Algs4-1.5.24适用于Erdos-Renyi模型的快速算

1.5.24适用于Erdos-Renyi模型的快速算法。在练习1.5.23的测试中增加加权quick-union算法和使用路径压缩的加权quick-union算法。你能分辨出这两种算法的区别吗？
答：加权quick-union最坏情况下树深度为lgN,N为节点数，路径压缩的加权quick-union算法最坏情况下树深度为1。


public class E1d5d24
{
     public static class Connection
    {
        int p;
        int q;
        public Connection(int p,int q)
        {this.p=p; this.q=q;}
       
        public int P()
        {return p;}
   
        public int Q()
        {return q;}
    }
        //
    public static int[][]  Generate(int N)
    {
        Queue<Connection> cnns=new Queue();
        WeightedQuickUnionUF uf=new WeightedQuickUnionUF(N);
         while (uf.count()>1)
           {
               int p=StdRandom.uniform(N);
               int q=StdRandom.uniform(N);
               uf.union(p,q);
               cnns.enqueue(new Connection(p,q));
            }//end while
       //
         int[][] cnnsOfArray=new int[cnns.size()][2];
         int i=0;
         while(!cnns.isEmpty())
         {
             Connection item=cnns.dequeue();
             cnnsOfArray[i][0]=item.P();
             cnnsOfArray[i][1]=item.Q();
             i++;
         }
         return cnnsOfArray;
    }
   

   public static double QuickFindElapsedTime(int[][] cnns,int T,int N)
   {
        Stopwatch timer=new Stopwatch();
        for (int t=1;t<=T;t++)
        {
             QuickFindUF uf=new QuickFindUF(N);
             int i=0;
             while(uf.count()>1)
             {
                 uf.union(cnns[i][0],cnns[i][1]);
                 i++;
             }
        }
         return timer.elapsedTime();
   }
     
     
  public static double QuickUnionElapsedTime(int[][] cnns,int T,int N)
   {
        Stopwatch timer=new Stopwatch();
        for (int t=1;t<=T;t++)
        {
             QuickUnionUF uf=new QuickUnionUF(N);
             int i=0;
             while(uf.count()>1)
             {
                 uf.union(cnns[i][0],cnns[i][1]);
                 i++;
             }
        }
         return timer.elapsedTime();
   }
  
    public static double WeightedQuickUnionElapsedTime(int[][] cnns,int T,int N)
   {
        Stopwatch timer=new Stopwatch();
        for (int t=1;t<=T;t++)
        {
             WeightedQuickUnionUF uf=new WeightedQuickUnionUF(N);
             int i=0;
             while(uf.count()>1)
             {
                 uf.union(cnns[i][0],cnns[i][1]);
                 i++;
             }
        }
         return timer.elapsedTime();
   }
   
        public static double CompressPathQuickUnionElapsedTime(int[][] cnns,int T,int N)
   {
        Stopwatch timer=new Stopwatch();
        for (int t=1;t<=T;t++)
        {
             E1d5d12 uf=new E1d5d12(N);
             int i=0;
             while(uf.count()>1)
             {
                 uf.union(cnns[i][0],cnns[i][1]);
                 i++;
             }
        }
         return timer.elapsedTime();
   }
      
    public static void main(String[] args)
    {
        int T=Integer.parseInt(args[0]);
        for (int N=2;N<=Math.pow(2,15);N=N+N)
        {
            int[][] cnns=Generate(N);
            double QuickFindTime=QuickFindElapsedTime(cnns,T,N);
            double QuickUnionTime= QuickUnionElapsedTime(cnns,T,N);
            double WeightedQuickUnionTime=WeightedQuickUnionElapsedTime(cnns,T,N);
            double CompressPathQuickUnionTime=CompressPathQuickUnionElapsedTime(cnns,T,N);
             StdOut.printf("N=%6d T=%3d  QF=%6.2f QU=%6.2f WQU=%6.2f  CPQU=%6.2f QF/QU=%10.2f QF/WQU=%10.2f QF/CPQU=%10.2f \n",  N,  T,QuickFindTime,QuickUnionTime,WeightedQuickUnionTime,CompressPathQuickUnionTime,QuickFindTime/QuickUnionTime,QuickFindTime/WeightedQuickUnionTime,QuickFindTime/CompressPathQuickUnionTime);
       }
       
    }
}