/// <summary>
/// find component
/// </summary>
/// <param name="graph"></param>
/// <returns></returns>
public static List <HashSet <int> > ConnectedComponent(this Graph.Graph graph)
{
if (graph == null)
{
return(new List <HashSet <int> >());
}
//
List <HashSet <int> > lists = new List <HashSet <int> >();
for (int i = 0; i < graph.V; i++)
{
HashSet <int> set = new HashSet <int>();
set.Add(i);
lists.Add(set);
}
List <Tuple <int, int> > tuples = new List <Tuple <int, int> >();
for (int i = 0; i < graph.V; i++)
{
foreach (int j in graph.Adj(i))
{
bool found = false;
foreach (var t in tuples)
{
if ((t.Item1 == i && t.Item2 == j) || (t.Item1 == j && t.Item2 == i))
{
found = true;
break;
}
}
if (!found)
{
tuples.Add(new Tuple <int, int>(i, j));
}
}
}
foreach (var tuple in tuples)
{
HashSet <int> set1 = null;
HashSet <int> set2 = null;
foreach (var list in lists)
{
if (list.Contains(tuple.Item1))
{
set1 = list;
}
if (list.Contains(tuple.Item2))
{
set2 = list;
}
if (set1 != null && set2 != null)
{
break;
}
}
if (set1 == set2)
{
continue;
}
lists.Remove(set1);
lists.Remove(set2);
set1.UnionWith(set2);
lists.Add(set1);
}
return(lists);
}