1.5.7分别为quick-find算法和quick-union算法实现QuickFindUF类和QuickUnionUF类。
{
private int[] id;
private int count;
public QuickFindUF(int N)
{
count=N;
id=new int[N];
for (int i=0;i<N;i++)
id[i]=i;
}
public int count()
{return count;}
boolean connected(int p,int q)
{return find(p)==find(q);}
public int find(int p)
{return id[p];}
public void union(int p,int q)
{
int pID=find(p);
int qID=find(q);
if (pID==qID) return;
for (int i=0;i<id.length;i++)
if(id[i]==pID) id[i]=qID;
count--;
}
public static void main(String[] qrgs)
{
int N=StdIn.readInt();
QuickFindUF uf=new QuickFindUF(N);
while (!StdIn.isEmpty())
{
int p=StdIn.readInt();
int q=StdIn.readInt();
if(uf.connected(p,q)) continue;
StdOut.println(p+ " " +q);
uf.union(p,q);
}//end while
}//end main
}//end class
public class QuickUnionUF
{
private int[] id;
private int count;
public QuickUnionUF(int N)
{
count=N;
id=new int[N];
for (int i=0;i<N;i++)
id[i]=i;
}
public int count()
{return count;}
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 pRoot=find(p);
int qRoot=find(q);
if(pRoot==qRoot) return;
id[pRoot]=qRoot;
count--;
}
public static void main(String[] qrgs)
{
int N=StdIn.readInt();
QuickUnionUF uf=new QuickUnionUF(N);
while (!StdIn.isEmpty())
{
int p=StdIn.readInt();
int q=StdIn.readInt();
if(uf.connected(p,q)) continue;
StdOut.println(p+ " " +q);
uf.union(p,q);
}//end while
}//end main
}//end class