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<HTML><HEAD><TITLE>Using Adjacency Matrices</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="tex2html7408" HREF="page544.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="../icons/next_motif.gif"></A> <A NAME="tex2html7406" HREF="page542.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="../icons/up_motif.gif"></A> <A NAME="tex2html7400" HREF="page542.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="../icons/previous_motif.gif"></A> <A NAME="tex2html7410" HREF="page611.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="../icons/index_motif.gif"></A> <BR><HR><H3><A NAME="SECTION0016271000000000000000">Using Adjacency Matrices</A></H3><P>The <tt>GraphAsMatrix</tt> class is introduced in Program <A HREF="page543.html#proggraphAsMatrixa"><IMG ALIGN=BOTTOM ALT="gif" SRC="../icons/cross_ref_motif.gif"></A>.The <tt>GraphAsMatrix</tt> class extendsthe abstract <tt>Graph</tt> classintroduced in Programs <A HREF="page537.html#proggrapha"><IMG ALIGN=BOTTOM ALT="gif" SRC="../icons/cross_ref_motif.gif"></A>, <A HREF="page538.html#proggraphb"><IMG ALIGN=BOTTOM ALT="gif" SRC="../icons/cross_ref_motif.gif"></A> and <A HREF="page539.html#proggraphc"><IMG ALIGN=BOTTOM ALT="gif" SRC="../icons/cross_ref_motif.gif"></A>.<P><P><A NAME="50008"> </A><A NAME="proggraphAsMatrixa"> </A> <IMG WIDTH=575 HEIGHT=142 ALIGN=BOTTOM ALT="program49779" SRC="img2271.gif" ><BR><STRONG>Program:</STRONG> <tt>GraphAsMatrix</tt> class <tt>__init__</tt> method.<BR><P><P>Each instance of the <tt>GraphAsMatrix</tt> classrepresents an undirected graph, say <IMG WIDTH=73 HEIGHT=24 ALIGN=MIDDLE ALT="tex2html_wrap_inline70549" SRC="img2166.gif" >.The set of vertices, <IMG WIDTH=11 HEIGHT=12 ALIGN=BOTTOM ALT="tex2html_wrap_inline70551" SRC="img2167.gif" >, is represented usingthe <tt>_vertex</tt> array inherited from the abstract <tt>Graph</tt> base class.Each vertex is represented by a separate <tt>Graph.Vertex</tt> instance.<P>Similarly,The set of edges, <IMG WIDTH=9 HEIGHT=13 ALIGN=BOTTOM ALT="tex2html_wrap_inline70557" SRC="img2168.gif" >, is represented usingthe <tt>_matrix</tt> instance attributewhich is a two-dimensional array of <tt>Edge</tt>s.Each edge is represented by a separate <tt>Graph.Edge</tt> instance.<P>In addition to <tt>self</tt>,the <tt>GraphAsMatrix</tt> <tt>__init__</tt> method takes a single argumentof type <tt>int</tt> that specifiesthe maximum number of vertices that the graph may contain.This quantity specifies the length of thearray of vertices and the dimensions of the adjacency matrix.The implementation of the <tt>GraphAsMatrix</tt> class is leftas programming project for the reader (Project <A HREF="page584.html#projectgraphsmatrix"><IMG ALIGN=BOTTOM ALT="gif" SRC="../icons/cross_ref_motif.gif"></A>).<P><HR><A NAME="tex2html7408" HREF="page544.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="../icons/next_motif.gif"></A> <A NAME="tex2html7406" HREF="page542.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="../icons/up_motif.gif"></A> <A NAME="tex2html7400" HREF="page542.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="../icons/previous_motif.gif"></A> <A NAME="tex2html7410" 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>⌨️ 快捷键说明
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