examples/example_bipgraph.cpp

   1 /*  This file is part of libDAI - http://www.libdai.org/
   2  *
   3  *  libDAI is licensed under the terms of the GNU General Public License version
   4  *  2, or (at your option) any later version. libDAI is distributed without any
   5  *  warranty. See the file COPYING for more details.
   6  *
   7  *  Copyright (C) 2008-2009  Joris Mooij  [joris dot mooij at libdai dot org]
   8  */
   9
  10
  11 #include <dai/bipgraph.h>
  12
  13 using namespace std;
  14 using namespace dai;
  15
  16 int main() {
  17     // Create a list of edges
  18     vector<BipartiteGraph::Edge> edges;
  19     edges.reserve( 5 );
  20     edges.push_back( BipartiteGraph::Edge(0, 0) );
  21     edges.push_back( BipartiteGraph::Edge(1, 0) );
  22     edges.push_back( BipartiteGraph::Edge(2, 0) );
  23     edges.push_back( BipartiteGraph::Edge(1, 1) );
  24     edges.push_back( BipartiteGraph::Edge(2, 1) );
  25
  26     // Create a bipartite graph with 3 nodes of type 1,
  27     // 2 nodes of type 2 and edge list edges.
  28     BipartiteGraph G( 3, 2, edges.begin(), edges.end() );
  29
  30     // Display some information about G
  31     cout << "G has " << G.nr1() << " nodes of type 1, " << G.nr2() << " nodes of type 2 and " << G.nrEdges() << " edges." << endl << endl;
  32
  33     // Iterate over all nodes n1 of type 1
  34     for( size_t n1 = 0; n1 < G.nr1(); n1++ ) {
  35         cout << "Node " << n1 << " of type 1 has " << G.nb1(n1).size() << " neighbors:" << endl;
  36         // Iterate over all neighbors n2 of n1
  37         foreach( const BipartiteGraph::Neighbor &n2, G.nb1(n1) ) {
  38             // The n2.iter'th neighbor of n1 is n2:
  39             assert( G.nb1(n1)[n2.iter] == n2 );
  40
  41             // The n2.dual'th neighbor of n2 is n1:
  42             assert( G.nb2(n2)[n2.dual] == n1 );
  43
  44             // n2 can be used as an abbreviation of n2.node:
  45             assert( static_cast<size_t>(n2) == n2.node );
  46
  47             cout << "  the " << n2.iter << "'th neighbor is node " << n2 << " of type 2" << endl;
  48         }
  49         cout << endl;
  50     }
  51 }