1.5.11实现加权quick-find算法，其中我们总是将较小的分量重命名为较大的分量的标识符。这种改变会对性能产生怎样的影响？

答：每次union需要多访问N次id数组进行判断，同时还需要对两个分量的触点个数的sz赋新值,也会增加数组的访问，性能将会降低。

public class E1d5d11

{

    private int[] id;

    private int[] sz;

    private int count;

    public E1d5d11(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++)

            sz[i]=1;

    }

   

    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;

          int totalSize=sz[p]+sz[q];

          int oldID;

          int newID;

          if(sz[p]<sz[q])

            {

              oldID=pID;

              newID=qID;

           }

          else

           {

              oldID=qID;

              newID=pID;

          }

         for (int i=0;i<id.length;i++)

             {

                 if(id[i]==oldID) id[i]=newID;

                 if(id[i]==newID) sz[i]=totalSize;

              }

           count--;

      }

         //

       public static void main(String[] qrgs)

       {

           int N=StdIn.readInt();

           E1d5d11 uf=new E1d5d11(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