source: lemon-0.x/test/max_matching_test.cc @ 2598:71f4bd3a9ae8

/* -*- C++ -*-
 *
 * This file is a part of LEMON, a generic C++ optimization library
 *
 * Copyright (C) 2003-2008
 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
 * (Egervary Research Group on Combinatorial Optimization, EGRES).
 *
 * Permission to use, modify and distribute this software is granted
 * provided that this copyright notice appears in all copies. For
 * precise terms see the accompanying LICENSE file.
 *
 * This software is provided "AS IS" with no warranty of any kind,
 * express or implied, and with no claim as to its suitability for any
 * purpose.
 *
 */

#include <iostream>
#include <vector>
#include <queue>
#include <lemon/math.h>
#include <cstdlib>

#include "test_tools.h"
#include <lemon/list_graph.h>
#include <lemon/max_matching.h>

using namespace std;
using namespace lemon;

int main() {

  typedef ListUGraph Graph;

  typedef Graph::Edge Edge;
  typedef Graph::UEdgeIt UEdgeIt;
  typedef Graph::IncEdgeIt IncEdgeIt;
  typedef Graph::NodeIt NodeIt;
  typedef Graph::Node Node;
   
  Graph g;
  g.clear();

  std::vector<Graph::Node> nodes;
  for (int i=0; i<13; ++i)
      nodes.push_back(g.addNode());

  g.addEdge(nodes[0], nodes[0]);
  g.addEdge(nodes[6], nodes[10]);
  g.addEdge(nodes[5], nodes[10]);
  g.addEdge(nodes[4], nodes[10]);
  g.addEdge(nodes[3], nodes[11]);  
  g.addEdge(nodes[1], nodes[6]);
  g.addEdge(nodes[4], nodes[7]);  
  g.addEdge(nodes[1], nodes[8]);
  g.addEdge(nodes[0], nodes[8]);
  g.addEdge(nodes[3], nodes[12]);
  g.addEdge(nodes[6], nodes[9]);
  g.addEdge(nodes[9], nodes[11]);
  g.addEdge(nodes[2], nodes[10]);
  g.addEdge(nodes[10], nodes[8]);
  g.addEdge(nodes[5], nodes[8]);
  g.addEdge(nodes[6], nodes[3]);
  g.addEdge(nodes[0], nodes[5]);
  g.addEdge(nodes[6], nodes[12]);
  
  MaxMatching<Graph> max_matching(g);
  max_matching.init();
  max_matching.startDense();
  
  int s=0;
  Graph::NodeMap<Node> mate(g,INVALID);
  max_matching.mateMap(mate);
  for(NodeIt v(g); v!=INVALID; ++v) {
    if ( mate[v]!=INVALID ) ++s;
  }
  int size=int(s/2);  //size will be used as the size of a maxmatching

  for(NodeIt v(g); v!=INVALID; ++v) {
    max_matching.mate(v);
  }

  check ( size == max_matching.size(), "mate() returns a different size matching than max_matching.size()" );

  Graph::NodeMap<MaxMatching<Graph>::DecompType> pos0(g);
  max_matching.decomposition(pos0);
  
  max_matching.init();
  max_matching.startSparse();
  s=0;
  max_matching.mateMap(mate);
  for(NodeIt v(g); v!=INVALID; ++v) {
    if ( mate[v]!=INVALID ) ++s;
  }
  check ( int(s/2) == size, "The size does not equal!" );

  Graph::NodeMap<MaxMatching<Graph>::DecompType> pos1(g);
  max_matching.decomposition(pos1);

  max_matching.run();
  s=0;
  max_matching.mateMap(mate);
  for(NodeIt v(g); v!=INVALID; ++v) {
    if ( mate[v]!=INVALID ) ++s;
  }
  check ( int(s/2) == size, "The size does not equal!" ); 
  
  Graph::NodeMap<MaxMatching<Graph>::DecompType> pos2(g);
  max_matching.decomposition(pos2);

  max_matching.run();
  s=0;
  max_matching.mateMap(mate);
  for(NodeIt v(g); v!=INVALID; ++v) {
    if ( mate[v]!=INVALID ) ++s;
  }
  check ( int(s/2) == size, "The size does not equal!" ); 
  
  Graph::NodeMap<MaxMatching<Graph>::DecompType> pos(g);
  max_matching.decomposition(pos);
   
  bool ismatching=true;
  for(NodeIt v(g); v!=INVALID; ++v) {
    if ( mate[v]!=INVALID ) {
      Node u=mate[v];
      if (mate[u]!=v) ismatching=false; 
    }
  }  
  check ( ismatching, "It is not a matching!" );

  bool coincide=true;
  for(NodeIt v(g); v!=INVALID; ++v) {
   if ( pos0[v] != pos1[v] || pos1[v]!=pos2[v] || pos2[v]!=pos[v] ) {
     coincide=false;
    }
  }
  check ( coincide, "The decompositions do not coincide! " );

  bool noedge=true;
  for(UEdgeIt e(g); e!=INVALID; ++e) {
   if ( (pos[g.target(e)]==max_matching.C && 
         pos[g.source(e)]==max_matching.D) || 
         (pos[g.target(e)]==max_matching.D && 
          pos[g.source(e)]==max_matching.C) )
      noedge=false; 
  }
  check ( noedge, "There are edges between D and C!" );
  
  bool oddcomp=true;
  Graph::NodeMap<bool> todo(g,true);
  int num_comp=0;
  for(NodeIt v(g); v!=INVALID; ++v) {
   if ( pos[v]==max_matching.D && todo[v] ) {
      int comp_size=1;
      ++num_comp;
      std::queue<Node> Q;
      Q.push(v);
      todo.set(v,false);
      while (!Q.empty()) {
        Node w=Q.front();       
        Q.pop();
        for(IncEdgeIt e(g,w); e!=INVALID; ++e) {
          Node u=g.runningNode(e);
          if ( pos[u]==max_matching.D && todo[u] ) {
            ++comp_size;
            Q.push(u);
            todo.set(u,false);
          }
        }
      }
      if ( !(comp_size % 2) ) oddcomp=false;  
    }
  }
  check ( oddcomp, "A component of g[D] is not odd." );

  int barrier=0;
  for(NodeIt v(g); v!=INVALID; ++v) {
    if ( pos[v]==max_matching.A ) ++barrier;
  }
  int expected_size=int( countNodes(g)-num_comp+barrier)/2;
  check ( size==expected_size, "The size of the matching is wrong." );
  
  return 0;
}