📄 page89.html
字号:
<HTML>
<HEAD>
<TITLE>An Implementation</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
<img src="cover75.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/cover75.gif" alt="Logo" align=right>
<b>Data Structures and Algorithms
with Object-Oriented Design Patterns in C++</b><br>
<A NAME="tex2html3010" HREF="page90.html" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page90.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="next_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/next_motif.gif"></A> <A NAME="tex2html3008" HREF="page88.html" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page88.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="up_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/up_motif.gif"></A> <A NAME="tex2html3002" HREF="page88.html" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page88.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="previous_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/previous_motif.gif"></A> <A NAME="tex2html3012" HREF="page9.html" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page9.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="contents_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/contents_motif.gif"></A> <A NAME="tex2html3013" HREF="page620.html" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page620.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="index_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/index_motif.gif"></A> <BR><HR>
<H2><A NAME="SECTION005210000000000000000">An Implementation</A></H2>
<P>
Figure <A HREF="page89.html#figlinklist3" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page89.html#figlinklist3"><IMG ALIGN=BOTTOM ALT="gif" SRC="cross_ref_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/cross_ref_motif.gif"></A> illustrates the
the singly-linked list scheme we have chosen to implement.
Two structures are used.
The elements of the list are represented using a structure
which comprises two fields--<tt>datum</tt> and <tt>next</tt>.
The former holds the a single data item;
the latter is a pointer to the next array element.
The main structure also comprises two fields-<tt>head</tt> and <tt>tail</tt>.
Which contain pointers to the first and last list elements, respectively.
<P>
<P><A NAME="3436"> </A><A NAME="figlinklist3"> </A> <IMG WIDTH=575 HEIGHT=284 ALIGN=BOTTOM ALT="figure3255" SRC="img613.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/img613.gif" ><BR>
<STRONG>Figure:</STRONG> Memory Representation of Linked List Objects<BR>
<P>
<P>
Program <A HREF="page89.html#proglinklist1h" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page89.html#proglinklist1h"><IMG ALIGN=BOTTOM ALT="gif" SRC="cross_ref_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/cross_ref_motif.gif"></A> gives the declaration of the
<tt>LinkedList<T></tt> and <tt>ListElement<T></tt> class templates.
The <tt>ListElement<T></tt> class
is used to represent the elements of a linked list.
It has two private member variables,
<tt>datum</tt> and <tt>next</tt>,
a private constructor, and two public accessor functions.
<P>
<P><A NAME="3797"> </A><A NAME="proglinklist1h"> </A> <IMG WIDTH=575 HEIGHT=811 ALIGN=BOTTOM ALT="program3445" SRC="img614.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/img614.gif" ><BR>
<STRONG>Program:</STRONG> <tt>LinkedList<T></tt> and <tt>ListElement<T></tt> Class Definitions<BR>
<P>
<P>
A <tt>LinkedList<T></tt> class object has two protected member variables,
<tt>head</tt> and <tt>tail</tt>,
several constructors, a destructor,
and various other member functions.
<P>
We can calculate the total storage required, <I>S</I>(<I>n</I>),
to hold a linked list of <I>n</I> items
from the class definitions given in Program <A HREF="page89.html#proglinklist1h" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page89.html#proglinklist1h"><IMG ALIGN=BOTTOM ALT="gif" SRC="cross_ref_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/cross_ref_motif.gif"></A> as follows:
<P> <IMG WIDTH=500 HEIGHT=87 ALIGN=BOTTOM ALT="eqnarray3492" SRC="img615.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/img615.gif" ><P>
Since <tt>LinkedList<T></tt> and <tt>ListElement<T></tt>
are generic classes,
we have no <em>a priori</em> knowledge of the amount of storage
used by an object of type <tt>T</tt>.
However, it is often reasonable to assume that <IMG WIDTH=123 HEIGHT=24 ALIGN=MIDDLE ALT="tex2html_wrap_inline61013" SRC="img616.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/img616.gif" >.<A NAME="tex2html140" HREF="footnode.html#3817" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/footnode.html#3817"><IMG ALIGN=BOTTOM ALT="gif" SRC="foot_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/foot_motif.gif"></A>
And since a pointer requires a constant amount of space,
<IMG WIDTH=189 HEIGHT=24 ALIGN=MIDDLE ALT="tex2html_wrap_inline61019" SRC="img619.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/img619.gif" >.
If we assume that the amount of storage used by an object
of type <tt>T</tt> is <I>O</I>(1), then <I>S</I>(<I>n</I>)=<I>O</I>(<I>n</I>).
<P>
<HR><A NAME="tex2html3010" HREF="page90.html" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page90.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="next_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/next_motif.gif"></A> <A NAME="tex2html3008" HREF="page88.html" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page88.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="up_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/up_motif.gif"></A> <A NAME="tex2html3002" HREF="page88.html" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page88.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="previous_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/previous_motif.gif"></A> <A NAME="tex2html3012" HREF="page9.html" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page9.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="contents_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/contents_motif.gif"></A> <A NAME="tex2html3013" HREF="page620.html" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/html/page620.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="index_motif.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/index_motif.gif"></A> <P><ADDRESS>
<img src="bruno.gif" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/icons/bruno.gif" alt="Bruno" align=right>
<a href="javascript:if(confirm('http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/copyright.html \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/copyright.html'" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/copyright.html">Copyright © 1997</a> by <a href="javascript:if(confirm('http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/signature.html \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/signature.html'" tppabs="http://dictator.uwaterloo.ca/Bruno.Preiss/books/opus4/signature.html">Bruno R. Preiss, P.Eng.</a> All rights reserved.
</ADDRESS>
</BODY>
</HTML>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -