resize(size() + 1);
  }
  for (size_type i = size(); i > current_index; --i) {
    data[i] = data[i - 1];
  }
  ++used;
  data[current_index] = entry;
}
 
//   void attach(const value_type& entry)
//     Postcondition: A new copy of entry has been inserted in the sequence after
//     the current item. If there was no current item, then the new entry has 
//     been attached to the end of the sequence. In either case, the newly
//     inserted item is now the current item of the sequence.
void sequence::attach(const value_type& entry) {
  if (is_item()) {
    advance();
  }
  insert(entry);
}
 
//   void remove_current( )
//     Precondition: is_item returns true.
//     Postcondition: The current item has been removed from the sequence, and the
//     item after this (if there is one) is now the new current item.
void sequence::remove_current() {
  if (is_item()) {
    for (size_type i = current_index; i < size(); ++i) {
      data[i] = data[i + 1];
    }
    --used;
  }
}
 
//   size_type size( ) const
//     Postcondition: The return value is the number of items in the sequence.
sequence::size_type sequence::size() const {
  return used;
}
 
//   bool is_item( ) const
//     Postcondition: A true return value indicates that there is a valid
//     "current" item that may be retrieved by activating the current
//     member function (listed below). A false return value indicates that
//     there is no valid current item.
bool sequence::is_item() const {
  return current_index < used;
}
 
//   value_type current( ) const
//     Precondition: is_item( ) returns true.
//     Postcondition: The item returned is the current item in the sequence.
sequence::value_type sequence::current() const {
  if (!is_item()) {
    throw std::overflow_error("no more elements in sequence");
  }
  return data[current_index];
}