graph/doc/find_flow_cost.html
2013-09-04 21:39:21 +00:00

140 lines
5.0 KiB
HTML

<HTML>
<!--
Copyright (c) Piotr Wygocki 2013
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE_1_0.txt or copy at
http://www.boost.org/LICENSE_1_0.txt)
-->
<Head>
<Title>Boost Graph Library: Find Flow Cost</Title>
<BODY BGCOLOR="#ffffff" LINK="#0000ee" TEXT="#000000" VLINK="#551a8b"
ALINK="#ff0000">
<IMG SRC="../../../boost.png"
ALT="C++ Boost" width="277" height="86">
<BR Clear>
<H1><A NAME="sec:find_flow_cost">
<TT>find_flow_cost</TT>
</H1>
<PRE>
<i>// named parameter version</i>
template &lt;class <a href="./Graph.html">Graph</a>&gt;
typename property_traits&lt;typename property_map &lt; Graph, edge_capacity_t &gt;::type&gt;::value_type
find_flow_cost(const Graph &amp; g,
const bgl_named_params&lt;P, T, R&gt; &amp; params = <i>all defaults</i>)
<i>// non-named parameter version</i>
template&lt;class <a href="./Graph.html">Graph</a>, class Capacity, class ResidualCapacity, class Weight&gt;
typename property_traits&lt;typename property_map &lt; Graph, edge_capacity_t &gt;::type&gt;::value_type
find_flow_cost(const Graph &amp; g, Capacity capacity, ResidualCapacity residual_capacity, Weight weight)
</PRE>
<P>
The <tt>find_flow_cost()</tt> function calculates the minimum cost maximum flow value of a network and given flow. See Section <a
href="./graph_theory_review.html#sec:network-flow-algorithms">Network
Flow Algorithms</a> for a description of maximum flow.
The function calculates the cost from the flow values <i>f(u,v)</i> for <i>(u,v)</i> in
<i>E</i>, which are passed in the form of the residual capacity
<i>r(u,v) = c(u,v) - f(u,v)</i>.
<p>
In order to compute the min cost max flow use :
<a href="./successive_shortest_path_nonnegative_weights.html"><tt>successive_shortest_path_nonnegative_weights()</tt></a> or
<a href="./cycle_canceling.html"><tt>cycle_canceling()</tt></a>.
<H3>Where Defined</H3>
<P>
<a href="../../../boost/graph/successive_shortest_path_nonnegative_weights.hpp"><TT>boost/graph/successive_shortest_path_nonnegative_weights.hpp</TT></a>
<P>
<h3>Parameters</h3>
IN: <tt>const Graph&amp; g</tt>
<blockquote>
A directed graph. The
graph's type must be a model of <a
href="./VertexListGraph.html">VertexListGraph</a> and <a href="./IncidenceGraph.html">IncidenceGraph</a> For each edge
<i>(u,v)</i> in the graph, the reverse edge <i>(v,u)</i> must also
be in the graph.
</blockquote>
<h3>Named Parameters</h3>
IN: <tt>capacity_map(CapacityEdgeMap cap)</tt>
<blockquote>
The edge capacity property map. The type must be a model of a
constant <a
href="../../property_map/doc/LvaluePropertyMap.html">Lvalue Property Map</a>. The
key type of the map must be the graph's edge descriptor type.<br>
<b>Default:</b> <tt>get(edge_capacity, g)</tt>
</blockquote>
IN: <tt>residual_capacity_map(ResidualCapacityEdgeMap res)</tt>
<blockquote>
This maps edges to their residual capacity. The type must be a model
of a mutable <a
href="../../property_map/doc/LvaluePropertyMap.html">Lvalue Property
Map</a>. The key type of the map must be the graph's edge descriptor
type.<br>
<b>Default:</b> <tt>get(edge_residual_capacity, g)</tt>
</blockquote>
IN: <tt>weight_map(WeightMap w_map)</tt>
<blockquote>
The weight or ``cost'' of each edge in the graph.
The type <tt>WeightMap</tt> must be a model of
<a href="../../property_map/doc/ReadablePropertyMap.html">Readable Property Map</a>. The edge descriptor type of
the graph needs to be usable as the key type for the weight
map. The value type for this map must be
the same as the value type of the distance map.<br>
<b>Default:</b> <tt>get(edge_weight, g)</tt><br>
</blockquote>
<h3>Complexity</h3>
The complexity is <i> O(|E|)</i>,
<h3>Example</h3>
The function is used in the successive_shortest_path_nonnegative_weights example. The program in <a
href="../example/successive_shortest_path_nonnegative_weights_example.cpp"><tt>example/successive_shortest_path_nonnegative_weights_example.cpp</tt></a>.
<h3>See Also</h3>
<a href="./cycle_canceling.html"><tt>cycle_canceling()</tt></a><br>
<a href="./successive_shortest_path_nonnegative_weights.html"><tt>successive_shortest_path_nonnegative_weights()</tt></a>.
<br>
<HR>
<TABLE>
<TR valign=top>
<TD nowrap>Copyright &copy; 2013</TD><TD>
Piotr Wygocki, University of Warsaw (<A HREF="mailto:wygos@mimuw.edu.pl">wygos at mimuw.edu.pl</A>)
</TD></TR></TABLE>
</BODY>
</HTML>
<!-- LocalWords: HTML Siek Edmonds BGCOLOR ffffff ee VLINK ALINK ff IMG SRC
-->
<!-- LocalWords: gif ALT BR sec edmonds karp TT DIV CELLPADDING TR TD PRE lt
-->
<!-- LocalWords: typename VertexListGraph CapacityEdgeMap ReverseEdgeMap gt
-->
<!-- LocalWords: ResidualCapacityEdgeMap VertexIndexMap src rev ColorMap pred
-->
<!-- LocalWords: PredEdgeMap tt href html hpp ul li nbsp br LvaluePropertyMap
-->
<!-- LocalWords: num ColorValue DIMACS cpp pre config iostream dimacs int std
-->
<!-- LocalWords: namespace vecS directedS cout endl iter ei HR valign nowrap
-->
<!-- LocalWords: jeremy siek htm Univ mailto jsiek lsc edu
p -->