src/work/jacint/max_matching.cc
author ladanyi
Tue, 05 Apr 2005 22:37:19 +0000
changeset 1308 0274efa2222f
parent 921 818510fa3d99
permissions -rw-r--r--
Applied the changes which somehow vanished during my last merge. Thanks goes
to Marci for noticing this. In detail:
- added amsmath and amssymb latex packages for latex documentation
- src/demo is also scanned for doxygen input files
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///Generates a random graph, and tests max_matching.h on it.
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#include <iostream>
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#include <queue>
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#include <math.h>
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#include <list_graph.h>
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#include <dimacs.h>
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#include <graph_gen.h>
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#include <max_matching.h>
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#include <time_measure.h>
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#include <graph_wrapper.h>
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using namespace lemon;
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int main(int, char **) {
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  typedef UndirGraph<ListGraph> UGW;
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  typedef UGW::Edge Edge;
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  typedef UGW::EdgeIt EdgeIt;
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  typedef UGW::OutEdgeIt OutEdgeIt;
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  typedef UGW::NodeIt NodeIt;
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  typedef UGW::Node Node;
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  UGW G;
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  //  random_init(); //If you want to use a random graph with a random
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  //  number of edges and nodes.
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  int i;
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  int j;
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  std::cout<<"Number of nodes: ";
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  std::cin >> i;
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  std::cout<<"Number of edges: ";
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  std::cin >> j;
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  //  readDimacs(std::cin, G); 
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  randomGraph(G, i, j );  
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  Timer ts;
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  bool noerror=true;
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  std::cout <<
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    "\n  Testing max_matching.h on a random graph with " << 
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    G.nodeNum() << " nodes and " << G.edgeNum() << " edges...\n"
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	    << std::endl;
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  MaxMatching<UGW> max_matching(G);
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  std::cout << 
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    "Running the plain edmonds algorithm runEdmonds(0) using no heuristic... " 
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	    <<std::endl;
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  ts.reset();  
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  max_matching.runEdmonds(0);
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  std::cout<<"Elapsed time: "<<ts<<std::endl;
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  int s=0;
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  UGW::NodeMap<Node> mate(G,INVALID);
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  max_matching.writeNMapNode(mate);
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  NodeIt v;
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  for(G.first(v); G.valid(v); G.next(v) ) {
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    if ( G.valid(mate[v]) ) {
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      ++s;
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    }
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  }
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  int size=(int)s/2;  //size will be used as the size of a maxmatching
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  std::cout << size << " is the size of the matching found by runEdmonds(0),"<<std::endl;
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  if ( size == max_matching.size() ) {
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    std::cout<< "which equals to the size of the actual matching reported by size().\n"<< std::endl;
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  } else {  
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    std::cout<< "which does not equal to the size of the actual matching reported by size()!\n"<< std::endl;
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    noerror=false;
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  }
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  std::cout<<"Writing the position by calling writePos...";
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  UGW::NodeMap<MaxMatching<UGW>::pos_enum> pos0(G);
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  max_matching.writePos(pos0);
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  std::cout << "OK" << std::endl;
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  std::cout << "Resetting the matching and the position by calling"<< std::endl;
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  std::cout<<"resetPos() and resetMatching()...";
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  max_matching.resetPos();
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  max_matching.resetMatching();
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  std::cout <<"OK" << std::endl;
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  std::cout << "\nRunning runEdmonds(1) using the 'postpone shrink' heuristic ... " <<std::endl;
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  ts.reset();  
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  max_matching.runEdmonds(1);
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  std::cout<<"Elapsed time: "<<ts<<std::endl;
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  s=0;
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  max_matching.writeNMapNode(mate);
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  for(G.first(v); G.valid(v); G.next(v) ) {
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    if ( G.valid(mate[v]) ) {
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      ++s;
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    }
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  }
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  std::cout << (int)s/2 << 
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    " is the size of the matching found by runEdmonds(1),"<<std::endl;
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  if ( (int)s/2 == size ) {
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    std::cout<< "which equals to the size of the matching found by runEdmonds(0)."<< std::endl;
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  } else {  
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    std::cout<< "which does not equal to the size of the matching found by runEdmonds(0)!"<< std::endl;
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    noerror=false;
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  } 
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  UGW::NodeMap<MaxMatching<UGW>::pos_enum> pos1(G);
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  max_matching.writePos(pos1);
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  std::cout << "\nStarting run() from the matching given by runEdmonds(1)... " <<std::endl;
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  max_matching.resetPos();
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  ts.reset();  
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  max_matching.run();
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  std::cout<<"Elapsed time: "<<ts<<std::endl;
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  s=0;
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  max_matching.writeNMapNode(mate);
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  for(G.first(v); G.valid(v); G.next(v) ) {
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    if ( G.valid(mate[v]) ) {
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      ++s;
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    }
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  }
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  if ( (int)s/2 == size ) {
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    std::cout<< "Found a matching of proper size."<< std::endl;
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  } else {  
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    std::cout<< "Found a matching of inproper size!"<< std::endl;
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    noerror=false;
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  }
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  UGW::NodeMap<MaxMatching<UGW>::pos_enum> pos2(G);
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  max_matching.writePos(pos2);
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  std::cout << "\nCalling resetPos() and resetMatching()...";
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  max_matching.resetPos();
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  max_matching.resetMatching();
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  std::cout<<"OK"<<std::endl;
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  std::cout <<"Calling greedyMatching() and then runEdmonds(1)... " <<std::endl;
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  ts.reset();  
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  max_matching.run();
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  std::cout<<"Elapsed time: "<<ts<<std::endl;
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  s=0;
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  max_matching.writeNMapNode(mate);
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  for(G.first(v); G.valid(v); G.next(v) ) {
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    if ( G.valid(mate[v]) ) {
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      ++s;
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    }
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  }
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  std::cout << (int)s/2 << " is the size of the matching found by run(),"<<std::endl;
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  if ( (int)s/2 == size ) {
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    std::cout<< "which equals to the size of the matching found by runEdmonds(0)."<< std::endl;
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  } else {  
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    std::cout<< "which does not equal to the size of the matching found by runEdmonds(0)!"<< std::endl;
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    noerror=false;
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  }
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  UGW::NodeMap<MaxMatching<UGW>::pos_enum> pos(G);
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  max_matching.writePos(pos);
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  std::cout<<"\nChecking if the output is a matching...";
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  bool ismatching=true;
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  for(G.first(v); G.valid(v); G.next(v) )
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    if ( G.valid(mate[v]) ) {
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      Node u=mate[v];
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      if (mate[u]!=v) ismatching=false; 
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    }
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  if ( ismatching ) std::cout<<"OK"<<std::endl;
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  else std::cout<< "It is not a matching!"<< std::endl;
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  noerror = noerror && ismatching;
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  std::cout<<"\nChecking the dual..."<<std::endl;
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  std::cout<<"Checking if the four position outputs coincide...";
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  bool coincide=true;
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  int err_node=0;
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  for(G.first(v); G.valid(v); G.next(v) ) {
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    if ( pos0[v] != pos1[v] || pos1[v]!=pos2[v] || pos2[v]!=pos[v] ) {
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      ++err_node;
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      coincide=false;
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    }
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  }
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  if ( coincide ) std::cout << "OK" <<std::endl;
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  else {
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    std::cout << "They do not coincide! Number of erroneous nodes: " 
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	      << err_node << std::endl;
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  }     
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  noerror=noerror && coincide;
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  std::cout<<"Checking if there is no edge between D and C...";
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  bool noedge=true;
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  EdgeIt e;
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  for(G.first(e); G.valid(e); G.next(e) ) {
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    if ( (pos[G.target(e)]==max_matching.C && pos[G.source(e)]==max_matching.D) || 
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	 (pos[G.target(e)]==max_matching.D && pos[G.source(e)]==max_matching.C) )
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      noedge=false; 
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  }
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  if ( noedge ) std::cout<<"OK"<<std::endl;
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  else std::cout<< "There are edges between D and C!"<< std::endl;
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  noerror = noerror && noedge;
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  std::cout<<"Checking if all the components of G[D] are odd...";
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  bool oddcomp=true;
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  UGW::NodeMap<bool> todo(G,true);
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  int num_comp=0;
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  for(G.first(v); G.valid(v); G.next(v) ) {
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    if ( pos[v]==max_matching.D && todo[v] ) {
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      int comp_size=1;
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      ++num_comp;
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      std::queue<Node> Q;
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      Q.push(v);
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      todo.set(v,false);
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      while (!Q.empty()) {
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	Node w=Q.front();	
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	Q.pop();
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	OutEdgeIt e;
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	for(G.first(e,w); G.valid(e); G.next(e)) {
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	  Node u=G.bNode(e);
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	  if ( pos[u]==max_matching.D && todo[u] ) {
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	    ++comp_size;
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	    Q.push(u);
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	    todo.set(u,false);
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	  }
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	}
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      }
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      if ( !(comp_size % 2) ) oddcomp=false;  
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    }
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  }
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  std::cout << "\n  found     " << num_comp << "     component(s) of G[D],";
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  if ( oddcomp ) std::cout<<" each is odd."<<std::endl;
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  else std::cout<< " but not all are odd!"<< std::endl;
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  noerror = noerror && oddcomp;
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  int barrier=0;
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  for(G.first(v); G.valid(v); G.next(v) ) 
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    if ( pos[v]==max_matching.A ) ++barrier;
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  std::cout << barrier << " is the number of nodes in A (i.e. the size of the barrier), so" << std::endl;
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  std::cout << num_comp - barrier << " is the deficiency of the graph, and hence" << std::endl; 
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  int expected_size=(int)(G.nodeNum()-num_comp+barrier)/2;
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  std::cout << expected_size << " should be the size of the maximum matching," << std::endl; 
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  if ( size==expected_size )
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    std::cout<<"which equals to the number of vertices missed by the found matching!"<<std::endl; 
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  else {
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    std::cout<<"which does not equal to the number of vertices missed by the matchings found!"
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	     <<std::endl; 
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    noerror=false;
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  }
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  if ( num_comp == 1 && barrier == 0 ) 
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    std::cout<<"\nThis graph is factor-critical."<<std::endl;
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  if ( num_comp == 0 && barrier == 0 ) 
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    std::cout<<"\nThis graph has a perfect matching."<<std::endl;
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  if( noerror ) std::cout<<"\nNo errors found.\n"<<std::endl;
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  else std::cout<<"\nSome errors found!\n"<<std::endl;
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  return 0;
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}
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