Shell Sort

C Program For Shell Sort

Source Code:

#include<stdio.h>
#include&l;conio.h>
#include<math.h>


void show(int A[20],int n)
{
  int i;
  printf("\n");
  for(i=1;i<=n;i++)
  {
     printf("  %d",A[i]);
  }
}

void shell_sort(int *A,int n)
{
   int l,d,p,j,i,key;
   l=ceil(((log(((2*n)/3)+1)/log(2))/(log(3)/log(2)))-1);
   d=(pow(3,l)-1)/2;
   for(p=d;p>=1;p--)
   {
      for(j=d+1;j<=n;j++)
      {
	 key=A[j];
	 i=j-d;
	 while(i>0 && key<A[i])
	 {
	    A[i+d]=A[i];
	    i=i-d;
	 }
	 A[i+d]=key;
      }
      d=(d-1)/3;
   }
}


void main()
{
  int A[20],n,i;
  clrscr();
  printf("\nEnter number of elements:");
  scanf("%d",&n);
  for(i=1;i<=n;i++)
  {
     printf("\nEnter element %d :",i);
     scanf("%d",&A[i]);
  }
  shell_sort(A,n);
  printf("\nAfter sorting the array is:\n");
  show(A,n);
  getch();
}