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- <Head>
- <Title>Boost Graph Library: Depth-First Visit</Title>
- <BODY BGCOLOR="#ffffff" LINK="#0000ee" TEXT="#000000" VLINK="#551a8b"
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- <IMG SRC="../../../boost.png"
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- <BR Clear>
- <H2><A NAME="sec:dfs"></A>
- <img src="figs/python.gif" alt="(Python)"/>
- <TT>depth_first_visit</TT>
- </H2>
- <P>
- <PRE>
- template <class <a href="./IncidenceGraph.html">IncidenceGraph</a>, class <a href="./DFSVisitor.html">DFSVisitor</a>, class ColorMap>
- void depth_first_visit(IncidenceGraph& g,
- typename graph_traits<IncidenceGraph>::vertex_descriptor s,
- DFSVisitor& vis, ColorMap color)
- template <class <a href="./IncidenceGraph.html">IncidenceGraph</a>, class <a href="./DFSVisitor.html">DFSVisitor</a>, class ColorMap,
- class TerminatorFunc>
- void depth_first_visit(IncidenceGraph& g,
- typename graph_traits<IncidenceGraph>::vertex_descriptor s,
- DFSVisitor& vis, ColorMap color, TerminatorFunc func = TerminatorFunc())
- </PRE>
- <P>
- This function visits all of the vertices in the same connected
- component as the source vertex <tt>s</tt>, using the <a
- href="./graph_theory_review.html#sec:dfs-algorithm">depth-first
- pattern</a>. The main purpose of the function is for the
- implementation of <TT>depth_first_search()</TT> though sometimes it is
- useful on its own.
- <p>
- The <tt>DFSVisitor</tt> supplied by the user determines what
- actions are taken at each event-point within the algorithm.
- <p>
- The <tt>ColorMap</tt> is used by the algorithm to keep track
- of which vertices have been visited.
- <p>The second variant can be used, for example, to find all marked vertices
- reachable from a start vertex by a path which does not contain any another
- marked vertices.
- <P>
- <h3>Where Defined:</h3>
- <a href="../../../boost/graph/depth_first_search.hpp"><TT>boost/graph/depth_first_search.hpp</TT></a>
- <h3>Parameters</h3>
- IN <tt>IncidenceGraph& g</tt>
- <blockquote>
- A directed or undirected graph. The graph's type must be a model of
- <a href="./IncidenceGraph.html">Incidence Graph</a>.<br>
- <b>Python</b>: The parameter is named <tt>graph</tt>.
- </blockquote>
- IN: <tt>vertex_descriptor s</tt>
- <blockquote>
- The source vertex from which to start the search.<br>
- <b>Python</b>: The parameter is named <tt>root_vertex</tt>.
- </blockquote>
- IN: <tt>DFSVisitor visitor</tt>
- <blockquote>
- A visitor object that is invoked inside the algorithm at the
- event-points specified by the <a href="./DFSVisitor.html">DFS
- Visitor</a> concept. The visitor object is passed by value <a
- href="#1">[1]</a>.<br>
- <b>Python</b>: The parameter should be an object that derives from
- the <a href="DFSVisitor.html#python"><tt>DFSVisitor</tt></a> type of
- the graph.
- </blockquote>
- UTIL: <tt>ColorMap color</tt>
- <blockquote>
- This is used by the algorithm to keep track of its progress through
- the graph. The type <tt>ColorMap</tt> must be a model of <a
- href="../../property_map/doc/ReadWritePropertyMap.html">Read/Write
- Property Map</a> and its key type must be the graph's vertex
- descriptor type and the value type of the color map map must model
- <a href="./ColorValue.html">Color Value</a>.<br>
- <b>Python</b>: The color map must be a <tt>vertex_color_map</tt> for
- the graph.
- </blockquote>
- IN: <tt>TerminatorFunc func</tt>
- <blockquote>
- A function object callable with two parameters - the descriptor of
- vertex and the graph instance - and returning bool. The call is made
- immediately after call to 'discover_vertex' visitor
- event. If <tt>true</tt> is returned, the out edges of the vertex are
- not examined, as if they don't exist.<br>
- <b>Python</b>: Unsupported parameter.
- </blockquote>
- <P>
- <h3>Complexity</h3>
- Time complexity is <i>O(E)</i>.
- <h3>Notes</h3>
- <p><a name="1">[1]</a>
- Since the visitor parameter is passed by value, if your visitor
- contains state then any changes to the state during the algorithm
- will be made to a copy of the visitor object, not the visitor object
- passed in. Therefore you may want the visitor to hold this state by
- pointer or reference.
- <br>
- <HR>
- <TABLE>
- <TR valign=top>
- <TD nowrap>Copyright © 2000-2001</TD><TD>
- <A HREF="http://www.boost.org/people/jeremy_siek.htm">Jeremy Siek</A>, Indiana University (<A HREF="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</A>)
- </TD></TR></TABLE>
- </BODY>
- </HTML>
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