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<Title>Vertex Mutable Graph</Title>
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<H2><A NAME="concept:VertexMutableGraph">
Vertex Mutable Graph
</H2>
A vertex mutable graph can be changed by adding or removing
vertices. The memory management is the responsibility of the graph
implementation. The graph user need only make calls to
<TT>add_vertex</TT> and <TT>remove_vertex</TT> and the graph
implementation does the rest.
<H3>Refinement of</H3>
<a href="./Graph.html">Graph</a> and <a
href="http://www.sgi.com/tech/stl/DefaultConstructible.html">DefaultConstructible</a>
<H3>Associated Types</H3>
No additional associated types.
<h3>Valid Expressions</h3>
<ul>
<li><a name="sec:add_vertex"><TT>add_vertex(g)</TT></a>
<b>returns</b> <TT>vertex_descriptor</TT>
<br><br>
<b>Semantics:</b> Add a new vertex to the graph. The
<TT>vertex_descriptor</TT> for the new vertex is returned.<br>
</li>
<li><a name="sec:remove_vertex"><tt>remove_vertex(u, g)</tt></a>
<b>returns</b> <tt>void</tt><br><br>
<b> Semantics:</b> Remove <i>u</i> from the vertex set of the graph.
<br>
<b> Preconditions:</b> <i>u</i> is a valid vertex descriptor of graph <i>g</i>
and there are no edges incident to vertex <i>u</i>. The function
<TT>clear_vertex</TT> can be used to remove all incident edges.
<br>
<b> Postconditions: </b> <TT>num_vertices(g)</TT> is one less; <i>u</i>
no longer appears in the vertex set of the graph and it
is no longer a valid vertex descriptor.
</li>
</ul>
<H3>Complexity guarantees</H3>
<ul>
<li> Vertex insertion is guaranteed to be amortized constant time.
<li> Vertex removal is at most <TT>O(|E| + |V|)</TT>.
</ul>
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<TABLE>
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<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>)
<A HREF="http://www.boost.org/people/jeremy_siek.htm">Lie-Quan Lee</A>, Indiana University (<A HREF="mailto:llee@cs.indiana.edu">llee@cs.indiana.edu</A>)
</TD></TR></TABLE>
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