//  Shell sort algorithm for n elements 
//  in a Monitored array, a.
//  Diminishing increment sort (Knuth)


#include <iostream.h>
#include "array.h"

extern MArray a;
void swap (int,int);

void shell (int n)
{  
   int h, j, i, t;
   
   h = n/2;		// increment
   while (h>=1)
     {  for (j=h; j<n; j++)
	  {  i = j - h;
	     t = a[j];
	     while (i>=0 && t<=a[i])
		{  a[i+h] = a[i];
		   i = i-h;
		}
	     a[i+h] = t;
	  }
	h = h/2;
      } 
}