/* -*- C++ -*-

  * src/test/max_matching_test.cc - Part of LEMON, a generic C++ optimization library

  *

  * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

  * (Egervary Combinatorial Optimization Research Group, 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 <queue>

 #include <math.h>

 #include <cstdlib>

 #include "test_tools.h"

 #include <lemon/invalid.h>

 #include <lemon/list_graph.h>

 #include <graph_gen.h>

 #include <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;

   random_init(); 

   randomGraph(G, random(5000), random(20000) );  

   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

   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.resetPos();

   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.resetPos();

   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.resetPos();

   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.target(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;

 }

 void random_init()

 {

   unsigned int seed = getpid();

   seed |= seed << 15;

   seed ^= time(0);

   srand(seed);

 }

 int random(int m)

 {

   return int( double(m) * rand() / (RAND_MAX + 1.0) );

 }

 /// Generates a random graph with n nodes and m edges.

 /// Before generating the random graph, \c g.clear() is called.

 template<typename Graph>

 void randomGraph(Graph& g, int n, int m) {

   g.clear();

   std::vector<typename Graph::Node> nodes;

   for (int i=0; i<n; ++i)

     nodes.push_back(g.addNode());

   for (int i=0; i<m; ++i) 

     g.addEdge(nodes[random(n)], nodes[random(n)]);

 }