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CodeBlocksPortable/Borland/BCC55/Examples/StdLib/graph.cpp

160 lines
5.1 KiB
C++

#include "stlexam.h"
#pragma hdrstop
/**************************************************************************
*
* graph.cpp - Graph program. Section 9.3.2
*
***************************************************************************
*
* (c) Copyright 1994, 1998 Rogue Wave Software, Inc.
* ALL RIGHTS RESERVED
*
* The software and information contained herein are proprietary to, and
* comprise valuable trade secrets of, Rogue Wave Software, Inc., which
* intends to preserve as trade secrets such software and information.
* This software is furnished pursuant to a written license agreement and
* may be used, copied, transmitted, and stored only in accordance with
* the terms of such license and with the inclusion of the above copyright
* notice. This software and information or any other copies thereof may
* not be provided or otherwise made available to any other person.
*
* Notwithstanding any other lease or license that may pertain to, or
* accompany the delivery of, this computer software and information, the
* rights of the Government regarding its use, reproduction and disclosure
* are as set forth in Section 52.227-19 of the FARS Computer
* Software-Restricted Rights clause.
*
* Use, duplication, or disclosure by the Government is subject to
* restrictions as set forth in subparagraph (c)(1)(ii) of the Rights in
* Technical Data and Computer Software clause at DFARS 252.227-7013.
* Contractor/Manufacturer is Rogue Wave Software, Inc.,
* P.O. Box 2328, Corvallis, Oregon 97339.
*
* This computer software and information is distributed with "restricted
* rights." Use, duplication or disclosure is subject to restrictions as
* set forth in NASA FAR SUP 18-52.227-79 (April 1985) "Commercial
* Computer Software-Restricted Rights (April 1985)." If the Clause at
* 18-52.227-74 "Rights in Data General" is specified in the contract,
* then the "Alternate III" clause applies.
*
**************************************************************************/
#include <map>
#include <vector>
#include <queue>
#ifdef _RW_STD_IOSTREAM
#include <iostream>
#else
#include <iostream.h>
#endif
#include <string>
#ifndef _RWSTD_NO_NAMESPACE
using namespace std;
#ifndef __BORLANDC__
using namespace std::rel_ops; // RW_BUG
#endif
#endif
typedef map<string, int, less<string>,allocator<string> > stringVector;
typedef map<string, stringVector, less<string>,allocator<string> > graph;
struct DistancePair
{
unsigned first;
string second;
DistancePair() : first(0) {}
DistancePair(unsigned f, const string& s) : first(f), second(s) {}
};
bool operator< (const DistancePair& lhs, const DistancePair& rhs)
{
return lhs.first < rhs.first;
}
bool operator> (const DistancePair& lhs, const DistancePair& rhs)
{
return lhs.first > rhs.first;
}
string pendleton("Pendleton");
string pensacola("Pensacola");
string peoria("Peoria");
string phoenix("Phoenix");
string pierre("Pierre");
string pittsburgh("Pittsburgh");
string princeton("Princeton");
string pueblo("Pueblo");
graph cityMap;
void shortestDistance (graph& cityMap, string& start, stringVector& distances)
{
//
// Process a priority queue of distances to nodes.
//
priority_queue<DistancePair, vector<DistancePair,allocator<DistancePair> >,
greater<DistancePair> > que;
que.push(DistancePair(0, start));
while (! que.empty())
{
//
// Pull nearest city from queue.
//
int distance = que.top().first;
string city = que.top().second;
que.pop();
//
// If we haven't seen it already, process it.
//
if (0 == distances.count(city))
{
//
// Then add it to shortest distance map.
//
distances[city] = distance;
//
// And put values into queue.
//
const stringVector& cities = cityMap[city];
stringVector::const_iterator start = cities.begin();
stringVector::const_iterator stop = cities.end();
for (; start != stop; ++start)
que.push(DistancePair(distance + (*start).second,
(*start).first));
}
}
}
int main ()
{
cout << "Graph example program, from Chapter 7" << endl;
cityMap[pendleton][phoenix] = 4;
cityMap[pendleton][pueblo] = 8;
cityMap[pensacola][phoenix] = 5;
cityMap[peoria][pittsburgh] = 5;
cityMap[peoria][pueblo] = 3;
cityMap[phoenix][peoria] = 4;
cityMap[phoenix][pittsburgh] = 10;
cityMap[phoenix][pueblo] = 3;
cityMap[pierre][pendleton] = 2;
cityMap[pittsburgh][pensacola] = 4;
cityMap[princeton][pittsburgh] = 2;
cityMap[pueblo][pierre] = 3;
stringVector distances;
shortestDistance(cityMap, pierre, distances);
stringVector::iterator where;
for (where = distances.begin(); where != distances.end(); ++where)
cout << "Distance to: " << (*where).first << ":"
<< (*where).second << endl;
cout << "End of graph example program" << endl;
return 0;
}