Написание класса

// FILE: sequence1.h
// CLASS PROVIDED: sequence (part of the namespace main_savitch_3)
// There is no implementation file provided for this class since it is
// an exercise from Section 3.2 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 CAPACITY = _____
//     sequence::CAPACITY is the maximum number of items that a sequence can hold.
//
// CONSTRUCTOR for the sequence class:
//   sequence( )
//     Postcondition: The sequence has been initialized as an empty sequence.
//
// MODIFICATION MEMBER FUNCTIONS for the sequence class:
//   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)
//     Precondition: size( ) < CAPACITY.
//     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)
//     Precondition: size( ) < CAPACITY.
//     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.
 
#ifndef MAIN_SAVITCH_SEQUENCE_H
#define MAIN_SAVITCH_SEQUENCE_H
#include <cstdlib>  // Provides size_t
 
namespace main_savitch_3
{
    class sequence
    {
    public:
        // TYPEDEFS and MEMBER CONSTANTS
        typedef double value_type;
        typedef std::size_t size_type;
        static const size_type CAPACITY = 30;
        // CONSTRUCTOR
        sequence( );
        // MODIFICATION MEMBER FUNCTIONS
        void start( );
        void advance( );
        void insert(const value_type& entry);
        void attach(const value_type& entry);
        void remove_current( );
        // CONSTANT MEMBER FUNCTIONS
        size_type size( ) const;
        bool is_item( ) const;
        value_type current( ) const;
    private:
        value_type data[CAPACITY];
        size_type used;
        size_type current_index;
    };
}
 
#endif

// 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 <algorithm>
#include <cassert>
#include "sequence1.h"
using namespace std;
 
namespace main_savitch_3
{
    // Static Member Constant
    const sequence::size_type sequence::CAPACITY;
    
    // size_type
    sequence::size_type sequence::erase(const value_type&target)
    {
        size_type index=0;
        size_type many_removed = 0;
        
        while (index < used)
        {
            if(data[index] == target)
            {
                --used;
                data[index] = data[used];
                ++many_removed;
            }
            else
                ++index;
        }
        return many_removed;
    }
    
    sequence::sequence()
    {
        reset();
    }
    
    //insert member functions
    
    
    
    void sequence::insert(const value_type&entry)
    {
        assert(size() < CAPACITY)
        data[used]=entry;
        ++used;
    }
 
    system("Pause");
    return 0;
}