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<HTML><HEAD><TITLE>A Simple Example</TITLE></HEAD><BODY bgcolor="#FFFFFF"> <a href="../index.html" target="_top"><img src="../icons/usins.gif" alt="Logo" align=right></a><b>Data Structures and Algorithms with Object-Oriented Design Patterns in Python</b><br><A NAME="tex2html2002" HREF="page70.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="../icons/next_motif.gif"></A> <A NAME="tex2html2000" HREF="page68.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="../icons/up_motif.gif"></A> <A NAME="tex2html1994" HREF="page68.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="../icons/previous_motif.gif"></A> <A NAME="tex2html2004" HREF="page611.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="../icons/index_motif.gif"></A> <BR><HR><H2><A NAME="SECTION003210000000000000000">A Simple Example</A></H2><P>Consider the function <IMG WIDTH=165 HEIGHT=28 ALIGN=MIDDLE ALT="tex2html_wrap_inline59389" SRC="img407.gif" >which is shown in Figure <A HREF="page69.html#figomega"><IMG ALIGN=BOTTOM ALT="gif" SRC="../icons/cross_ref_motif.gif"></A>.Clearly, <I>f</I>(<I>n</I>) is non-negative for all integers <IMG WIDTH=39 HEIGHT=24 ALIGN=MIDDLE ALT="tex2html_wrap_inline58503" SRC="img238.gif" >.We wish to show that <IMG WIDTH=91 HEIGHT=28 ALIGN=MIDDLE ALT="tex2html_wrap_inline59395" SRC="img408.gif" >.According to Definition <A HREF="page68.html#defnomega"><IMG ALIGN=BOTTOM ALT="gif" SRC="../icons/cross_ref_motif.gif"></A>,in order to show this we need to find an integer <IMG WIDTH=16 HEIGHT=14 ALIGN=MIDDLE ALT="tex2html_wrap_inline58491" SRC="img235.gif" > and a constant <I>c</I><I>></I>0such that for all integers <IMG WIDTH=47 HEIGHT=22 ALIGN=MIDDLE ALT="tex2html_wrap_inline58525" SRC="img239.gif" >, <IMG WIDTH=75 HEIGHT=28 ALIGN=MIDDLE ALT="tex2html_wrap_inline59403" SRC="img409.gif" >.<P>As with big oh, it does not matter what the particular constants are--as long as they exist!For example, suppose we choose <I>c</I>=1.Then<P> <IMG WIDTH=500 HEIGHT=66 ALIGN=BOTTOM ALT="eqnarray1734" SRC="img410.gif" ><P>Since <IMG WIDTH=85 HEIGHT=28 ALIGN=MIDDLE ALT="tex2html_wrap_inline59407" SRC="img411.gif" > for all values of <IMG WIDTH=39 HEIGHT=24 ALIGN=MIDDLE ALT="tex2html_wrap_inline58503" SRC="img238.gif" >,we conclude that <IMG WIDTH=46 HEIGHT=22 ALIGN=MIDDLE ALT="tex2html_wrap_inline59411" SRC="img412.gif" >.<P>So, we have that for <I>c</I>=1 and <IMG WIDTH=46 HEIGHT=22 ALIGN=MIDDLE ALT="tex2html_wrap_inline59411" SRC="img412.gif" >, <IMG WIDTH=75 HEIGHT=28 ALIGN=MIDDLE ALT="tex2html_wrap_inline59403" SRC="img409.gif" >for all integers <IMG WIDTH=47 HEIGHT=22 ALIGN=MIDDLE ALT="tex2html_wrap_inline58525" SRC="img239.gif" >.Hence, <IMG WIDTH=91 HEIGHT=28 ALIGN=MIDDLE ALT="tex2html_wrap_inline59395" SRC="img408.gif" >.Figure <A HREF="page69.html#figomega"><IMG ALIGN=BOTTOM ALT="gif" SRC="../icons/cross_ref_motif.gif"></A> clearly showsthat the function <IMG WIDTH=67 HEIGHT=28 ALIGN=MIDDLE ALT="tex2html_wrap_inline58565" SRC="img246.gif" > is less thanthe function <I>f</I>(<I>n</I>)=5<I>n</I>-64<I>n</I>+256 for all values of <IMG WIDTH=39 HEIGHT=24 ALIGN=MIDDLE ALT="tex2html_wrap_inline58503" SRC="img238.gif" >.Of course, there are many other values of <I>c</I> and <IMG WIDTH=16 HEIGHT=14 ALIGN=MIDDLE ALT="tex2html_wrap_inline58491" SRC="img235.gif" > that will do.For example, <I>c</I>=2 and <IMG WIDTH=54 HEIGHT=22 ALIGN=MIDDLE ALT="tex2html_wrap_inline58553" SRC="img245.gif" >.<P><P><A NAME="1791"> </A><A NAME="figomega"> </A> <IMG WIDTH=575 HEIGHT=322 ALIGN=BOTTOM ALT="figure1737" SRC="img414.gif" ><BR><STRONG>Figure:</STRONG> Showing that <IMG WIDTH=226 HEIGHT=28 ALIGN=MIDDLE ALT="tex2html_wrap_inline59467" SRC="img413.gif" >.<BR><P><HR><A NAME="tex2html2002" HREF="page70.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="../icons/next_motif.gif"></A> <A NAME="tex2html2000" HREF="page68.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="../icons/up_motif.gif"></A> <A NAME="tex2html1994" HREF="page68.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="../icons/previous_motif.gif"></A> <A NAME="tex2html2004" HREF="page611.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="../icons/index_motif.gif"></A> <P><ADDRESS><img src="../icons/bruno.gif" alt="Bruno" align=right><a href="../copyright.html">Copyright © 2003</a> by <a href="../signature.html">Bruno R. Preiss, P.Eng.</a> All rights reserved.</ADDRESS></BODY></HTML>
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