Sequence class

Question1:
Implement the sequence class from Section 3.2. You may wish to provide some additional useful member functions, such as: (1) a function to add a new item at the front of the sequence; (2) a function to remove the item from the front of the sequence; (3) a function to add a new item at the end of the sequence; (4) a function that makes the last item of the sequence become the current item; (5) operators for - and +=. For the + operator, x + y contains all the items of x, followed by all the items of y. The statement x += y appends all of the items of y to the end of what’s already in x.
My answer:
まず本の要求を完成します.作成者が提供するヘッダファイルsequence 1.h:

// 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   // 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

作成者が提供するテストファイルsequence_test.cpp:

// FILE: sequence_test.cxx
// An interactive test program for the new sequence class
#include        // Provides toupper
#include      // Provides cout and cin
#include       // Provides EXIT_SUCCESS
#include "sequence1.h"  // With value_type defined as double
using namespace std;
using namespace main_savitch_3;

// PROTOTYPES for functions used by this test program:
void print_menu( );
// Postcondition: A menu of choices for this program has been written to cout.

char get_user_command( );
// Postcondition: The user has been prompted to enter a one character command.
// The next character has been read (skipping blanks and newline characters), 
// and this character has been returned.

void show_sequence(sequence display);
// Postcondition: The items on display have been printed to cout (one per line).

double get_number( );
// Postcondition: The user has been prompted to enter a real number. The
// number has been read, echoed to the screen, and returned by the function.


int main( )
{
    sequence test; // A sequence that we’ll perform tests on
    char choice;   // A command character entered by the user
    
    cout << "I have initialized an empty sequence of real numbers." << endl;

    do
    {
        print_menu( );
        choice = toupper(get_user_command( ));
        switch (choice)
        {
            case '!': test.start( );
                      break;
            case '+': test.advance( );
                      break;
            case '?': if (test.is_item( ))
                          cout << "There is an item." << endl;
                      else 
                          cout << "There is no current item." << endl;
                      break;
            case 'C': if (test.is_item( ))
                           cout << "Current item is: " << test.current( ) << endl;
                      else
                          cout << "There is no current item." << endl;
                      break;
            case 'P': show_sequence(test);
                      break;
            case 'S': cout << "Size is " << test.size( ) << '.' << endl;
                      break;
            case 'I': test.insert(get_number( ));
                      break;
            case 'A': test.attach(get_number( ));
                      break;
            case 'R': test.remove_current( );
                      cout << "The current item has been removed." << endl;
                      break;     
            case 'Q': cout << "Ridicule is the best test of truth." << endl;
                      break;
            default:  cout << choice << " is invalid." << endl;
        }
    }
    while ((choice != 'Q'));

    return EXIT_SUCCESS;
}

void print_menu( )
// Library facilities used: iostream.h
{
    cout << endl; // Print blank line before the menu
    cout << "The following choices are available: " << endl;
    cout << " !   Activate the start( ) function" << endl;
    cout << " +   Activate the advance( ) function" << endl;
    cout << " ?   Print the result from the is_item( ) function" << endl;
    cout << " C   Print the result from the current( ) function" << endl;
    cout << " P   Print a copy of the entire sequence" << endl;
    cout << " S   Print the result from the size( ) function" << endl;
    cout << " I   Insert a new number with the insert(...) function" << endl;
    cout << " A   Attach a new number with the attach(...) function" << endl;
    cout << " R   Activate the remove_current( ) function" << endl;
    cout << " Q   Quit this test program" << endl;
}

char get_user_command( )
// Library facilities used: iostream
{
    char command;

    cout << "Enter choice: ";
    cin >> command; // Input of characters skips blanks and newline character

    return command;
}

void show_sequence(sequence display)
// Library facilities used: iostream
{
    for (display.start( ); display.is_item( ); display.advance( ))
        cout << display.current( ) << endl;
}

double get_number( )
// Library facilities used: iostream
{
    double result;
    
    cout << "Please enter a real number for the sequence: ";
    cin  >> result;
    cout << result << " has been read." << endl;
    return result;
}

1、2、3のsequence 1を実現する.cppファイル:

#include "sequence1.h"
#include 
#include 

using namespace std;
using namespace main_savitch_3;

sequence::sequence(){
    // If there is a current item, then it lies in data[current_index];
    // if there is no current item, then current_index equals used.
    current_index = used = 0;
}

void sequence::start(){
    current_index = 0;
}

void sequence::advance(){
    current_index = (current_index + 1) % CAPACITY;
    // the max of current_index is CAPACITY-1
}

void sequence::insert(const value_type& entry){
    assert(size() < CAPACITY);
    size_type i;
    if(current_index == used){//no current item
        for(i = current_index; i != 0; i--){
            data[i] = data[i-1];
        }
        data[i] = entry;
        used++;
        current_index = i;
        return;
    }
    for(i = current_index; i < size(); i++);
    for(; i != current_index; i--){
        data[i] = data[i-1];
    }
    data[i] = entry;// now i equals current_index
    used++;
}

void sequence::attach(const value_type& entry){
    assert(size() < CAPACITY);
    size_type i;
    if(current_index == used){//no current item
        data[current_index] = entry;
        used++;
        return;
    }
    for(i = current_index; i < size(); i++);
    for(; i != current_index; i--){
        data[i] = data[i-1];
    }
    data[i+1] = entry;// put entry in data[current_index+1]
    used++;
}

void sequence::remove_current(){
    assert(is_item());
    if(current_index == size()-1){
        // the last one
        used--;
    } else {
        for(size_type i = current_index; i < size(); i++){
            data[i] = data[i+1];
        }
        used--;
    }
}

sequence::size_type sequence::size() const{
    return used;
}

bool sequence::is_item() const{
    if(current_index >= used){
        return false;
    } else {
        return true;
    }
}

sequence::value_type sequence::current() const{
    assert(is_item());
    return data[current_index];
}

実行結果:

I have initialized an empty sequence of real numbers.

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: A
Please enter a real number for the sequence: 4.13
4.13 has been read.

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: S
Size is 1.

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: I
Please enter a real number for the sequence: 9
9 has been read.

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: S
Size is 2.

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: A
Please enter a real number for the sequence: 4
4 has been read.

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: S
Size is 3.

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: !

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: C
Current item is: 9

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: +

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: C
Current item is: 4

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: +

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: C
Current item is: 4.13

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: P
9
4
4.13

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: R
The current item has been removed.

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: D
D is invalid.

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: S
Size is 2.

The following choices are available: 
 !   Activate the start( ) function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 Q   Quit this test program
Enter choice: Q
Ridicule is the best test of truth.
[1] + Done                       /usr/bin/gdb --interpreter=mi --tty=${DbgTerm} 0/tmp/Microsoft-MIEngine-Out-cgrqdfyo.aov

      ...

問題に必要な5つの関数を追加します.

void sequence::insert_head(const value_type& entry){
    assert(size() < CAPACITY);
    size_t i = size();
    for(; i > 0; i--){
        data[i] = data[i-1];//    
    }
    // i = 0
    data[i] = entry;
    used++;
}

void sequence::remove_head(){
    assert(size() > 0);
    size_t i = 0;
    for(; i < size(); i++){
        data[i] = data[i+1];
    }
    used--;
}

void sequence::insert_tail(const value_type& entry){
    assert(size() < CAPACITY);
    data[size()] = entry;
    used++;    
}

void sequence::end(){
    current_index = size() - 1;
}

sequence sequence::operator -(sequence& entry){
    sequence res;
    for(this->start(); this->is_item(); this->advance()){
        res.insert(this->current());
    }
    for(entry.start(); entry.is_item(); entry.advance()){
        for(res.start(); res.is_item(); res.advance()){
            if(res.current() == entry.current()){
                res.remove_current();
            }
        }
    }
    return res;
}

void sequence::operator -=(sequence& entry){
    for(entry.start(); entry.is_item(); entry.advance()){
        for(start(); is_item(); advance()){
            if(entry.current() == current()){
                remove_current();
            }
        }
    }
}

インタラクティブテストプログラムを変更するには、次の手順に従います.

// FILE: sequence_test.cxx
// An interactive test program for the new sequence class
#include        // Provides toupper
#include      // Provides cout and cin
#include       // Provides EXIT_SUCCESS
#include "sequence1.h"  // With value_type defined as double
using namespace std;
using namespace main_savitch_3;

// PROTOTYPES for functions used by this test program:
void print_menu( );
// Postcondition: A menu of choices for this program has been written to cout.

char get_user_command( );
// Postcondition: The user has been prompted to enter a one character command.
// The next character has been read (skipping blanks and newline characters), 
// and this character has been returned.

void show_sequence(sequence display);
// Postcondition: The items on display have been printed to cout (one per line).

double get_number( );
// Postcondition: The user has been prompted to enter a real number. The
// number has been read, echoed to the screen, and returned by the function.


int main( )
{
    sequence test, test1, test2; // A sequence that we’ll perform tests on
    char choice;   // A command character entered by the user
    
    cout << "I have initialized an empty sequence of real numbers." << endl;

    do
    {
        print_menu( );
        choice = toupper(get_user_command( ));
        switch (choice)
        {
            case '!': test.start( );
                      break;
            case '@': test.end();
                      break;
            case '+': test.advance( );
                      break;
            case '?': if (test.is_item( ))
                          cout << "There is an item." << endl;
                      else 
                          cout << "There is no current item." << endl;
                      break;
            case 'C': if (test.is_item( ))
                           cout << "Current item is: " << test.current( ) << endl;
                      else
                          cout << "There is no current item." << endl;
                      break;
            case 'P': show_sequence(test);
                      break;
            case 'S': cout << "Size is " << test.size( ) << '.' << endl;
                      break;
            case 'I': test.insert(get_number( ));
                      break;
            case 'A': test.attach(get_number( ));
                      break;
            case 'R': test.remove_current( );
                      cout << "The current item has been removed." << endl;
                      break;
            case 'H': test.insert_head(get_number());
                      break;
            case 'L': test.remove_head();
                      cout << "The item in the head has been removed." << endl;
                      break;     
            case 'Z': test.insert_tail(get_number());
                      cout << "A new item has been inserted into the tail." << endl;
                      break;
            case 'T': test1.insert(1);
                      test1.insert(2);
                      test1.insert(3);
                      cout << "test:" << endl;
                      show_sequence(test);
                      cout << "test1:" << endl;
                      show_sequence(test1);
                      test2 = test - test1;
                      cout << "test2 = test - test1, its result is" << endl;
                      show_sequence(test2);
                      test -= test1;
                      cout << "test -= test1, its result is" << endl;
                      show_sequence(test);
                      break;
            case 'Q': cout << "Ridicule is the best test of truth." << endl;
                      break;
            default:  cout << choice << " is invalid." << endl;
        }
    }
    while ((choice != 'Q'));

    return EXIT_SUCCESS;
}

void print_menu( )
// Library facilities used: iostream.h
{
    cout << endl; // Print blank line before the menu
    cout << "The following choices are available: " << endl;
    cout << " !   Activate the start( ) function" << endl;
    cout << " @   Activate the end() function" << endl;
    cout << " +   Activate the advance( ) function" << endl;
    cout << " ?   Print the result from the is_item( ) function" << endl;
    cout << " C   Print the result from the current( ) function" << endl;
    cout << " P   Print a copy of the entire sequence" << endl;
    cout << " S   Print the result from the size( ) function" << endl;
    cout << " I   Insert a new number with the insert(...) function" << endl;
    cout << " A   Attach a new number with the attach(...) function" << endl;
    cout << " R   Activate the remove_current( ) function" << endl;
    cout << " H   Insert a new item with insert_head() function" << endl;
    cout << " L   Remove an item with remove_head() function" << endl;
    cout << " Z   Insert a new item with insert_tail() function" << endl;
    cout << " T   Test the operator - and -=" << endl;
    cout << " Q   Quit this test program" << endl;
}

char get_user_command( )
// Library facilities used: iostream
{
    char command;

    cout << "Enter choice: ";
    cin >> command; // Input of characters skips blanks and newline character

    return command;
}

void show_sequence(sequence display)
// Library facilities used: iostream
{
    for (display.start( ); display.is_item( ); display.advance( ))
        cout << display.current( ) << endl;
}

double get_number( )
// Library facilities used: iostream
{
    double result;
    
    cout << "Please enter a real number for the sequence: ";
    cin  >> result;
    cout << result << " has been read." << endl;
    return result;
}

テスト結果:

I have initialized an empty sequence of real numbers.

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: 1
1 is invalid.

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: I
Please enter a real number for the sequence: 2
2 has been read.

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: I
Please enter a real number for the sequence: 3
3 has been read.

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: I4
Please enter a real number for the sequence: 4 has been read.

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: I7
Please enter a real number for the sequence: 7 has been read.

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: I
Please enter a real number for the sequence: 5
5 has been read.

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: P
5
7
4
3
2

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: H
Please enter a real number for the sequence: 2
2 has been read.

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: H
Please enter a real number for the sequence: 0
0 has been read.

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: P
0
2
5
7
4
3
2

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: L
The item in the head has been removed.

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: P
2
5
7
4
3
2

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: Z
Please enter a real number for the sequence: 9.9
9.9 has been read.
A new item has been inserted into the tail.

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: P
2
5
7
4
3
2
9.9

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Enter choice: T
test:
2
5
7
4
3
2
9.9
test1:
3
2
1
test2 = test - test1, its result is
9.9
4
7
5
test -= test1, its result is
5
7
4
9.9

The following choices are available: 
 !   Activate the start( ) function
 @   Activate the end() function
 +   Activate the advance( ) function
 ?   Print the result from the is_item( ) function
 C   Print the result from the current( ) function
 P   Print a copy of the entire sequence
 S   Print the result from the size( ) function
 I   Insert a new number with the insert(...) function
 A   Attach a new number with the attach(...) function
 R   Activate the remove_current( ) function
 H   Insert a new item with insert_head() function
 L   Remove an item with remove_head() function
 Z   Insert a new item with insert_tail() function
 T   Test the operator - and -=
 Q   Quit this test program
Q
Enter choice: Ridicule is the best test of truth.

Data Structures and Other Objects Using C++ ( Fourth Edition ) Michael Main, Walter Savitch. p179 ↩︎