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/*
* $Revision: 2523 $
*
* last checkin:
* $Author: gutwenger $
* $Date: 2012-07-02 20:59:27 +0200 (Mon, 02 Jul 2012) $
***************************************************************/
/** \file
* \brief Declaration of base class of shortest path algorithms
* including some useful functions dealing with
* shortest paths flow (generater, checker).
*
* \author Gunnar W. Klau
*
* \par License:
* This file is part of the Open Graph Drawing Framework (OGDF).
*
* \par
* Copyright (C)<br>
* See README.txt in the root directory of the OGDF installation for details.
*
* \par
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* Version 2 or 3 as published by the Free Software Foundation;
* see the file LICENSE.txt included in the packaging of this file
* for details.
*
* \par
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* \par
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the Free
* Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
* \see http://www.gnu.org/copyleft/gpl.html
***************************************************************/
#ifdef _MSC_VER
#pragma once
#endif
#ifndef OGDF_SHORTEST_PATH_MODULE_H
#define OGDF_SHORTEST_PATH_MODULE_H
#include <ogdf/basic/Graph.h>
namespace ogdf {
class OGDF_EXPORT ShortestPathModule
{
public:
ShortestPathModule() { }
virtual ~ShortestPathModule() {}
// computes shortest paths
// Precond.:
// returns true iff a feasible min-cost flow exists
virtual bool call(
const Graph &G, // directed graph
const node s, // source node
const EdgeArray<int> &length, // length of an edge
NodeArray<int> &d, // contains shortest path distances after call
NodeArray<edge> &pi
) = 0;
protected:
//
// static functions
//
// generates a shortest path problem instance with n nodes and m+n edges
/*
static void generateProblem(
Graph &G,
int n,
int m,
EdgeArray<int> &lowerBound,
EdgeArray<int> &upperBound,
EdgeArray<int> &cost,
NodeArray<int> &supply);
// checks if a given min-cost flow problem instance satisfies
// the preconditions
//
// lowerBound[e] <= upperBound[e] for all edges e
// cost[e] >= 0 for all edges e
// sum over all supply[v] = 0
static bool checkProblem(
const Graph &G,
const EdgeArray<int> &lowerBound,
const EdgeArray<int> &upperBound,
const EdgeArray<int> &cost,
const NodeArray<int> &supply);
// checks if a computed flow is a feasible solution to the given problem
// instance, i.e., checks if
// lowerBound[e] <= flow[e] <= upperBound[e]
// sum flow[e], e is outgoing edge of v -
// sum flow[e], e is incoming edge of v = supply[v] for each v
// returns true iff the solution is feasible and in value the value of
// the computed flow
static bool checkComputedFlow(
Graph &G,
EdgeArray<int> &lowerBound,
EdgeArray<int> &upperBound,
EdgeArray<int> &cost,
NodeArray<int> &supply,
EdgeArray<int> &flow,
int &value);
static bool checkComputedFlow(
Graph &G,
EdgeArray<int> &lowerBound,
EdgeArray<int> &upperBound,
EdgeArray<int> &cost,
NodeArray<int> &supply,
EdgeArray<int> &flow)
{
int value;
return checkComputedFlow(
G,lowerBound,upperBound,cost,supply,flow,value);
}
*/
};
} // end namespace ogdf
#endif
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