amp pause scale compare nim ppk merge eight fast

2.1.27希爾排序的用時是次平方級的。在你的計算機上用SortCompare比較希爾排序和插入排序以及選擇排序。測試數組的大小按照2的冪次遞增，從128開始。
shell排序的倍率是2.5，選擇和插入都是在4.

public class SortCompare
{
public static double time (String alg,Double[] a)
{
Stopwatch timer =new Stopwatch();
if(alg.equals("Insertion")) Insertion.sort(a);
//exercise2.1.24
if(alg.equals("Insertion2")) Insertion2.sort(a);
//exercise2.1.25
if(alg.equals("Insertion3")) Insertion3.sort(a);
//exercise2.1.26
if(alg.equals("Insertion4")) Insertion3.sort(a);
if(alg.equals("Selection")) Selection.sort(a);
if(alg.equals("Shell")) Shell.sort(a);
// if(alg.equals("Merge")) Merge.sort(a);
// if(alg.equals("Quick")) Quick.sort(a);
// if(alg.equals("Heap")) Heap.sort(a);
return timer.elapsedTime();
}

public static double timeRandomInput(String alg,int N,int T)
{
double total =0.0;
Double[] a=new Double[N];
for (int t=0;t<T;t++)
{
for (int i=0;i<N;i++)
a[i]=StdRandom.uniform();
total+=time(alg,a);
}
return total;
}//end timeRandomInput


public static void main(String[] args)
{
/*
String alg1=args[0];
String alg2=args[1];
int N=Integer.parseInt(args[2]);
int T=Integer.parseInt(args[3]);
double t1=timeRandomInput(alg1,N,T);
double t2=timeRandomInput(alg2,N,T);
StdOut.printf("For %d random Doubles\n %s is",N,alg1);
StdOut.printf(" %.2f times faster than %s\n",t2/t1,alg2);
*/
double prevT1=0.0;
double prevT2=0.0;
double prevT3=0.0;
double thisT1=0.0;
double thisT2=0.0;
double thisT3=0.0;
for (int i=128;i<1000000;i=2*i)
{
prevT1=thisT1;
prevT2=thisT2;
prevT3=thisT3;
//
thisT1=timeRandomInput("Insertion",i,1);
thisT2=timeRandomInput("Selection",i,1);
thisT3=timeRandomInput("Shell",i,1);
//
StdOut.printf("---For %d random Doubles\n",i);
StdOut.printf("Insertion use time=%.2f ,tihisTime/prevTime=%.2f\n",thisT1,thisT1/prevT1);
StdOut.printf("Selection use time=%.2f ,tihisTime/prevTime=%.2f\n",thisT2,thisT2/prevT2);
StdOut.printf("Shell use time=%.2f ,tihisTime/prevTime=%.2f\n",thisT3,thisT3/prevT3);
}
}

}

public class Insertion
{
public static void sort(Comparable[] a)
{
int N=a.length;
for (int i=0;i<N;i++)
{
for(int j=i;j>0 && less(a[j],a[j-1]);j--)
exch(a,j,j-1);
}
}

private static boolean less(Comparable v,Comparable w)
{ return v.compareTo(w)<0;}

private static void exch(Comparable[] a,int i,int j)
{
Comparable t=a[i];
a[i]=a[j];
a[j]=t;
}

private static void show(Comparable[] a)
{
for (int i=0;i<a.length;i++)
StdOut.print(a[i]+" ");
StdOut.println();
}

public static boolean isSorted(Comparable[] a)
{
for (int i=0;i<a.length;i++)
if(less(a[i],a[i-1])) return false;
return true;
}

public static void main(String[] args)
{
int N=Integer.parseInt(args[0]);
Double[] a=new Double[N];
for(int i=0;i<N;i++)
a[i]=StdRandom.uniform(0.0,N*1.0);
//
sort(a);
}
}


public class Selection
{
public static void sort(Comparable[] a)
{
int N=a.length;
for (int i=0;i<N;i++)
{
int min=i;
for (int j=i+1;j<N;j++)
if (less(a[j],a[min])) min=j;
exch(a,i,min);
//showAnimation(a);
}
}


private static boolean less(Comparable v,Comparable w)
{ return v.compareTo(w)<0;}

private static void exch(Comparable[] a,int i,int j)
{
Comparable t=a[i];
a[i]=a[j];
a[j]=t;
}

private static void show(Comparable[] a)
{
for (int i=0;i<a.length;i++)
StdOut.print(a[i]+" ");
StdOut.println();
}


private static void showAnimation(Comparable[] a)
{
StdDraw.setXscale(0.0,a.length);
StdDraw.setYscale(0.0,a.length);
StdDraw.setPenRadius(0.005);
StdDraw.pause(100);
StdDraw.clear(StdDraw.GRAY);
StdDraw.setPenColor(StdDraw.BLACK);
for(int i=0;i<a.length;i++)
{
StdDraw.line(i*1.0,0.0,i*1.0,(Double)a[i]*1.0);
}
}
public static boolean isSorted(Comparable[] a)
{
for (int i=0;i<a.length;i++)
if(less(a[i],a[i-1])) return false;
return true;
}

public static void main(String[] args)
{
int N=Integer.parseInt(args[0]);
Double[] a=new Double[N];
for(int i=0;i<N;i++)
a[i]=StdRandom.uniform(0.0,N*1.0);
//
StdDraw.pause(5000);
sort(a);
}
}


public class Shell
{
public static int timesOfCompare;
public static int timesOfCompareTotal;
public static void sort(Comparable[] a)
{
int N=a.length;
int h=1;
while (h<N/3) h=3*h+1;
while (h>=1)
{
for (int i=h;i<N;i++)
{
for (int j=i;j>=h && less(a[j],a[j-h]);j-=h)
{
timesOfCompare++;
exch(a,j,j-h);
}
}
/* if (h>1)
{
StdOut.printf("\nsort-%d\n",h);
for(int l=0;l<N;l++)
{
if (l%h==0) StdOut.println();
StdOut.printf("%3d",a[l]);
}
}
*/
h=h/3;
}
}
//sort40
public static void sort40(Comparable[] a)
{
int N=a.length;
int h=40;
for (int i=h;i<N;i++)
{
for (int j=i;j>=h;j-=h)
{
timesOfCompare++;
timesOfCompareTotal++;
// StdOut.printf("timesOfCompare=%d ,i=%d ,j=%d ,j-h=%d \n",timesOfCompare,i,j,j-h);
if (less(a[j],a[j-h]))
exch(a,j,j-h);
else
break;
}
}

/* StdOut.printf("\nsort-%d\n",h);
for(int l=0;l<N;l++)
{
if (l%h==0) StdOut.println();
StdOut.printf("%3d",a[l]);
}
*/
}
//sort13
public static void sort13(Comparable[] a)
{
int N=a.length;
int h=13;
for (int i=h;i<N;i++)
{
for (int j=i;j>=h;j-=h)
{
timesOfCompare++;
timesOfCompareTotal++;
if (less(a[j],a[j-h]))
exch(a,j,j-h);
else
break;
}
}
/*
StdOut.printf("\nsort-%d\n",h);
for(int l=0;l<N;l++)
{
if (l%h==0) StdOut.println();
StdOut.printf("%3d",a[l]);
}
*/
}
//sort4
public static void sort4(Comparable[] a)
{
int N=a.length;
int h=4;
for (int i=h;i<N;i++)
{
for (int j=i;j>=h;j-=h)
{
timesOfCompare++;
timesOfCompareTotal++;
if (less(a[j],a[j-h]))
exch(a,j,j-h);
else
break;
}
}
/*
StdOut.printf("\nsort-%d\n",h);
for(int l=0;l<N;l++)
{
if (l%h==0) StdOut.println();
StdOut.printf("%3d",a[l]);
}
*/
}
//sort1
public static void sort1(Comparable[] a)
{
int N=a.length;
int h=1;
for (int i=h;i<N;i++)
{
for (int j=i;j>=h;j-=h)
{
timesOfCompare++;
timesOfCompareTotal++;
if (less(a[j],a[j-h]))
exch(a,j,j-h);
else
break;
}
}
/*
StdOut.printf("\nsort-%d\n",h);
for(int l=0;l<N;l++)
{
if (l%h==0) StdOut.println();
StdOut.printf("%3d",a[l]);
}
*/
}


private static boolean less(Comparable v,Comparable w)
{
return v.compareTo(w)<0;
}

private static void exch(Comparable[] a,int i,int j)
{
Comparable t=a[i];
a[i]=a[j];
a[j]=t;
}

private static void show(Comparable[] a)
{
for (int i=0;i<a.length;i++)
StdOut.print(a[i]+" ");
StdOut.println();
}

public static boolean isSorted(Comparable[] a)
{
for (int i=0;i<a.length;i++)
if(less(a[i],a[i-1])) return false;
return true;
}

public static void main(String[] args)
{

//worst sort13
Integer[] worst13={100,92,84,76,68,60,52,44,36,28,21,14,7,99,91,83,75,67,59,51,43,35,27,20,13,6,98,90,82,74,66,58,50,42,34,26,19,12,5,97,89,81,73,65,57,49,41,33,25,18,11,4,96,88,80,72,64,56,48,40,32,24,17,10,3,95,87,79,71,63,55,47,39,31,23,16,9,2,94,86,78,70,62,54,46,38,30,22,15,8,1,93,85,77,69,61,53,45,37,29};
timesOfCompareTotal=0;
timesOfCompare=0;
sort40(worst13);
StdOut.printf("worst13 sort40 timesOfCompare=%4d timesOfCompareTotal=%4d\n" , timesOfCompare,timesOfCompareTotal);

timesOfCompare=0;
sort13(worst13);
StdOut.printf("worst13 sort13 timesOfCompare=%4d timesOfCompareTotal=%4d\n" , timesOfCompare,timesOfCompareTotal);

timesOfCompare=0;
sort4(worst13);
StdOut.printf("worst13 sort4 timesOfCompare=%4d timesOfCompareTotal=%4d\n" , timesOfCompare,timesOfCompareTotal);

timesOfCompare=0;
sort1(worst13);
StdOut.printf("worst13 sort1 timesOfCompare=%4d timesOfCompareTotal=%4d\n" , timesOfCompare,timesOfCompareTotal);
StdOut.println("------------------------------");




String[] files={
"a40-13-4.txt","a40-4-13.txt","a13-4-40.txt","a13-40-4.txt","a4-40-13.txt","a4-13-40.txt",
"b40-13-4.txt","b40-4-13.txt","b13-4-40.txt","b13-40-4.txt","b4-40-13.txt","b4-13-40.txt",
"c40-13-4.txt","c40-4-13.txt","c13-4-40.txt","c13-40-4.txt","c4-40-13.txt","c4-13-40.txt",
"d-big-small.txt","asc.txt"
};
for(int f=0;f<files.length;f++)
{
int[] a=In.readInts(files[f]);
Integer[] worst=new Integer[a.length];
for(int i=0;i<a.length;i++)
worst[i]=a[i];
timesOfCompareTotal=0;
timesOfCompare=0;
sort40(worst);
StdOut.println("---"+files[f]+"---");
StdOut.printf("sort40 timesOfCompare=%4d timesOfCompareTotal=%4d\n" , timesOfCompare,timesOfCompareTotal);

timesOfCompare=0;
sort13(worst);
StdOut.printf("sort13 timesOfCompare=%4d timesOfCompareTotal=%4d\n" , timesOfCompare,timesOfCompareTotal);

timesOfCompare=0;
sort4(worst);
StdOut.printf("sort4 timesOfCompare=%4d timesOfCompareTotal=%4d\n" , timesOfCompare,timesOfCompareTotal);

timesOfCompare=0;
sort1(worst);
StdOut.printf("sort1 timesOfCompare=%4d timesOfCompareTotal=%4d\n" , timesOfCompare,timesOfCompareTotal);
StdOut.println("");
}
}


}

Algs4-2.1.27希爾排序的用時是次平方級的