/* -*- C++ -*-

 * src/test/max_matching_test.cc - 

 * Part of LEMON, a generic C++ optimization library

 *

 * Copyright (C) 2005 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 <math.h>

#include <cstdlib>

#include "test_tools.h"

#include <lemon/invalid.h>

#include <lemon/list_graph.h>

#include <lemon/max_matching.h>

using namespace std;

using namespace lemon;

int main() {

  typedef UndirListGraph Graph;

  typedef Graph::Edge Edge;

  typedef Graph::UndirEdgeIt UndirEdgeIt;

  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.runEdmonds(0);

  int s=0;

  Graph::NodeMap<Node> mate(g,INVALID);

  max_matching.writeNMapNode(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>::pos_enum> pos0(g);

  max_matching.writePos(pos0);

  max_matching.resetMatching();

  max_matching.runEdmonds(1);

  s=0;

  max_matching.writeNMapNode(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>::pos_enum> pos1(g);

  max_matching.writePos(pos1);

  max_matching.run();

  s=0;

  max_matching.writeNMapNode(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>::pos_enum> pos2(g);

  max_matching.writePos(pos2);

  max_matching.resetMatching();

  max_matching.run();

  s=0;

  max_matching.writeNMapNode(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>::pos_enum> pos(g);

  max_matching.writePos(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(UndirEdgeIt 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;

}