union-find算法

public class UF
{
	private int[] id;     //分量id（以触点作为索引）
	private int count;    //分量数量
	public UF(int N)
	{
		//初始化分量数组
		count = N;
		id = new int[N];
		for (int i = 0; i < N; i++)
			id[i] = i;
	}
	public int count()
	{	return count;	}
	public boolean connected(int p,int q)
	{	return find(p) == find(q);	}
	public int find(int p)
	public void union(int p,int q)
	public static void main(String[] args)
	{
		int N = StdIn.readInt();     //读取触点数量
		UF uf = new UF(N);           //初始化N个分量
		while (!StdIn.isEmpty())
		{
			int p = StdIn.readInt();
			int q = StdIn.readInt();  //读取整数对
			if (uf.connected(p, q)) continue;  //已经连通则忽略
			uf.union(p, q);           //归并分量
			StdOut.println(p + " " + q);       //打印连接
		}
		StdOut.println(uf.count() + "components");
	}
}
public class UF
{
	private int[] id;     //分