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//=======================================================================
// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//=======================================================================
#include <boost/config.hpp>
#include <iostream>
#include <vector>
#include <algorithm>
#include <utility>
#include <boost/graph/graph_utility.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/pending/disjoint_sets.hpp>
#include <boost/graph/incremental_components.hpp>
/*
This example shows how to use the disjoint set data structure
to compute the connected components of an undirected, changing
graph.
Sample output:
An undirected graph:
0 <--> 1 4
1 <--> 0 4
2 <--> 5
3 <-->
4 <--> 1 0
5 <--> 2
representative[0] = 1
representative[1] = 1
representative[2] = 5
representative[3] = 3
representative[4] = 1
representative[5] = 5
component 0 contains: 4 1 0
component 1 contains: 3
component 2 contains: 5 2
*/
using namespace std;
int main(int , char* [])
{
using namespace boost;
typedef adjacency_list <vecS, vecS, undirectedS> Graph;
typedef graph_traits<Graph>::vertex_descriptor Vertex;
typedef graph_traits<Graph>::vertices_size_type size_type;
const int N = 6;
Graph G(N);
std::vector<size_type> rank(num_vertices(G));
std::vector<Vertex> parent(num_vertices(G));
typedef size_type* Rank;
typedef Vertex* Parent;
disjoint_sets<Rank, Parent> ds(&rank[0], &parent[0]);
initialize_incremental_components(G, ds);
incremental_components(G, ds);
graph_traits<Graph>::edge_descriptor e;
bool flag;
boost::tie(e,flag) = add_edge(0, 1, G);
ds.union_set(0,1);
boost::tie(e,flag) = add_edge(1, 4, G);
ds.union_set(1,4);
boost::tie(e,flag) = add_edge(4, 0, G);
ds.union_set(4,0);
boost::tie(e,flag) = add_edge(2, 5, G);
ds.union_set(2,5);
cout << "An undirected graph:" << endl;
print_graph(G, get(vertex_index, G));
cout << endl;
graph_traits<Graph>::vertex_iterator i,end;
for (boost::tie(i, end) = vertices(G); i != end; ++i)
cout << "representative[" << *i << "] = " <<
ds.find_set(*i) << endl;;
cout << endl;
typedef component_index<unsigned int> Components;
Components components(&parent[0], &parent[0] + parent.size());
for (Components::size_type c = 0; c < components.size(); ++c) {
cout << "component " << c << " contains: ";
Components::value_type::iterator
j = components[c].begin(),
jend = components[c].end();
for ( ; j != jend; ++j)
cout << *j << " ";
cout << endl;
}
return 0;
}
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