twain3.0/3rdparty/boost_1_73_0/boost/graph/detail/augment.hpp

67 lines
2.2 KiB
C++

//=======================================================================
// Copyright 2013 University of Warsaw.
// Authors: Piotr Wygocki
//
// 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)
//=======================================================================
#ifndef BOOST_GRAPH_AUGMENT_HPP
#define BOOST_GRAPH_AUGMENT_HPP
#include <boost/graph/filtered_graph.hpp>
namespace boost
{
namespace detail
{
template < class Graph, class ResCapMap >
filtered_graph< const Graph, is_residual_edge< ResCapMap > > residual_graph(
const Graph& g, ResCapMap residual_capacity)
{
return filtered_graph< const Graph, is_residual_edge< ResCapMap > >(
g, is_residual_edge< ResCapMap >(residual_capacity));
}
template < class Graph, class PredEdgeMap, class ResCapMap,
class RevEdgeMap >
inline void augment(const Graph& g,
typename graph_traits< Graph >::vertex_descriptor src,
typename graph_traits< Graph >::vertex_descriptor sink, PredEdgeMap p,
ResCapMap residual_capacity, RevEdgeMap reverse_edge)
{
typename graph_traits< Graph >::edge_descriptor e;
typename graph_traits< Graph >::vertex_descriptor u;
typedef typename property_traits< ResCapMap >::value_type FlowValue;
// find minimum residual capacity along the augmenting path
FlowValue delta = (std::numeric_limits< FlowValue >::max)();
e = get(p, sink);
do
{
BOOST_USING_STD_MIN();
delta = min BOOST_PREVENT_MACRO_SUBSTITUTION(
delta, get(residual_capacity, e));
u = source(e, g);
e = get(p, u);
} while (u != src);
// push delta units of flow along the augmenting path
e = get(p, sink);
do
{
put(residual_capacity, e, get(residual_capacity, e) - delta);
put(residual_capacity, get(reverse_edge, e),
get(residual_capacity, get(reverse_edge, e)) + delta);
u = source(e, g);
e = get(p, u);
} while (u != src);
}
} // namespace detail
} // namespace boost
#endif /* BOOST_GRAPH_AUGMENT_HPP */