src/test/dijkstra_heap_test.cc
author alpar
Tue, 11 Jan 2005 09:04:08 +0000
changeset 1069 7b81a36809c6
parent 921 818510fa3d99
child 1139 f59038affc7e
permissions -rw-r--r--
- Minor correction in time_measure.h
- A bit more meaningful test in time_measure_test.cc
     1 /* -*- C++ -*-
     2  * src/test/dijkstra_heap_test.cc - Part of LEMON, a generic C++ optimization library
     3  *
     4  * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     5  * (Egervary Combinatorial Optimization Research Group, 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 //Tests dijsktra.h with two heap implementations:
    18 //the default binary heap of bin_heap.h, and the 
    19 //Fibonacci heap of fib_heap.h.
    20 
    21 //The input is a graph in standard dimacs format from the standard input (like
    22 //in /lemon_loc/testfiles/dimacs). It runs dijkstra.h on this graph with both
    23 //heaps, checking two postconditions:
    24 
    25 //- if the edges e=uv of the shortest path tree reported by dijkstra.h have
    26 //dist(v)-dist(u)=length(e)
    27 
    28 // - if all edges e=uv with u reachable from the root have
    29 //dist(v)-dist(u)>=length(e)
    30 #include <iostream>
    31 #include <math.h>
    32 
    33 #include <lemon/smart_graph.h>
    34 #include <lemon/dimacs.h>
    35 #include <lemon/dijkstra.h>
    36 #include <lemon/time_measure.h>
    37 #include <lemon/bin_heap.h>
    38 #include <lemon/fib_heap.h>
    39 
    40 using namespace lemon;
    41 
    42 int main(int, char **) {
    43   
    44   typedef SmartGraph Graph;
    45 
    46   typedef Graph::Edge Edge;
    47   typedef Graph::Node Node;
    48   typedef Graph::EdgeIt EdgeIt;
    49   typedef Graph::NodeIt NodeIt;
    50   typedef Graph::template EdgeMap<int> LengthMap;
    51 
    52   Graph G;
    53   Node s, t;
    54   LengthMap cap(G);
    55   readDimacsMaxFlow(std::cin, G, s, t, cap);
    56   Timer ts;
    57     
    58   std::cout <<
    59     "\n  Testing dijkstra.h with binary heap implementation bin_heap.h,"
    60 	    <<std::endl;
    61   std::cout<<"  on a graph with " << 
    62     G.nodeNum() << " nodes and " << G.edgeNum() << " edges..."
    63 	   << std::endl<<std::endl;
    64   
    65   Dijkstra<Graph, LengthMap> 
    66     dijkstra_test(G, cap);
    67   ts.reset();
    68   dijkstra_test.run(s);
    69   std::cout << "elapsed time: " << ts << std::endl;
    70   
    71   int error1=0;
    72   int error2=0;
    73 
    74   EdgeIt e;
    75   for(G.first(e); e!=INVALID; ++e) {
    76     Node u=G.source(e);
    77     Node v=G.target(e);
    78     if ( dijkstra_test.dist(v) - dijkstra_test.dist(u) > cap[e] )
    79       if ( dijkstra_test.reached(u) ) {
    80 	std::cout<<"Error! dist(target)-dist(source)- edge_length= " 
    81 		 <<dijkstra_test.dist(v) - dijkstra_test.dist(u) 
    82 	  - cap[e]<<std::endl;
    83 	++error1;
    84       }
    85   }
    86 
    87   NodeIt v;
    88   for(G.first(v); v!=INVALID; ++v) {
    89     if ( dijkstra_test.reached(v) ) {
    90       Edge e=dijkstra_test.pred(v);
    91       Node u=G.source(e);
    92       if ( dijkstra_test.dist(v) - dijkstra_test.dist(u) != cap[e] ) {
    93 	std::cout<<"Error in a shortest path tree edge! Difference: " 
    94 		 <<std::abs(dijkstra_test.dist(v) - dijkstra_test.dist(u) 
    95 			    - cap[e])<<std::endl;
    96 	++error2;
    97       }
    98     }
    99   }
   100 
   101 
   102   
   103   std::cout << error1 << " non-tree and " << error2 
   104 	    << " shortest path tree edge is erroneous."<<std::endl;
   105 
   106 
   107 
   108   std::cout <<
   109     "\n\n  Testing dijkstra.h with Fibonacci heap implementation fib_heap.h,"
   110 	    <<std::endl;
   111   std::cout<<"  on a graph with " << 
   112     G.nodeNum() << " nodes and " << G.edgeNum() << " edges..."
   113 	   << std::endl<<std::endl;
   114   
   115   Dijkstra<Graph, LengthMap, FibHeap> 
   116     dijkstra_test2(G, cap);
   117   ts.reset();
   118   dijkstra_test2.run(s);
   119   std::cout << "elapsed time: " << ts << std::endl;
   120   
   121   error1=0;
   122   error2=0;
   123 
   124   for(G.first(e); e!=INVALID; ++e) {
   125     Node u=G.source(e);
   126     Node v=G.target(e);
   127     if ( dijkstra_test2.dist(v) - dijkstra_test2.dist(u) > cap[e] )
   128       if ( dijkstra_test2.reached(u) ) {
   129 	std::cout<<"Error! dist(target)-dist(source)- edge_length= " 
   130 		 <<dijkstra_test2.dist(v) - dijkstra_test2.dist(u) 
   131 	  - cap[e]<<std::endl;
   132 	++error1;
   133       }
   134   }
   135 
   136   for(G.first(v); v!=INVALID; ++v) {
   137     if ( dijkstra_test2.reached(v) ) {
   138       Edge e=dijkstra_test2.pred(v);
   139       Node u=G.source(e);
   140       if ( dijkstra_test2.dist(v) - dijkstra_test2.dist(u) != cap[e] ) {
   141 	std::cout<<"Error in a shortest path tree edge! Difference: " 
   142 		 <<std::abs(dijkstra_test2.dist(v) - dijkstra_test2.dist(u) 
   143 			    - cap[e])<<std::endl;
   144 	++error2;
   145       }
   146     }
   147   }
   148 
   149 
   150   std::cout << error1 << " non-tree and " << error2 
   151 	    << " shortest path tree edge is erroneous."<<std::endl;
   152 
   153 
   154   return 0;
   155 }