算法 加权quick-union

public class MyWeightedQuickUnionUF {

    private int[] id;
    private int[] sz;
    private int count;


    public MyWeightedQuickUnionUF(int N) {
        count = N;
        id = new int[N];
        for(int i = 0; i < N; i++)
            id[i] = i;
        sz = new int[N];
        for(int i = 0; i < N; i++)
            id[i] = 1;
    }

    public int count()
    {
        return count;
    }

    public boolean connected(int p, int q)
    {
        return find(p) == find(q);
    }

    public int find(int p)
    {
        while(p != id[p]) p = id[p];
        return p;
    }
    public void union(int p, int q)
    {
        int i = find(p);
        int j = find(q);

        if(i == j) return;
        if(sz[i] < sz[j]) { id[i] = j; sz[j] += sz[i];}
        else { id[j] = i; sz[i] += sz[j];}
        count--;
    }

}