<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <!--Converted with LaTeX2HTML 2012 (1.2) original version by: Nikos Drakos, CBLU, University of Leeds * revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan * with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --> <HTML> <HEAD> <TITLE>Heap data structure</TITLE> <META NAME="description" CONTENT="Heap data structure"> <META NAME="keywords" CONTENT="userhtml"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <META NAME="Generator" CONTENT="LaTeX2HTML v2012"> <META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css"> <LINK REL="STYLESHEET" HREF="userhtml.css"> <LINK REL="previous" HREF="node49.html"> <LINK REL="up" HREF="node9.html"> <LINK REL="next" HREF="node51.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html856" HREF="node51.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html852" HREF="node9.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html848" HREF="node49.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html854" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <BR> <B> Next:</B> <A NAME="tex2html857" HREF="node51.html">Computational routines</A> <B> Up:</B> <A NAME="tex2html853" HREF="node9.html">Data Structures and Classes</A> <B> Previous:</B> <A NAME="tex2html849" HREF="node49.html">Preconditioner data structure</A> <B> <A NAME="tex2html855" HREF="node1.html">Contents</A></B> <BR> <BR> <!--End of Navigation Panel--> <H2><A NAME="SECTION00045000000000000000"> Heap data structure</A> </H2> <P> Among the tools routines of sec. <A HREF="node70.html#sec:toolsrout">6</A>, we have a number of sorting utilities; the heap sort is implemented in terms of heaps having the following signatures: <DL> <DT><STRONG><TT>psb_T_heap</TT></STRONG></DT> <DD>: a heap containing elements of type T, where T can be <code>i,s,c,d,z</code> for integer, real and complex data; </DD> <DT><STRONG><TT>psb_T_idx_heap</TT></STRONG></DT> <DD>: a heap containing elements of type T, as above, together with an integer index. </DD> </DL> Given a heap object, the following methods are defined on it: <DL> <DT><STRONG>init</STRONG></DT> <DD>Initialize memory; also choose ascending or descending order; </DD> <DT><STRONG>howmany</STRONG></DT> <DD>Current heap occupancy; </DD> <DT><STRONG>insert</STRONG></DT> <DD>Add an item (or an item and its index); </DD> <DT><STRONG>get_first</STRONG></DT> <DD>Remove and return the first element; </DD> <DT><STRONG>dump</STRONG></DT> <DD>Print on file; </DD> <DT><STRONG>free</STRONG></DT> <DD>Release memory. </DD> </DL> These objects are used in MLD2P4 to implement the factorization algorithms. <P> <BR><HR> </BODY> </HTML>