Chapter 11: Review Questions

 1. Given the following class and sample program:

//
//  list.h  - a singly linked list
//
#include
#include

class List
{
public:
    List() { head = NULL; }
    List( char *str );
    ~List() { release(); }
    int getLength( void );
    void append( List& nlst );
    void add( char *str );   // adds to front of list
    void delete( void )
    {
         ListEntry *temp = head;
         current = head = head->next;
         delete temp;
    }
    int search( char *str );
    ListEntry *getFirst( void )
    {
         current = head;
         return head;
    }
    ListEntry *getNext( void )
    {
    ListEntry *temp = current;
         current = current->next;
         return temp;
    }
    void printList( void );
    void release( void );

private:

    typedef
         struct list_entry
         {
              list_entry *next;
              char *data;

         } ListEntry;

    ListEntry *head     // head of list
              , *current     // current node in list
              ;
};
//
//  list.cpp
//
List::List( char *str )
{
    // code this
}

int List::getLength( void )
{
    // code this
}

void List::append( List& nlst )
{
    // code this
}

void List::add( char *str )
{
    ListEntry *temp = new ListEntry;   // new element

    temp->next = head;
    temp->data = new char[strlen(str)+1];
    strcpy( temp->data, str );
    current = head = temp;
}

void List::printList( void )
{
    ListEntry *temp = head;

    cout << "********* Beginning of List ***********" << endl;
    while ( temp != NULL )
    {
         cout << temp->data << endl;
         temp = temp->next;
    }
    cout << "********* End of List ****************" << endl;
}

int List::search( char *str )
{
    // code this
}

void List::release( void )
{
    while ( head != NULL )
         del();
}

int main()
{
List *p;
    {
         List w;

         w.add( "First" );
         w.add( "Second" );
         w.add( "Third" );
         w.add( "Fourth" );
         w.printList();
         cout << "\nThere are "
              << w.getLength()
              << " items in the list."
              << endl;
         cout << "Searching for Second in list. " << endl;
         w.search( "Second" ) ? cout << "\tFound Match " << endl
                             : cout << "\tMatch Not Found" << endl;
         w.delete();
         w.printList();
         p =
         p->printList();
         cout << "\nThere are "
              << w.getLength()
              << " items in the list."
              << endl;
         cout << "Searching for Fourth in list. " << endl;
         w.search( "Fourth" ) ? cout << "\tFound Match " << endl
                             : cout << "\tMatch Not Found" << endl;

    }
    p->printList();
//
//  another List
//
List list2("Item #1");
    list2.add( "Item #2" );
    list2.add( "Item #3" );
    list2.add( "Item #4" );
    list2.add( "Item #5" );
    list2.printList();
    cout << "\nThere are "
         << list2.getLength()
         << " items in the list."
         << endl;
//
//  create another list
//
List list3;
    list3.add( "jim" );
    list3.add( "mary" );
    list3.add( "david" );
    list3.add( "laura" );
    list3.pr_list();
    //
    //   append one list to another
    //
    list3.append( list2 );
    list3.printList();
}

 1. What happens upon exit from the inner block?



 2. Code the following member functions:

    A. // List constructor whose initializer is a character array
       // that is the value held at the first element of the list
       List::List( char *str );


    B. // length returns the length of the list, number of nodes
       int List::getLength( void );


    C. // return true if a match is found, false if not
       int List::search( char *str );


 3. Write a member function  **append** that will add a
    list to the rear of the existing list, then clear the
    list passed by zeroing the head.

    void List::append( List& nlst );

Given the following class implementation:
//
//  clock.cpp - implement a clock class and example program
//
#include

class Clock
{

public:
    Clock( unsigned int i )
    {
         tot_secs = i;
         secs = tot_secs % 60;
         mins = (tot_secs / 60 ) % 60;
         hours = (tot_secs / 3600 ) % 24;
         days = tot_secs / 86400;
    }
    void tick();   // add one second

    friend Clock& operator++(Clock& ck);
    friend ostream& operator<<( ostream& out, Clock& x);

private:
    unsigned int
         tot_secs
         , secs
         , mins
         , hours
         , days
         ;
    void print( void ); // formatted printout

};

void Clock::tick( void )
{
    // code this
}

void Clock::print( void )
{
    cout << days << "d : " << hours << " h : "
         << mins << "m : " << secs << " s" << endl;
}

Clock& operator++(Clock& ck)
{
    // code this
}

ostream& operator<<( ostream& out, Clock& x)
{
}

int main()
{
Clock t1(59), t2(172799);

    cout << "Initial times are " << endl;
    cout << t1;
    cout << t2;
    ++t1;
    ++t2;     // t1++ or t2++ are the same
    cout << "After one second - times are " << endl;
    cout << t1;
    cout << t2;
}

 4. A. Implement the following method:

       void tick();   // add one second


    B. Implement the following method:

       friend Clock& operator++(Clock& ck);


    C. Define the prototype for the above method and
       implement the method as an inline member function
       and not as a friend function.


    D. Implement the following method:

       friend ostream& operator<<( ostream& out, Clock& x);