1 | //Tests dijsktra.h with two heap implementations: |
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2 | //the default binary heap of bin_heap.h, and the |
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3 | //Fibonacci heap of fib_heap.h. |
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4 | |
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5 | //The input is a graph in standard dimacs format from the standard input (like |
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6 | //in /hugo_loc/testfiles/dimacs). It runs dijkstra.h on this graph with both |
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7 | //heaps, checking two postconditions: |
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8 | |
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9 | //- if the edges e=uv of the shortest path tree reported by dijkstra.h have |
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10 | //dist(v)-dist(u)=length(e) |
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11 | |
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12 | // - if all edges e=uv with u reachable from the root have |
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13 | //dist(v)-dist(u)>=length(e) |
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14 | #include <iostream> |
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15 | #include <math.h> |
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16 | |
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17 | #include <hugo/smart_graph.h> |
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18 | #include <hugo/dimacs.h> |
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19 | #include <hugo/dijkstra.h> |
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20 | #include <hugo/time_measure.h> |
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21 | #include <hugo/bin_heap.h> |
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22 | #include <hugo/fib_heap.h> |
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23 | |
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24 | using namespace hugo; |
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25 | |
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26 | int main(int, char **) { |
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27 | |
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28 | typedef SmartGraph Graph; |
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29 | |
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30 | typedef Graph::Edge Edge; |
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31 | typedef Graph::Node Node; |
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32 | typedef Graph::EdgeIt EdgeIt; |
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33 | typedef Graph::NodeIt NodeIt; |
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34 | typedef Graph::EdgeMap<int> LengthMap; |
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35 | |
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36 | Graph G; |
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37 | Node s, t; |
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38 | LengthMap cap(G); |
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39 | readDimacsMaxFlow(std::cin, G, s, t, cap); |
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40 | Timer ts; |
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41 | |
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42 | std::cout << |
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43 | "\n Testing dijkstra.h with binary heap implementation bin_heap.h," |
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44 | <<std::endl; |
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45 | std::cout<<" on a graph with " << |
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46 | G.nodeNum() << " nodes and " << G.edgeNum() << " edges..." |
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47 | << std::endl<<std::endl; |
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48 | |
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49 | Dijkstra<Graph, LengthMap> |
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50 | dijkstra_test(G, cap); |
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51 | ts.reset(); |
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52 | dijkstra_test.run(s); |
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53 | std::cout << "elapsed time: " << ts << std::endl; |
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54 | |
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55 | int error1=0; |
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56 | int error2=0; |
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57 | |
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58 | EdgeIt e; |
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59 | for(G.first(e); e!=INVALID; ++e) { |
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60 | Node u=G.tail(e); |
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61 | Node v=G.head(e); |
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62 | if ( dijkstra_test.dist(v) - dijkstra_test.dist(u) > cap[e] ) |
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63 | if ( dijkstra_test.reached(u) ) { |
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64 | std::cout<<"Error! dist(head)-dist(tail)- edge_length= " |
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65 | <<dijkstra_test.dist(v) - dijkstra_test.dist(u) |
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66 | - cap[e]<<std::endl; |
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67 | ++error1; |
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68 | } |
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69 | } |
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70 | |
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71 | NodeIt v; |
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72 | for(G.first(v); v!=INVALID; ++v) { |
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73 | if ( dijkstra_test.reached(v) ) { |
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74 | Edge e=dijkstra_test.pred(v); |
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75 | Node u=G.tail(e); |
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76 | if ( dijkstra_test.dist(v) - dijkstra_test.dist(u) != cap[e] ) { |
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77 | std::cout<<"Error in a shortest path tree edge! Difference: " |
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78 | <<std::abs(dijkstra_test.dist(v) - dijkstra_test.dist(u) |
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79 | - cap[e])<<std::endl; |
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80 | ++error2; |
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81 | } |
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82 | } |
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83 | } |
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84 | |
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85 | |
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86 | |
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87 | std::cout << error1 << " non-tree and " << error2 |
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88 | << " shortest path tree edge is erroneous."<<std::endl; |
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89 | |
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90 | |
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91 | |
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92 | std::cout << |
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93 | "\n\n Testing dijkstra.h with Fibonacci heap implementation fib_heap.h," |
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94 | <<std::endl; |
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95 | std::cout<<" on a graph with " << |
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96 | G.nodeNum() << " nodes and " << G.edgeNum() << " edges..." |
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97 | << std::endl<<std::endl; |
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98 | |
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99 | Dijkstra<Graph, LengthMap, FibHeap> |
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100 | dijkstra_test2(G, cap); |
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101 | ts.reset(); |
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102 | dijkstra_test2.run(s); |
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103 | std::cout << "elapsed time: " << ts << std::endl; |
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104 | |
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105 | error1=0; |
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106 | error2=0; |
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107 | |
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108 | for(G.first(e); e!=INVALID; ++e) { |
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109 | Node u=G.tail(e); |
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110 | Node v=G.head(e); |
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111 | if ( dijkstra_test2.dist(v) - dijkstra_test2.dist(u) > cap[e] ) |
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112 | if ( dijkstra_test2.reached(u) ) { |
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113 | std::cout<<"Error! dist(head)-dist(tail)- edge_length= " |
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114 | <<dijkstra_test2.dist(v) - dijkstra_test2.dist(u) |
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115 | - cap[e]<<std::endl; |
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116 | ++error1; |
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117 | } |
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118 | } |
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119 | |
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120 | for(G.first(v); v!=INVALID; ++v) { |
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121 | if ( dijkstra_test2.reached(v) ) { |
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122 | Edge e=dijkstra_test2.pred(v); |
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123 | Node u=G.tail(e); |
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124 | if ( dijkstra_test2.dist(v) - dijkstra_test2.dist(u) != cap[e] ) { |
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125 | std::cout<<"Error in a shortest path tree edge! Difference: " |
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126 | <<std::abs(dijkstra_test2.dist(v) - dijkstra_test2.dist(u) |
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127 | - cap[e])<<std::endl; |
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128 | ++error2; |
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129 | } |
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130 | } |
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131 | } |
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132 | |
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133 | |
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134 | std::cout << error1 << " non-tree and " << error2 |
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135 | << " shortest path tree edge is erroneous."<<std::endl; |
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136 | |
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137 | |
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138 | return 0; |
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139 | } |
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