//虽然代码少，思想和不简单
public DisjointSetNode <T> Find(DisjointSetNode <T> node)
{
if (node != node.Parent)
{
node.Parent = Find(node.Parent);
}
return(node.Parent);
}
public DisjointSet(T value)
{
var node = new DisjointSetNode <T>();
node.Value = value;
node.Parent = node;
node.Rank = 0;
_nodes.Add(node.Value, node);
Delegate = node;
}
private DisjointSetNode <T> Link(DisjointSetNode <T> first, DisjointSetNode <T> second)
{
if (first.Rank > second.Rank)
{
second.Parent = first;
return(first);
}
first.Parent = second;
if (first.Rank == second.Rank)
{
second.Rank = second.Rank + 1;
}
return(second);
}
public DisjointSet <T> Union(DisjointSet <T> set)
{
var newdelegate = Link(Find(Delegate), Find(set.Delegate));
//消灭旧的DisjointSet，而不是创建全新的Set
//虽然它们的引用还是不一样，但是Delegate和node是完全一样的。
Delegate = newdelegate;
set.Delegate = newdelegate;
foreach (var item in set._nodes)
{
_nodes.Add(item);
}
set._nodes = _nodes;
return(this);
}
