[1583] | 1 | /* -*- C++ -*- |
---|
[1636] | 2 | * demo/dijkstra_demo.cc - Part of LEMON, a generic C++ optimization library |
---|
[1583] | 3 | * |
---|
| 4 | * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
---|
| 5 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
---|
| 6 | * |
---|
| 7 | * Permission to use, modify and distribute this software is granted |
---|
| 8 | * provided that this copyright notice appears in all copies. For |
---|
| 9 | * precise terms see the accompanying LICENSE file. |
---|
| 10 | * |
---|
| 11 | * This software is provided "AS IS" with no warranty of any kind, |
---|
| 12 | * express or implied, and with no claim as to its suitability for any |
---|
| 13 | * purpose. |
---|
| 14 | * |
---|
| 15 | */ |
---|
| 16 | |
---|
| 17 | ///\ingroup demos |
---|
| 18 | ///\file |
---|
[1715] | 19 | ///\brief Demonstrating the usage of LEMON's Dijkstra algorithm |
---|
[1583] | 20 | /// |
---|
| 21 | /// Dijkstra's algorithm computes shortest paths between two nodes in |
---|
| 22 | /// a graph with edge lengths. Here we only show some of the |
---|
| 23 | /// facilities supplied by our implementation: for the detailed |
---|
| 24 | /// documentation of the LEMON Dijkstra class read \ref lemon::Dijkstra "this". |
---|
[1641] | 25 | /// |
---|
| 26 | /// \include dijkstra_demo.cc |
---|
[1583] | 27 | |
---|
[1182] | 28 | #include <iostream> |
---|
| 29 | |
---|
| 30 | #include <lemon/list_graph.h> |
---|
| 31 | #include <lemon/dijkstra.h> |
---|
| 32 | |
---|
| 33 | using namespace lemon; |
---|
| 34 | |
---|
| 35 | |
---|
| 36 | int main (int, char*[]) |
---|
| 37 | { |
---|
| 38 | |
---|
| 39 | typedef ListGraph Graph; |
---|
| 40 | typedef Graph::Node Node; |
---|
| 41 | typedef Graph::Edge Edge; |
---|
| 42 | typedef Graph::EdgeMap<int> LengthMap; |
---|
| 43 | |
---|
| 44 | Graph g; |
---|
| 45 | |
---|
| 46 | //An example from Ahuja's book |
---|
| 47 | |
---|
| 48 | Node s=g.addNode(); |
---|
| 49 | Node v2=g.addNode(); |
---|
| 50 | Node v3=g.addNode(); |
---|
| 51 | Node v4=g.addNode(); |
---|
| 52 | Node v5=g.addNode(); |
---|
| 53 | Node t=g.addNode(); |
---|
| 54 | |
---|
| 55 | Edge s_v2=g.addEdge(s, v2); |
---|
| 56 | Edge s_v3=g.addEdge(s, v3); |
---|
| 57 | Edge v2_v4=g.addEdge(v2, v4); |
---|
| 58 | Edge v2_v5=g.addEdge(v2, v5); |
---|
| 59 | Edge v3_v5=g.addEdge(v3, v5); |
---|
| 60 | Edge v4_t=g.addEdge(v4, t); |
---|
| 61 | Edge v5_t=g.addEdge(v5, t); |
---|
| 62 | |
---|
| 63 | LengthMap len(g); |
---|
| 64 | |
---|
| 65 | len.set(s_v2, 10); |
---|
| 66 | len.set(s_v3, 10); |
---|
| 67 | len.set(v2_v4, 5); |
---|
| 68 | len.set(v2_v5, 8); |
---|
| 69 | len.set(v3_v5, 5); |
---|
| 70 | len.set(v4_t, 8); |
---|
| 71 | len.set(v5_t, 8); |
---|
| 72 | |
---|
[1641] | 73 | std::cout << "This program is a simple demo of the LEMON Dijkstra class." |
---|
| 74 | << std::endl; |
---|
| 75 | std::cout << |
---|
| 76 | "We calculate the shortest path from node s to node t in a graph." |
---|
| 77 | << std::endl; |
---|
| 78 | std::cout << std::endl; |
---|
[1530] | 79 | |
---|
| 80 | |
---|
[1641] | 81 | std::cout << "The id of s is " << g.id(s)<< ", the id of t is " |
---|
| 82 | << g.id(t) << "." << std::endl; |
---|
[1182] | 83 | |
---|
[1583] | 84 | std::cout << "Dijkstra algorithm demo..." << std::endl; |
---|
[1182] | 85 | |
---|
| 86 | Dijkstra<Graph, LengthMap> dijkstra_test(g,len); |
---|
| 87 | |
---|
| 88 | dijkstra_test.run(s); |
---|
[1641] | 89 | |
---|
| 90 | std::cout << "The distance of node t from node s: " |
---|
| 91 | << dijkstra_test.dist(t) << std::endl; |
---|
[1182] | 92 | |
---|
[1641] | 93 | std::cout << "The shortest path from s to t goes through the following " |
---|
| 94 | << "nodes (the first one is t, the last one is s): " |
---|
| 95 | << std::endl; |
---|
| 96 | |
---|
| 97 | for (Node v=t;v != s; v=dijkstra_test.predNode(v)) { |
---|
| 98 | std::cout << g.id(v) << "<-"; |
---|
| 99 | } |
---|
[1182] | 100 | |
---|
| 101 | std::cout << g.id(s) << std::endl; |
---|
| 102 | |
---|
| 103 | return 0; |
---|
| 104 | } |
---|