athos@1583: /* -*- C++ -*-
ladanyi@1636:  * demo/dijkstra_demo.cc - Part of LEMON, a generic C++ optimization library
athos@1583:  *
athos@1583:  * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
athos@1583:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
athos@1583:  *
athos@1583:  * Permission to use, modify and distribute this software is granted
athos@1583:  * provided that this copyright notice appears in all copies. For
athos@1583:  * precise terms see the accompanying LICENSE file.
athos@1583:  *
athos@1583:  * This software is provided "AS IS" with no warranty of any kind,
athos@1583:  * express or implied, and with no claim as to its suitability for any
athos@1583:  * purpose.
athos@1583:  *
athos@1583:  */
athos@1583: 
athos@1583: ///\ingroup demos
athos@1583: ///\file
athos@1583: ///\brief Demonstrating LEMON implementation of the Dijkstra algorithm
athos@1583: ///
athos@1583: /// Dijkstra's algorithm computes shortest paths between two nodes in
athos@1583: /// a graph with edge lengths. Here we only show some of the
athos@1583: /// facilities supplied by our implementation: for the detailed
athos@1583: /// documentation of the LEMON Dijkstra class read \ref lemon::Dijkstra "this".
alpar@1641: ///
alpar@1641: /// \include dijkstra_demo.cc
athos@1583: 
athos@1182: #include <iostream>
athos@1182: 
athos@1182: #include <lemon/list_graph.h>
athos@1182: #include <lemon/dijkstra.h>
athos@1182: 
athos@1182: using namespace lemon;
athos@1182: 
athos@1182: 
athos@1182: int main (int, char*[])
athos@1182: {
athos@1182: 
athos@1182:     typedef ListGraph Graph;
athos@1182:     typedef Graph::Node Node;
athos@1182:     typedef Graph::Edge Edge;
athos@1182:     typedef Graph::EdgeMap<int> LengthMap;
athos@1182: 
athos@1182:     Graph g;
athos@1182: 
athos@1182:     //An example from Ahuja's book
athos@1182: 
athos@1182:     Node s=g.addNode();
athos@1182:     Node v2=g.addNode();
athos@1182:     Node v3=g.addNode();
athos@1182:     Node v4=g.addNode();
athos@1182:     Node v5=g.addNode();
athos@1182:     Node t=g.addNode();
athos@1182: 
athos@1182:     Edge s_v2=g.addEdge(s, v2);
athos@1182:     Edge s_v3=g.addEdge(s, v3);
athos@1182:     Edge v2_v4=g.addEdge(v2, v4);
athos@1182:     Edge v2_v5=g.addEdge(v2, v5);
athos@1182:     Edge v3_v5=g.addEdge(v3, v5);
athos@1182:     Edge v4_t=g.addEdge(v4, t);
athos@1182:     Edge v5_t=g.addEdge(v5, t);
athos@1182:   
athos@1182:     LengthMap len(g);
athos@1182: 
athos@1182:     len.set(s_v2, 10);
athos@1182:     len.set(s_v3, 10);
athos@1182:     len.set(v2_v4, 5);
athos@1182:     len.set(v2_v5, 8);
athos@1182:     len.set(v3_v5, 5);
athos@1182:     len.set(v4_t, 8);
athos@1182:     len.set(v5_t, 8);
athos@1182: 
alpar@1641:     std::cout << "This program is a simple demo of the LEMON Dijkstra class."
alpar@1641: 	      << std::endl;
alpar@1641:     std::cout <<
alpar@1641:       "We calculate the shortest path from node s to node t in a graph."
alpar@1641: 	      << std::endl;
alpar@1641:     std::cout << std::endl;
athos@1530: 
athos@1530: 
alpar@1641:     std::cout << "The id of s is " << g.id(s)<< ", the id of t is "
alpar@1641: 	      << g.id(t) << "." << std::endl;
athos@1182: 
athos@1583:     std::cout << "Dijkstra algorithm demo..." << std::endl;
athos@1182: 
athos@1182:     Dijkstra<Graph, LengthMap> dijkstra_test(g,len);
athos@1182:     
athos@1182:     dijkstra_test.run(s);
alpar@1641:     
alpar@1641:     std::cout << "The distance of node t from node s: "
alpar@1641: 	      << dijkstra_test.dist(t) << std::endl;
athos@1182: 
alpar@1641:     std::cout << "The shortest path from s to t goes through the following "
alpar@1641: 	      << "nodes (the first one is t, the last one is s): "
alpar@1641: 	      << std::endl;
alpar@1641: 
alpar@1641:     for (Node v=t;v != s; v=dijkstra_test.predNode(v)) {
alpar@1641:       std::cout << g.id(v) << "<-";
alpar@1641:     }
athos@1182:     
athos@1182:     std::cout << g.id(s) << std::endl;	
athos@1182:     
athos@1182:     return 0;
athos@1182: }